Browsing by Author "Banerjee, I."

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Axial distribution of plasma fluctuations, plasma parameters, deposition rate and grain size during copper deposition
(Taylor and Francis Inc., 2017) Gopikishan, S.; Banerjee, I.; Pathak, Anand; Mahapatra, S. K.
Floating potential fluctuations, plasma parameters and deposition rate have been investigated as a function of axial distance during deposition of copper in direct current (DC) magnetron sputtering system. Fluctuations were analyzed using phase space, power spectra and amplitude bifurcation plots. It has been observed that the fluctuations are modified from chaotic to ordered state with increase in the axial distance from cathode. Plasma parameters such as electron density (ne), electron temperature (Te) and deposition rate (Dr) were measured and correlated with plasma fluctuations. It was found that more the deposition rate, greater the grain size, higher the electron density, higher the electron temperature and more chaotic the oscillations near the cathode. This observation could be helpful to the thin film technology industry to optimize the required film. ? 2017 Informa UK Limited, trading as Taylor & Francis Group.
Carbon nanotubes for rapid capturing of SARS-COV-2 virus: revealing a mechanistic aspect of binding based on computational studies
(Royal Society of Chemistry, 2021-02-02T00:00:00) Patel, Shivkumar; Srivastav, Amit Kumar; Gupta, Sanjeev K.; Kumar, Umesh; Mahapatra, S.K.; Gajjar, P.N.; Banerjee, I.
We investigate the binding interactions of synthesized multi-walled carbon nanotubes (MWCNTs) with SARS-CoV-2 virus. Two essential components of the SARS-CoV-2 structurei.e(spike receptor-binding domain complexed with its receptor ACE2) were used for computational studies. MWCNTs of different morphologies (zigzag, armchair and chiral) were synthesized through a thermal chemical vapour deposition process as a function of pyrolysis temperature. A direct correlation between radius to volume ratio of the synthesized MWCNTs and the binding energies for all three (zigzag, armchair and chiral) conformations were observed in our computational studies. Our result suggests that MWCNTs interact with the active sites of the main protease along with the host angiotensin-converting enzyme2 (ACE2) receptors. Furthermore, it is also observed that MWCNTs have significant binding affinities towards SARS-CoV-2. However, the highest free binding energy of ?87.09 kcal mol?1with were shown by the armchair MWCNTs with SARS-CoV-2 through the simulated molecular dynamic trajectories, which could alter the SARS-CoV-2 structure with higher accuracy. The radial distribution function also confirms the density variation as a function of distance from a reference particle of MWCNTs for the study of interparticle interactions of the MWCNT and SARS-CoV-2. Due to these interesting attributes, such MWCNTs could find potential application in personal protective equipment (PPE) and diagnostic kits. � The Royal Society of Chemistry 2021.
Design and development of a compact ion implanter and plasma diagnosis facility based on a 2.45 GHz microwave ion source
(American Institute of Physics Inc., 2021-05-25T00:00:00) Swaroop, Ram; Kumar, Narender; Rodrigues, G.; Kanjilal, D.; Banerjee, I.; Mahapatra, S.K.
A project on developing a 2.45 GHz microwave ion source based compact ion implanter and plasma diagnostic facility has been taken up by the Central University of Punjab, Bathinda. It consists of a double-wall ECR plasma cavity, a four-step ridge waveguide, an extraction system, and an experimental beam chamber. The mechanical design has been carried out in such a way that both types of experiments, plasma diagnosis and ion implantation, can be easily accommodated simultaneously and separately. To optimize microwave coupling to the ECR plasma cavity, a four-step ridge waveguide is designed. Microwave coupling simulation for the ECR plasma cavity has been performed at different power inputs using COMSOL Multiphysics. An enhanced electric field profile has been obtained at the center of the ECR plasma cavity with the help of a four-step ridge waveguide compared to the WR284 waveguide. The magnetic field distribution for two magnetic rings and the extraction system's focusing properties have been simulated using the computer simulation technique. A tunable axial magnetic field profile has been obtained with a two permanent magnetic ring arrangement. The dependency of the beam emittance and beam current on accelerating voltages up to 50 kV has been simulated with different ions. It shows that ion masses have a great impact on the beam emittance and output current. This facility has provision for in situ plasma diagnosis using a Langmuir probe and optical emission spectroscopy setups. This system will be used for ion implantation, surface patterning, and studies of basic plasma sciences. � 2021 Author(s).
