Sesha Srinivasan
Florida Polytechnic University, Physics, Faculty Member
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Dr. Sesha Srinivasan is the Chair of the Natural Sciences Department and Assistant Professor of Physics at Florida Po... moreDr. Sesha Srinivasan is the Chair of the Natural Sciences Department and Assistant Professor of Physics at Florida Polytechnic University, Florida, USA. He has a decade of teaching experience in the US Higher Education and has more than two decades of research experience in frontier research areas renewable energy and hydrogen technologies, wastewater remediation technologies, energy storage, nanotechnologies, and multi-functional materials. Dr. Srinivasan received his Ph.D. in Physics from Banaras Hindu University, Varanasi in the year 2000. After his Ph.D., Dr. Srinivasan did a couple of Post-Doctoral Fellowships in the USA, at the University of Hawaii and the University of South Florida. In his current and previous academic positions at Tuskegee University and Florida Polytechnic University, Dr. Srinivasan was awarded many research grants, worth of $2 Million from both federal, state, and private funding sources. He has awarded two US patents on Hydrogen storage nano-materials’ development and methodologies. He has published ten book chapters and review articles, more than 120 journal publications, and many more peer-reviewed conference proceedings. Dr. Srinivasan has served as a reviewer in the panel review committee of the National Science Foundation, US Department of Energy, and panelist for Qatar National Research Fund and Irish Research Council. He is the faculty advisor and mentors for the students’ focused professional societies such as the Society of Physics Students, American Institute of Physics, American Physical Society-National Mentoring Community. edit
The future is bright for hydrogen as a clean, mobile energy source to replace petroleum products. This paper examines new and emerging technologies for hydrogen production, storage and conversion and highlights recent commercialization... more
The future is bright for hydrogen as a clean, mobile energy source to replace petroleum products. This paper examines new and emerging technologies for hydrogen production, storage and conversion and highlights recent commercialization efforts to realize its potential. Also, the paper presents selected notable patents issued within the last few years. There is no shortage of inventions and innovations in hydrogen technologies in both academia and industry. While metal hydrides and functionalized carbon-based materials have improved tremendously as hydrogen storage materials over the years, storing gaseous hydrogen in underground salt caverns has also become feasible in many commercial projects. Production of "blue hydrogen" is rising as a method of producing hydrogen in large quantities economically. Although electric/battery powered vehicles are dominating the green transport today, innovative hydrogen fuel cell technologies are knocking at the door, because of their lower refueling time compared to EV charging time. However, the highest impact of hydrogen technologies in transportation might be seen in the aviation industry. Hydrogen is expected to play a key role and provides hope in transforming aviation into a zero-carbon emission transportation over the next few decades.
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With the support from the Sigma Pi Sigma and SPS-AIP Undergraduate research award, the current project is successfully implemented and executed to develop both novel materials' and the home-made reactor for the decontamination of... more
With the support from the Sigma Pi Sigma and SPS-AIP Undergraduate research award, the current project is successfully implemented and executed to develop both novel materials' and the home-made reactor for the decontamination of water based organics such as Methyl Orange via visible light photocatalysis. For the novel materials', we have successfully developed visible light activated photocatalyst by varying the concentrations of low band gap semiconductor oxide InVO4 with high band gap TiO2 anatase matrix. Extensive analytical characterizations have been carried out using SEM, FTIR and BET to explore the surface morphology, chemical, surface area and pore size distribution of these nanocomposites. The new materials' selection TiO2-Xwt.%InVO4 have shown enhancement in photocatalytic degradation (by at least 50%) of Methyl Orange (MO), an azo dye decontamination in DI H2O under visible light irradiation only. The visible light photocatalytic degradation performance of either plain TiO2 or plain InVO4 seems inert under the same operating conditions used for the above nanocomposites.
