Point defects create exotic properties in materials such as defect-induced luminescence in wide-bandgap semiconductors, magnetism in nonmagnetic materials, single-photon emission from semiconductors, etc. In this article, oxygen defect... more
Point defects create exotic properties in materials such as defect-induced luminescence in wide-bandgap semiconductors, magnetism in nonmagnetic materials, single-photon emission from semiconductors, etc. In this article, oxygen defect formation in metallic TiN and semiconducting rock salt-(Al,Sc)N is investigated with a combination of first-principles density functional theory, synchrotron-based x-ray absorption spectroscopy (XAS) analysis, and scanning transmission electron microscopy–energy-dispersive x-ray spectroscopy mapping. Modeling results show that oxygen in TiN and rock salt-(Al,Sc)N prefers to be in the defect complex of substitutional and interstitial oxygen (nON + Oi) types. While in TiN, the preferential interstitial sites of oxygen in ON + Oi are at the tetrahedral site, in rock salt-(Al,Sc)N, a split interstitial site along the [111] direction was found to be energetically preferable. Simulations performed as a function of the oxygen partial pressure show that under...
Using machine learning (ML) approach, we unearthed a new III–V semiconducting material having an optimal bandgap for high-efficient photovoltaics with the chemical composition of Gallium–Boron–Phosphide ( $$\\hbox {GaBP}_{2}$$ , space... more
Using machine learning (ML) approach, we unearthed a new III–V semiconducting material having an optimal bandgap for high-efficient photovoltaics with the chemical composition of Gallium–Boron–Phosphide ( $$\\hbox {GaBP}_{2}$$ , space group: $$\\hbox {Pna2}_{1}$$ ). ML predictions are further validated by state-of-the-art ab initio density functional theory simulations. The stoichiometric Heyd–Scuseria–Ernzerhof bandgap of $$\\hbox {GaBP}_{2}$$ is noted to be 1.65 eV, a close ideal value (1.4–1.5 eV) to reach the theoretical Queisser–Shockley limit. The calculated electron mobility is similar to that of silicon. Unlike perovskites, the newly discovered material is thermally, dynamically and mechanically stable. Above all the chemical composition of $$\\hbox {GaBP}_{2}$$ is non-toxic and relatively earth abundant, making it a new generation of PV material. Using ML, we showed that with a minimal set of features, the bandgap of III–III–V and II–IV–V semiconductor can be predicted up to an RMSE of less than 0.4 eV. We have presented a set of scaling laws, which can be used to estimate the bandgap of new III–III–V and II–IV–V semiconductor, with three different crystal phases, within an RMSE of $$\\approx $$ 0.4 eV.
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... Calcium changes induced by presynaptic 5-hydroxytryptamine-3 serotonin receptors on isolated terminals from various regions of the rat brain. SV Nayak * , P. Rondé * , AD Spier , SCR Lummis , and RA Nichols * , Corresponding... more
... Calcium changes induced by presynaptic 5-hydroxytryptamine-3 serotonin receptors on isolated terminals from various regions of the rat brain. SV Nayak * , P. Rondé * , AD Spier , SCR Lummis , and RA Nichols * , Corresponding Author Contact Information. ...
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The present study summarizes the designing of a green transducer phase based on nano-cerium oxide (CeO2) decorated reduced graphene oxide (RGO) reinforced chitosan nanocomposites as an effective enzyme immobilizer and bio-sensing matrix... more
The present study summarizes the designing of a green transducer phase based on nano-cerium oxide (CeO2) decorated reduced graphene oxide (RGO) reinforced chitosan nanocomposites as an effective enzyme immobilizer and bio-sensing matrix for glucose analyte. Also, it scrutinizes the biocompatibility and cell viability of the synthesized nanohybrid with human fibroblastic macrophage cell line. CeO2 nanoparticles (NPs) were successfully grown on graphene nanosheet in the presence of cationic surfactant followed by facile hydrothermal treatment. The eventual growth of synthesized CeO2 nanocrystals on the graphene layer was confirmed from X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman analysis. The biocompatibility of the synthesized nanohybrid was also evident from the MTT assay. Glucose oxidase (GOx) was employed on the green polymer nanocomposites modified FTO electrode to fabricate an enzymatic bioelectrode. The electroanalytical response of the GOx/nano-CeO2/RGO/CS/FTO bioelectrode towards electrooxidation of glucose analyte was investigated by electrochemical impedance (EIS) and cyclic voltammetry (CV) study. The resulting biosensor exhibited a good electrochemical response to glucose within the linear detection range of 0.05-6.5 mM with a low detection limit of 2 μM and a sensitivity of 7.198 μA mM(-1) cm(-2). The bioelectrode also showed good shelf life (~10 weeks) and negligible interfering ability under controlled environment. The obtained results indicate that nano-CeO2/RGO nanohybrid based chitosan nanocomposites achieve a biocompatible biosensing platform for effective enzyme immobilization due to the excellent synergistic effects between the CeO2 nanoparticles and graphene sheet.