Effect of plasma power on reduction of printable graphene oxide thin films on flexible substrates
(Institute of Physics Publishing, 2018) Banerjee, I.; Mahapatra, S.K.; Pal, C.; Sharma, A.K.; Ray, A.K.
Room temperature hydrogen plasma treatment on solution processed 300 nm graphene oxide (GO) films on flexible indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates has been performed by varying the plasma power between 20 W and 60 W at a constant exposure time of 30 min with a view to examining the effect of plasma power on reduction of GO. X-ray powder diffraction (XRD) and Raman spectroscopic studies show that high energy hydrogen species generated in the plasma assist fast exfoliation of the oxygenated functional groups present in the GO samples. Significant decrease in the optical band gap is observed from 4.1 eV for untreated samples to 0.5 eV for 60 W plasma treated samples. The conductivity of the films treated with 60 W plasma power is estimated to be six orders of magnitude greater than untreated GO films and this enhancement of conductivity on plasma reduction has been interpreted in terms of UV-visible absorption spectra and density functional based first principle computational calculations. Plasma reduction of GO/ITO/PET structures can be used for efficiently tuning the electrical and optical properties of reduced graphene oxide (rGO) for flexible electronics applications. ? 2018 IOP Publishing Ltd.
Effect of TiO2 and Fe doped TiO2 nanoparticles on mitochondrial membrane potential in HBL-100 cells
(American Institute of Physics, 2019) Barkhade, T; Mishra, S; Chander, Harish; Mahapatra, S.K; Banerjee, I.
Titanium dioxide (TiO2) nanoparticles (NPs) have made unbelievable progress in the field of nanotechnology and biomedical research. The proper toxicological assessment of TiO2 NPs and the reduction of its cytotoxicity need to be addressed. Fe doping in TiO2 has been investigated to reduce the toxic effects of TiO2 NPs. Fe doped TiO2 powder samples were synthesized by sol-gel methods. The prepared samples were characterized by x-ray diffractometer (XRD), transmission electron microscope (TEM), and Raman spectroscopy to study their structure, morphology, and molecular conformation. XRD results revealed the coexistence of anatase (A) and rutile (R) phases of TiO2. The A-R transformation was observed with an increase in Fe doping along with the formation of α-Fe2O3 phase. TEM showed changes in morphology from spherical nanoparticles to elongated rod-shaped nanostructures with increasing Fe content. Shape variation of TiO2 nanoparticles after incorporation of Fe is a key reason behind the toxicity reduction. The authors observed that the toxicity of TiO2 nanoparticles was rescued upon Fe incorporation. The effect of NPs on the mitochondrial membrane potential (MMP) was assessed using flow cytometry. The MMP (%) decreased in TiO2 treated cells and increased by 1% Fe doped TiO2 NPs treated cells. Confocal imaging revealed the presence of functional mitochondria upon the exposure of Fe doped TiO2 NPs. The goal of the present study was to decrease the toxic effects induced by TiO2 NPs on mitochondrial potential and its prevention by Fe doping. © 2019 Author(s).
Engineering of gadolinium-decorated graphene oxide nanosheets for multimodal bioimaging and drug delivery
(American Chemical Society, 2019) Chawda, N; Basu, M; Majumdar, D; Poddar, R; Mahapatra, S.K; Banerjee, I.