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The wide bandgap semiconductor TiO2 has become the dominant UV-activated photocatalyst in the field of air and water detoxification because of its high stability, low cost, high oxidation potential and chemically favorable properties. The... more
The wide bandgap semiconductor TiO2 has become the dominant UV-activated photocatalyst in the field of air and water detoxification because of its high stability, low cost, high oxidation potential and chemically favorable properties. The demand for visible-light activated photocatalytic systems is increasing rapidly; however, currently, the efficiency and availability of photocatalysts that can be activated effectively by the solar spectrum and particularly indoor lighting is severely limited. In this paper, a new coprecipitation/hydrolysis synthesis route is used to create a TiO2-ZnFe2O4 nanocomposite that is directed towards extending the photoresponse of TiO2 from UV to visible wavelengths (>400nm). The effect of TiO2's accelerated anatase-rutile phase transformation due to the presence of the coupled ZnFe2O4 narrow bandgap semiconductor is evaluated. The transformation's dependence on pH, calcination temperature, particle size, and ZnFe2O4 concentration has been analyzed using XRD, SEM, and UV-Visible spectrometry. The requirements for retaining the highly photoactive anatase phase present in a ZnFe2O4 nanocomposite are outlined. The visible-light activated photocatalytic activity of the TiO2-ZnFe2O4 nanocomposites have been compared to an Aldrich TiO2 reference catalyst, using a solar-simulated photoreactor for the degradation of phenol.
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Nowadays, cancer is increasingly becoming one of the foremost threats to human being life worldwide, and diagnosing this deadly disease is one of the major priorities of researchers. Described as a monolayer-thin-sheet of hexagonally... more
Nowadays, cancer is increasingly becoming one of the foremost threats to human being life worldwide, and diagnosing this deadly disease is one of the major priorities of researchers. Described as a monolayer-thin-sheet of hexagonally patterned carbon atoms, ‘graphene’ is considered an innovative evergreen carbon material ideal for a wide array of sensing applications and nanotechnologies. Graphene-based materials (GBMs) have acquired a huge share of interest in the scope of biosensor fabrication for early and accurate cancer diagnosis. Herein, we have insights reviewed the various routes and technologies for synthesized graphene, and GBMs including 3D graphene (i.e. hydrogels, foams, sponges and porous) and 0D graphene (i.e. quantum dots). Moreover, we have introduced the different types of graphene/GBMs biosensors (i.e. electrochemical biosensors, optical biosensors, field-effect transistors biosensors, electrochemiluminescence biosensors and microfluidics biosensors) and their mer...
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The use of technology in higher education science classrooms rose significantly in the advent of the COVID-19 pandemic. In many universities, academic programs including introductory physics classes were taken online. Some institutions... more
The use of technology in higher education science classrooms rose significantly in the advent of the COVID-19 pandemic. In many universities, academic programs including introductory physics classes were taken online. Some institutions adopted online learning but also maintained face-to-face (F2F) laboratories when COVID-19 restrictions began to ease. Here, the effectiveness of the online learning approach in comparison with F2F learning is explored. The percentage difference in performance for students who took the online introductory physics course, Physics for Scientists and Engineers, versus that of students simultaneously taking the same course F2F is reported. This is done both across different sections taught by different instructors, and for the same course taught online versus F2F by the same professor. Furthermore, a short survey was conducted to assess the student learning experience and opinion about online and F2F learning. The results show equal or better overall perfo...
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A significantly large amount of thermal energy is lost from or gained in buildings as a result of solar radiation. A comfortable temperature can be maintained by correctly designing and arranging a building’s windows and smart roof... more
A significantly large amount of thermal energy is lost from or gained in buildings as a result of solar radiation. A comfortable temperature can be maintained by correctly designing and arranging a building’s windows and smart roof coatings. Single layer or multilayer thin film coatings, with spectrally desirable characteristics, are deposited on glass or roof surfaces and can greatly improve a building’s energy efficiency. Thermochromic materials present some advantages due to their reversible color and phase change behavior near ambient temperature. For example, a thermochromic coating on a roof’s surface can change color (black to white) reversibly when heated at around 30 °C, reflecting solar radiation and reducing a building’s cooling needs. In the present study, various thermochromic coatings on glass slides are investigated. In this work, the effect of non-toxic titanium dioxide (TiO2), used as a UV radiation protective coating on thermochromic particles (such as a three-component blue dye synthesized in the lab or a commercially available black dye), is discussed. The composite coatings of the chosen components can reduce a building’s cooling and heating energy needs and provide an environmentally sustainable solution for a green economy. Several physico-chemical characterization techniques were used to understand the surface, interfacial, spectroscopic, and thermal behavior of TiO2 or SiO2 coatings and phase change thermochromic materials for applications in thermal storage and enhanced energy efficiency.
