Amorphous MoSx thin-film-coated carbon fiber paper as a binder-free 3D electrode was synthesized ... more Amorphous MoSx thin-film-coated carbon fiber paper as a binder-free 3D electrode was synthesized by a facile hydrothermal method. The maximum specific capacitance of a single electrode was 83.9 mF cm(-2), while it was 41.9 mF cm(-2) for the symmetric device. Up to 600% capacitance retention was observed for 4750 cycles.
Abstract Nd substituted Y 3 Fe 5 O 12 (YIG) was synthesized using sol–gel auto-combustion method.... more Abstract Nd substituted Y 3 Fe 5 O 12 (YIG) was synthesized using sol–gel auto-combustion method. The phases present in the samples were identified using XRD. The asprepared dried gel was found to transform to the rare earth iron garnet phase at lower temperature when the Nd concentration is lower. Higher concentration of Nd resulted in the formation of orthoferrite as the major phase. The Curie temperature was recorded using thermomagnetic analysis and it was found to increase with the concentration of Nd. The crystallization kinetics of the Nd-substituted garnet phase was studied using TG–DTA. Two stage crystallization was observed from the DTA analysis for Nd 1 Y 2 Fe 5 O 12 . The activation energy for the formation of Nd 1 Y 2 Fe 5 O 12 was 610 kJ/mol, found by using Johnson–Mehl–Avrami (JMA) equation. Three dimensional growth mechanism dominate at lower heating rates for the Nd-substituted YIG.
Magnetic materials have received much attention due to their use in various applications such as ... more Magnetic materials have received much attention due to their use in various applications such as biomedical, waste water treatment, photocatalytic, and electrocatalytic applications. Among the magnetic materials, Fe3O4 magnetic nanoparticles (MNPs) are the finest choice, due to their easy preparation process and flexible magnetic characteristics with adjustable morphology and size. Surface modifications of Fe3O4 MNPs with suitable surface modifier are necessary to utilize the hybrid materials for any specific required applications. The selection of surface modifier is important, as it is having a major role for the specific applications. The MNPs with higher saturation magnetization are essential for any magnetic field-assisted applications even with the surface modifier. In this chapter, the progresses on the surface modifications of Fe3O4 for the potential use in the heavy metal ion and radioactive toxin ion removal from water solutions are discussed. The possibility for the development of highly magnetic surface-modified MNPs of Fe–Fe3O4–Prussian blue system as a recoverable adsorbent is proposed.
Magnetic nanoparticles (MNPs) are found interesting for various applications owing to their speci... more Magnetic nanoparticles (MNPs) are found interesting for various applications owing to their specific characteristics that could be enhanced/fine-tuned for the potential applications by an external magnetic field. Moreover, the surface modification of MNPs is advantageous to utilize both the magnetic and surface modifier characteristics. Because of the high-electronic conductivity and high-surface area, carbon-based materials are in high demand as a surface modifier to achieve hybrid MNPs. The carbon-modified MNPs are widely used for electrochemical applications, including supercapacitor, hydrogen evolution reaction, water splitting, and batteries. The presence of an external magnetic field during the preparation of nanomaterials and the electrochemical reactions has a significant influence on the magnetic and electrochemical characteristics and performance. Here the ferrites or ferrite-based oxides are MNPs that could modify their properties in the presence of carbon. The magnetic f...
Recent advancements in nanotechnology have pushed the boundary of nanomaterial studies and their ... more Recent advancements in nanotechnology have pushed the boundary of nanomaterial studies and their applications so far that almost each and every aspect of science is looking for their application based on them. The extensive studies and industrial applications have raised demand for nanomaterial in leaps and bounds. To fulfill the demand, new strategies for their synthesis and industrial preparation have been discovered and applied. However, the logarithmic expansion of production of nanomaterials, especially metal and metal oxide nanomaterials, has slowly raised the issue of their toxicity and biocompatibility with respect to ecosystems and human health. Traditional synthesis of nanomaterials by chemical and physical synthesis procedures has been reported to impose higher toxicity on both ecosystems and human health. There are regular quests for new methods to discover biocompatible nanomaterials. In view of the above facts, green synthesis of nanomaterials, using biological agents, has been shown to be a solution to this issue. However, to address this issue, discussion about their detailed biological effects is urgently needed. To illuminate these concerns, this chapter provides a brief review of the current strategies for green synthesis of nanomaterials, especially focusing on metal and metal oxide nanoparticles and their detail mechanisms of biological effects in view of their antibacterial efficacy and cytotoxicity.
Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) (2018) 19096-1 2017/10581-1 Comisio... more Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) (2018) 19096-1 2017/10581-1 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 3160170 National Council for Scientific and Technological Development (CNPq) 310230/2017-9 Fundacao de Amparo a Pesquisa do Estado de Goias 201710267000511
We have extensively studied the laser-induced Fano scattering, electron–phonon coupling, bond len... more We have extensively studied the laser-induced Fano scattering, electron–phonon coupling, bond length and phonon lifetime of the α-Fe2O3 nanostructure prepared through a simple co-precipitation method.
Equiatomic FeCo alloy was synthesized through polyol process and size reduction was attempted usi... more Equiatomic FeCo alloy was synthesized through polyol process and size reduction was attempted using heterogeneous nucleating agents such as Cu and Pt. The average particle size of FeCo reduced from 138 to 17 nm using 5 × 10 −6 M of Pt whereas significant size reduction could not be achieved with Cu up to 1 × 10 −5 M. The as-prepared FeCo and the particles prepared using Cu as nucleating agent revealed a flower-like morphology whereas the shape crumbled with Pt nuclei. All the FeCo nanoparticles exhibited exchange bias effect due to the oxide layer present as a shell. The exchange bias field and coercivity at 15 K were 185 Oe and 1016 Oe, respectively, for the particles synthesized using Pt as a nucleating agent.
Journal of Materials Science: Materials in Electronics
Cu doped ZnO nanoparticles abbreviated as Zn1−xCuxO (x = 0, 0.01 and 0.03) were synthesized by me... more Cu doped ZnO nanoparticles abbreviated as Zn1−xCuxO (x = 0, 0.01 and 0.03) were synthesized by mechanical alloying. The change in structure, morphology, band gap and dielectric properties of the synthesized nanoparticles were investigated by XRD, FE-SEM, FTIR, UV–Vis and impedance analyzer respectively. The incorporation of the dopant Cu into ZnO hexagonal wurtzite structure has been verified by X-ray diffraction (XRD) and the Cu doping on the structural bonding of ZnO has been verified by fourier transformation infrared spectra (FTIR).The XRD spectra shows that all the synthesized nanoparticles are single phase, hexagonal wurtzite structure and belong to the space group of P63mc.Crystallite size of Cu doped ZnO (15 nm) nanoparticles is smaller than pure ZnO (18 nm) and peak broadening exists in the system. FE-SEM analysis indicates that Cu doping affects the surface morphology of ZnO. The band gap (Eg) of ZnO decreases with Cu doping which can be attributed to sp-d exchange interaction between the ZnO band electrons and localized d electrons of Cu2+ ions. The dielectric constant of ZnO decreases with Cu doping.
Toxicological impact of TiO2 nanoparticles synthesized by HEBM on embryonic zebrafish at molecula... more Toxicological impact of TiO2 nanoparticles synthesized by HEBM on embryonic zebrafish at molecular level.
Mucoadhesive type ocular film has been prepared for studying the anti-inflammatory potential of a... more Mucoadhesive type ocular film has been prepared for studying the anti-inflammatory potential of amlodipine (AML) on carrageenan-induced rabbit model and the effect of sulphobutyl-ether-beta-cyclodextrin on corneal permeation was tested. Hydroxypropyl methylcellulose (HPMC) ocular film was prepared after complexation of amlodipine with β-cyclodextrin, (BCD), hydroxypropyl β-cyclodextrin (HPCD), and sulfobutylether β-cyclodextrin (SBCD). The film without cyclodextrin showed a maximum swelling, and erosion to the highest extent. Both drug release and permeation were highly diffusion controlled and highest improvement was observed with SBCD due to increased dissolution, compared to other formulations with or without cyclodextrin. Highest binding energy and highest extent of amorphization were noticed in the SBCD film formulation. Improved amlodipine release in-vitro and ocular permeation were found by the HPMC film formulation after complexation of the drug with cyclodextrins wherein SBCD exhibited both to the highest extent. Binary and ternary systems molecular docking studies confirmed the lowest energy of binding between amlodipine and BCD compared to HBCD and SBCD. Signs of acute inflammation were mitigated within 2 h of film application in the cul-de-sac. Presence of sulphobutyl-ether β-cyclodextrin in the amlodipine-HPMC film can improve ocular permeation significantly and could be utilized as mucoadhesive type formulation for anti-inflammatory activity.