Engineering of water-dispersible Gd3+ ions-decorated reduced graphene oxide (Gd-rGO) nanosheets (NSs) has been performed. The multifunctional capability of the sample was studied as a novel contrast agent for swept source optical coherence tomography and magnetic resonance imaging, and also as an efficient drug-delivery nanovehicle. The synthesized samples were fabricated in a chemically stable condition, and efforts have been put toward improving its biocompatibility by functionalizing with carbohydrates molecules. Gd incorporation in rGO matrix enhanced the fluorouracil (5-FU) drug loading capacity by 34%. The release of the drug was -92% within 72 h. Gd-rGO nanosheets showed significant contrast in comparison to optically responsive bare GO for swept source optical coherence tomography. The longitudinal relaxivity rate (r1) of 16.85 mM-1 s-1 for Gd-rGO was recorded, which was 4 times larger than that of the commercially used clinical contrast agent Magnevist (4 mM-1 s-1) at a magnetic field strength of 1.5 T. © 2019 American Chemical Society.
Enhanced capacitive behaviour of graphene nanoplatelets embedded epoxy nanocomposite
(Springer, 2021-01-06T00:00:00) Raval, Bhargav; Sahare, P.D.; Mahapatra, S.K.; Banerjee, I.
For the development of advanced polymer nanocomposite processability, high-quality and cost-efficiency plays a crucial role which combines mechanical robustness with functional electrochemical properties. In this study, we fabricated the epoxy/graphene nanocomposite (EGNC) with different wt% ratio of graphene nanoplatelets (GNPs). The EGNCs were fabricated through a solution mixing process and used it as an electrode to enhance electrochemical properties. The GNPs and EGNCs characterized using XRD, Raman spectroscopy, ATR FT-IR, and FE-SEM for the structural conformation and surface morphological study. The electrochemical analysis results show significant improvement in the specific capacitance in the EGNC samples as compared to the blank epoxy film. Specific capacitance 17.74 Fg?1 was recorded at 10 mVs?1 scan rate in 1.0�M KOH electrolyte solution for the 1.0 wt% EGNC film by cyclic voltammetry analysis. The Galvanostatic charge�discharge and Ragone plots also show mended results by the addition of GNPs. � 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.
Flexible zinc oxide photoelectrode for photo electrochemical energy conversion
(Springer, 2021-05-18T00:00:00) Shiyani, T.; Banerjee, I.; Mahapatra, Santosh K.; Ray, Asim K.
Photoelectrochemical properties have been investigated for flexible photoelectrodes containing 310�nm thick ZnO film on spin-coated ITO/PET. The high crystalline structure of ZnO was studied using x-ray diffraction pattern. A value of 3.4�eV has been estimated for optical band gap from its absorption spectra. The flexible ZnO photoelectrode was demonstrated to generate photoelectrochemical current. The photocurrents are enhanced by 4% whereas flat-band potential is shifted by 8�V due to the illumination. Values of 1.022 and 0.714 AW?1 were found to be for photo switching and photoresponsivity, respectively. ZnO/ITO/PET can be used as a substrate for making flexible hybrid PEC devices to generate solar power and solar fuels. � 2021, This is a U.S. government work and not under copyright protection in the U.S.; foreign copyright protection may apply.
Irradiation effects of 6 mev-electrons on optical and electrical properties of TiO2/Al2o3 multilayer thin films
(Bellwether Publishing, Ltd., 2020-08-28T00:00:00) Laha, P.; Mahapatra, S.K.; Banerjee, I.; Bhoraskar, V.N.
We report the irradiation effects on rf reactive magnetron sputter deposited TiO2/Al2O3 hetero-structured thin films. These films are irradiated with 6 MeV electron beams by maintaining the dose rate at ?1 kGy/min at three different doses 10, 20, and 30 kGy. Optical properties of the irradiated films are studied by XRD, AFM, UV Visible spectroscopy and PL spectroscopy and electrical properties are measured by Keithley Source meter. Experimental results confirm that the optical and electrical properties of the TiO2/Al2O3 multilayer films are mostly influenced by the electron dose. Optical analysis showed that irradiation modifies the optical band gap. The film properties are mainly governed by the overall clusters� formation in the oxide surface and defects due to electron irradiation. High electron doses cause the recombination of defects which reduces the film resistivity and increases the current. Optical and electrical measurement results show a reasonable qualitative agreement with each other. � 2020 Informa UK Limited, trading as Taylor & Francis Group.