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In recent years, due to the advancement in nanotechnology, advanced oxidation processes (AOPs), especially sonocatalysis and photocatalysis, have become a topic of interest for the elimination of pollutants from contaminated water. In the... more
In recent years, due to the advancement in nanotechnology, advanced oxidation processes (AOPs), especially sonocatalysis and photocatalysis, have become a topic of interest for the elimination of pollutants from contaminated water. In the research work reported here, an attempt has been made to study and establish a physicochemical mechanism for the catalytic activity of copper oxide nanoparticles (CuO NPs) in AOPs using the degradation of dyes as model contaminants. CuO NPs exhibited brilliant sonocatalytic and photocatalytic activities for the degradation of a cationic dye (Victoria Blue) as well as an anionic dye (Direct Red 81). The degradation efficiency of CuO NPs was calculated by analysing the variation in the absorbance of dye under a UV-Vis spectrophotometer. The influence of different operating parameters on the catalytic activity of CuO NPs, such as the amount of catalysts dose, pH of the solution, and the initial dye concentration, was thoroughly investigated. In additi...
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ABSTRACT Nanoparticles of Zinc Ferrite (ZnFe2 O4 ) prepared by both wet- and dry- high-energy ball milling (HEBM), have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission... more
ABSTRACT Nanoparticles of Zinc Ferrite (ZnFe2 O4 ) prepared by both wet- and dry- high-energy ball milling (HEBM), have been investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), surface area and pore size distribution (BET) and wavelength-dependent diffuse reflectance and scattering turned into absorption coefficient estimation using the Kubelka-Munk theory. It was found that after 72 hours of HEBM, the particle size was decreased from 220 nm for the initial material to 16.5 nm and 9.4 nm for the wet- and dry-milled samples, respectively. The optical absorption analysis revealed that the energy gap is increased (blue shift) by 0.45 eV for wet-milled and decreased (“anomalous” red shift) by 0.15 eV for dry-milled samples of ZnFe2 O4 as the particle size decreased.
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Hydrogen is a good alternative to fossil fuels for the production, distribution, and storage of energy. Steam reforming of natural gas, or steam methane reformation (SMR), is one of the most developed and commercially used technologies... more
Hydrogen is a good alternative to fossil fuels for the production, distribution, and storage of energy. Steam reforming of natural gas, or steam methane reformation (SMR), is one of the most developed and commercially used technologies for hydrogen production. Partial oxidation (POX) refers to the conversion of heavy hydrocarbon feedstocks into a mixture of H2, CO, and CO2 using superheated steam and oxygen. In the thermal path hydrogen can be produced in two ways: direct gasification and pyrolysis to produce liquid bio-oil, followed by steam reforming. Fossil fuels, electricity, biomass, and sunlight are four potential resources to use in H2 production. Photochemical and photoelectrochemical systems are currently at a very early stage of development. Hydrogen storage is essential, especially for the on-board vehicular applications that lead to a hydrogen-based economy. This chapter presents various hydrogen storage methods with respect to their physical and chemical phenomena. Keywords: biomass; hydrogen energy; hydrogen storage methods; partial oxidation (POX); steam methane reformation (SMR)
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The future is bright for hydrogen as a clean, mobile energy source to replace petroleum products. This paper examines new and emerging technologies for hydrogen production, storage and conversion and highlights recent commercialization... more
The future is bright for hydrogen as a clean, mobile energy source to replace petroleum products. This paper examines new and emerging technologies for hydrogen production, storage and conversion and highlights recent commercialization efforts to realize its potential. Also, the paper presents selected notable patents issued within the last few years. There is no shortage of inventions and innovations in hydrogen technologies in both academia and industry. While metal hydrides and functionalized carbon-based materials have improved tremendously as hydrogen storage materials over the years, storing gaseous hydrogen in underground salt caverns has also become feasible in many commercial projects. Production of "blue hydrogen" is rising as a method of producing hydrogen in large quantities economically. Although electric/battery powered vehicles are dominating the green transport today, innovative hydrogen fuel cell technologies are knocking at the door, because of their lower refueling time compared to EV charging time. However, the highest impact of hydrogen technologies in transportation might be seen in the aviation industry. Hydrogen is expected to play a key role and provides hope in transforming aviation into a zero-carbon emission transportation over the next few decades.
