Ice Nucleation Properties of Oxidized Carbon Nanomaterials
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† Institute for Climate and Atmospheric Science, School of Earth and Environment, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
‡ Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
*E-mail: [email protected]
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Abstract
Heterogeneous ice nucleation is an important process in many fields, particularly atmospheric science, but is still poorly understood. All known inorganic ice nucleating particles are relatively large in size and tend to be hydrophilic. Hence it is not obvious that carbon nanomaterials should nucleate ice. However, in this paper we show that four different readily water-dispersible carbon nanomaterials are capable of nucleating ice. The tested materials were carboxylated graphene nanoflakes, graphene oxide, oxidized single walled carbon nanotubes and oxidized multiwalled carbon nanotubes. The carboxylated graphene nanoflakes have a diameter of ∼30 nm and are among the smallest entities observed so far to nucleate ice. Overall, carbon nanotubes were found to nucleate ice more efficiently than flat graphene species, and less oxidized materials nucleated ice more efficiently than more oxidized species. These well-defined carbon nanomaterials may pave the way to bridging the gap between experimental and computational studies of ice nucleation.
Freezing of liquid water to ice must be initiated by an ice nucleation event. In many situations this event is induced by a heterogeneous ice nucleating particle (INP). Ice nucleation is an important process for understanding of atmospheric processes (1-3) and also has relevance in other fields such as the cryopreservation of biological samples, (4) freeze-drying of pharmaceuticals (5) and other substances, (6) and freezing of foodstuffs. (7) Much effort has been devoted to the quantification of the efficiencies of heterogeneous ice nucleants of potential atmospheric relevance. As such, the ice nucleating efficiencies of various mineral dusts, biological entities, volcanic ashes and carbonaceous combustion aerosols (8, 9) have been measured using a wide range of techniques. (1, 2)
It is often assumed that INPs tend to be relatively “large” in size. (3) Indeed, the concentration of atmospheric INPs is correlated with the concentration of particles larger than 0.5 μm in diameter. (10) However, it has been found that nanoscale, readily dispersible biological particles that are shed from both pollen particles and fungi in water can also nucleate ice efficiently, (11-13) and that small particles of poly(vinyl alcohol) can nucleate ice. (14) Of late, there has been a great deal of interest in the synthesis and characterization of carbon nanomaterials. Yet, the ice nucleation activities of these species have not been examined to date.
Here, we have synthesized four different carbon nanomaterials and determined their ice nucleating efficiencies. These are carboxylated graphene nanoflakes (cx-GNFs) and graphene oxide (GO) as well as oxidized multiwall (o-MWCNTs) and single-wall carbon nanotubes (o-SWCNTs). Representative structures for these species are shown in Figure 1. The oxygen/carbon ratios for these materials were determined by X-ray photoelectron spectroscopy (XPS). The cx-GNFs are small graphene sheets with an average lateral diameter of ∼30 nm. (15) The edges of the flakes are decorated with carboxylic acid groups. They contain 66.3% carbon and 33.7% oxygen. GO consists of much larger sheets of carbon, average diameter ∼1 μm. The structure has a wider range of functional groups than that of the cx-GNFs with alcohol and epoxide groups present as well as carboxylic acids. (16) The face of the GO sheets is oxidized as well as the edges. The GO sample contains 72.0% carbon and 28.0% oxygen. MWCNTs are needle-like tubes of carbon and consist of multiple single layers of carbon wrapped concentrically. Our oxidized material contains 82.2% carbon and 17.8% oxygen. SWCNTs are structurally similar but consist of a single layer of carbon only. After chemical oxidation of the SWCNTs, we find 86.2% carbon and 13.8% oxygen according to XPS. We also present freezing data for a solution of mellitic acid, a molecular species structurally analogous to cx-GNFs, consisting of a single benzene ring with six carboxylic acid groups.
Figure 1
Figure 1. Chemical structures of the various of carbon nanomaterials tested for their ice nucleation activity: (a) small carboxylated graphene nanoflake (cx-GNF), (b) mellitic acid, (c) graphene oxide (GO), (d) multiwalled carbon nanotube (MWCNT), and (e) single walled carbon nanotube (SWCNT). GO sheets have an average lateral diameter of ∼1 μm, while the GNFs have an average lateral diameter of ∼30 nm. (15)
These materials were chosen for this study because their oxidized nature allows them to readily disperse in water. Attempts to conduct experiments with carbonized cx-GNFs, for example, proved impossible, as they did not disperse in water. The oxidized carbon nanomaterials, apart from the o-SWCNTs, all disperse readily in water with stirring. No more than 0.07 wt % of the o-SWCNTs could be dispersed. The 1 and 0.1 wt % dispersions of cx-GNFs are very stable and were not observed to settle even after several months. Suspensions of GO, o-MWCNTs, and o-SWCNTs were less stable, and settled over the course of hours. Dispersions of carbon nanomaterials were tested for the ice nucleating activity immediately after the preparation.
Ice nucleation experiments were conducted using the μL-Nucleation by Immersed Particles Instrument (μL-NIPI). (17) This instrument allows determination of the freezing temperatures of around 50 μL droplets of water under constant cooling. Here, a cooling rate of 1 °C min–1 has been used. The freezing curve for pure water in Figure 2a consists of 737 separate freezing events from 17 experiments and has been reported previously by Umo et al. (18) The freezing observed in the pure water is unlikely to be induced by homogeneous nucleation, which is predicted by classical nucleation theory to occur at temperatures colder than −30 °C in 1 μL droplets. (19, 20) Instead it is likely that the freezing observed is caused by a combination of impurities in the water and on the silanized glass slides used to support the droplets.
Figure 2
Figure 2. (a) Droplet fraction frozen against temperature for 1 and 0.1 wt % dispersions of GO and cx-GNFs, a 1 wt % dispersion of o-MWCNTs, a 0.07 wt % dispersion of o-SWCNTs, a 1 wt % solution of mellitic acid, and pure water. (b) ns values for all tested carbon nanomaterials. The ns values reported for the o-MWCNTs assume that they have nine layers, the average number of the starting material for their synthesis. The shaded area shows the area encompassed by calculating ns for the minimum and maximum wall numbers of the starting material. Experimental uncertainty in ns was calculated by propagation of uncertainty from weighing, droplet size, and background subtraction. In many cases, uncertainties are too small to show on the plot. Temperature uncertainty is ±0.4 °C in panels a and b.
Droplets containing cx-GNFs, GO, o-MWCNTs, and o-SWCNTs all nucleate ice at temperatures higher than the pure water droplets, as shown in Figure 2a. This constitutes the first observations of ice nucleation by these types of materials. In contrast, it can be seen in Figure 2a that mellitic acid does not nucleate ice within the sensitivity of the experimental setup used, with recorded freezing temperatures indistinguishable to those of pure water. This is entirely expected as mellitic acid is a dissolved molecular species so there is no reason to suppose it would interact with water in a way that would encourage ice formation. It is interesting to note that the structurally analogous cx-GNFs do nucleate ice well, showing that the increase in size allows interactions with water suitable for encouraging ice nucleation to occur.
To allow comparison between the carbon nanomaterial nucleants, these values have been normalized to surface area according to a time-independent description of ice nucleation. (21, 22) To calculate theoretical ns values for the graphene species presented in Figure 2b, the total surface area of the cx-GNFs and GO was calculated by assuming that all graphene sheets were completely dissociated from each other and using
(1)
It can be seen in Figure 2a that GO nucleates ice more efficiently than the cx-GNFs per mass of material, and that the o-MWCNTs and o-SWCNTs nucleate ice more efficiently than the flat species. The carbon nanotubes (CNTs) are similar to each other. The shapes of the ns curves for the two CNT species are different, however. The curve for the o-MWCNTs flattens at lower temperature, meaning that the number of effective INPs increases less quickly with increasing supersaturation than for the o-SWCNTs. There has been interest in the ordering of water in CNT cavities. (23) It is intriguing to suggest that the interior cavities of the CNTs interact with water in a way that promotes ice nucleation and that this is responsible for the strong nucleation we have observed. Both kinds of CNTs are rather less oxidized than the graphene species. The overall trend is therefore that the less oxidized species nucleate ice more efficiently. The 1 wt % dispersion of cx-GNFs has a median nucleation temperature of −21.3 °C and an oxygen content of 33.7%, while the 1 wt % dispersion of o-MWCNTs has a median nucleation temperature of −12.2 °C and an oxygen content of 17.8%. We note in this context that XPS is a surface-sensitive technique, and the determined atom percentages may therefore not necessarily reflect the bulk composition of the samples but more the composition of the sample at the interface with water.
The cx-GNFs in particular are light compared to most other INPs. Their average mass is approximately 325 kDa. In their recent paper, Pummer et al. (24) reviewed a range of small INPs. The cx-GNFs are comparable in mass to the Birch pollen-derived ice nucleating macromolecules discovered by Pummer et al. (11) and the fungal proteins sized by O’Sullivan et al., (13) and somewhat larger than certain poly(vinyl alcohol)s discovered by Ogawa et al., (14) which were shown to nucleate ice at molecular weights as low as 1.7 kDa. All other known INPs are heavier than the cx-GNFs.
The approach we have used to calculate ns assumes that all possible surface area is in contact with water. It is hard to evaluate how realistic this is for the carbon nanomaterials, hence, the ns values reported are most likely lower limits in the case of these nanomaterials. This also means that comparison with existing measurements of other carbon materials such as soots (8, 9) is difficult. It can be seen in Figure 2b that ns derived from lower concentrations dispersions of GO and cx-GNF fall on the same line as higher concentrations suggesting that similar surface areas of material are available per mass of material in both concentrations. This indicates that the materials are not aggregated in dispersion since aggregation is concentration dependent. Calculating ns for the o-MWCNTs was less straightforward, as the precise number of layers in the MWCNTs from which the o-MWCNTs were synthesized is unknown. Manufacturer specifications for the starting material includes the maximum and minimum numbers of walls; ns values have been calculated using these to provide upper and lower limits as seen in Figure 2b. We have assumed that the exterior surface area of the o-MWCNTs is solely responsible for nucleation observed and calculated surface area exposed to water on this basis. The interior surfaces may well play a role, even a dominant one, in the nucleation observed, but the assumptions made seem reasonable for comparative purposes.
While it is difficult to infer details about the specific mechanism of ice nucleation from droplet freezing experiments, some insight into the nature of ice nucleation observed can be derived from its time dependence. The Framework for Reconciling Observable Stochastic Time-dependence (FROST) condenses the key information about time dependence of ice nucleation into a single parameter, λ, which is a nucleant-specific parameter that describes the time dependence of the ice nucleation properties (further details are given in the Supporting Information (SI)). (22) FROST facilitates comparison of different materials through calculation of λ using
(2)
We have cooled cx-GNFs at rates from 0.2 °C min–1 to 5 °C min–1, the results of which are shown in Figure 3a, and analyzed the resulting data using FROST. (22) A λ value of 3.3 °C–1 has been determined, and Figure 3b shows the normalized data. This λ value is higher than those of the majority of nucleants evaluated by Herbert et al. (22) and might be regarded as a “large” λ value, indicating that ice nucleation by cx-GNFs is relatively insensitive to changes in cooling rate.
Figure 3
The FROST analysis also reveals whether there is a strong particle-to-particle variability in ice nucleating ability. If the value d ln(ns)/dT, termed ω, is equal to λ, then all surfaces of the nucleant have the same potential to nucleate ice. In contrast, if ω < λ then some parts of the surface have a greater potential to nucleate ice. For cx-GNFs cooled at 1 °C min–1 we have determined ω to be 0.83 °C–1, which is clearly much smaller than λ. This suggests that the nucleation observed may be site specific, meaning that there may be specific sites on the cx-GNFs that are responsible for the ice nucleation. (21, 22) The precise nature of these sites and the reason for their apparent nucleating activity is unclear. It is known that small molecules such as the water molecule can interact with carboxylic acid groups such as those present on cx-GNFs. (25-27) It may be that such site-specific interactions are related to the observed ice nucleation.
At present, there is no case where the mechanism of heterogeneous ice nucleation is well understood. Even the longstanding and elegant lattice matching hypothesis to which the ice nucleating activity of silver iodide is attributed has been questioned. (28, 29) Various molecular dynamics simulations have been conducted by a few different groups in order to address this issue. (30-35) This includes several studies looking specifically at carbon species. (36-39) Currently, there is a gap between experimental and computational work into ice nucleation that has proved very difficult to bridge, due to the vast differences in spatial scale and time scale of the systems that can be examined experimentally and computationally.
Recent work by Lupi et al. (38, 39) using molecular dynamics simulations to study ice nucleation on carbon surfaces has provided certain qualitative predictions that it might be experimentally accessible. Specifically, they found that flat carbon surfaces without any oxidation or roughness nucleated ice most efficiently. Any oxidation, (38) roughness or curvature (39) was found to decrease the nucleation temperatures observed in the simulations. The result that oxidized carbon surfaces nucleate ice less well than pristine ones is somewhat counterintuitive and in contrast to the commonly stated “chemical bonding” requirement for ice nucleation, (3) as it might be expected that oxidation will offer greater opportunity for water to bond to a surface and so promote water structuring and ice nucleation. Our work here is consistent with the alternative hypothesis that a lower degree of oxidation leads to enhanced ice nucleation efficiency, although more species would need to be investigated to establish a statistically significant trend. Also, there are differences in structure and size between the nanomaterials investigated here, as well as extent of oxidation. These differences would need to be closely controlled to generate a firm experimental conclusion as to the effect of oxidation of carbon nanomaterials on ice nucleation efficiency. By thoroughly characterizing relatively simple ice nucleating species, it might be possible to conduct practical experiments that can be meaningfully related to computational studies. In general, by investigating closely related nucleants and observing differences in their ice nucleating efficiency, it may be possible to infer information about the causes of ice nucleating activity in these samples. Work here might be regarded as a first step in this direction and, now that their capacity to nucleate ice is known, carbon nanomaterials may prove to be a good candidate for further work on building a fundamental understanding of ice nucleation.
Supporting Information
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Details of the synthesis of the carbon nanomaterials used, XPS analysis of the nanomaterials, the μL-NIPI ice nucleation instrument, and the FROST method for analysis of ice nucleation data are available in the Supporting Information. The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jpclett.5b01096.
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Most electronic Supporting Information files are available without a subscription to ACS Web Editions. Such files may be downloaded by article for research use (if there is a public use license linked to the relevant article, that license may permit other uses). Permission may be obtained from ACS for other uses through requests via the RightsLink permission system: http://pubs.acs.org/page/copyright/permissions.html.
Acknowledgment
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We would like to thank Dr. D. O’Sullivan, Dr. R. J. Herbert, Dr. H. C. Price and Dr. T. W. Wilson for useful discussions. B.J.M. and T.F.W. thank the Natural Environment Research Council (NERC, NE/I013466/1; NE/I020059/1; NE/I019057/1) the European Research Council (ERC, 240449 ICE; 632272 IceControl), and the Engineering and Physical Sciences Research Council (EPSRC, EP/M003027/1) for funding. C.G.S. thanks the Royal Society for a University Research Fellowship (UF100144) and the Leverhulme Trust for a Research Grant (RPG-2014-04).