Research Interests: Chemical Engineering, Biomedical Engineering, Chitosan, Nanocomposites, Agricultural Biotechnology, and 15 moreMacrophages, Metal Nanoparticles, Humans, Glucose, Graphite, Cerium, Particle Size, Electrodes, Biocompatible Materials, Equipment Design, Cell Survival, Equipment Failure Analysis, Biosensing Techniques, Glucose Oxidase, and conductometry
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Graphene, a single sp2 bonded carbon, is now a burgeoning interest with various fascinating properties in a large number of biomedical applications. Consequently, the impact of graphene-based functional nanohybrid and its potential risk... more
Graphene, a single sp2 bonded carbon, is now a burgeoning interest with various fascinating properties in a large number of biomedical applications. Consequently, the impact of graphene-based functional nanohybrid and its potential risk to human health have raised considerable public concerns. In this present study, we have synthesized cerium oxide ( CeO 2) anchored reduced graphene oxide (RGO) nanohybrid and a detailed study on its nanotoxicity profile has also been scrutinized. To confirm the efficient synthesis of nano- CeO 2/RGO nanohybrid, the systematic characterization has been carried out using FTIR, Raman and UV-Vis spectroscopic analysis. The successful imprint of CeO 2 nanoparticles (NPs) on RGO nanosheet was also evident from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) micrographs. A dose-dependent in vitro nanotoxicity of the nanohybrid has been assessed by using monocyte macrophage cells-Raw264.7 and colon cancer cells-HCT116 as co...
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Research Interests: Taxonomy, Biology, Cell Cycle, Biometrics, Morphology, and 4 moreCell Division, Meiosis, Karyotype, and Caryotype
ABSTRACT Renewable resource based epoxidized castor oil (ECO) synthesized and used as a prime material to develop the acrylated epoxidized castor oil (AECO) networks. AECO nanocomposites prepared via sol-gel method from OMMT clay and... more
ABSTRACT Renewable resource based epoxidized castor oil (ECO) synthesized and used as a prime material to develop the acrylated epoxidized castor oil (AECO) networks. AECO nanocomposites prepared via sol-gel method from OMMT clay and silane. It is found that AECO/1 wt.% OMMT system increases in tensile strength from 28 to 37 MPa and flexural strength from 54 to 63 MPa as compared with the AECO system, respectively. The non-isothermal cure kinetics of bio-based systems has been studied using differential scanning calorimetry (DSC). The activation energy of AECO/OMMT system obtained from Kissinger and Flynn-Wall-Ozawa models is lower than that of AECO system.
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Interfacial agents such as compatibilizers have recently been introduced into polymer blends to improve microstructure and mechanical properties of thermoplastics materials. This method is proven to be an effective way to prepare a... more
Interfacial agents such as compatibilizers have recently been introduced into polymer blends to improve microstructure and mechanical properties of thermoplastics materials. This method is proven to be an effective way to prepare a mixture of polymeric materials from E-waste that can have superior mechanical properties over a wide temperature range. This study is focused on the characterization and mechanical recycling of plastics, namely Polycarbonate (PC), Acrylonitrile Butadiene Styrene (ABS) and PC/ABS blends via melt blending technique. Mechanical characterization of prepared blend has been carried out to determine the optimum composition range. The experimental results showed that the prepared blends were incompatible in nature. Addition of maleic anhydride grafted ABS and SBS suggests improved compatibility and impact performance. The grafting mechanism of MA into ABS was explored, which is considered as a key factor resulting a special morphology of ABS domains dispersed in PC matrix. The thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), and morphology results revealed improved stability as compared to recycled plastics.