After highlighting the fundamental contributions of van’t Hoff to the emergence of modern physical chemistry, we bring out the relevance of his ideas to a problem of great contemporary interest—storageof hydrogen in nanomaterials.
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An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storagematerials at pressures up to 10 MPa and temperatures up to 823 K. High throughput is obtained by employing a 60 mm... more
An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storagematerials at pressures up to 10 MPa and temperatures up to 823 K. High throughput is obtained by employing a 60 mm diameter × 9 mm thick sapphire window, with a corresponding 50 mm diameter unobstructed optical aperture. To reproducibly seal this relatively large window to the cell body at elevated temperatures and pressures, a gold o-ring is employed. The sample holder-to-window distance is adjustable, making this cell design compatible with optical measurement systems incorporating lenses of significantly different focal lengths, e.g., microscope objectives and single element lenses. For combinatorial investigations, up to 19 individual powder samples can be loaded into the optical cell at one time. This cell design is also compatible with thin-film samples. To demonstrate the capabilities of the cell,in situ measurements of the Ca(BH4)2 and nano-LiBH4–LiNH2–MgH2hydr...
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One of the biggest challenges for the commercial application of existing hydrogen storage materials is to meet the desired high volumetric and gravimetric hydrogen storage capacity and the ability to refuel quickly and repetitively as a... more
One of the biggest challenges for the commercial application of existing hydrogen storage materials is to meet the desired high volumetric and gravimetric hydrogen storage capacity and the ability to refuel quickly and repetitively as a safe transportation system at moderate temperature and pressure. In this work, we have synthesized polyaniline nanocomposites (PANI-NC) and hypercrosslinked polyaniline (PANI-HYP) materials to provide structure and composition which could meet the specific demands of a practical hydrogen storage system. Hydrogen sorption measurements showed that high surface area porous structure enhanced the storage capacity significantly at 77.3K and 1atm (i.e., 0.8wt% for PANI-HYP). However at 298K, storage capacity of all samples is less than 0.5wt% at 70 bar. Hydrogen sorption results along with the surface area measurements confirmed that hydrogen storage mechanism predominantly based on physisorption for polyaniline.
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This review is focused on the topical developments in the synthesis of nanocomposites using the simplest top-down approach, mechanochemical milling, and the related aspects of the interfacial interactions. Milling constraints include time... more
This review is focused on the topical developments in the synthesis of nanocomposites using the simplest top-down approach, mechanochemical milling, and the related aspects of the interfacial interactions. Milling constraints include time duration of milling, ball size, the ball-to-sample content proportion, rotation speed, and energy that took part in a vital part of the structure–property relationships and composite interactions. Milled nanocomposites are being used in different structural applications for their higher performance rate and throughput. The synthesis of different nanocomposites and the effect of various parameters on the mill-ability of nanocomposites are discussed. Moreover, some of the major advancements in the energy sector are discussed in the latter part of the review.