Nano-bio interface study between Fe content TiO2 nanoparticles and adenosine triphosphate biomolecules
(Wiley, 2019) Barkhade, T; Phatangare, A; Dahiwale, S; Mahapatra, S.K; Banerjee, I.
The advent of nano-biotechnology has inspired the interface interaction study between engineered nanoparticles (NPs) and biomolecules. The interaction between Fe content titanium dioxide (TiO2) NPs and adenosine triphosphate (ATP) biomolecules has been envisioned. The effect of Fe content in TiO2 matrix was studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The increase in Fe content caused a decrease in particle size with change in morphology from spherical to one-dimensional rod structure. The Fe incorporation in the TiO2 matrix reduced the transition temperature from anatase to rutile (A-R) phase along with formation of haematite phase of iron oxide at 400°C. The interaction of Fe content TiO2 NPs with ATP molecule has been studied using spectroscopic method of Raman scattering and infrared vibration spectrum along with TEM. Fe content in TiO2 has enhanced the interaction efficiency of the NPs with ATP biomolecules. Raman spectroscopy confirms that the NPs interact strongly with nitrogen (N7) site in the adenine ring of ATP biomolecule. Engineering of Fe content TiO2 NP could successfully tune the coordination between metal oxide NPs with biomolecules, which could help in designing devices for biomedical applications. © 2019 John Wiley & Sons, Ltd.
Natural Basil as Photosensitizer with ZnO Thin Films for Solar Cell Applications
(Taylor and Francis Ltd, 2020) Shiyani, T; Mahapatra, S.K; Banerjee, I.
The hybrid solar cell has been fabricated using natural dye extracted from basil or ocimum leaves and ZnO thin film. The extracted natural dye was deposited on ZnO thin films and dried at room temperature. The semiconductor layer of ZnO was fabricated on FTO-coated glass substrate using magnetron sputtering with a thickness of 500 nm. A photocathode was prepared from the Au�Pd mixture using sputtering for a top electrode. ZnO has been confirmed using X-ray diffraction and UV�visible absorption spectroscopy measurements. The photovoltaic characteristics of the prepared DSSCs were studied by measuring the I�V characteristics under the illumination of halogen light. Photocurrent and photovoltage both are increased in the cell. The value of short-circuit current (Isc), open-circuit voltage (Voc), and photon energy conversion efficiency (?) were calculated for a dye-sensitized solar cell (DSSC). DSSCs provide the promising light to electrical energy conversion efficiency due to their low-cost fabrication, environmentally friendly elements, and low maintenance. DSSC offers transparent solar cell modules with the capabilities of the use of hybrid composition such as organic and inorganic materials. The basil/ZnO-based hybrid devices can also be useful for photoelectrochemical cell and water splitting applications. � 2020, � 2020 IETE.
Nucleation and Growth of Iron (II) Oxide Nanoparticles in Thermal Arc Plasma and Their Interaction Study with SARS-CoV-2: A Computational Approach
(Institute of Electrical and Electronics Engineers Inc., 2021-07-01T00:00:00) Mitra, Rahul; Patel, Shivkumar; Ghorui, S.; Mahapatra, S.K.; Banerjee, I.
A computational model for nucleation and growth of iron (II) oxide nanoparticle (IONP) in thermal plasma has been developed. A nondimensional form of the aerosol general dynamic equations (GDEs) along with a discrete volume sectional model assumption is used to numerically solve the coupled system of GDEs. The variation in supersaturation ratio and the mean particle diameter of IONPs with respect to temperature across the plasma reactor has been presented. The scatter plot showing the distribution of particle number density of certain size across the reactor chamber is shown. In silico molecular docking study was performed to reveal the putative interaction of the IONPs with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus. The results revealed significant binding affinity of IONPs with 6LZG (spike receptor-binding domain complexed with its receptor ACE2) and 5RH4 (main protease) of SARS-COV-2 by forming hydrogen and hydrophobic bonds with nearby amino acid residues. The interactions of IONPs are associated with the conformational changes in the protein which could be used to treat and control SARS-CoV-2 infection. � 1973-2012 IEEE.
