Phone: +82-10-4626-8298 Address: Photonics and Electronics Thin-film Lab Room No. 6-210, Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-dong, Buk-gu, Gwangju, South Korea 500-757.
Abstract Fe3O4 magnetic nanoparticles (MNPs) were prepared using the modified green synthesis met... more Abstract Fe3O4 magnetic nanoparticles (MNPs) were prepared using the modified green synthesis method and the effects of reaction time on the structural and magnetic properties of MNPs were evaluated. For the synthesis of MNPs, green tea extract and ethylene glycol were used as a reducing agent and solvent, respectively. The MNPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), thermogravimetric analysis and vibrating sample magnetometer. It was observed that the reaction time strongly influenced the magnetic and structural properties. With increasing reaction time, the crystallite size was found to be increased from 7.5 to 12 nm along with improvement in saturation magnetization (MS). The magnetic measurement study revealed that MNPs were superparamagnetic at room temperature, while at 60 K they have ferromagnetic as well as superparamagnetic contributions. The effect of an increase in particle size with reaction time was also reflected with an increase in blocking temperature, which is consistent with the Stoner–Wohlfarth theory.
Direct functionalization strategy has been employed to modify the surface of the magnetic hollow ... more Direct functionalization strategy has been employed to modify the surface of the magnetic hollow spheres (MHS) with (3-aminopropyl)triethoxysilane (APTES) for controlled drug release. The MHS were prepared by the solvothermal method and characterized by X-ray diffraction, field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy, and vibrating sample magnetometer. The FE-SEM study shows that MHS have a size of ~200 nm and are made up of smaller nanoparticles (NPs) having average size of ~20–25 nm. MHS exhibits a superparamagnetic behavior with a saturation magnetization of 74 emu/g at room temperature. The direct functionalization of MHS with APTES provided an efficient loading of model anti-cancer drug Camptothecin (CPT). The drug release study performed at pH of 7.4 showed 30% of CPT release in a controlled way after 4 h.
The facile green synthesis method has been employed for the synthesis of biocompatible Fe3O4 magn... more The facile green synthesis method has been employed for the synthesis of biocompatible Fe3O4 magnetic nanoparticles (MNPs) using green tea extract. The effective reduction of ferric ions (Fe3+) were done using an aqueous green tea extract where it acts as reducing as well as capping agent. The effect of iron precursor to green tea extract ratio and reaction temperature was studied. The MNPs were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, dynamic light scattering and vibrating sample magnetometer. It was observed that the reaction temperature strongly affects the magnetic and structural properties of MNPs. The magnetic measurements study showed that Fe3O4 MNPs are superparamagnetic at 300 K, while at 60 K have ferromagnetic as well as superparamagnetic contributions.
The objective of this work is twofold: (1) to improve the electrochemical performance of reduced ... more The objective of this work is twofold: (1) to improve the electrochemical performance of reduced graphene oxide (RGO) by decorating RGO sheets with magnetic nanoparticles (MNPs) and (2) to evaluate the electrochemical performance of RGO and MNP-decorated RGO (MRGO) in various aqueous electrolyte solutions (phosphate buffer solution (PBS) containing ferricyanide, PBS containing ferricyanide and KCl, Na2SO4, and KOH). The morphological and structural characteristics of solvothermal synthesized RGO and MRGO revealed the decoration of phase pure Fe3O4 nanoparticles on RGO sheets. In FC-PBS-KCl electrolyte solution, MRGO showed higher redox peak current (83.89 μA) and lower peak potential separation (0.11 V) at 50 mV s−1 scan rate compared with that in FC-PBS electrolyte solution. MRGO showed 15.5% higher peak current than that for the RGO in FC-PBS-KCl electrolyte solution. Moreover, the peak current for MRGO in FC-PBS-KCl was increased by 30% when compared with that in FC-PBS electroly...
Processing in Memory (PIM) is a computing paradigm that promises enormous gain in processing spee... more Processing in Memory (PIM) is a computing paradigm that promises enormous gain in processing speed by eradicating latencies in the typical von Neumann architecture. It has gained popularity owing to its throughput by embedding storage and computation of data in a single unit. We portray implementation of Akers array architecture endowed with PIM computation using Quantum-dot Cellular Automata (QCA). We present the proof of concept of PIM with its realization in the QCA designer paradigm. We illustrate implementation of Ex-OR gate with the help of QCA based Akers Array and put forth many interesting potential possibilities.
A NiCo-LDH nanowire electrode synthesized via a hydrothermal method presented excellent catalytic... more A NiCo-LDH nanowire electrode synthesized via a hydrothermal method presented excellent catalytic activity for both the OER and MOR, proving it to be an outstanding bifunctional electrocatalyst for energy conversion devices.