References
ARTICLE SECTIONS
This article references 39 other publications.
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1Murray, B. J.; O’Sullivan, D.; Atkinson, J. D.; Webb, M. E. Ice Nucleation by Particles Immersed in Supercooled Cloud Droplets Chem. Soc. Rev. 2012, 41, 6519– 6554 DOI: 10.1039/c2cs35200aGoogle Scholar1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhtlaktr7L&md5=5a331f4c83c33d5d7a99d6dca8cf9b3fIce nucleation by particles immersed in supercooled cloud dropletsMurray, B. J.; O'Sullivan, D.; Atkinson, J. D.; Webb, M. E.Chemical Society Reviews (2012), 41 (19), 6519-6554CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)A review. The formation of ice particles in the Earth's atm. strongly affects the properties of clouds and their impact on climate. Despite the importance of ice formation in detg. the properties of clouds, the Intergovernmental Panel on Climate Change (IPCC, 2007) was unable to assess the impact of atm. ice formation in their most recent report because our basic knowledge is insufficient. Part of the problem is the paucity of quant. information on the ability of various atm. aerosol species to initiate ice formation. Here we review and assess the existing quant. knowledge of ice nucleation by particles immersed within supercooled water droplets. We introduce aerosol species which have been identified in the past as potentially important ice nuclei and address their ice-nucleating ability when immersed in a supercooled droplet. We focus on mineral dusts, biol. species (pollen, bacteria, fungal spores and plankton), carbonaceous combustion products and volcanic ash. In order to make a quant. comparison we first introduce several ways of describing ice nucleation and then summarise the existing information according to the time-independent (singular) approxn. Using this approxn. in combination with typical atm. loadings, we est. the importance of ice nucleation by different aerosol types. According to these ests. we find that ice nucleation below about -15 °C is dominated by soot and mineral dusts. Above this temp. the only materials known to nucleate ice are biol., with quant. data for other materials absent from the literature. We conclude with a summary of the challenges our community faces.
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2Hoose, C.; Möhler, O. Heterogeneous Ice Nucleation on Atmospheric Aerosols: a Review of Results From Laboratory Experiments Atmos. Chem. Phys. 2012, 12, 9817– 9854 DOI: 10.5194/acp-12-9817-2012Google Scholar2https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1Omtr0%253D&md5=20313e79a4bcdc12a065bff0a1d93e8fHeterogeneous ice nucleation on atmospheric aerosols: a review of results from laboratory experimentsHoose, C.; Moehler, O.Atmospheric Chemistry and Physics (2012), 12 (20), 9817-9854CODEN: ACPTCE; ISSN:1680-7316. (Copernicus Publications)A review. A small subset of the atm. aerosol population has the ability to induce ice formation at conditions under which ice would not form without them (heterogeneous ice nucleation). While no closed theor. description of this process and the requirements for good ice nuclei is available, numerous studies have attempted to quantify the ice nucleation ability of different particles empirically in lab. expts. In this article, an overview of these results is provided. Ice nucleation "onset" conditions for various mineral dust, soot, biol., org. and ammonium sulfate particles are summarized. Typical temp.-supersatn. regions can be identified for the "onset" of ice nucleation of these different particle types, but the various particle sizes and activated fractions reported in different studies have to be taken into account when comparing results obtained with different methodologies. When intercomparing only data obtained under the same conditions, it is found that dust mineralogy is not a consistent predictor of higher or lower ice nucleation ability. However, the broad majority of studies agrees on a redn. of deposition nucleation by various coatings on mineral dust. The ice nucleation active surface site (INAS) d. is discussed as a simple and empirical normalized measure for ice nucleation activity. For most immersion and condensation freezing measurements on mineral dust, ests. of the temp.-dependent INAS d. agree within about two orders of magnitude. For deposition nucleation on dust, the spread is significantly larger, but a general trend of increasing INAS densities with increasing supersatn. is found. For soot, the presently available results are divergent. Estd. av. INAS densities are high for ice-nucleation active bacteria at high subzero temps. At the same time, it is shown that INAS densities of some other biol. aerosols, like certain pollen grains, fungal spores and diatoms, tend to be similar to those of dust. These particles may owe their high ice nucleation onsets to their large sizes. Surface-area-dependent parameterizations of heterogeneous ice nucleation are discussed. For immersion freezing on mineral dust, fitted INAS densities are available, but should not be used outside the temp. interval of the data they were based on. Classical nucleation theory, if employed with only one fitted contact angle, does not reproduce the obsd. temp. dependence for immersion nucleation, the temp. and supersatn. dependence for deposition nucleation, and the time dependence of ice nucleation. Formulations of classical nucleation theory with distributions of contact angles offer possibilities to overcome these weaknesses.
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3Pruppacher, H. R.; Klett, J. D. Microphysics of Clouds and Precipitation, 2nd ed.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 1997.Google ScholarThere is no corresponding record for this reference.
-
4Morris, G. J.; Acton, E. Controlled Ice Nucleation in Cryopreservation - a Review Cryobiology 2013, 66, 85– 92 DOI: 10.1016/j.cryobiol.2012.11.007Google ScholarThere is no corresponding record for this reference.
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5Searles, J. A.; Carpenter, J. F.; Randolph, T. W. The Ice Nucleation Temperature Determines the Primary Drying Rate of Lyophilization for Samples Frozen on a Temperature-Controlled Shelf J. Pharm. Sci. 2001, 90, 860– 871 DOI: 10.1002/jps.1039Google Scholar5https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXlt1Cqu7k%253D&md5=02bf23873bc796db11687a0207ef7b44The ice nucleation temperature determines the primary drying rate of lyophilization for samples frozen on a temperature-controlled shelfSearles, James A.; Carpenter, John F.; Randolph, Theodore W.Journal of Pharmaceutical Sciences (2001), 90 (7), 860-871CODEN: JPMSAE; ISSN:0022-3549. (Wiley-Liss, Inc.)The objective of this study was to det. the influence of ice nucleation temp. on the primary drying rate during lyophilization for samples in vials that were frozen on a lyophilizer shelf. Aq. solns. of 10% (w/v) hydroxyethyl starch were frozen in vials with externally mounted thermocouples and then partially lyophilized to det. the primary drying rate. Low- and high-particulate-contg. samples, ice-nucleating additives silver iodide and Pseudomonas syringae, and other methods were used to obtain a wide range of nucleation temps. In cases where the supercooling exceeded 5°, freezing took place in the following three steps: (1) primary nucleation, (2) secondary nucleation encompassing the entire liq. vol., and (3) final solidification. The primary drying rate was dependent on the ice nucleation temp., which is stochastic in nature but is affected by particulate content and the presence of ice nucleators. Sample cooling rates of 0.05 to 1°/min had no effect on nucleation temps. and drying rate. We found that the ice nucleation temp. is the primary determinant of the primary drying rate. However, the nucleation temp. is not under direct control, and its stochastic nature and sensitivity to difficult-to-control parameters result in drying rate heterogeneity. Nucleation temp. heterogeneity may also result in variation in other morphol.-related parameters such as surface area and secondary drying rate. Overall, these results document that factors such as particulate content and vial condition, which influence ice nucleation temp., must be carefully controlled to avoid, for example, lot-to-lot variability during cGMP prodn. In addn., if these factors are not controlled and/or are inadvertently changed during process development and scaleup, a lyophilization cycle that was successful on the research scale may fail during large-scale prodn.
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6Aksan, A.; Ragoonanan, V.; Hirschmugl, C. Freezing- and Drying-Induced Micro- and Nano-Heterogeneity in Biological Solutions. In Biophysical Methods for Biotherapeutics; John Wiley & Sons, Inc.: Hoboken, NJ, 2014.Google ScholarThere is no corresponding record for this reference.
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7Kiani, H.; Sun, D. W. Water Crystallization and its Importance to Freezing of Foods: A Review Trends Food Sci. Technol. 2011, 22, 407– 426 DOI: 10.1016/j.tifs.2011.04.011Google Scholar7https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXptlWjsr4%253D&md5=f523cb86cc00cf9024503f62143c23b0Water crystallization and its importance to freezing of foods: A reviewKiani, Hossein; Sun, Da-WenTrends in Food Science & Technology (2011), 22 (8), 407-426CODEN: TFTEEH; ISSN:0924-2244. (Elsevier Ltd.)In this review, different aspects of water crystn. including modeling approaches, process evaluation methods and the effect of novel freezing techniques is presented. There are different methods available to explain the nucleation and growth of crystals. The characteristics of ice crystals are studied by light and electron microscopy methods for many years, and recently a no. of novel methods including magnetic resonance imaging, X-ray anal., and IR spectroscopy are employed. Several emerging techniques are developed to improve the crystn. of water during freezing, including ultrasound assisted freezing, high pressure freezing, ice nucleating proteins, and supersession of nucleation. Understanding the mechanisms of these new techniques and their relationship to the crystn. phenomenon can be helpful for improving freezing processes.
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8Diehl, K.; Mitra, S. K. A Laboratory Study of the Effects of a Kerosene-Burner Exhaust on Ice Nucleation and the Evaporation Rate of Ice Crystals Atmos. Environ. 1998, 32, 3145– 3151 DOI: 10.1016/S1352-2310(97)00467-6Google ScholarThere is no corresponding record for this reference.
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9Demott, P. J. An Exploratory-Study of Ice Nucleation by Soot Aerosols J. Appl. Meteorol. 1990, 29, 1072– 1079 DOI: 10.1175/1520-0450(1990)029<1072:AESOIN>2.0.CO;2Google ScholarThere is no corresponding record for this reference.
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10DeMott, P. J.; Prenni, A. J.; Liu, X.; Kreidenweis, S. M.; Petters, M. D.; Twohy, C. H.; Richardson, M. S.; Eidhammer, T.; Rogers, D. C. Predicting Global Atmospheric Ice Nuclei Distributions and Their Impacts on Climate Proc. Natl. Acad. Sci. U. S. A. 2010, 107, 11217– 11222 DOI: 10.1073/pnas.0910818107Google Scholar10https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3crktFOgtg%253D%253D&md5=7f4e5a242e7e2187872e05f413944d95Predicting global atmospheric ice nuclei distributions and their impacts on climateDeMott P J; Prenni A J; Liu X; Kreidenweis S M; Petters M D; Twohy C H; Richardson M S; Eidhammer T; Rogers D CProceedings of the National Academy of Sciences of the United States of America (2010), 107 (25), 11217-22 ISSN:.Knowledge of cloud and precipitation formation processes remains incomplete, yet global precipitation is predominantly produced by clouds containing the ice phase. Ice first forms in clouds warmer than -36 degrees C on particles termed ice nuclei. We combine observations from field studies over a 14-year period, from a variety of locations around the globe, to show that the concentrations of ice nuclei active in mixed-phase cloud conditions can be related to temperature and the number concentrations of particles larger than 0.5 microm in diameter. This new relationship reduces unexplained variability in ice nuclei concentrations at a given temperature from approximately 10(3) to less than a factor of 10, with the remaining variability apparently due to variations in aerosol chemical composition or other factors. When implemented in a global climate model, the new parameterization strongly alters cloud liquid and ice water distributions compared to the simple, temperature-only parameterizations currently widely used. The revised treatment indicates a global net cloud radiative forcing increase of approximately 1 W m(-2) for each order of magnitude increase in ice nuclei concentrations, demonstrating the strong sensitivity of climate simulations to assumptions regarding the initiation of cloud glaciation.
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11Pummer, B. G.; Bauer, H.; Bernardi, J.; Bleicher, S.; Grothe, H. Suspendable Macromolecules are Responsible for Ice Nucleation Activity of Birch and Conifer Pollen Atmos. Chem. Phys. 2012, 12, 2541– 2550 DOI: 10.5194/acp-12-2541-2012Google Scholar11https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xpt12iurg%253D&md5=70cd2ea58dc1a2321693e52dde19b124Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollenPummer, B. G.; Bauer, H.; Bernardi, J.; Bleicher, S.; Grothe, H.Atmospheric Chemistry and Physics (2012), 12 (5), 2541-2550CODEN: ACPTCE; ISSN:1680-7316. (Copernicus Publications)The ice nucleation of bioaerosols (bacteria, pollen, spores, etc.) is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. Here we show that pollen of different species strongly differ in their ice nucleation behavior. The av. freezing temps. in lab. expts. range from 240 to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen) have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. Far more intriguingly, it has turned out that water, which has been in contact with pollen and then been sepd. from the bodies, nucleates as good as the pollen grains themselves. The ice nuclei have to be easily-suspendable macromols. located on the pollen. Once extd., they can be distributed further through the atm. than the heavy pollen grains and so presumably augment the impact of pollen on ice cloud formation even in the upper troposphere. Our expts. lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compds.
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12Fröhlich-Nowoisky, J.; Hill, T. C. J.; Pummer, B. G.; Franc, G. D.; Pöschl, U. Ice Nucleation Activity in the Widespread Soil Fungus Mortierella alpina Biogeosciences Discuss. 2014, 11, 12697– 12731 DOI: 10.5194/bgd-11-12697-2014Google ScholarThere is no corresponding record for this reference.
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13O′Sullivan, D.; Murray, B. J.; Ross, J. F.; Whale, T. F.; Price, H. C.; Atkinson, J. D.; Umo, N. S.; Webb, M. E. The Relevance of Nanoscale Biological Fragments for Ice Nucleation in Clouds Sci. Rep. 2015, 5, 8082 DOI: 10.1038/srep08082Google Scholar13https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXosVKlt7o%253D&md5=7155a0732de7f1a1b9bb5dee9168a555The relevance of nanoscale biological fragments for ice nucleation in cloudsO'Sullivan, D.; Murray, B. J.; Ross, J. F.; Whale, T. F.; Price, H. C.; Atkinson, J. D.; Umo, N. S.; Webb, M. E.Scientific Reports (2015), 5 (), 8082/1-8082/7CODEN: SRCEC3; ISSN:2045-2322. (Nature Publishing Group)Most studies of the role of biol. entities as atm. ice-nucleating particles have focused on relatively rare supermicron particles such as bacterial cells, fungal spores and pollen grains. However, it is not clear that there are sufficient nos. of these particles in the atm. to strongly influence clouds. Here, we show that the ice-nucleating activity of a fungus from the ubiquitous genus Fusarium is related to the presence of nanometer-scale particles which are far more numerous, and therefore potentially far more important for cloud glaciation than whole intact spores or hyphae. In addn., we quantify the ice-nucleating activity of nano-ice nucleating particles (nano-INPs) washed off pollen and also show that nano-INPs are present in a soil sample. Based on these results, we suggest that there is a reservoir of biol. nano-INPs present in the environment which may, for example, become aerosolised in assocn. with fertile soil dust particles.