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Thermochromism and thermochromic materials research and development are of great interest because of their importance in versatile applications with respect to energy-efficient building structures, textile industries, thermal or heat... more
Thermochromism and thermochromic materials research and development are of great interest because of their importance in versatile applications with respect to energy-efficient building structures, textile industries, thermal or heat storage, antique maintenance processing and sensors. In general, thermochromic materials have been classified into four categories including inorganic, organic, polymeric, and hybrid systems, based on their unique material properties and operating conditions. Thermochromic materials have been prepared via different physicochemical techniques with some of them combined to maximize the yield, stability, and efficiency of the prepared TCMs. Pristine TCMs often undergo severe degradation when exposed to various external stimuli including UV irradiation from sunlight and ambient environmental conditions such as temperature, pressure, and humidity variations. Such degradation causes property and physical behavioral changes in TCMs. Various microencapsulation procedures and coating techniques are utilized to enhance the thermochromic performance of the materials and to protect the core TCMs from the degradation. Many desirable candidate materials have been developed, and extensive metrological tools have been deployed to understand the structural, morphological, microstructural, thermal, chemical, surface, and interfacial characteristics of these TCMs and their microencapsulated variants. The potential applications of the microencapsulated TCMs in industrial, commercial, and residential sectors are briefly discussed in this review paper. The future looks bright for the development of novel microencapsulated TCMs possessing nanostructural derived properties that can be effectively used in inks, paints, and coating agents for sustainable energy efficiency and many other applications. Enhanced energy efficiency of buildings with smart coatings of microencapsulated TCMs
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Electrospinning is an inexpensive and versatile technique for fabricating micro- and nano- scaled fibers. There have been limited attempts to employ it for the fabrication of thermochromic (TC) fibers, and the fabrication of a... more
Electrospinning is an inexpensive and versatile technique for fabricating micro- and nano- scaled fibers. There have been limited attempts to employ it for the fabrication of thermochromic (TC) fibers, and the fabrication of a three-component (dye, developer, and solvent) TC material has required the use of a more complicated coaxial electrospinning technique. Herein, a simple and novel method for creating thermochromic fibers by electrospinning single strands of poly (methyl methacrylate) (PMMA) with embedded thermochromic powder of a polymer encapsulated three-component system was employed. Unlike past leuco dye-based thermochromic fibers, an unmodified syringe tip can be used for the spinning process and only one flow rate needs to be determined. A solution of solvent (either N-dimethylformamide or chloroform), PMMA, and a commercially available black thermochromic powder was prepared and spun using a custom-made electrospinning apparatus. The spun fibers exhibited a clear color ...
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Dye Sensitized Solar Cells, Diffusion, Hydrogen Fuel, Flow induced vibration, Dynamic Modeling, and 15 moreHeat transfer enhancement, Hydrogen absorption, Capacitance, Binder, Four Point, Carbon Materials, Charge Density, Extended Kalman Filter, Gas storage, Ball Milling, Cathode, Anode, Fischer Tropsch, Bacterial Sulfate Reduction, and complex hydrides
This study is mainly focused on the fabrication of SiO2 as an inorganic shell material encapsulated an organic thermochromic (TC) core material comprises of either the (i) three-component as-synthesized blue dyes [BDTCM@SiO2] or (ii)... more
This study is mainly focused on the fabrication of SiO2 as an inorganic shell material encapsulated an organic thermochromic (TC) core material comprises of either the (i) three-component as-synthesized blue dyes [BDTCM@SiO2] or (ii) off-the-shelf (commercial) black dyes [CDTCM@SiO2]. Both the SiO2 encapsulated thermochromic systems have successfully demonstrated the color transition at around 31 °C. For the three-component thermochromic microcapsules, we have used the crystal violet lactone (CVL) as a leuco dye, bisphenol-A (BPA) as a color developer, and 1-tetradecanol (TD) as a solvent. Different ratios of the thermochromic dye and the metal oxide were prepared to examine the effect of the core@shell ratio on the microstructural and thermal properties of the encapsulated microcapsules. The mean particles sizes of the BDTCM@SiO2 are below 100 nm, whereas, the CDTCM@SiO2 samples exhibited the mean particle sizes varied in a range of 100-1000 nm. The endothermic phase transition due...