The recent advances and theories in the studies of the toughening mechanism have been reviewed to explain the effect of rubber particles in different rubber modified Polyolefin materials. To elucidate toughening effect, major theories... more
The recent advances and theories in the studies of the toughening mechanism have been reviewed to explain the effect of rubber particles in different rubber modified Polyolefin materials. To elucidate toughening effect, major theories e.g., critical particle distance, particle size, micro deformation by stress field of rubber, shear yielding and crazing phenomena has been reviewed. Based on these theories, variety of blends of rubber modified Polyolefin materials has been compared but no one of these provided adequate information to be considered as total theory of toughening. To achieve the objective of toughening, it is important to maintain critical particle size, uniform particle distribution and good interfacial adhesion by inclusion of suitable compatibilizer in the matrix. Particular attention has been paid to study the type of morphology and bimodal distribution of rubber particles to elucidated toughening effect. Rubber particle cavitation, which comes from micro-voids and rubber phase interface are then further discussed. GRAPHICAL ABSTRACT
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A candid approach to analyze the performance characteristics of phenyl phosphonate-functionalized zirconium oxide and pure zirconium oxide (ZrO2) fillers reinforced chitosan nanocomposites and their suitability as a potential biomaterial... more
A candid approach to analyze the performance characteristics of phenyl phosphonate-functionalized zirconium oxide and pure zirconium oxide (ZrO2) fillers reinforced chitosan nanocomposites and their suitability as a potential biomaterial for the development of transducer surface in biosensing device has been investigated in this communication. Functionalization of ZrO2 has been carried out using sulfophenylphosphonate which was confirmed using Fourier transform infrared spectrographs. The electrostatic intercalation of chitosan with filler particles was monitored using electrochemical impedance analyzer which exhibits lowest bulk resistance which is highly effective for ionic switching. Incorporation of zirconium sulfophenylphosphonate (ZrSP) the ionic conductivity of the chitosan film attained a value of 1.2 × 10−6 S/cm as compared to the unmodified one which is a prefeasibility work for the fabrication of biosensing platform. Variation in performance characteristics has been evaluated through morphological and thermal characterization. TGA and DSC analysis reveal that the thermal stability and decomposition temperature of the nanocomposites were improved by the addition of reinforcing filler particles. XRD and SEM and TEM results support the above assumption. The continuous alignment of the proton transfer channels of the nanocomposites was thoroughly investigated by AFM analysis which revealed phase morphology for improved enzyme entrapment. Further, surface functionalized nanofillers result considerable increment of mechanical properties in terms of elastic modulus and tensile stress.Graphical Abstract
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Research Interests: Materials Engineering, Mechanical Engineering, Materials Science, Nanocomposites, Transmission Electron Microscopy, and 10 morePolymer Blends, Differential scanning calorimetry, Nanocomposite, TEM, XRD, Thermogravimetry, X ray diffraction, Thermal Stability, Tensile Strength, and Dynamic Mechanical Analysis
Hybrid composites consisting of polypropylene (PP) and short sisal fibers were prepared by melt mixing followed by compression molding. Various types of chemical treatments such as alkali treatment, cyanoethylation, coupling agent... more
Hybrid composites consisting of polypropylene (PP) and short sisal fibers were prepared by melt mixing followed by compression molding. Various types of chemical treatments such as alkali treatment, cyanoethylation, coupling agent treatment etc. were performed to improve the interfacial adhesion between the fibers and PP matrix. Variations in fiber loading, fiber length, coupling agent concentration and its treatment time period as a function of mechanical strength were studied. The morphology of the interface region was investigated through SEM analysis. Mechanical tests showed that the composites treated with MAPP of grade HC5 exhibited optimum strength. Nearly 50% increase in tensile, 30% in flexural and 58% increase in impact strengths were obtained in the case of composites treated with 1% MAPP concentration. Accelerated weathering and water absorption behavior of the MAPP-treated composites further confirmed an efficient fiber–matrix adhesion. Thermal measurements through DSC ...
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Aqueous polymerization of methyl methacrylate in visible light was studied using isoquinoline–sulphur dioxide (IQ–SO2) charge–transfer complex as the photoinitiator. Analysis of kinetic and other data indicate that the polymerization... more
Aqueous polymerization of methyl methacrylate in visible light was studied using isoquinoline–sulphur dioxide (IQ–SO2) charge–transfer complex as the photoinitiator. Analysis of kinetic and other data indicate that the polymerization proceed via a radical mechanism and the termination is dependent on the initiator concentration. Chain–termination via degradative chain (initiator) transfer appears to be predominant here.
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ABSTRACT Esterification of lactic acid with secondary alcohols such as isopropanol and isobutanol followed by acrylic acid was carried out by azeotropic distillation. Mass, Fourier Transform Infrared,1H-Nuclear Magnetic Resonance and... more
ABSTRACT Esterification of lactic acid with secondary alcohols such as isopropanol and isobutanol followed by acrylic acid was carried out by azeotropic distillation. Mass, Fourier Transform Infrared,1H-Nuclear Magnetic Resonance and proton decoupled 13C-Nuclear Magnetic Resonance spectroscopic techniques confirmed the formation of isoalkyl lactates and isoalkyl lactate acrylates. Poly(isoalkyl lactate acrylate)s were synthesized by free radical solution polymerization technique and molecular weights of the polymers were determined by gel permeation chromatography. Wide angle X-ray Diffraction studies indicated the polymers were amorphous and their average molecular interchain spacing () value was calculated from 2 value of amorphous halo. Moisture absorption and glass transition temperature of the polymers decreased with increase in number of carbon atoms of isoalkyl groups and value. Moisture absorption of the polymers were in the range of 2 to 6% (w/w) depending upon the isoalkyl lactate group, relative humidity and time. The moisture absorption of polymers followed Fikian process. Two-step thermal degradation was observed in nitrogen atmosphere and the thermal stability trend can be explained on the basis of value.