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14Ogawa, S.; Koga, M.; Osanai, S. Anomalous Ice Nucleation Behavior in Aqueous Polyvinyl Alcohol Solutions Chem. Phys. Lett. 2009, 480, 86– 89 DOI: 10.1016/j.cplett.2009.08.046Google Scholar14https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtF2htLvN&md5=52b1dfe8ecb3c76f39f6a6816da026acAnomalous ice nucleation behavior in aqueous polyvinyl alcohol solutionsOgawa, S.; Koga, M.; Osanai, S.Chemical Physics Letters (2009), 480 (1-3), 86-89CODEN: CHPLBC; ISSN:0009-2614. (Elsevier B.V.)The effect of polymers on the ice nucleation temp. (T f) was studied in a W/O emulsion using ∼5 μm diam. droplets by differential scanning calorimetry (DSC). Four types of polymers were used. Among them, only poly(vinyl alc.) (PVA) showed the addnl. effect of increasing the T f of the aq. solns. This increase was logarithmic with the concn. of PVA and the difference in mol. wt. did not have any significant effect on T f for the same wt. concn. It was shown that the no. of the structural unit (CH2CHOH) was the key parameter for the increasing degree of T f.
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15Salzmann, C. G.; Nicolosi, V.; Green, M. L. Edge-carboxylated Graphene Nanoflakes from Nitric Acid Oxidised Arc-discharge Material J. Mater. Chem. 2010, 20, 314– 319 DOI: 10.1039/B914288FGoogle ScholarThere is no corresponding record for this reference.
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16He, H.; Riedl, T.; Lerf, A.; Klinowski, J. Solid-State NMR Studies of the Structure of Graphite Oxide J. Phys. Chem. 1996, 100, 19954– 19958 DOI: 10.1021/jp961563tGoogle Scholar16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK28XntFSgsLY%253D&md5=cc1ddc4aacc11eee0f55ea5d4faadc3eSolid-State NMR Studies of the Structure of Graphite OxideHe, Heyong; Riedl, Thomas; Lerf, Anton; Klinowski, JacekJournal of Physical Chemistry (1996), 100 (51), 19954-19958CODEN: JPCHAX; ISSN:0022-3654. (American Chemical Society)Graphite oxide (GO) and its derivs. have been studied using 13C and 1H NMR. The 13C NMR lines at 60, 70, and 130 ppm are assigned to C-OH, C-O-C, and >C:C< groups in the bulk of the material, resp. The >C:C< double bonds are relatively stable, while C-OH groups may condense to form C-O-C (ether) linkages. There are at least two magnetically inequivalent C-OH sites, and the structure does not necessarily possess long-range order. Water mols. interact very strongly with the structure. The results reveal a no. of new structural features.
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17Whale, T. F.; Murray, B. J.; O’Sullivan, D.; Wilson, T. W.; Umo, N. S.; Baustian, K. J.; Atkinson, J. D.; Workneh, D. A.; Morris, G. J. A Technique for Quantifying Heterogeneous Ice Nucleation in Microlitre Supercooled Water Droplets Atmos. Meas. Tech. 2015, 8, 2437– 2447 DOI: 10.5194/amt-8-2437-2015Google Scholar17https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsVKqsLjP&md5=49796ff1769052db1bf9e4493109391cA technique for quantifying heterogeneous ice nucleation in microlitre supercooled water dropletsWhale, T. F.; Murray, B. J.; O'Sullivan, D.; Wilson, T. W.; Umo, N. S.; Baustian, K. J.; Atkinson, J. D.; Workneh, D. A.; Morris, G. J.Atmospheric Measurement Techniques (2015), 8 (6), 2437-2447CODEN: AMTTC2; ISSN:1867-8548. (Copernicus Publications)In many clouds, the formation of ice requires the presence of particles capable of nucleating ice. Ice-nucleating particles (INPs) are rare in comparison to cloud condensation nuclei. However, the fact that only a small fraction of aerosol particles can nucleate ice means that detection and quantification of INPs is challenging. This is particularly true at temps. above about -20 °C since the population of particles capable of serving as INPs decreases dramatically with increasing temp. In this paper, we describe an exptl. technique in which droplets of microlitre vol. contg. ice-nucleating material are cooled down at a controlled rate and their freezing temps. recorded. The advantage of using large droplet vols. is that the surface area per droplet is vastly larger than in expts. focused on single aerosol particles or cloud-sized droplets. This increases the probability of observing the effect of less common, but important, high-temp. INPs and therefore allows the quantification of their ice nucleation efficiency. The potential artifacts which could influence data from this expt., and other similar expts., are mitigated and discussed. Exptl. detd. heterogeneous ice nucleation efficiencies for K-feldspar (microcline), kaolinite, chlorite, NX-illite, Snomax and silver iodide are presented.
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18Umo, N. S.; Murray, B. J.; Baeza-Romero, M. T.; Jones, J. M.; Lea-Langton, A. R.; Malkin, T. L.; O’Sullivan, D.; Neve, L.; Plane, J. M. C.; Williams, A. Ice Nucleation by Combustion Ash Particles at Conditions Relevant to Mixed-phase Clouds Atmos. Chem. Phys. 2015, 15, 5195– 5210 DOI: 10.5194/acp-15-5195-2015Google Scholar18https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXptlCktrc%253D&md5=de6b2575bca8376bc5c47bed4ecff861Ice nucleation by combustion ash particles at conditions relevant to mixed-phase cloudsUmo, N. S.; Murray, B. J.; Baeza-Romero, M. T.; Jones, J. M.; Lea-Langton, A. R.; Malkin, T. L.; O'Sullivan, D.; Neve, L.; Plane, J. M. C.; Williams, A.Atmospheric Chemistry and Physics (2015), 15 (9), 5195-5210CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Ice-nucleating particles can modify cloud properties with implications for climate and the hydrol. cycle; hence, it is important to understand which aerosol particle types nucleate ice and how efficiently they do so. It has been shown that aerosol particles such as natural dusts, volcanic ash, bacteria and pollen can act as ice-nucleating particles, but the ice-nucleating ability of combustion ashes has not been studied. Combustion ashes are major byproducts released during the combustion of solid fuels and a significant amt. of these ashes are emitted into the atm. either during combustion or via aerosolization of bottom ashes. Here, we show that combustion ashes (coal fly ash, wood bottom ash, domestic bottom ash, and coal bottom ash) nucleate ice in the immersion mode at conditions relevant to mixed-phase clouds. Hence, combustion ashes could play an important role in primary ice formation in mixed-phase clouds, esp. in clouds that are formed near the emission source of these aerosol particles. In order to quant. assess the impact of combustion ashes on mixed-phase clouds, we propose that the atm. abundance of combustion ashes should be quantified since up to now they have mostly been classified together with mineral dust particles. Also, in reporting ice residue compns., a distinction should be made between natural mineral dusts and combustion ashes in order to quantify the contribution of combustion ashes to atm. ice nucleation.
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19Riechers, B.; Wittbracht, F.; Hütten, A.; Koop, T. The Homogeneous Ice Nucleation Rate of Water Droplets Produced in a Microfluidic Device and the Role of Temperature Uncertainty Phys. Chem. Chem. Phys. 2013, 15, 5873– 5887 DOI: 10.1039/c3cp42437eGoogle Scholar19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksFOitro%253D&md5=8869ff5078cc44eed477eed39452f493The homogeneous ice nucleation rate of water droplets produced in a microfluidic device and the role of temperature uncertaintyRiechers, Birte; Wittbracht, Frank; Huetten, Andreas; Koop, ThomasPhysical Chemistry Chemical Physics (2013), 15 (16), 5873-5887CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)Ice nucleation was investigated exptl. in water droplets with diams. between 53-96 μm. The droplets were produced in a microfluidic device in which a flow of methyl-cyclohexane and water was combined at the T-junction of micro-channels yielding inverse (water-in-oil) emulsions consisting of water droplets with small std. deviations. In cryo-microscopic expts. it is confirmed that upon cooling of such emulsion samples ice nucleation in individual droplets occurred independently of each other as required for the investigation of a stochastic process. The emulsion samples were then subjected to cooling at 1 K per min in a differential scanning calorimeter with high temp. accuracy. From the latent heat released by freezing water droplets the vol.-dependent homogeneous ice nucleation rate coeff. of water at temps. between 236.5-237.9 K is inferred. A comparison of the newly derived values to existing rate coeffs. from other studies suggests that the vol.-dependent ice nucleation rate in supercooled water is slightly lower than previously thought. Moreover, a comprehensive error anal. suggests that abs. temp. accuracy is the single most important exptl. parameter detg. the uncertainty of the derived ice nucleation rates in the expts., and presumably also in many previous expts. The anal., thus, also provides a route for improving the accuracy of future ice nucleation rate measurements.
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20Murray, B. J.; Broadley, S. L.; Wilson, T. W.; Bull, S. J.; Wills, R. H.; Christenson, H. K.; Murray, E. J. Kinetics of the Homogeneous Freezing of Water Phys. Chem. Chem. Phys. 2010, 12, 10380– 7 DOI: 10.1039/c003297bGoogle Scholar20https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtVOns7vO&md5=4c108508ae185a9196d868e5a53cb994Kinetics of the homogeneous freezing of waterMurray, B. J.; Broadley, S. L.; Wilson, T. W.; Bull, S. J.; Wills, R. H.; Christenson, H. K.; Murray, E. J.Physical Chemistry Chemical Physics (2010), 12 (35), 10380-10387CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)Rates of homogeneous nucleation of ice in μm-sized water droplets are reported. Measurements were made using a new system in which droplets were supported on a hydrophobic substrate and their phase was monitored using optical microscopy as they were cooled at a controlled rate. Obtained nucleation rates are in agreement, given the quoted uncertainties, with the most recent literature data. However, the level of uncertainty in the rate of homogeneous freezing remains unacceptable given the importance of homogeneous nucleation to cloud formation in the Earth's atm. The most recent thermodn. data for cubic ice (the metastable phase thought to nucleate from supercooled water) are used to est. the interfacial energy of the cubic ice-supercooled water interface. A value of 20.8 ± 1.2 mJ m-2 in the temp. range 234.9-236.7 K is estd.
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21Vali, G. Interpretation of Freezing Nucleation Experiments: Singular and Stochastic; Sites and Surfaces Atmos. Chem. Phys. 2014, 14, 5271– 5294 DOI: 10.5194/acp-14-5271-2014Google Scholar21https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1CmurzN&md5=be27e82fc93f01c774fd15f1df46d7c8Interpretation of freezing nucleation experiments: singular and stochastic; sites and surfacesVali, G.Atmospheric Chemistry and Physics (2014), 14 (11), 5271-5294, 24 pp.CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Publications of recent years dealing with lab. expts. of immersion freezing reveal uncertainties about the fundamentals of heterogeneous freezing nucleation. While it appears well accepted that there are two major factors that det. the process, namely fluctuations in the size and configuration of incipient embryos of the solid phase and the role of the substrate to aid embryo formation, views have been evolving about the relative importance of these two elements. The importance of sp. surface sites is being established in a growing no. of expts. and a no. of approaches have been proposed to incorporate these results into model descriptions. Many of these models share a common conceptual basis yet diverge in the way random and deterministic factors are combined. The divergence can be traced to uncertainty about the permanence of nucleating sites, to the lack of detailed knowledge about what surface features constitute nucleating sites, and to the consequent need to rely on empirical or parametric formulas to define the population of sites of different effectiveness. Recent expts. and models, consistent with earlier work, demonstrate the existence and primary role of permanent nucleating sites and the continued need for empirically based formulations of heterogeneous freezing. In order to clarify some aspects of the processes controlling immersion freezing, the paper focuses on three identifiably sep. but interrelated issues: (i) the combination of singular and stochastic factors, (ii) the role of sp. surface sites, and (iii) the modeling of heterogeneous ice nucleation.
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22Herbert, R. J.; Murray, B. J.; Whale, T. F.; Dobbie, S. J.; Atkinson, J. D. Representing Time-Dependent Freezing Behaviour in Immersion Mode Ice Nucleation Atmos. Chem. Phys. 2014, 14, 8501– 8520 DOI: 10.5194/acp-14-8501-2014Google ScholarThere is no corresponding record for this reference.
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23Koga, K.; Gao, G. T.; Tanaka, H.; Zeng, X. C. Formation of Ordered Ice Nanotubes Inside Carbon Nanotubes Nature 2001, 412, 802– 805 DOI: 10.1038/35090532Google Scholar23https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXms1antL4%253D&md5=481e8a147777cff4c8c2aac6b121d6dcFormation of ordered ice nanotubes inside carbon nanotubesKoga, Kenichiro; Gao, G. T.; Tanaka, Hideld; Zeng, X. C.Nature (London, United Kingdom) (2001), 412 (6849), 802-805CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)Following their discovery, carbon nanotubes have attracted interest not only for their unusual elec. and mech. properties, but also because their hollow interior can serve as a nanometer-sized capillary, mold or template in material fabrication. The ability to encapsulate a material in a nanotube also offers new possibilities for investigating dimensionally confined phase transitions. Particularly intriguing is the conjecture that matter within the narrow confines of a carbon nanotube might exhibit a solid-liq. crit. point beyond which the distinction between solid and liq. phases disappears. This unusual feature, which cannot occur in bulk material, would allow for the direct and continuous transformation of liq. matter into a solid. Here we report simulations of the behavior of water encapsulated in carbon nanotubes that suggest the existence of a variety of new ice phases not seen in bulk ice, and of a solid-liq. crit. point. Using carbon nanotubes with diams. ranging from 1.1 nm to 1.4 nm and applied axial pressures of 50 MPa to 500 MPa, we find that water can exhibit a first-order freezing transition to hexagonal and heptagonal ice nanotubes, and a continuous phase transformation into solid-like square or pentagonal ice nanotubes.