Abstract Fe3O4 magnetic nanoparticles (MNPs) were prepared using the modified green synthesis met... more Abstract Fe3O4 magnetic nanoparticles (MNPs) were prepared using the modified green synthesis method and the effects of reaction time on the structural and magnetic properties of MNPs were evaluated. For the synthesis of MNPs, green tea extract and ethylene glycol were used as a reducing agent and solvent, respectively. The MNPs were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), thermogravimetric analysis and vibrating sample magnetometer. It was observed that the reaction time strongly influenced the magnetic and structural properties. With increasing reaction time, the crystallite size was found to be increased from 7.5 to 12 nm along with improvement in saturation magnetization (MS). The magnetic measurement study revealed that MNPs were superparamagnetic at room temperature, while at 60 K they have ferromagnetic as well as superparamagnetic contributions. The effect of an increase in particle size with reaction time was also reflected with an increase in blocking temperature, which is consistent with the Stoner–Wohlfarth theory.
Direct functionalization strategy has been employed to modify the surface of the magnetic hollow ... more Direct functionalization strategy has been employed to modify the surface of the magnetic hollow spheres (MHS) with (3-aminopropyl)triethoxysilane (APTES) for controlled drug release. The MHS were prepared by the solvothermal method and characterized by X-ray diffraction, field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy, and vibrating sample magnetometer. The FE-SEM study shows that MHS have a size of ~200 nm and are made up of smaller nanoparticles (NPs) having average size of ~20–25 nm. MHS exhibits a superparamagnetic behavior with a saturation magnetization of 74 emu/g at room temperature. The direct functionalization of MHS with APTES provided an efficient loading of model anti-cancer drug Camptothecin (CPT). The drug release study performed at pH of 7.4 showed 30% of CPT release in a controlled way after 4 h.
The facile green synthesis method has been employed for the synthesis of biocompatible Fe3O4 magn... more The facile green synthesis method has been employed for the synthesis of biocompatible Fe3O4 magnetic nanoparticles (MNPs) using green tea extract. The effective reduction of ferric ions (Fe3+) were done using an aqueous green tea extract where it acts as reducing as well as capping agent. The effect of iron precursor to green tea extract ratio and reaction temperature was studied. The MNPs were characterized by x-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, dynamic light scattering and vibrating sample magnetometer. It was observed that the reaction temperature strongly affects the magnetic and structural properties of MNPs. The magnetic measurements study showed that Fe3O4 MNPs are superparamagnetic at 300 K, while at 60 K have ferromagnetic as well as superparamagnetic contributions.
The objective of this work is twofold: (1) to improve the electrochemical performance of reduced ... more The objective of this work is twofold: (1) to improve the electrochemical performance of reduced graphene oxide (RGO) by decorating RGO sheets with magnetic nanoparticles (MNPs) and (2) to evaluate the electrochemical performance of RGO and MNP-decorated RGO (MRGO) in various aqueous electrolyte solutions (phosphate buffer solution (PBS) containing ferricyanide, PBS containing ferricyanide and KCl, Na2SO4, and KOH). The morphological and structural characteristics of solvothermal synthesized RGO and MRGO revealed the decoration of phase pure Fe3O4 nanoparticles on RGO sheets. In FC-PBS-KCl electrolyte solution, MRGO showed higher redox peak current (83.89 μA) and lower peak potential separation (0.11 V) at 50 mV s−1 scan rate compared with that in FC-PBS electrolyte solution. MRGO showed 15.5% higher peak current than that for the RGO in FC-PBS-KCl electrolyte solution. Moreover, the peak current for MRGO in FC-PBS-KCl was increased by 30% when compared with that in FC-PBS electroly...
Processing in Memory (PIM) is a computing paradigm that promises enormous gain in processing spee... more Processing in Memory (PIM) is a computing paradigm that promises enormous gain in processing speed by eradicating latencies in the typical von Neumann architecture. It has gained popularity owing to its throughput by embedding storage and computation of data in a single unit. We portray implementation of Akers array architecture endowed with PIM computation using Quantum-dot Cellular Automata (QCA). We present the proof of concept of PIM with its realization in the QCA designer paradigm. We illustrate implementation of Ex-OR gate with the help of QCA based Akers Array and put forth many interesting potential possibilities.
A NiCo-LDH nanowire electrode synthesized via a hydrothermal method presented excellent catalytic... more A NiCo-LDH nanowire electrode synthesized via a hydrothermal method presented excellent catalytic activity for both the OER and MOR, proving it to be an outstanding bifunctional electrocatalyst for energy conversion devices.
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Papers by Vijay Karade