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Recently, natural fiber-reinforced polymer composites have experienced a tremendous growth in the composite industry because of their eco-friendliness and cost effectiveness.1, 2 Compared to inorganic fibers, natural fibers present some... more
Recently, natural fiber-reinforced polymer composites have experienced a tremendous growth in the composite industry because of their eco-friendliness and cost effectiveness.1, 2 Compared to inorganic fibers, natural fibers present some advantages, such as low density and ...
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Research Interests: Zoology, Probiotics, Fish Diseases, Innate immunity, Animals, and 15 moreFisheries Sciences, Bacillus subtilis, Veterinary Sciences, Aeromonas Hydrophila, Cyprinidae, Fish and Shellfish Diseases, Leukocytes, Respiratory Burst, Control Group, Fish and Shellfish Immunology, Bactericidal Activity, Phosphate Buffer Saline, Random Allocation, innate immune response, and positive control
The present paper summarizes an experimental study on the molten viscoelastic behavior of PP/sisal composites under steady and dynamic state. Variations in melt viscosity and die swell of the composites with an increase in shear rate,... more
The present paper summarizes an experimental study on the molten viscoelastic behavior of PP/sisal composites under steady and dynamic state. Variations in melt viscosity and die swell of the composites with an increase in shear rate, fibre loading and coupling agent ...
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ABSTRACT: Polystyrene (PS)/layered silicate nanocomposites are prepared by the melt blending technique. Na-MMT is modified with stearyltrimethyl ammonium chloride to evaluate the effect of clay modification on the performance of the... more
ABSTRACT: Polystyrene (PS)/layered silicate nanocomposites are prepared by the melt blending technique. Na-MMT is modified with stearyltrimethyl ammonium chloride to evaluate the effect of clay modification on the performance of the nanocomposites. A comparative account ...
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... a , Sanjay Kumar Nayak a * , Smita Mohanty a & Gautam Sarkhel b pages 1419-1427. ... Cappadonia , M. ; Niaki , SMS ; Wilhelm Erning , J. ; Stimming , U. Conductance of Nafion 117 membranes as a function of temperature and... more
... a , Sanjay Kumar Nayak a * , Smita Mohanty a & Gautam Sarkhel b pages 1419-1427. ... Cappadonia , M. ; Niaki , SMS ; Wilhelm Erning , J. ; Stimming , U. Conductance of Nafion 117 membranes as a function of temperature and water content . Sol. St. Ion. 1995 , 77 , 65 . ...
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Bio-nanocomposite hybrids based on poly (butylene adipate-co-terephthalate) (PBAT) and layered silicates were prepared by melt interaction technique using co-rotating twin screw extruder having a blown film unit. Sodium montmorillonite... more
Bio-nanocomposite hybrids based on poly (butylene adipate-co-terephthalate) (PBAT) and layered silicates were prepared by melt interaction technique using co-rotating twin screw extruder having a blown film unit. Sodium montmorillonite (Na+MMT) along with three different commercially available nanoclays i.e., Cloisite30B (C30B), Cloisite20A (C20A), Bentonite (B109) have been used as a reinforcing agent. Wide angle X-ray diffraction (WAXD) studies indicated an increase
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Research Interests: Cognitive Science, Biology, Medicine, Serotonin, Humans, and 15 moreKidney, Animals, Male, Rat Brain, Fluorescent Antibody Technique, Rats, Polyclonal Antibodies, Lateral Hypothalamus, Recombinant Proteins, Ligands, Neurosciences, Plasma Membrane, Enzyme Linked Immunosorbent Assay, Cell Membrane, and Corpus striatum
Hybrid composites consisting of polypropylene (PP) and short sisal fibers were prepared by melt mixing followed by compression molding. Various types of chemical treatments such as alkali treatment, cyanoethylation, coupling agent... more
Hybrid composites consisting of polypropylene (PP) and short sisal fibers were prepared by melt mixing followed by compression molding. Various types of chemical treatments such as alkali treatment, cyanoethylation, coupling agent treatment etc. were ...
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Page 1. Rheological Characterization of PP/Jute Composite Melts Smita Mohanty,1 Sushil K. Verma,1 Sanjay K. Nayak2 1Central Institute of Plastics Engineering and Technology, Guindy, Chennai 600032, India 2Central Institute ...