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24Pummer, B. G.; Budke, C.; Augustin-Bauditz, S.; Niedermeier, D.; Felgitsch, L.; Kampf, C. J.; Huber, R. G.; Liedl, K. R.; Loerting, T.; Moschen, T.; Schauperl, M. Ice Nucleation by Water-Soluble Macromolecules Atmos. Chem. Phys. 2015, 15, 4077– 4091 DOI: 10.5194/acp-15-4077-2015Google Scholar24https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXns1ahsL4%253D&md5=b851059d5ff5097c39d6cdc4a27914aaIce nucleation by water-soluble macromoleculesPummer, B. G.; Budke, C.; Augustin-Bauditz, S.; Niedermeier, D.; Felgitsch, L.; Kampf, C. J.; Huber, R. G.; Liedl, K. R.; Loerting, T.; Moschen, T.; Schauperl, M.; Tollinger, M.; Morris, C. E.; Wex, H.; Grothe, H.; Poeschl, U.; Koop, T.; Froehlich-Nowoisky, J.Atmospheric Chemistry and Physics (2015), 15 (8), 4077-4091CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Cloud glaciation is critically important for the global radiation budget (albedo) and for initiation of pptn. But the freezing of pure water droplets requires cooling to temps. as low as 235 K. Freezing at higher temps. requires the presence of an ice nucleator, which serves as a template for arranging water mols. in an ice-like manner. It is often assumed that these ice nucleators have to be insol. particles. We point out that also free macromols. which are dissolved in water can efficiently induce ice nucleation: the size of such ice nucleating macromols. (INMs) is in the range of nanometers, corresponding to the size of the crit. ice embryo. As the latter is temp.-dependent, we see a correlation between the size of INMs and the ice nucleation temp. as predicted by classical nucleation theory. Different types of INMs have been found in a wide range of biol. species and comprise a variety of chem. structures including proteins, saccharides, and lipids. Our investigation of the fungal species Acremonium implicatum, Isaria farinosa, and Mortierella alpina shows that their ice nucleation activity is caused by proteinaceous water-sol. INMs. We combine these new results and literature data on INMs from fungi, bacteria, and pollen with theor. calcns. to develop a chem. interpretation of ice nucleation and water-sol. INMs. This has atm. implications since many of these INMs can be released by fragmentation of the carrier cell and subsequently may be distributed independently. Up to now, this process has not been accounted for in atm. models.
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25Cheng, J.; Soetjipto, C.; Hoffmann, M. R.; Colussi, A. J. Confocal Fluorescence Microscopy of the Morphology and Composition of Interstitial Fluids in Freezing Electrolyte Solutions J. Phys. Chem. Lett. 2010, 1, 374– 378 DOI: 10.1021/jz9000888Google Scholar25https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhsFektLzO&md5=d4755ee330c9bdbcf92a12caad9287ceConfocal Fluorescence Microscopy of the Morphology and Composition of Interstitial Fluids in Freezing Electrolyte SolutionsCheng, Jie; Soetjipto, Cherrie; Hoffmann, Michael R.; Colussi, A. J.Journal of Physical Chemistry Letters (2010), 1 (1), 374-378CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)Ice rheol., the integrity of polar ice core records, and ice-atm. interactions are among the phenomena controlled by the morphol. and compn. of interstitial fluids threading polycryst. ice. Herein, the authors study how ionic impurities affect such features via time-resolved confocal fluorescence microscopy of freezing electrolyte solns. doped with a pH probe. The 10 μM probe accumulates into 12 μm thick glassy channels in frozen water, but it is incorporated into randomly distributed <1 μm diam. inclusions in freezing 1 mM NaCl. The authors infer that morphol. is largely detd. by the dynamic instabilities generated upon advancing ice by the rejected solute, rather than by thermodn. The protracted alkalinization of the fluid inclusions reveals that the excess neg. charge generated by the preferential incorporation of Cl- over Na+ in ice is neutralized by the seepage of the OH- slowly produced via H2O → H+ + OH- thermal dissocn.
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26Guzmán, M. I.; Hildebrandt, L.; Colussi, A. J.; Hoffmann, M. R. Cooperative Hydration of Pyruvic Acid in Ice J. Am. Chem. Soc. 2006, 128, 10621– 10624 DOI: 10.1021/ja062039vGoogle Scholar26https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28Xnt12nsrY%253D&md5=5abd261743f2ab504a2d1996492d313bCooperative Hydration of Pyruvic Acid in IceGuzman, Marcelo I.; Hildebrandt, Lea; Colussi, Agustin J.; Hoffmann, Michael R.Journal of the American Chemical Society (2006), 128 (32), 10621-10624CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)About 3.5 ± 0.3 water mols. are still involved in the exothermic hydration of 2-oxopropanoic acid (PA) into its monohydrate (2,2-dihydroxypropanoic acid, PAH) in ice at 230 K. This is borne out by thermodn. anal. of the fact that QH(T) = [PAH]/[PA] becomes temp. independent .ltorsim.250 K (in chem. and thermally equilibrated frozen 0.1 ≤ [PA]/M ≤ 4.6 solns. in D2O), which requires that the enthalpy of PA hydration (ΔHH approx. -22 kJ mol-1) be balanced by a multiple of the enthalpy of ice melting (ΔHM = 6.3 kJ mol-1). Considering that: (1) thermograms of frozen PA solns. display a single endotherm, at the onset of ice melting, (2) the sum of the integral intensities of the 1δPAH and 1δPA Me proton NMR resonances is nearly const. while, (3) line widths increase exponentially with decreasing temp. before diverging .ltorsim.230 K, the authors infer that PA in ice remains cooperatively hydrated within interstitial microfluids until they vitrify.
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27Guzmán, M. I.; Colussi, A. J.; Hoffmann, M. R. Photogeneration of Distant Radical Pairs in Aqueous Pyruvic Acid Glasses J. Phys. Chem. A 2006, 110, 931– 935 DOI: 10.1021/jp053449tGoogle Scholar27https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XlsFGg&md5=a3805ff01c20fe4b6e5b756a41166b9ePhotogeneration of Distant Radical Pairs in Aqueous Pyruvic Acid GlassesGuzman, Marcelo I.; Colussi, A. J.; Hoffmann, Michael R.Journal of Physical Chemistry A (2006), 110 (3), 931-935CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)The λ > 300 nm photolysis of h4- or d4-pyruvic acid aq. glasses at 77 K yields identical electron magnetic resonance (EMR) spectra arising from distant (r ⪆ 0.5 nm) triplet radical pairs. Spectra comprise: (1) well-resolved quartets, X, at g ∼ ge, that closely match the powder spectra of spin pairs interacting across r ∼ 1.0 nm with D ∼ 3.0 mT, E ∼ 0 mT zero field splittings (ZFS), and (2) broad signals, Y, centered at g ∼ 2.07 that display marked g-anisotropy and g-strain, exclude D ⪆ 20.0 mT values (i.e., r .ltorsim. 0.5 spin nm sepns.), and track the temp. dependence of related g ∼ 4 features. These results imply that the n-π* excitation of pyruvic acid, PA, induces long-range electron transfer from the promoted carbonyl chromophore into neighboring carbonyl acceptors, rather than homolysis into contact radical pairs or concerted decarboxylation into a carbene. Since PA is assocd. into hydrogen-bonded dimers prior to vitrification, X signals arise from radical pairs ensuing intradimer electron transfer to a locked acceptor, while Y signals involve carbonyl groups attached to randomly arranged, disjoint monomers. The ultrafast decarboxylation of primary radical ion pairs, 3[PA+• PA-•], accounts for the release of CO2 under cryogenic conditions, the lack of thermal hysteresis displayed by magnetic signals between 10 and 160 K, and averted charge retro-transfer. All EMR signals disappear irreversibly above the onset of ice diffusivity at ∼190 K.
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28Finnegan, W. G.; Chai, S. K. A New Hypothesis for the Mechanism of ice Nucleation on Wetted AgI and AgI Center Dot AgCl Particulate Aerosols J. Atmos. Sci. 2003, 60, 1723– 1731 DOI: 10.1175/1520-0469(2003)060<1723:ANHFTM>2.0.CO;2Google ScholarThere is no corresponding record for this reference.
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29Massey, A.; McBride, F.; Darling, G. R.; Nakamura, M.; Hodgson, A. The Role of Lattice Parameter in Water Adsorption and Wetting of a Solid Surface Phys. Chem. Chem. Phys. 2014, 16, 24018– 24025 DOI: 10.1039/C4CP03164DGoogle Scholar29https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1Gmu73O&md5=bc94853808db5c3d52bd310e8ce09bbaThe role of lattice parameter in water adsorption and wetting of a solid surfaceMassey, A.; McBride, F.; Darling, G. R.; Nakamura, M.; Hodgson, A.Physical Chemistry Chemical Physics (2014), 16 (43), 24018-24025CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)Ice formation is a complex cooperative process that is almost invariably catalyzed by the presence of an interface on which ice crystals nucleate. As yet there is no clear picture of what factors make a surface particularly good at nucleating ice, but the importance of having a template with a suitable lattice parameter has often been proposed. Here the authors report the contrasting wetting behavior of pseudomorphic surfaces, designed to form an ordered template that matches the arrangement of H2O in a bulk ice Ih(0001) bilayer. The close-packed M(111) surfaces (M = Pt, Pd, Rh, Cu and Ni) form a [√3×√3] Sn substitutional alloy surface, with Sn atoms occupying sites that match the symmetry of an ice bilayer. The lattice const. of the alloy changes from 4% smaller to 7% greater than the lateral spacing of ice across the series. Only the PtSn surface, with a lattice parameter some 7% greater than that of a bulk ice layer, forms a stable H2O layer, all the other surfaces being nonwetting and instead forming multilayer ice clusters. This observation is consistent with the idea that the repeat spacing of the surface should ideally match the O-O spacing in ice, rather than the bulk ice lattice parameter, to form a continuous commensurate H2O monolayer. The role of the lattice parameter in stabilizing the 1st layer of H2O and the factors that give a simple commensurate structure rather than an incommensurate or large unit cell H2O network are discussed. The authors argue that lattice match is not a good criteria for a material to give low energy nucleation sites for bulk ice, and that considerations such as binding energy and mobility of the surface layer are more relevant.
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30Hu, X. L.; Michaelides, A. Ice Formation on Kaolinite: Lattice Match or Amphoterism? Surf. Sci. 2007, 601, 5378– 5381 DOI: 10.1016/j.susc.2007.09.012Google Scholar30https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXhtlGjt7vP&md5=9b8c4b8afd039a4cab03a1d8f33ac694Ice formation on kaolinite: Lattice match or amphoterism?Hu, Xiao Liang; Michaelides, AngelosSurface Science (2007), 601 (23), 5378-5381CODEN: SUSCAS; ISSN:0039-6028. (Elsevier B.V.)The long-standing belief that kaolinite is one of the most efficient natural ice nucleating agents because it provides a close lattice match to the basal plane of ice is called into question. Instead we show through an extensive series of first principles calcns. that amphoterism is key to many of the interesting properties of kaolinite with regard to water adsorption and ice nucleation.
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31Fraux, G.; Doye, J. P. K. Note: Heterogeneous Ice Nucleation on Silver-Iodide-Like Surfaces J. Chem. Phys. 2014, 141, 216101 DOI: 10.1063/1.4902382Google Scholar31https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitValt7zE&md5=5e8b0c7250cea205d369cc2e362f2e85Note: Heterogeneous ice nucleation on silver-iodide-like surfacesFraux, Guillaume; Doye, Jonathan P. K.Journal of Chemical Physics (2014), 141 (21), 216101/1-216101/2CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)The authors attempt to simulate the heterogeneous nucleation of ice at model silver-iodide surfaces and find relatively facile ice nucleation and growth at the Ag+ terminated basal face, but never see nucleation at the I- terminated basal face or the prism and normal faces. Water mols. strongly adsorb onto the Ag+ terminated face to give a well-ordered hexagonal ice-like bilayer that then acts as a template for further ice growth. (c) 2014 American Institute of Physics.
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32Reinhardt, A.; Doye, J. P. K. Effects of Surface Interactions on Heterogeneous Ice Nucleation for a Monatomic Water Model J. Chem. Phys. 2014, 141, 084501 DOI: 10.1063/1.4892804Google Scholar32https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVWks73N&md5=8c6bca7c78e510c45a24e2c0129a9d0cEffects of surface interactions on heterogeneous ice nucleation for a monatomic water modelReinhardt, Aleks; Doye, Jonathan P. K.Journal of Chemical Physics (2014), 141 (8), 084501/1-084501/10CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)Despite its importance in atm. science, much remains unknown about the microscopic mechanism of heterogeneous ice nucleation. The authors performed hybrid Monte Carlo simulations of the heterogeneous nucleation of ice on a range of generic surfaces, both flat and structured, in order to probe the underlying factors affecting the nucleation process. The structured surfaces studied comprise one basal plane bilayer of ice with varying lattice parameters and interaction strengths. What dets. the propensity for nucleation is not just the surface attraction, but also the orientational ordering imposed on liq. water near a surface. In particular, varying the ratio of the surface's attraction and orientational ordering can change the mechanism by which nucleation occurs: ice can nucleate on the structured surface even when the orientational ordering imposed by the surface is weak, as the water mols. that interact strongly with the surface are themselves a good template for further growth. Lattice matching is important for heterogeneous nucleation on the structured surface studied. The authors rationalize these brute-force simulation results by explicitly calcg. the interfacial free energies of ice and liq. water in contact with the nucleating surface and their variation with surface interaction parameters. (c) 2014 American Institute of Physics.
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33Cox, S. J.; Raza, Z.; Kathmann, S. M.; Slater, B.; Michaelides, A. The Microscopic Features of Heterogeneous Ice Nucleation May Affect the Macroscopic Morphology of Atmospheric Ice Crystals Faraday Discuss. 2013, 167, 389– 403 DOI: 10.1039/c3fd00059aGoogle Scholar33https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2crltVajtg%253D%253D&md5=17ee125d0e5eba1a57663d49013d2742The microscopic features of heterogeneous ice nucleation may affect the macroscopic morphology of atmospheric ice crystalsCox Stephen J; Raza Zamaan; Kathmann Shawn M; Slater Ben; Michaelides AngelosFaraday discussions (2013), 167 (), 389-403 ISSN:1359-6640.It is surprisingly difficult to freeze water. Almost all ice that forms under "mild" conditions (temperatures > -40 degrees C) requires the presence of a nucleating agent--a solid particle that facilitates the freezing process--such as clay mineral dust, soot or bacteria. In a computer simulation, the presence of such ice nucleating agents does not necessarily alleviate the difficulties associated with forming ice on accessible timescales. Nevertheless, in this work we present results from molecular dynamics simulations in which we systematically compare homogeneous and heterogeneous ice nucleation, using the atmospherically important clay mineral kaolinite as our model ice nucleating agent. From our simulations, we do indeed find that kaolinite is an excellent ice nucleating agent but that contrary to conventional thought, non-basal faces of ice can nucleate at the basal face of kaolinite. We see that in the liquid phase, the kaolinite surface has a drastic effect on the density profile of water, with water forming a dense, tightly bound first contact layer. Monitoring the time evolution of the water density reveals that changes away from the interface may play an important role in the nucleation mechanism. The findings from this work suggest that heterogeneous ice nucleating agents may not only enhance the ice nucleation rate, but also alter the macroscopic structure of the ice crystals that form.