Abstract LaMnO3 perovskite oxide has got tremendous attraction in electrochemical field owing to ... more Abstract LaMnO3 perovskite oxide has got tremendous attraction in electrochemical field owing to their favourable physical and chemical properties. However, aggregated and distorted morphology of regular perovskites that are prepared at higher temperatures (>500 °C) led to lesser active sites provided to enable the electrochemical reaction. Here we propose a green synthetic approach to overcome these deficiencies and to obtain better electrochemical performance. 3D polyhedron structured LaMnO3 nanoparticles are synthesized using natural lemon juice (LJ) as a green surfactant. The aggregation of these particles is removed and a well separated individual particle has been formed. This well defined polyhedron structured LMO nanoparticle possessed a 3 fold enhancement in its specific capacitance. A symmetric two electrode cell system has also been fabricated to investigate the real life application of LMO as a supercapacitor. The electrode in this symmetric cell configuration could deliver a maximum energy density of 52.5 Wh kg−1 at a power density of 1000 W kg−1. This is an outstanding result among aqueous electrolyte symmetric supercapacitors. Moreover, the room temperature fluctuation effect on the specific capacitance of LMO cell has also been investigated. This LJ assisted synthesize of LMO perovskite presented here enlighten a simple paradigm for fabricating high energy electrochemical storage devices.
Amorphous MoSx thin-film-coated carbon fiber paper as a binder-free 3D electrode was synthesized ... more Amorphous MoSx thin-film-coated carbon fiber paper as a binder-free 3D electrode was synthesized by a facile hydrothermal method. The maximum specific capacitance of a single electrode was 83.9 mF cm(-2), while it was 41.9 mF cm(-2) for the symmetric device. Up to 600% capacitance retention was observed for 4750 cycles.
Abstract Nd substituted Y 3 Fe 5 O 12 (YIG) was synthesized using sol–gel auto-combustion method.... more Abstract Nd substituted Y 3 Fe 5 O 12 (YIG) was synthesized using sol–gel auto-combustion method. The phases present in the samples were identified using XRD. The asprepared dried gel was found to transform to the rare earth iron garnet phase at lower temperature when the Nd concentration is lower. Higher concentration of Nd resulted in the formation of orthoferrite as the major phase. The Curie temperature was recorded using thermomagnetic analysis and it was found to increase with the concentration of Nd. The crystallization kinetics of the Nd-substituted garnet phase was studied using TG–DTA. Two stage crystallization was observed from the DTA analysis for Nd 1 Y 2 Fe 5 O 12 . The activation energy for the formation of Nd 1 Y 2 Fe 5 O 12 was 610 kJ/mol, found by using Johnson–Mehl–Avrami (JMA) equation. Three dimensional growth mechanism dominate at lower heating rates for the Nd-substituted YIG.
Magnetic materials have received much attention due to their use in various applications such as ... more Magnetic materials have received much attention due to their use in various applications such as biomedical, waste water treatment, photocatalytic, and electrocatalytic applications. Among the magnetic materials, Fe3O4 magnetic nanoparticles (MNPs) are the finest choice, due to their easy preparation process and flexible magnetic characteristics with adjustable morphology and size. Surface modifications of Fe3O4 MNPs with suitable surface modifier are necessary to utilize the hybrid materials for any specific required applications. The selection of surface modifier is important, as it is having a major role for the specific applications. The MNPs with higher saturation magnetization are essential for any magnetic field-assisted applications even with the surface modifier. In this chapter, the progresses on the surface modifications of Fe3O4 for the potential use in the heavy metal ion and radioactive toxin ion removal from water solutions are discussed. The possibility for the development of highly magnetic surface-modified MNPs of Fe–Fe3O4–Prussian blue system as a recoverable adsorbent is proposed.