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Objectives • Determine the chemical nature of the titanium species responsible for the enhanced kinetics of Ti-doped NaAlH4. • Determine the mechanism of action of the dopants of Ti-doped NaAlH4 in the dehydrogenation and rehydrogenation... more
Objectives • Determine the chemical nature of the titanium species responsible for the enhanced kinetics of Ti-doped NaAlH4. • Determine the mechanism of action of the dopants of Ti-doped NaAlH4 in the dehydrogenation and rehydrogenation processes. • Apply insights gained from fundamental studies of Ti-doped NaAlH4 to the design and synthesis of hydrogen storage materials that meet the FreedomCAR 2010 hydrogen storage targets, especially cost, specific energy, and energy density.
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We have investigated the complex metal hydrides involving light weight elements or compounds for the reversible hydrogen storage. The complex hydrides are prepared via an inexpensive solid state mechanochemical process under reactive... more
We have investigated the complex metal hydrides involving light weight elements or compounds for the reversible hydrogen storage. The complex hydrides are prepared via an inexpensive solid state mechanochemical process under reactive atmosphere at ambient temperatures. The complex metal hydride, LiBH4 with different mole concentrations of ZnCl2 were characterized for the new phase formation and hydrogen decomposition characteristics of Zn(BH4)2. Furthermore, the complex metal hydride is destabilized using the addition of nano MgH2 for the reversible hydrogen storage characteristics. The structural, microstructural, surface, and other physicochemical behaviors of these lightweight complex metal hydrides have been studied via various metrological tools such as x-ray diffraction, Fourier transform infrared spectroscopy, thermal programed desorption, and PCT hydrogen absorption methods.
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Ferrite-Ferroelectric composites with the generic formula y (Mn 0.5 Cu 0.5 Fe 2 O 4 )1 − y [Ca 0.1 Ba 0.9 Zr 0.1 Ti 0.9 ] ( y = 25%, 50% and 75%) are prepared by solid-state reaction. One of the prepared samples of the composites 25%Mn... more
Ferrite-Ferroelectric composites with the generic formula y (Mn 0.5 Cu 0.5 Fe 2 O 4 )1 − y [Ca 0.1 Ba 0.9 Zr 0.1 Ti 0.9 ] ( y = 25%, 50% and 75%) are prepared by solid-state reaction. One of the prepared samples of the composites 25%Mn 0.5 Cu 0.5 Fe 2 O 4 –75%Ca 0.1 Ba 0.9 Zr 0.1 Ti 0.9 O 3 (MCF-CBZT) is subjected to high-energy mechanical milling for different durations (12 h, 18 h and 30 h). The compositional stoichiometry of all the samples is checked by Energy Dispersive Spectroscopy. All the un-milled and milled samples are characterized by X-ray diffraction, scanning electron microscopy, FTIR, magnetometry, and dielectric and magnetoelectric coefficient measurements. Magnetoelectric composite possesses biphasic surrounding to exhibit complex behavior of ME effect. The present study reveals influence of mechanical milling on MCF-CBZT magnetoelectric composite. The XRD confirms the presence of ferrite and ferroelectric phases for all the samples and microstructural changes appear in SEM images of milled specimens. FTIR spectra show four characteristic bands in 400–800 cm −1 range. Saturation magnetization and Curie temperature decrease as milling duration increases. Relaxed broad doublet with the distribution of nuclear hyperfine fields is found in Mossbauer spectra indicating good coupling between ferrite-ferroelectric phases caused by mechanical milling for the multiferroic composite. The frequency response of dielectric constant and loss tangent is recorded in the frequency range from 100 Hz to 1 MHz. The static value of magnetoelectric factor has been studied as a function of magnetic field for un-milled and milled MCF-CBZT samples. The maximum value 382 μV/cm·Oe of (ME) H is observed for the 18 h milled MCF-CBZT sample.