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34Cox, S. J.; Kathmann, S. M.; Purton, J. A.; Gillan, M. J.; Michaelides, A. Non-hexagonal Ice at Hexagonal Surfaces: the Role of Lattice Mismatch Phys. Chem. Chem. Phys. 2012, 14, 7944– 7949 DOI: 10.1039/c2cp23438fGoogle Scholar34https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XntVShtbk%253D&md5=f8261a6e551f7b182171eb20aef6ba1cNon-hexagonal ice at hexagonal surfaces: the role of lattice mismatchCox, Stephen J.; Kathmann, Shawn M.; Purton, John A.; Gillan, Michael J.; Michaelides, AngelosPhysical Chemistry Chemical Physics (2012), 14 (22), 7944-7949CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)It has long been known that ice nucleation usually proceeds heterogeneously on the surface of a foreign body. However, little is known at the microscopic level about which properties of a material det. its effectiveness at nucleating ice. This work focuses on the long standing, conceptually simple, view on the role of a good crystallog. match between bulk ice and the underlying substrate. The authors use grand canonical Monte Carlo to generate the 1st overlayer of H2O at the surface and find that the traditional view of heterogeneous nucleation does not adequately account for the array of structures that H2O may form at the surface. To describe the structures formed, a good match between the substrate and the nearest neighbor O-O distance is a better descriptor than a good match to the bulk ice lattice const.
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35Cox, S. J.; Kathmann, S. M.; Slater, B.; Michaelides, A. Molecular Simulations of Heterogeneous Ice Nucleation. I. Controlling Ice Nucleation Through Surface Hydrophilicity J. Chem. Phys. 2015, 142, 184704 DOI: 10.1063/1.4919714Google Scholar35https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXot1CjtLw%253D&md5=4ba289fc04c5c951be4267cf5cdec999Molecular simulations of heterogeneous ice nucleation. I. Controlling ice nucleation through surface hydrophilicityCox, Stephen J.; Kathmann, Shawn M.; Slater, Ben; Michaelides, AngelosJournal of Chemical Physics (2015), 142 (18), 184704/1-184704/5CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)Ice formation is one of the most common and important processes on earth and almost always occurs at the surface of a material. A basic understanding of how the physicochem. properties of a material's surface affect its ability to form ice has remained elusive. Here, we use mol. dynamics simulations to directly probe heterogeneous ice nucleation at a hexagonal surface of a nanoparticle of varying hydrophilicity. Surprisingly, we find that structurally identical surfaces can both inhibit and promote ice formation and analogous to a chem. catalyst, it is found that an optimal interaction between the surface and the water exists for promoting ice nucleation. We use our microscopic understanding of the mechanism to design a modified surface in silico with enhanced ice nucleating ability. (c) 2015 American Institute of Physics.
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36Cox, S. J.; Kathmann, S. M.; Slater, B.; Michaelides, A. Molecular Simulations of Heterogeneous Ice Nucleation. II. Peeling Back the Layers J. Chem. Phys. 2015, 142, 184705 DOI: 10.1063/1.4919715Google Scholar36https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXot1CjtLo%253D&md5=07bf3a4e192cc45a7d89d7a94a388a7fMolecular simulations of heterogeneous ice nucleation. II. Peeling back the layersCox, Stephen J.; Kathmann, Shawn M.; Slater, Ben; Michaelides, AngelosJournal of Chemical Physics (2015), 142 (18), 184705/1-184705/8CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)Coarse grained mol. dynamics simulations are presented in which the sensitivity of the ice nucleation rate to the hydrophilicity of a graphene nanoflake is investigated. We find that an optimal interaction strength for promoting ice nucleation exists, which coincides with that found previously for a fcc. (111) surface. We further investigate the role that the layering of interfacial water plays in heterogeneous ice nucleation and demonstrate that the extent of layering is not a good indicator of ice nucleating ability for all surfaces. Our results suggest that to be an efficient ice nucleating agent, a surface should not bind water too strongly if it is able to accommodate high coverages of water. (c) 2015 American Institute of Physics.
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37Cabriolu, R.; Li, T. Ice Nucleation on Carbon Surface Supports the Classical Theory for Heterogeneous Nucleation Phys. Rev. E: Stat. Phys., Plasmas, Fluids 2015, 91, 052402 DOI: 10.1103/PhysRevE.91.052402Google ScholarThere is no corresponding record for this reference.
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38Lupi, L.; Molinero, V. Does Hydrophilicity of Carbon Particles Improve Their Ice Nucleation Ability? J. Phys. Chem. A 2014, 118, 7330– 7337 DOI: 10.1021/jp4118375Google Scholar38https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXis1egsrw%253D&md5=23475ed8d095f6dc565c78451bd64990Does Hydrophilicity of Carbon Particles Improve Their Ice Nucleation Ability?Lupi, Laura; Molinero, ValeriaJournal of Physical Chemistry A (2014), 118 (35), 7330-7337CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Carbonaceous particles account for 10% of the particulate matter in the atm. Atm. oxidn. and aging of soot modulates its ice nucleation ability. An increase in the ice nucleation ability of aged soot results from an increase in the hydrophilicity of the surfaces upon oxidn. Oxidn., however, also impacts the nanostructure of soot, making it difficult to assess the sep. effects of soot nanostructure and hydrophilicity in expts. Here we use mol. dynamics simulations to investigate the effect of changes in hydrophilicity of model graphitic surfaces on the freezing temp. of ice. Our results indicate that the hydrophilicity of the surface is not in general a good predictor of ice nucleation ability. We find a correlation between the ability of a surface to promote nucleation of ice and the layering of liq. water at the surface. The results of this work suggest that ordering of liq. water in contact with the surface plays an important role in the heterogeneous ice nucleation mechanism.
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39Lupi, L.; Hudait, A.; Molinero, V. Heterogeneous Nucleation of Ice on Carbon Surfaces J. Am. Chem. Soc. 2014, 136, 3156– 3164 DOI: 10.1021/ja411507aGoogle Scholar39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslygsL8%253D&md5=a6efa985c5e7275212f2b8a982ffa9c7Heterogeneous Nucleation of Ice on Carbon SurfacesLupi, Laura; Hudait, Arpa; Molinero, ValeriaJournal of the American Chemical Society (2014), 136 (8), 3156-3164CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)Atm. aerosols can promote the heterogeneous nucleation of ice, impacting the radiative properties of clouds and Earth's climate. The exptl. study of heterogeneous freezing of water droplets by carbonaceous particles reveals widespread ice freezing temps. It is not known which structural and chem. characteristics of soot account for the variability in ice nucleation efficiency. Here the authors use mol. dynamics simulations to study the nucleation of ice from liq. water in contact with graphitic surfaces. Atomically flat carbon surfaces promote heterogeneous nucleation of ice, while molecularly rough surfaces with the same hydrophobicity do not. Graphitic surfaces and other surfaces that promote ice nucleation induce layering in the interfacial water, suggesting that the order imposed by the surface on liq. water may play an important role in the heterogeneous nucleation mechanism. The authors study a large set of graphitic surfaces of various dimensions and radii of curvature and find that variations in nanostructures alone could account for the spread in the freezing temps. of ice on soot in expts. A characterization of the nanostructure of soot is needed to predict its ice nucleation efficiency.
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- Andreas Peckhaus, Alexei Kiselev, Thibault Hiron, Martin Ebert, Thomas Leisner. A comparative study of K-rich and Na/Ca-rich feldspar ice-nucleating particles in a nanoliter droplet freezing assay. Atmospheric Chemistry and Physics 2016, 16 (18) , 11477-11496. https://doi.org/10.5194/acp-16-11477-2016
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Abstract
Figure 1
Figure 1. Chemical structures of the various of carbon nanomaterials tested for their ice nucleation activity: (a) small carboxylated graphene nanoflake (cx-GNF), (b) mellitic acid, (c) graphene oxide (GO), (d) multiwalled carbon nanotube (MWCNT), and (e) single walled carbon nanotube (SWCNT). GO sheets have an average lateral diameter of ∼1 μm, while the GNFs have an average lateral diameter of ∼30 nm. (15)
Figure 2
Figure 2. (a) Droplet fraction frozen against temperature for 1 and 0.1 wt % dispersions of GO and cx-GNFs, a 1 wt % dispersion of o-MWCNTs, a 0.07 wt % dispersion of o-SWCNTs, a 1 wt % solution of mellitic acid, and pure water. (b) ns values for all tested carbon nanomaterials. The ns values reported for the o-MWCNTs assume that they have nine layers, the average number of the starting material for their synthesis. The shaded area shows the area encompassed by calculating ns for the minimum and maximum wall numbers of the starting material. Experimental uncertainty in ns was calculated by propagation of uncertainty from weighing, droplet size, and background subtraction. In many cases, uncertainties are too small to show on the plot. Temperature uncertainty is ±0.4 °C in panels a and b.
Figure 3
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References
ARTICLE SECTIONS
This article references 39 other publications.
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1Murray, B. J.; O’Sullivan, D.; Atkinson, J. D.; Webb, M. E. Ice Nucleation by Particles Immersed in Supercooled Cloud Droplets Chem. Soc. Rev. 2012, 41, 6519– 6554 DOI: 10.1039/c2cs35200a1https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xhtlaktr7L&md5=5a331f4c83c33d5d7a99d6dca8cf9b3fIce nucleation by particles immersed in supercooled cloud dropletsMurray, B. J.; O'Sullivan, D.; Atkinson, J. D.; Webb, M. E.Chemical Society Reviews (2012), 41 (19), 6519-6554CODEN: CSRVBR; ISSN:0306-0012. (Royal Society of Chemistry)A review. The formation of ice particles in the Earth's atm. strongly affects the properties of clouds and their impact on climate. Despite the importance of ice formation in detg. the properties of clouds, the Intergovernmental Panel on Climate Change (IPCC, 2007) was unable to assess the impact of atm. ice formation in their most recent report because our basic knowledge is insufficient. Part of the problem is the paucity of quant. information on the ability of various atm. aerosol species to initiate ice formation. Here we review and assess the existing quant. knowledge of ice nucleation by particles immersed within supercooled water droplets. We introduce aerosol species which have been identified in the past as potentially important ice nuclei and address their ice-nucleating ability when immersed in a supercooled droplet. We focus on mineral dusts, biol. species (pollen, bacteria, fungal spores and plankton), carbonaceous combustion products and volcanic ash. In order to make a quant. comparison we first introduce several ways of describing ice nucleation and then summarise the existing information according to the time-independent (singular) approxn. Using this approxn. in combination with typical atm. loadings, we est. the importance of ice nucleation by different aerosol types. According to these ests. we find that ice nucleation below about -15 °C is dominated by soot and mineral dusts. Above this temp. the only materials known to nucleate ice are biol., with quant. data for other materials absent from the literature. We conclude with a summary of the challenges our community faces.
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2Hoose, C.; Möhler, O. Heterogeneous Ice Nucleation on Atmospheric Aerosols: a Review of Results From Laboratory Experiments Atmos. Chem. Phys. 2012, 12, 9817– 9854 DOI: 10.5194/acp-12-9817-20122https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXht1Omtr0%253D&md5=20313e79a4bcdc12a065bff0a1d93e8fHeterogeneous ice nucleation on atmospheric aerosols: a review of results from laboratory experimentsHoose, C.; Moehler, O.Atmospheric Chemistry and Physics (2012), 12 (20), 9817-9854CODEN: ACPTCE; ISSN:1680-7316. (Copernicus Publications)A review. A small subset of the atm. aerosol population has the ability to induce ice formation at conditions under which ice would not form without them (heterogeneous ice nucleation). While no closed theor. description of this process and the requirements for good ice nuclei is available, numerous studies have attempted to quantify the ice nucleation ability of different particles empirically in lab. expts. In this article, an overview of these results is provided. Ice nucleation "onset" conditions for various mineral dust, soot, biol., org. and ammonium sulfate particles are summarized. Typical temp.-supersatn. regions can be identified for the "onset" of ice nucleation of these different particle types, but the various particle sizes and activated fractions reported in different studies have to be taken into account when comparing results obtained with different methodologies. When intercomparing only data obtained under the same conditions, it is found that dust mineralogy is not a consistent predictor of higher or lower ice nucleation ability. However, the broad majority of studies agrees on a redn. of deposition nucleation by various coatings on mineral dust. The ice nucleation active surface site (INAS) d. is discussed as a simple and empirical normalized measure for ice nucleation activity. For most immersion and condensation freezing measurements on mineral dust, ests. of the temp.-dependent INAS d. agree within about two orders of magnitude. For deposition nucleation on dust, the spread is significantly larger, but a general trend of increasing INAS densities with increasing supersatn. is found. For soot, the presently available results are divergent. Estd. av. INAS densities are high for ice-nucleation active bacteria at high subzero temps. At the same time, it is shown that INAS densities of some other biol. aerosols, like certain pollen grains, fungal spores and diatoms, tend to be similar to those of dust. These particles may owe their high ice nucleation onsets to their large sizes. Surface-area-dependent parameterizations of heterogeneous ice nucleation are discussed. For immersion freezing on mineral dust, fitted INAS densities are available, but should not be used outside the temp. interval of the data they were based on. Classical nucleation theory, if employed with only one fitted contact angle, does not reproduce the obsd. temp. dependence for immersion nucleation, the temp. and supersatn. dependence for deposition nucleation, and the time dependence of ice nucleation. Formulations of classical nucleation theory with distributions of contact angles offer possibilities to overcome these weaknesses.
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3Pruppacher, H. R.; Klett, J. D. Microphysics of Clouds and Precipitation, 2nd ed.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 1997.There is no corresponding record for this reference.
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4Morris, G. J.; Acton, E. Controlled Ice Nucleation in Cryopreservation - a Review Cryobiology 2013, 66, 85– 92 DOI: 10.1016/j.cryobiol.2012.11.007There is no corresponding record for this reference.
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5Searles, J. A.; Carpenter, J. F.; Randolph, T. W. The Ice Nucleation Temperature Determines the Primary Drying Rate of Lyophilization for Samples Frozen on a Temperature-Controlled Shelf J. Pharm. Sci. 2001, 90, 860– 871 DOI: 10.1002/jps.10395https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXlt1Cqu7k%253D&md5=02bf23873bc796db11687a0207ef7b44The ice nucleation temperature determines the primary drying rate of lyophilization for samples frozen on a temperature-controlled shelfSearles, James A.; Carpenter, John F.; Randolph, Theodore W.Journal of Pharmaceutical Sciences (2001), 90 (7), 860-871CODEN: JPMSAE; ISSN:0022-3549. (Wiley-Liss, Inc.)The objective of this study was to det. the influence of ice nucleation temp. on the primary drying rate during lyophilization for samples in vials that were frozen on a lyophilizer shelf. Aq. solns. of 10% (w/v) hydroxyethyl starch were frozen in vials with externally mounted thermocouples and then partially lyophilized to det. the primary drying rate. Low- and high-particulate-contg. samples, ice-nucleating additives silver iodide and Pseudomonas syringae, and other methods were used to obtain a wide range of nucleation temps. In cases where the supercooling exceeded 5°, freezing took place in the following three steps: (1) primary nucleation, (2) secondary nucleation encompassing the entire liq. vol., and (3) final solidification. The primary drying rate was dependent on the ice nucleation temp., which is stochastic in nature but is affected by particulate content and the presence of ice nucleators. Sample cooling rates of 0.05 to 1°/min had no effect on nucleation temps. and drying rate. We found that the ice nucleation temp. is the primary determinant of the primary drying rate. However, the nucleation temp. is not under direct control, and its stochastic nature and sensitivity to difficult-to-control parameters result in drying rate heterogeneity. Nucleation temp. heterogeneity may also result in variation in other morphol.-related parameters such as surface area and secondary drying rate. Overall, these results document that factors such as particulate content and vial condition, which influence ice nucleation temp., must be carefully controlled to avoid, for example, lot-to-lot variability during cGMP prodn. In addn., if these factors are not controlled and/or are inadvertently changed during process development and scaleup, a lyophilization cycle that was successful on the research scale may fail during large-scale prodn.