Magnetic nanoparticles (MNPs) are found interesting for various applications owing to their speci... more Magnetic nanoparticles (MNPs) are found interesting for various applications owing to their specific characteristics that could be enhanced/fine-tuned for the potential applications by an external magnetic field. Moreover, the surface modification of MNPs is advantageous to utilize both the magnetic and surface modifier characteristics. Because of the high-electronic conductivity and high-surface area, carbon-based materials are in high demand as a surface modifier to achieve hybrid MNPs. The carbon-modified MNPs are widely used for electrochemical applications, including supercapacitor, hydrogen evolution reaction, water splitting, and batteries. The presence of an external magnetic field during the preparation of nanomaterials and the electrochemical reactions has a significant influence on the magnetic and electrochemical characteristics and performance. Here the ferrites or ferrite-based oxides are MNPs that could modify their properties in the presence of carbon. The magnetic f...
Recent advancements in nanotechnology have pushed the boundary of nanomaterial studies and their ... more Recent advancements in nanotechnology have pushed the boundary of nanomaterial studies and their applications so far that almost each and every aspect of science is looking for their application based on them. The extensive studies and industrial applications have raised demand for nanomaterial in leaps and bounds. To fulfill the demand, new strategies for their synthesis and industrial preparation have been discovered and applied. However, the logarithmic expansion of production of nanomaterials, especially metal and metal oxide nanomaterials, has slowly raised the issue of their toxicity and biocompatibility with respect to ecosystems and human health. Traditional synthesis of nanomaterials by chemical and physical synthesis procedures has been reported to impose higher toxicity on both ecosystems and human health. There are regular quests for new methods to discover biocompatible nanomaterials. In view of the above facts, green synthesis of nanomaterials, using biological agents, has been shown to be a solution to this issue. However, to address this issue, discussion about their detailed biological effects is urgently needed. To illuminate these concerns, this chapter provides a brief review of the current strategies for green synthesis of nanomaterials, especially focusing on metal and metal oxide nanoparticles and their detail mechanisms of biological effects in view of their antibacterial efficacy and cytotoxicity.
Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) (2018) 19096-1 2017/10581-1 Comisio... more Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) (2018) 19096-1 2017/10581-1 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 3160170 National Council for Scientific and Technological Development (CNPq) 310230/2017-9 Fundacao de Amparo a Pesquisa do Estado de Goias 201710267000511
We have extensively studied the laser-induced Fano scattering, electron–phonon coupling, bond len... more We have extensively studied the laser-induced Fano scattering, electron–phonon coupling, bond length and phonon lifetime of the α-Fe2O3 nanostructure prepared through a simple co-precipitation method.
Equiatomic FeCo alloy was synthesized through polyol process and size reduction was attempted usi... more Equiatomic FeCo alloy was synthesized through polyol process and size reduction was attempted using heterogeneous nucleating agents such as Cu and Pt. The average particle size of FeCo reduced from 138 to 17 nm using 5 × 10 −6 M of Pt whereas significant size reduction could not be achieved with Cu up to 1 × 10 −5 M. The as-prepared FeCo and the particles prepared using Cu as nucleating agent revealed a flower-like morphology whereas the shape crumbled with Pt nuclei. All the FeCo nanoparticles exhibited exchange bias effect due to the oxide layer present as a shell. The exchange bias field and coercivity at 15 K were 185 Oe and 1016 Oe, respectively, for the particles synthesized using Pt as a nucleating agent.