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Metallovesicles are an emerging class of soft nanomaterials where spherical bilayer membranes, resulting from self-aggregation of amphiphilic metal complexes, amalgamate the advantages of metal specific catalytic properties and small... more
Metallovesicles are an emerging class of soft nanomaterials where spherical bilayer membranes, resulting from self-aggregation of amphiphilic metal complexes, amalgamate the advantages of metal specific catalytic properties and small hydrophobic...
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Ti doped NaAlH4 hydride is proposed as a reversible hydrogen storage material. In this work, the microstructure of NaAlH4 with 2% TiCl3 additive was studied after 5 hydrogen cycles using a combination of transmission electron microscopy... more
Ti doped NaAlH4 hydride is proposed as a reversible hydrogen storage material. In this work, the microstructure of NaAlH4 with 2% TiCl3 additive was studied after 5 hydrogen cycles using a combination of transmission electron microscopy (TEM) techniques including energy dispersive spectroscopy (EDS) X-ray analysis. Selected area diffraction and high-resolution (HR) imaging confirmed the presence of the NaH phase in the material. Electron diffraction was dominated by Al. HRTEM showed the presence of edge dislocations, which might influence the hydrogen diffusivity process in these materials.
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In this study, the synthesis of nonspherical composite particles of poly(ethylene glycol) diacrylate (PEG-DA)/SiO2and PEG-DA/Al2O3with single or multiple vias and the corresponding inorganic particles of SiO2and Al2O3synthesized using the... more
In this study, the synthesis of nonspherical composite particles of poly(ethylene glycol) diacrylate (PEG-DA)/SiO2and PEG-DA/Al2O3with single or multiple vias and the corresponding inorganic particles of SiO2and Al2O3synthesized using the Stop Flow Lithography (SFL) method is reported. Precursor suspensions of PEG-DA, 2-hydroxy-2-methylpropiophenone, and SiO2or Al2O3nanoparticles were prepared. The precursor suspension flows through a microfluidic device mounted on an upright microscope and is polymerized in an automated process. A patterned photomask with transparent geometric features masks UV light to synthesize the particles. Composite particles with vias were synthesized and corresponding inorganic SiO2and Al2O3particles were obtained through polymer burn-off and sintering of the composites. The synthesis of porous inorganic particles of SiO2and Al2O3with vias and overall dimensions in the range of ~35–90 µm was achieved. BET specific surface area measurements for single via in...
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Engineering, Materials Science, High Pressure, Raman Spectroscopy, Hydrogen Storage, and 12 moreMedicine, Scientific Instruments, Raman, Scientific, High throughput screening, Hydrogen Storage Materials, Thin Film, Physical sciences, CHEMICAL SCIENCES, Elevated Temperature, Optical Microscope, and Measurement System
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Calcium magnesium carbonate, also known as dolomite, is dispersed throughout Florida as a constituent of phosphate-mined resources. The mineral is problematic in the phosphoric acid production of phosphate for agriculture and must be... more
Calcium magnesium carbonate, also known as dolomite, is dispersed throughout Florida as a constituent of phosphate-mined resources. The mineral is problematic in the phosphoric acid production of phosphate for agriculture and must be separated so that it does not negatively affect the process. This means that this natural resource has no beneficial end use. In the present study, we characterize high-concentration dolomite phosphatic pebbles from the Florida Industrial and Phosphate Research Institute and examined their feasibility for thermochemical energy storage at high temperatures. The dolomite mineral composition was studied prior to and after calcination (decarbonation) using scanning electron microscopy with energy-dispersive X-ray spectroscopy, powder X-ray diffraction, Fourier Transform Infrared Spectroscopy, and thermogravimetric analysis. The local samples were compared to a commercial dolomite sample and results confirm a high percentage of dolomite in the central Florida samples. Thermogravimetric analysis and powder X-ray diffraction indicated that the dolomite calcination is not fully complete at lower temperature, and at least 700 °C heat is required for the release of CO2 from the dolomite pebbles. Overall, the results show that the waste dolomite phosphatic pebbles are suitable for potential use in high-temperature thermochemical energy storage with long-term reversibility and cyclability.