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6Aksan, A.; Ragoonanan, V.; Hirschmugl, C. Freezing- and Drying-Induced Micro- and Nano-Heterogeneity in Biological Solutions. In Biophysical Methods for Biotherapeutics; John Wiley & Sons, Inc.: Hoboken, NJ, 2014.There is no corresponding record for this reference.
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7Kiani, H.; Sun, D. W. Water Crystallization and its Importance to Freezing of Foods: A Review Trends Food Sci. Technol. 2011, 22, 407– 426 DOI: 10.1016/j.tifs.2011.04.0117https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXptlWjsr4%253D&md5=f523cb86cc00cf9024503f62143c23b0Water crystallization and its importance to freezing of foods: A reviewKiani, Hossein; Sun, Da-WenTrends in Food Science & Technology (2011), 22 (8), 407-426CODEN: TFTEEH; ISSN:0924-2244. (Elsevier Ltd.)In this review, different aspects of water crystn. including modeling approaches, process evaluation methods and the effect of novel freezing techniques is presented. There are different methods available to explain the nucleation and growth of crystals. The characteristics of ice crystals are studied by light and electron microscopy methods for many years, and recently a no. of novel methods including magnetic resonance imaging, X-ray anal., and IR spectroscopy are employed. Several emerging techniques are developed to improve the crystn. of water during freezing, including ultrasound assisted freezing, high pressure freezing, ice nucleating proteins, and supersession of nucleation. Understanding the mechanisms of these new techniques and their relationship to the crystn. phenomenon can be helpful for improving freezing processes.
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8Diehl, K.; Mitra, S. K. A Laboratory Study of the Effects of a Kerosene-Burner Exhaust on Ice Nucleation and the Evaporation Rate of Ice Crystals Atmos. Environ. 1998, 32, 3145– 3151 DOI: 10.1016/S1352-2310(97)00467-6There is no corresponding record for this reference.
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9Demott, P. J. An Exploratory-Study of Ice Nucleation by Soot Aerosols J. Appl. Meteorol. 1990, 29, 1072– 1079 DOI: 10.1175/1520-0450(1990)029<1072:AESOIN>2.0.CO;2There is no corresponding record for this reference.
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10DeMott, P. J.; Prenni, A. J.; Liu, X.; Kreidenweis, S. M.; Petters, M. D.; Twohy, C. H.; Richardson, M. S.; Eidhammer, T.; Rogers, D. C. Predicting Global Atmospheric Ice Nuclei Distributions and Their Impacts on Climate Proc. Natl. Acad. Sci. U. S. A. 2010, 107, 11217– 11222 DOI: 10.1073/pnas.091081810710https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC3crktFOgtg%253D%253D&md5=7f4e5a242e7e2187872e05f413944d95Predicting global atmospheric ice nuclei distributions and their impacts on climateDeMott P J; Prenni A J; Liu X; Kreidenweis S M; Petters M D; Twohy C H; Richardson M S; Eidhammer T; Rogers D CProceedings of the National Academy of Sciences of the United States of America (2010), 107 (25), 11217-22 ISSN:.Knowledge of cloud and precipitation formation processes remains incomplete, yet global precipitation is predominantly produced by clouds containing the ice phase. Ice first forms in clouds warmer than -36 degrees C on particles termed ice nuclei. We combine observations from field studies over a 14-year period, from a variety of locations around the globe, to show that the concentrations of ice nuclei active in mixed-phase cloud conditions can be related to temperature and the number concentrations of particles larger than 0.5 microm in diameter. This new relationship reduces unexplained variability in ice nuclei concentrations at a given temperature from approximately 10(3) to less than a factor of 10, with the remaining variability apparently due to variations in aerosol chemical composition or other factors. When implemented in a global climate model, the new parameterization strongly alters cloud liquid and ice water distributions compared to the simple, temperature-only parameterizations currently widely used. The revised treatment indicates a global net cloud radiative forcing increase of approximately 1 W m(-2) for each order of magnitude increase in ice nuclei concentrations, demonstrating the strong sensitivity of climate simulations to assumptions regarding the initiation of cloud glaciation.
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11Pummer, B. G.; Bauer, H.; Bernardi, J.; Bleicher, S.; Grothe, H. Suspendable Macromolecules are Responsible for Ice Nucleation Activity of Birch and Conifer Pollen Atmos. Chem. Phys. 2012, 12, 2541– 2550 DOI: 10.5194/acp-12-2541-201211https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38Xpt12iurg%253D&md5=70cd2ea58dc1a2321693e52dde19b124Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollenPummer, B. G.; Bauer, H.; Bernardi, J.; Bleicher, S.; Grothe, H.Atmospheric Chemistry and Physics (2012), 12 (5), 2541-2550CODEN: ACPTCE; ISSN:1680-7316. (Copernicus Publications)The ice nucleation of bioaerosols (bacteria, pollen, spores, etc.) is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. Here we show that pollen of different species strongly differ in their ice nucleation behavior. The av. freezing temps. in lab. expts. range from 240 to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen) have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. Far more intriguingly, it has turned out that water, which has been in contact with pollen and then been sepd. from the bodies, nucleates as good as the pollen grains themselves. The ice nuclei have to be easily-suspendable macromols. located on the pollen. Once extd., they can be distributed further through the atm. than the heavy pollen grains and so presumably augment the impact of pollen on ice cloud formation even in the upper troposphere. Our expts. lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compds.
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12Fröhlich-Nowoisky, J.; Hill, T. C. J.; Pummer, B. G.; Franc, G. D.; Pöschl, U. Ice Nucleation Activity in the Widespread Soil Fungus Mortierella alpina Biogeosciences Discuss. 2014, 11, 12697– 12731 DOI: 10.5194/bgd-11-12697-2014There is no corresponding record for this reference.
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13O′Sullivan, D.; Murray, B. J.; Ross, J. F.; Whale, T. F.; Price, H. C.; Atkinson, J. D.; Umo, N. S.; Webb, M. E. The Relevance of Nanoscale Biological Fragments for Ice Nucleation in Clouds Sci. Rep. 2015, 5, 8082 DOI: 10.1038/srep0808213https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXosVKlt7o%253D&md5=7155a0732de7f1a1b9bb5dee9168a555The relevance of nanoscale biological fragments for ice nucleation in cloudsO'Sullivan, D.; Murray, B. J.; Ross, J. F.; Whale, T. F.; Price, H. C.; Atkinson, J. D.; Umo, N. S.; Webb, M. E.Scientific Reports (2015), 5 (), 8082/1-8082/7CODEN: SRCEC3; ISSN:2045-2322. (Nature Publishing Group)Most studies of the role of biol. entities as atm. ice-nucleating particles have focused on relatively rare supermicron particles such as bacterial cells, fungal spores and pollen grains. However, it is not clear that there are sufficient nos. of these particles in the atm. to strongly influence clouds. Here, we show that the ice-nucleating activity of a fungus from the ubiquitous genus Fusarium is related to the presence of nanometer-scale particles which are far more numerous, and therefore potentially far more important for cloud glaciation than whole intact spores or hyphae. In addn., we quantify the ice-nucleating activity of nano-ice nucleating particles (nano-INPs) washed off pollen and also show that nano-INPs are present in a soil sample. Based on these results, we suggest that there is a reservoir of biol. nano-INPs present in the environment which may, for example, become aerosolised in assocn. with fertile soil dust particles.
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14Ogawa, S.; Koga, M.; Osanai, S. Anomalous Ice Nucleation Behavior in Aqueous Polyvinyl Alcohol Solutions Chem. Phys. Lett. 2009, 480, 86– 89 DOI: 10.1016/j.cplett.2009.08.04614https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhtF2htLvN&md5=52b1dfe8ecb3c76f39f6a6816da026acAnomalous ice nucleation behavior in aqueous polyvinyl alcohol solutionsOgawa, S.; Koga, M.; Osanai, S.Chemical Physics Letters (2009), 480 (1-3), 86-89CODEN: CHPLBC; ISSN:0009-2614. (Elsevier B.V.)The effect of polymers on the ice nucleation temp. (T f) was studied in a W/O emulsion using ∼5 μm diam. droplets by differential scanning calorimetry (DSC). Four types of polymers were used. Among them, only poly(vinyl alc.) (PVA) showed the addnl. effect of increasing the T f of the aq. solns. This increase was logarithmic with the concn. of PVA and the difference in mol. wt. did not have any significant effect on T f for the same wt. concn. It was shown that the no. of the structural unit (CH2CHOH) was the key parameter for the increasing degree of T f.
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15Salzmann, C. G.; Nicolosi, V.; Green, M. L. Edge-carboxylated Graphene Nanoflakes from Nitric Acid Oxidised Arc-discharge Material J. Mater. Chem. 2010, 20, 314– 319 DOI: 10.1039/B914288FThere is no corresponding record for this reference.
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16He, H.; Riedl, T.; Lerf, A.; Klinowski, J. Solid-State NMR Studies of the Structure of Graphite Oxide J. Phys. Chem. 1996, 100, 19954– 19958 DOI: 10.1021/jp961563t16https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK28XntFSgsLY%253D&md5=cc1ddc4aacc11eee0f55ea5d4faadc3eSolid-State NMR Studies of the Structure of Graphite OxideHe, Heyong; Riedl, Thomas; Lerf, Anton; Klinowski, JacekJournal of Physical Chemistry (1996), 100 (51), 19954-19958CODEN: JPCHAX; ISSN:0022-3654. (American Chemical Society)Graphite oxide (GO) and its derivs. have been studied using 13C and 1H NMR. The 13C NMR lines at 60, 70, and 130 ppm are assigned to C-OH, C-O-C, and >C:C< groups in the bulk of the material, resp. The >C:C< double bonds are relatively stable, while C-OH groups may condense to form C-O-C (ether) linkages. There are at least two magnetically inequivalent C-OH sites, and the structure does not necessarily possess long-range order. Water mols. interact very strongly with the structure. The results reveal a no. of new structural features.
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17Whale, T. F.; Murray, B. J.; O’Sullivan, D.; Wilson, T. W.; Umo, N. S.; Baustian, K. J.; Atkinson, J. D.; Workneh, D. A.; Morris, G. J. A Technique for Quantifying Heterogeneous Ice Nucleation in Microlitre Supercooled Water Droplets Atmos. Meas. Tech. 2015, 8, 2437– 2447 DOI: 10.5194/amt-8-2437-201517https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXhsVKqsLjP&md5=49796ff1769052db1bf9e4493109391cA technique for quantifying heterogeneous ice nucleation in microlitre supercooled water dropletsWhale, T. F.; Murray, B. J.; O'Sullivan, D.; Wilson, T. W.; Umo, N. S.; Baustian, K. J.; Atkinson, J. D.; Workneh, D. A.; Morris, G. J.Atmospheric Measurement Techniques (2015), 8 (6), 2437-2447CODEN: AMTTC2; ISSN:1867-8548. (Copernicus Publications)In many clouds, the formation of ice requires the presence of particles capable of nucleating ice. Ice-nucleating particles (INPs) are rare in comparison to cloud condensation nuclei. However, the fact that only a small fraction of aerosol particles can nucleate ice means that detection and quantification of INPs is challenging. This is particularly true at temps. above about -20 °C since the population of particles capable of serving as INPs decreases dramatically with increasing temp. In this paper, we describe an exptl. technique in which droplets of microlitre vol. contg. ice-nucleating material are cooled down at a controlled rate and their freezing temps. recorded. The advantage of using large droplet vols. is that the surface area per droplet is vastly larger than in expts. focused on single aerosol particles or cloud-sized droplets. This increases the probability of observing the effect of less common, but important, high-temp. INPs and therefore allows the quantification of their ice nucleation efficiency. The potential artifacts which could influence data from this expt., and other similar expts., are mitigated and discussed. Exptl. detd. heterogeneous ice nucleation efficiencies for K-feldspar (microcline), kaolinite, chlorite, NX-illite, Snomax and silver iodide are presented.
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18Umo, N. S.; Murray, B. J.; Baeza-Romero, M. T.; Jones, J. M.; Lea-Langton, A. R.; Malkin, T. L.; O’Sullivan, D.; Neve, L.; Plane, J. M. C.; Williams, A. Ice Nucleation by Combustion Ash Particles at Conditions Relevant to Mixed-phase Clouds Atmos. Chem. Phys. 2015, 15, 5195– 5210 DOI: 10.5194/acp-15-5195-201518https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXptlCktrc%253D&md5=de6b2575bca8376bc5c47bed4ecff861Ice nucleation by combustion ash particles at conditions relevant to mixed-phase cloudsUmo, N. S.; Murray, B. J.; Baeza-Romero, M. T.; Jones, J. M.; Lea-Langton, A. R.; Malkin, T. L.; O'Sullivan, D.; Neve, L.; Plane, J. M. C.; Williams, A.Atmospheric Chemistry and Physics (2015), 15 (9), 5195-5210CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Ice-nucleating particles can modify cloud properties with implications for climate and the hydrol. cycle; hence, it is important to understand which aerosol particle types nucleate ice and how efficiently they do so. It has been shown that aerosol particles such as natural dusts, volcanic ash, bacteria and pollen can act as ice-nucleating particles, but the ice-nucleating ability of combustion ashes has not been studied. Combustion ashes are major byproducts released during the combustion of solid fuels and a significant amt. of these ashes are emitted into the atm. either during combustion or via aerosolization of bottom ashes. Here, we show that combustion ashes (coal fly ash, wood bottom ash, domestic bottom ash, and coal bottom ash) nucleate ice in the immersion mode at conditions relevant to mixed-phase clouds. Hence, combustion ashes could play an important role in primary ice formation in mixed-phase clouds, esp. in clouds that are formed near the emission source of these aerosol particles. In order to quant. assess the impact of combustion ashes on mixed-phase clouds, we propose that the atm. abundance of combustion ashes should be quantified since up to now they have mostly been classified together with mineral dust particles. Also, in reporting ice residue compns., a distinction should be made between natural mineral dusts and combustion ashes in order to quantify the contribution of combustion ashes to atm. ice nucleation.