Journal of Materials Science: Materials in Electronics
Cu doped ZnO nanoparticles abbreviated as Zn1−xCuxO (x = 0, 0.01 and 0.03) were synthesized by me... more Cu doped ZnO nanoparticles abbreviated as Zn1−xCuxO (x = 0, 0.01 and 0.03) were synthesized by mechanical alloying. The change in structure, morphology, band gap and dielectric properties of the synthesized nanoparticles were investigated by XRD, FE-SEM, FTIR, UV–Vis and impedance analyzer respectively. The incorporation of the dopant Cu into ZnO hexagonal wurtzite structure has been verified by X-ray diffraction (XRD) and the Cu doping on the structural bonding of ZnO has been verified by fourier transformation infrared spectra (FTIR).The XRD spectra shows that all the synthesized nanoparticles are single phase, hexagonal wurtzite structure and belong to the space group of P63mc.Crystallite size of Cu doped ZnO (15 nm) nanoparticles is smaller than pure ZnO (18 nm) and peak broadening exists in the system. FE-SEM analysis indicates that Cu doping affects the surface morphology of ZnO. The band gap (Eg) of ZnO decreases with Cu doping which can be attributed to sp-d exchange interaction between the ZnO band electrons and localized d electrons of Cu2+ ions. The dielectric constant of ZnO decreases with Cu doping.
Toxicological impact of TiO2 nanoparticles synthesized by HEBM on embryonic zebrafish at molecula... more Toxicological impact of TiO2 nanoparticles synthesized by HEBM on embryonic zebrafish at molecular level.
Mucoadhesive type ocular film has been prepared for studying the anti-inflammatory potential of a... more Mucoadhesive type ocular film has been prepared for studying the anti-inflammatory potential of amlodipine (AML) on carrageenan-induced rabbit model and the effect of sulphobutyl-ether-beta-cyclodextrin on corneal permeation was tested. Hydroxypropyl methylcellulose (HPMC) ocular film was prepared after complexation of amlodipine with β-cyclodextrin, (BCD), hydroxypropyl β-cyclodextrin (HPCD), and sulfobutylether β-cyclodextrin (SBCD). The film without cyclodextrin showed a maximum swelling, and erosion to the highest extent. Both drug release and permeation were highly diffusion controlled and highest improvement was observed with SBCD due to increased dissolution, compared to other formulations with or without cyclodextrin. Highest binding energy and highest extent of amorphization were noticed in the SBCD film formulation. Improved amlodipine release in-vitro and ocular permeation were found by the HPMC film formulation after complexation of the drug with cyclodextrins wherein SBCD exhibited both to the highest extent. Binary and ternary systems molecular docking studies confirmed the lowest energy of binding between amlodipine and BCD compared to HBCD and SBCD. Signs of acute inflammation were mitigated within 2 h of film application in the cul-de-sac. Presence of sulphobutyl-ether β-cyclodextrin in the amlodipine-HPMC film can improve ocular permeation significantly and could be utilized as mucoadhesive type formulation for anti-inflammatory activity.
Abstract LaMnO3 perovskite oxide has got tremendous attraction in electrochemical field owing to ... more Abstract LaMnO3 perovskite oxide has got tremendous attraction in electrochemical field owing to their favourable physical and chemical properties. However, aggregated and distorted morphology of regular perovskites that are prepared at higher temperatures (>500 °C) led to lesser active sites provided to enable the electrochemical reaction. Here we propose a green synthetic approach to overcome these deficiencies and to obtain better electrochemical performance. 3D polyhedron structured LaMnO3 nanoparticles are synthesized using natural lemon juice (LJ) as a green surfactant. The aggregation of these particles is removed and a well separated individual particle has been formed. This well defined polyhedron structured LMO nanoparticle possessed a 3 fold enhancement in its specific capacitance. A symmetric two electrode cell system has also been fabricated to investigate the real life application of LMO as a supercapacitor. The electrode in this symmetric cell configuration could deliver a maximum energy density of 52.5 Wh kg−1 at a power density of 1000 W kg−1. This is an outstanding result among aqueous electrolyte symmetric supercapacitors. Moreover, the room temperature fluctuation effect on the specific capacitance of LMO cell has also been investigated. This LJ assisted synthesize of LMO perovskite presented here enlighten a simple paradigm for fabricating high energy electrochemical storage devices.
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Papers by Arun Thirumurugan