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Materials Science and MRS
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Dolomite, a calcium magnesium mineral (CaMg(CO3)2), is considered an undesirable accompanying mineral in the phosphoric acid production process and, as such, large quantities of this mineral are available in Florida. This study is aimed... more
Dolomite, a calcium magnesium mineral (CaMg(CO3)2), is considered an undesirable accompanying mineral in the phosphoric acid production process and, as such, large quantities of this mineral are available in Florida. This study is aimed toward the characterization of the high-concentration phosphatic dolomite pebbles (handpicked dolomites) received from the Florida Industrial and Phosphate Research Institute (FIPR) and investigate their feasibility for thermochemical energy storage (TCES). The chemical composition, structural and microstructural characteristics of commercial and handpicked dolomite minerals was studied using a variety of techniques such as X-ray Fluorescence (XRF), Fourier-transform infrared spectroscopy (FTIR), and an automated mineralogy Automated SEM-EDX Mineralogy (or automated scanning electron microscopy) with energy dispersive X-rays spectrometer (SEM-EDX), which confirmed the phosphatic pebbles received contains dolomite (CaMg(CO3)2) phase in a high percenta...
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In the field of energy storage, recently investigated nanocomposites show promise in terms of high hydrogen uptake and release with enhancement in the reaction kinetics. Among several, carbonaceous nanovariants like carbon nanotubes... more
In the field of energy storage, recently investigated nanocomposites show promise in terms of high hydrogen uptake and release with enhancement in the reaction kinetics. Among several, carbonaceous nanovariants like carbon nanotubes (CNTs), fullerenes, and graphitic nanofibers reveal reversible hydrogen sorption characteristics at 77 K, due to their van der Waals interaction. The spillover mechanism combining Pd nanoparticles on the host metal-organic framework (MOF) show room temperature uptake of hydrogen. Metal or complex hydrides either in the nanocomposite form and its subset, nanocatalyst dispersed alloy phases illustrate the concept of nanoengineering and nanoconfinement of particles with tailor-made properties for reversible hydrogen storage. Another class of materials comprising polymeric nanostructures such as conducting polyaniline and their functionalized nanocomposites are versatile hydrogen storage materials because of their unique size, high specific surface-area, por...
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A significantly large amount of thermal energy is lost from or gained in buildings as a result of solar radiation. A comfortable temperature can be maintained by correctly designing and arranging a building's windows and smart roof... more
A significantly large amount of thermal energy is lost from or gained in buildings as a result of solar radiation. A comfortable temperature can be maintained by correctly designing and arranging a building's windows and smart roof coatings. Single layer or multilayer thin film coatings, with spectrally desirable characteristics, are deposited on glass or roof surfaces and can greatly improve a building's energy efficiency. Thermochromic materials present some advantages due to their reversible color and phase change behavior near ambient temperature. For example, a thermochromic coating on a roof's surface can change color (black to white) reversibly when heated at around 30 o C, reflecting solar radiation and reducing a building's cooling needs. In the present study, various thermochromic coatings on glass slides are investigated. In this work, the effect of non-toxic titanium dioxide (TiO2), used as a UV radiation protective coating on thermochromic particles (such as a three-component blue dye synthesized in the lab or a commercially available black dye), is discussed. The composite coatings of the chosen components can reduce a building's cooling and heating energy needs and provide an environmentally sustainable solution for a green economy. Several physico-chemical characterization techniques were used to understand the surface, interfacial, spectroscopic, and thermal behavior of TiO2 or SiO2 coatings and phase change thermochromic materials for applications in thermal storage and enhanced energy efficiency.