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19Riechers, B.; Wittbracht, F.; Hütten, A.; Koop, T. The Homogeneous Ice Nucleation Rate of Water Droplets Produced in a Microfluidic Device and the Role of Temperature Uncertainty Phys. Chem. Chem. Phys. 2013, 15, 5873– 5887 DOI: 10.1039/c3cp42437e19https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXksFOitro%253D&md5=8869ff5078cc44eed477eed39452f493The homogeneous ice nucleation rate of water droplets produced in a microfluidic device and the role of temperature uncertaintyRiechers, Birte; Wittbracht, Frank; Huetten, Andreas; Koop, ThomasPhysical Chemistry Chemical Physics (2013), 15 (16), 5873-5887CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)Ice nucleation was investigated exptl. in water droplets with diams. between 53-96 μm. The droplets were produced in a microfluidic device in which a flow of methyl-cyclohexane and water was combined at the T-junction of micro-channels yielding inverse (water-in-oil) emulsions consisting of water droplets with small std. deviations. In cryo-microscopic expts. it is confirmed that upon cooling of such emulsion samples ice nucleation in individual droplets occurred independently of each other as required for the investigation of a stochastic process. The emulsion samples were then subjected to cooling at 1 K per min in a differential scanning calorimeter with high temp. accuracy. From the latent heat released by freezing water droplets the vol.-dependent homogeneous ice nucleation rate coeff. of water at temps. between 236.5-237.9 K is inferred. A comparison of the newly derived values to existing rate coeffs. from other studies suggests that the vol.-dependent ice nucleation rate in supercooled water is slightly lower than previously thought. Moreover, a comprehensive error anal. suggests that abs. temp. accuracy is the single most important exptl. parameter detg. the uncertainty of the derived ice nucleation rates in the expts., and presumably also in many previous expts. The anal., thus, also provides a route for improving the accuracy of future ice nucleation rate measurements.
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20Murray, B. J.; Broadley, S. L.; Wilson, T. W.; Bull, S. J.; Wills, R. H.; Christenson, H. K.; Murray, E. J. Kinetics of the Homogeneous Freezing of Water Phys. Chem. Chem. Phys. 2010, 12, 10380– 7 DOI: 10.1039/c003297b20https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3cXhtVOns7vO&md5=4c108508ae185a9196d868e5a53cb994Kinetics of the homogeneous freezing of waterMurray, B. J.; Broadley, S. L.; Wilson, T. W.; Bull, S. J.; Wills, R. H.; Christenson, H. K.; Murray, E. J.Physical Chemistry Chemical Physics (2010), 12 (35), 10380-10387CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)Rates of homogeneous nucleation of ice in μm-sized water droplets are reported. Measurements were made using a new system in which droplets were supported on a hydrophobic substrate and their phase was monitored using optical microscopy as they were cooled at a controlled rate. Obtained nucleation rates are in agreement, given the quoted uncertainties, with the most recent literature data. However, the level of uncertainty in the rate of homogeneous freezing remains unacceptable given the importance of homogeneous nucleation to cloud formation in the Earth's atm. The most recent thermodn. data for cubic ice (the metastable phase thought to nucleate from supercooled water) are used to est. the interfacial energy of the cubic ice-supercooled water interface. A value of 20.8 ± 1.2 mJ m-2 in the temp. range 234.9-236.7 K is estd.
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21Vali, G. Interpretation of Freezing Nucleation Experiments: Singular and Stochastic; Sites and Surfaces Atmos. Chem. Phys. 2014, 14, 5271– 5294 DOI: 10.5194/acp-14-5271-201421https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXht1CmurzN&md5=be27e82fc93f01c774fd15f1df46d7c8Interpretation of freezing nucleation experiments: singular and stochastic; sites and surfacesVali, G.Atmospheric Chemistry and Physics (2014), 14 (11), 5271-5294, 24 pp.CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Publications of recent years dealing with lab. expts. of immersion freezing reveal uncertainties about the fundamentals of heterogeneous freezing nucleation. While it appears well accepted that there are two major factors that det. the process, namely fluctuations in the size and configuration of incipient embryos of the solid phase and the role of the substrate to aid embryo formation, views have been evolving about the relative importance of these two elements. The importance of sp. surface sites is being established in a growing no. of expts. and a no. of approaches have been proposed to incorporate these results into model descriptions. Many of these models share a common conceptual basis yet diverge in the way random and deterministic factors are combined. The divergence can be traced to uncertainty about the permanence of nucleating sites, to the lack of detailed knowledge about what surface features constitute nucleating sites, and to the consequent need to rely on empirical or parametric formulas to define the population of sites of different effectiveness. Recent expts. and models, consistent with earlier work, demonstrate the existence and primary role of permanent nucleating sites and the continued need for empirically based formulations of heterogeneous freezing. In order to clarify some aspects of the processes controlling immersion freezing, the paper focuses on three identifiably sep. but interrelated issues: (i) the combination of singular and stochastic factors, (ii) the role of sp. surface sites, and (iii) the modeling of heterogeneous ice nucleation.
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22Herbert, R. J.; Murray, B. J.; Whale, T. F.; Dobbie, S. J.; Atkinson, J. D. Representing Time-Dependent Freezing Behaviour in Immersion Mode Ice Nucleation Atmos. Chem. Phys. 2014, 14, 8501– 8520 DOI: 10.5194/acp-14-8501-2014There is no corresponding record for this reference.
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23Koga, K.; Gao, G. T.; Tanaka, H.; Zeng, X. C. Formation of Ordered Ice Nanotubes Inside Carbon Nanotubes Nature 2001, 412, 802– 805 DOI: 10.1038/3509053223https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD3MXms1antL4%253D&md5=481e8a147777cff4c8c2aac6b121d6dcFormation of ordered ice nanotubes inside carbon nanotubesKoga, Kenichiro; Gao, G. T.; Tanaka, Hideld; Zeng, X. C.Nature (London, United Kingdom) (2001), 412 (6849), 802-805CODEN: NATUAS; ISSN:0028-0836. (Nature Publishing Group)Following their discovery, carbon nanotubes have attracted interest not only for their unusual elec. and mech. properties, but also because their hollow interior can serve as a nanometer-sized capillary, mold or template in material fabrication. The ability to encapsulate a material in a nanotube also offers new possibilities for investigating dimensionally confined phase transitions. Particularly intriguing is the conjecture that matter within the narrow confines of a carbon nanotube might exhibit a solid-liq. crit. point beyond which the distinction between solid and liq. phases disappears. This unusual feature, which cannot occur in bulk material, would allow for the direct and continuous transformation of liq. matter into a solid. Here we report simulations of the behavior of water encapsulated in carbon nanotubes that suggest the existence of a variety of new ice phases not seen in bulk ice, and of a solid-liq. crit. point. Using carbon nanotubes with diams. ranging from 1.1 nm to 1.4 nm and applied axial pressures of 50 MPa to 500 MPa, we find that water can exhibit a first-order freezing transition to hexagonal and heptagonal ice nanotubes, and a continuous phase transformation into solid-like square or pentagonal ice nanotubes.
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24Pummer, B. G.; Budke, C.; Augustin-Bauditz, S.; Niedermeier, D.; Felgitsch, L.; Kampf, C. J.; Huber, R. G.; Liedl, K. R.; Loerting, T.; Moschen, T.; Schauperl, M. Ice Nucleation by Water-Soluble Macromolecules Atmos. Chem. Phys. 2015, 15, 4077– 4091 DOI: 10.5194/acp-15-4077-201524https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXns1ahsL4%253D&md5=b851059d5ff5097c39d6cdc4a27914aaIce nucleation by water-soluble macromoleculesPummer, B. G.; Budke, C.; Augustin-Bauditz, S.; Niedermeier, D.; Felgitsch, L.; Kampf, C. J.; Huber, R. G.; Liedl, K. R.; Loerting, T.; Moschen, T.; Schauperl, M.; Tollinger, M.; Morris, C. E.; Wex, H.; Grothe, H.; Poeschl, U.; Koop, T.; Froehlich-Nowoisky, J.Atmospheric Chemistry and Physics (2015), 15 (8), 4077-4091CODEN: ACPTCE; ISSN:1680-7324. (Copernicus Publications)Cloud glaciation is critically important for the global radiation budget (albedo) and for initiation of pptn. But the freezing of pure water droplets requires cooling to temps. as low as 235 K. Freezing at higher temps. requires the presence of an ice nucleator, which serves as a template for arranging water mols. in an ice-like manner. It is often assumed that these ice nucleators have to be insol. particles. We point out that also free macromols. which are dissolved in water can efficiently induce ice nucleation: the size of such ice nucleating macromols. (INMs) is in the range of nanometers, corresponding to the size of the crit. ice embryo. As the latter is temp.-dependent, we see a correlation between the size of INMs and the ice nucleation temp. as predicted by classical nucleation theory. Different types of INMs have been found in a wide range of biol. species and comprise a variety of chem. structures including proteins, saccharides, and lipids. Our investigation of the fungal species Acremonium implicatum, Isaria farinosa, and Mortierella alpina shows that their ice nucleation activity is caused by proteinaceous water-sol. INMs. We combine these new results and literature data on INMs from fungi, bacteria, and pollen with theor. calcns. to develop a chem. interpretation of ice nucleation and water-sol. INMs. This has atm. implications since many of these INMs can be released by fragmentation of the carrier cell and subsequently may be distributed independently. Up to now, this process has not been accounted for in atm. models.
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25Cheng, J.; Soetjipto, C.; Hoffmann, M. R.; Colussi, A. J. Confocal Fluorescence Microscopy of the Morphology and Composition of Interstitial Fluids in Freezing Electrolyte Solutions J. Phys. Chem. Lett. 2010, 1, 374– 378 DOI: 10.1021/jz900088825https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXhsFektLzO&md5=d4755ee330c9bdbcf92a12caad9287ceConfocal Fluorescence Microscopy of the Morphology and Composition of Interstitial Fluids in Freezing Electrolyte SolutionsCheng, Jie; Soetjipto, Cherrie; Hoffmann, Michael R.; Colussi, A. J.Journal of Physical Chemistry Letters (2010), 1 (1), 374-378CODEN: JPCLCD; ISSN:1948-7185. (American Chemical Society)Ice rheol., the integrity of polar ice core records, and ice-atm. interactions are among the phenomena controlled by the morphol. and compn. of interstitial fluids threading polycryst. ice. Herein, the authors study how ionic impurities affect such features via time-resolved confocal fluorescence microscopy of freezing electrolyte solns. doped with a pH probe. The 10 μM probe accumulates into 12 μm thick glassy channels in frozen water, but it is incorporated into randomly distributed <1 μm diam. inclusions in freezing 1 mM NaCl. The authors infer that morphol. is largely detd. by the dynamic instabilities generated upon advancing ice by the rejected solute, rather than by thermodn. The protracted alkalinization of the fluid inclusions reveals that the excess neg. charge generated by the preferential incorporation of Cl- over Na+ in ice is neutralized by the seepage of the OH- slowly produced via H2O → H+ + OH- thermal dissocn.
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26Guzmán, M. I.; Hildebrandt, L.; Colussi, A. J.; Hoffmann, M. R. Cooperative Hydration of Pyruvic Acid in Ice J. Am. Chem. Soc. 2006, 128, 10621– 10624 DOI: 10.1021/ja062039v26https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28Xnt12nsrY%253D&md5=5abd261743f2ab504a2d1996492d313bCooperative Hydration of Pyruvic Acid in IceGuzman, Marcelo I.; Hildebrandt, Lea; Colussi, Agustin J.; Hoffmann, Michael R.Journal of the American Chemical Society (2006), 128 (32), 10621-10624CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)About 3.5 ± 0.3 water mols. are still involved in the exothermic hydration of 2-oxopropanoic acid (PA) into its monohydrate (2,2-dihydroxypropanoic acid, PAH) in ice at 230 K. This is borne out by thermodn. anal. of the fact that QH(T) = [PAH]/[PA] becomes temp. independent .ltorsim.250 K (in chem. and thermally equilibrated frozen 0.1 ≤ [PA]/M ≤ 4.6 solns. in D2O), which requires that the enthalpy of PA hydration (ΔHH approx. -22 kJ mol-1) be balanced by a multiple of the enthalpy of ice melting (ΔHM = 6.3 kJ mol-1). Considering that: (1) thermograms of frozen PA solns. display a single endotherm, at the onset of ice melting, (2) the sum of the integral intensities of the 1δPAH and 1δPA Me proton NMR resonances is nearly const. while, (3) line widths increase exponentially with decreasing temp. before diverging .ltorsim.230 K, the authors infer that PA in ice remains cooperatively hydrated within interstitial microfluids until they vitrify.
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27Guzmán, M. I.; Colussi, A. J.; Hoffmann, M. R. Photogeneration of Distant Radical Pairs in Aqueous Pyruvic Acid Glasses J. Phys. Chem. A 2006, 110, 931– 935 DOI: 10.1021/jp053449t27https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD28XlsFGg&md5=a3805ff01c20fe4b6e5b756a41166b9ePhotogeneration of Distant Radical Pairs in Aqueous Pyruvic Acid GlassesGuzman, Marcelo I.; Colussi, A. J.; Hoffmann, Michael R.Journal of Physical Chemistry A (2006), 110 (3), 931-935CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)The λ > 300 nm photolysis of h4- or d4-pyruvic acid aq. glasses at 77 K yields identical electron magnetic resonance (EMR) spectra arising from distant (r ⪆ 0.5 nm) triplet radical pairs. Spectra comprise: (1) well-resolved quartets, X, at g ∼ ge, that closely match the powder spectra of spin pairs interacting across r ∼ 1.0 nm with D ∼ 3.0 mT, E ∼ 0 mT zero field splittings (ZFS), and (2) broad signals, Y, centered at g ∼ 2.07 that display marked g-anisotropy and g-strain, exclude D ⪆ 20.0 mT values (i.e., r .ltorsim. 0.5 spin nm sepns.), and track the temp. dependence of related g ∼ 4 features. These results imply that the n-π* excitation of pyruvic acid, PA, induces long-range electron transfer from the promoted carbonyl chromophore into neighboring carbonyl acceptors, rather than homolysis into contact radical pairs or concerted decarboxylation into a carbene. Since PA is assocd. into hydrogen-bonded dimers prior to vitrification, X signals arise from radical pairs ensuing intradimer electron transfer to a locked acceptor, while Y signals involve carbonyl groups attached to randomly arranged, disjoint monomers. The ultrafast decarboxylation of primary radical ion pairs, 3[PA+• PA-•], accounts for the release of CO2 under cryogenic conditions, the lack of thermal hysteresis displayed by magnetic signals between 10 and 160 K, and averted charge retro-transfer. All EMR signals disappear irreversibly above the onset of ice diffusivity at ∼190 K.
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28Finnegan, W. G.; Chai, S. K. A New Hypothesis for the Mechanism of ice Nucleation on Wetted AgI and AgI Center Dot AgCl Particulate Aerosols J. Atmos. Sci. 2003, 60, 1723– 1731 DOI: 10.1175/1520-0469(2003)060<1723:ANHFTM>2.0.CO;2There is no corresponding record for this reference.
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29Massey, A.; McBride, F.; Darling, G. R.; Nakamura, M.; Hodgson, A. The Role of Lattice Parameter in Water Adsorption and Wetting of a Solid Surface Phys. Chem. Chem. Phys. 2014, 16, 24018– 24025 DOI: 10.1039/C4CP03164D29https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhs1Gmu73O&md5=bc94853808db5c3d52bd310e8ce09bbaThe role of lattice parameter in water adsorption and wetting of a solid surfaceMassey, A.; McBride, F.; Darling, G. R.; Nakamura, M.; Hodgson, A.Physical Chemistry Chemical Physics (2014), 16 (43), 24018-24025CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)Ice formation is a complex cooperative process that is almost invariably catalyzed by the presence of an interface on which ice crystals nucleate. As yet there is no clear picture of what factors make a surface particularly good at nucleating ice, but the importance of having a template with a suitable lattice parameter has often been proposed. Here the authors report the contrasting wetting behavior of pseudomorphic surfaces, designed to form an ordered template that matches the arrangement of H2O in a bulk ice Ih(0001) bilayer. The close-packed M(111) surfaces (M = Pt, Pd, Rh, Cu and Ni) form a [√3×√3] Sn substitutional alloy surface, with Sn atoms occupying sites that match the symmetry of an ice bilayer. The lattice const. of the alloy changes from 4% smaller to 7% greater than the lateral spacing of ice across the series. Only the PtSn surface, with a lattice parameter some 7% greater than that of a bulk ice layer, forms a stable H2O layer, all the other surfaces being nonwetting and instead forming multilayer ice clusters. This observation is consistent with the idea that the repeat spacing of the surface should ideally match the O-O spacing in ice, rather than the bulk ice lattice parameter, to form a continuous commensurate H2O monolayer. The role of the lattice parameter in stabilizing the 1st layer of H2O and the factors that give a simple commensurate structure rather than an incommensurate or large unit cell H2O network are discussed. The authors argue that lattice match is not a good criteria for a material to give low energy nucleation sites for bulk ice, and that considerations such as binding energy and mobility of the surface layer are more relevant.
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30Hu, X. L.; Michaelides, A. Ice Formation on Kaolinite: Lattice Match or Amphoterism? Surf. Sci. 2007, 601, 5378– 5381 DOI: 10.1016/j.susc.2007.09.01230https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXhtlGjt7vP&md5=9b8c4b8afd039a4cab03a1d8f33ac694Ice formation on kaolinite: Lattice match or amphoterism?Hu, Xiao Liang; Michaelides, AngelosSurface Science (2007), 601 (23), 5378-5381CODEN: SUSCAS; ISSN:0039-6028. (Elsevier B.V.)The long-standing belief that kaolinite is one of the most efficient natural ice nucleating agents because it provides a close lattice match to the basal plane of ice is called into question. Instead we show through an extensive series of first principles calcns. that amphoterism is key to many of the interesting properties of kaolinite with regard to water adsorption and ice nucleation.
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31Fraux, G.; Doye, J. P. K. Note: Heterogeneous Ice Nucleation on Silver-Iodide-Like Surfaces J. Chem. Phys. 2014, 141, 216101 DOI: 10.1063/1.490238231https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXitValt7zE&md5=5e8b0c7250cea205d369cc2e362f2e85Note: Heterogeneous ice nucleation on silver-iodide-like surfacesFraux, Guillaume; Doye, Jonathan P. K.Journal of Chemical Physics (2014), 141 (21), 216101/1-216101/2CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)The authors attempt to simulate the heterogeneous nucleation of ice at model silver-iodide surfaces and find relatively facile ice nucleation and growth at the Ag+ terminated basal face, but never see nucleation at the I- terminated basal face or the prism and normal faces. Water mols. strongly adsorb onto the Ag+ terminated face to give a well-ordered hexagonal ice-like bilayer that then acts as a template for further ice growth. (c) 2014 American Institute of Physics.
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32Reinhardt, A.; Doye, J. P. K. Effects of Surface Interactions on Heterogeneous Ice Nucleation for a Monatomic Water Model J. Chem. Phys. 2014, 141, 084501 DOI: 10.1063/1.489280432https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhsVWks73N&md5=8c6bca7c78e510c45a24e2c0129a9d0cEffects of surface interactions on heterogeneous ice nucleation for a monatomic water modelReinhardt, Aleks; Doye, Jonathan P. K.Journal of Chemical Physics (2014), 141 (8), 084501/1-084501/10CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)Despite its importance in atm. science, much remains unknown about the microscopic mechanism of heterogeneous ice nucleation. The authors performed hybrid Monte Carlo simulations of the heterogeneous nucleation of ice on a range of generic surfaces, both flat and structured, in order to probe the underlying factors affecting the nucleation process. The structured surfaces studied comprise one basal plane bilayer of ice with varying lattice parameters and interaction strengths. What dets. the propensity for nucleation is not just the surface attraction, but also the orientational ordering imposed on liq. water near a surface. In particular, varying the ratio of the surface's attraction and orientational ordering can change the mechanism by which nucleation occurs: ice can nucleate on the structured surface even when the orientational ordering imposed by the surface is weak, as the water mols. that interact strongly with the surface are themselves a good template for further growth. Lattice matching is important for heterogeneous nucleation on the structured surface studied. The authors rationalize these brute-force simulation results by explicitly calcg. the interfacial free energies of ice and liq. water in contact with the nucleating surface and their variation with surface interaction parameters. (c) 2014 American Institute of Physics.
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33Cox, S. J.; Raza, Z.; Kathmann, S. M.; Slater, B.; Michaelides, A. The Microscopic Features of Heterogeneous Ice Nucleation May Affect the Macroscopic Morphology of Atmospheric Ice Crystals Faraday Discuss. 2013, 167, 389– 403 DOI: 10.1039/c3fd00059a33https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A280%3ADC%252BC2crltVajtg%253D%253D&md5=17ee125d0e5eba1a57663d49013d2742The microscopic features of heterogeneous ice nucleation may affect the macroscopic morphology of atmospheric ice crystalsCox Stephen J; Raza Zamaan; Kathmann Shawn M; Slater Ben; Michaelides AngelosFaraday discussions (2013), 167 (), 389-403 ISSN:1359-6640.It is surprisingly difficult to freeze water. Almost all ice that forms under "mild" conditions (temperatures > -40 degrees C) requires the presence of a nucleating agent--a solid particle that facilitates the freezing process--such as clay mineral dust, soot or bacteria. In a computer simulation, the presence of such ice nucleating agents does not necessarily alleviate the difficulties associated with forming ice on accessible timescales. Nevertheless, in this work we present results from molecular dynamics simulations in which we systematically compare homogeneous and heterogeneous ice nucleation, using the atmospherically important clay mineral kaolinite as our model ice nucleating agent. From our simulations, we do indeed find that kaolinite is an excellent ice nucleating agent but that contrary to conventional thought, non-basal faces of ice can nucleate at the basal face of kaolinite. We see that in the liquid phase, the kaolinite surface has a drastic effect on the density profile of water, with water forming a dense, tightly bound first contact layer. Monitoring the time evolution of the water density reveals that changes away from the interface may play an important role in the nucleation mechanism. The findings from this work suggest that heterogeneous ice nucleating agents may not only enhance the ice nucleation rate, but also alter the macroscopic structure of the ice crystals that form.
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34Cox, S. J.; Kathmann, S. M.; Purton, J. A.; Gillan, M. J.; Michaelides, A. Non-hexagonal Ice at Hexagonal Surfaces: the Role of Lattice Mismatch Phys. Chem. Chem. Phys. 2012, 14, 7944– 7949 DOI: 10.1039/c2cp23438f34https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC38XntVShtbk%253D&md5=f8261a6e551f7b182171eb20aef6ba1cNon-hexagonal ice at hexagonal surfaces: the role of lattice mismatchCox, Stephen J.; Kathmann, Shawn M.; Purton, John A.; Gillan, Michael J.; Michaelides, AngelosPhysical Chemistry Chemical Physics (2012), 14 (22), 7944-7949CODEN: PPCPFQ; ISSN:1463-9076. (Royal Society of Chemistry)It has long been known that ice nucleation usually proceeds heterogeneously on the surface of a foreign body. However, little is known at the microscopic level about which properties of a material det. its effectiveness at nucleating ice. This work focuses on the long standing, conceptually simple, view on the role of a good crystallog. match between bulk ice and the underlying substrate. The authors use grand canonical Monte Carlo to generate the 1st overlayer of H2O at the surface and find that the traditional view of heterogeneous nucleation does not adequately account for the array of structures that H2O may form at the surface. To describe the structures formed, a good match between the substrate and the nearest neighbor O-O distance is a better descriptor than a good match to the bulk ice lattice const.
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35Cox, S. J.; Kathmann, S. M.; Slater, B.; Michaelides, A. Molecular Simulations of Heterogeneous Ice Nucleation. I. Controlling Ice Nucleation Through Surface Hydrophilicity J. Chem. Phys. 2015, 142, 184704 DOI: 10.1063/1.491971435https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXot1CjtLw%253D&md5=4ba289fc04c5c951be4267cf5cdec999Molecular simulations of heterogeneous ice nucleation. I. Controlling ice nucleation through surface hydrophilicityCox, Stephen J.; Kathmann, Shawn M.; Slater, Ben; Michaelides, AngelosJournal of Chemical Physics (2015), 142 (18), 184704/1-184704/5CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)Ice formation is one of the most common and important processes on earth and almost always occurs at the surface of a material. A basic understanding of how the physicochem. properties of a material's surface affect its ability to form ice has remained elusive. Here, we use mol. dynamics simulations to directly probe heterogeneous ice nucleation at a hexagonal surface of a nanoparticle of varying hydrophilicity. Surprisingly, we find that structurally identical surfaces can both inhibit and promote ice formation and analogous to a chem. catalyst, it is found that an optimal interaction between the surface and the water exists for promoting ice nucleation. We use our microscopic understanding of the mechanism to design a modified surface in silico with enhanced ice nucleating ability. (c) 2015 American Institute of Physics.
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36Cox, S. J.; Kathmann, S. M.; Slater, B.; Michaelides, A. Molecular Simulations of Heterogeneous Ice Nucleation. II. Peeling Back the Layers J. Chem. Phys. 2015, 142, 184705 DOI: 10.1063/1.491971536https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXot1CjtLo%253D&md5=07bf3a4e192cc45a7d89d7a94a388a7fMolecular simulations of heterogeneous ice nucleation. II. Peeling back the layersCox, Stephen J.; Kathmann, Shawn M.; Slater, Ben; Michaelides, AngelosJournal of Chemical Physics (2015), 142 (18), 184705/1-184705/8CODEN: JCPSA6; ISSN:0021-9606. (American Institute of Physics)Coarse grained mol. dynamics simulations are presented in which the sensitivity of the ice nucleation rate to the hydrophilicity of a graphene nanoflake is investigated. We find that an optimal interaction strength for promoting ice nucleation exists, which coincides with that found previously for a fcc. (111) surface. We further investigate the role that the layering of interfacial water plays in heterogeneous ice nucleation and demonstrate that the extent of layering is not a good indicator of ice nucleating ability for all surfaces. Our results suggest that to be an efficient ice nucleating agent, a surface should not bind water too strongly if it is able to accommodate high coverages of water. (c) 2015 American Institute of Physics.
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37Cabriolu, R.; Li, T. Ice Nucleation on Carbon Surface Supports the Classical Theory for Heterogeneous Nucleation Phys. Rev. E: Stat. Phys., Plasmas, Fluids 2015, 91, 052402 DOI: 10.1103/PhysRevE.91.052402There is no corresponding record for this reference.
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38Lupi, L.; Molinero, V. Does Hydrophilicity of Carbon Particles Improve Their Ice Nucleation Ability? J. Phys. Chem. A 2014, 118, 7330– 7337 DOI: 10.1021/jp411837538https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXis1egsrw%253D&md5=23475ed8d095f6dc565c78451bd64990Does Hydrophilicity of Carbon Particles Improve Their Ice Nucleation Ability?Lupi, Laura; Molinero, ValeriaJournal of Physical Chemistry A (2014), 118 (35), 7330-7337CODEN: JPCAFH; ISSN:1089-5639. (American Chemical Society)Carbonaceous particles account for 10% of the particulate matter in the atm. Atm. oxidn. and aging of soot modulates its ice nucleation ability. An increase in the ice nucleation ability of aged soot results from an increase in the hydrophilicity of the surfaces upon oxidn. Oxidn., however, also impacts the nanostructure of soot, making it difficult to assess the sep. effects of soot nanostructure and hydrophilicity in expts. Here we use mol. dynamics simulations to investigate the effect of changes in hydrophilicity of model graphitic surfaces on the freezing temp. of ice. Our results indicate that the hydrophilicity of the surface is not in general a good predictor of ice nucleation ability. We find a correlation between the ability of a surface to promote nucleation of ice and the layering of liq. water at the surface. The results of this work suggest that ordering of liq. water in contact with the surface plays an important role in the heterogeneous ice nucleation mechanism.
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39Lupi, L.; Hudait, A.; Molinero, V. Heterogeneous Nucleation of Ice on Carbon Surfaces J. Am. Chem. Soc. 2014, 136, 3156– 3164 DOI: 10.1021/ja411507a39https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2cXhslygsL8%253D&md5=a6efa985c5e7275212f2b8a982ffa9c7Heterogeneous Nucleation of Ice on Carbon SurfacesLupi, Laura; Hudait, Arpa; Molinero, ValeriaJournal of the American Chemical Society (2014), 136 (8), 3156-3164CODEN: JACSAT; ISSN:0002-7863. (American Chemical Society)Atm. aerosols can promote the heterogeneous nucleation of ice, impacting the radiative properties of clouds and Earth's climate. The exptl. study of heterogeneous freezing of water droplets by carbonaceous particles reveals widespread ice freezing temps. It is not known which structural and chem. characteristics of soot account for the variability in ice nucleation efficiency. Here the authors use mol. dynamics simulations to study the nucleation of ice from liq. water in contact with graphitic surfaces. Atomically flat carbon surfaces promote heterogeneous nucleation of ice, while molecularly rough surfaces with the same hydrophobicity do not. Graphitic surfaces and other surfaces that promote ice nucleation induce layering in the interfacial water, suggesting that the order imposed by the surface on liq. water may play an important role in the heterogeneous nucleation mechanism. The authors study a large set of graphitic surfaces of various dimensions and radii of curvature and find that variations in nanostructures alone could account for the spread in the freezing temps. of ice on soot in expts. A characterization of the nanostructure of soot is needed to predict its ice nucleation efficiency.
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Details of the synthesis of the carbon nanomaterials used, XPS analysis of the nanomaterials, the μL-NIPI ice nucleation instrument, and the FROST method for analysis of ice nucleation data are available in the Supporting Information. The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jpclett.5b01096.
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