Paschen curve approach to investigate electron density and deposition rate of Cu in magnetron sputtering system
(Taylor and Francis Inc., 2016) Gopikishan, S.; Banerjee, I.; Bogle, K.A.; Das, A.K.; Pathak, A.P.; Mahapatra, S.K.
In this work, Paschen curve for argon gas was obtained during copper deposition using a DC magnetron sputtering system. Five process parameters of Paschen curve were used to obtain the electron density and deposition rate of the deposited nanostructured thin films. Plasma parameter such as electron density was correlated with the deposition rate. It is observed that a minimum deposition rate was obtained for the plasma process parameter corresponding to the Paschen minimum. This investigation helps to understand and optimize the quality of nanostructured thin films depending on the process parameters. ? 2016 Informa UK Limited, trading as Taylor & Francis Group.
Plasmonic Solar Cells
(wiley, 2021-08-06T00:00:00) Shiyani, T.; Mahapatra, S.K.; Banerjee, I.
Photovoltaic (PV) cell is a fundamental solar energy conversion device that converts light energy into electric energy. The light absorption and charge recombination are main limiting factors on the efficiency of PV cell or solar cell. A limited efficiency of PV devices makes them less effective in market for clean energy production. Various tactics and methods are demonstrated to enhance the solar cell performance. Metallic nanoparticles have been utilized to fabricate solar cells because of its novel properties such as large surface to volume ratio and surface plasmon resonance (SPR). Plasmonic nanostructures can influence the absorption of light through scattering of surrounding molecules or particles. The plasmonic nanostructures can scatter or concentrate light at subwavelength scale for increasing absorption in active layer and hence enhancing the efficiency of PV devices. Therefore, the plasmonic nanostructures are promising candidates to develop high efficiency solar cells. We discuss about the fundamental mechanisms, ability to scale up the plasmonic with tailored optical properties, solar cell design, and recent advancements in plasmonic solar cells to generate clean energy and solar fuels. � 2021 Scrivener Publishing LLC.
Surface-engineered gadolinium oxide nanorods and nanocuboids for bioimaging
(University of Science and Technology Beijing, 2020) Chawda, N.R; Mahapatra, S.K; Banerjee, I.
Abstract: Folic acid and D-gluconic acid-capped gadolinium oxide nanorods and nanocuboids were synthesized via co-precipitation method. Comparative study of relaxivity factor on the role of capping and morphology for enhancing contrast ability for T1 and T2 magnetic resonance imaging (MRI) was investigated. The obtained r2/r1 ratio for folic acid and D-gluconic acid-capped gadolinium oxide nanorods and nanocuboids was 1.5 and 1.3, respectively. The nanocrystals were characterized and presented with properties such as good dispersity and stability required for standard contrast agent used in MRI. The characterization and the analysis of capping agent for nanocrystals suggest the preferable use of carbohydrate moieties with higher number of hydroxyl functional group reacted with urea and hydrogen peroxide for desired morphology and anisotropic growth. Thermogravimetric�differential thermal analysis (TG�DTA) illustrated the amount of capping, transition temperature from Gd(OH)3 to GdOOH and crystallization temperature from GdOOH to Gd2O3. These nanocrystals would be significant for other biomedical applications such as drug delivery when equipped with well-functionalized drug molecules. Graphic abstract: Synergistic effects and mechanism of urea, hydrogen peroxide and capping agent for growth and morphology. [Figure not available: see fulltext.] � 2020, The Nonferrous Metals Society of China and Springer-Verlag GmbH Germany, part of Springer Nature.
Synthesis of exfoliated multilayer graphene and its putative interactions with SARS-CoV-2 virus investigated through computational studies
(Taylor and Francis Ltd., 2020-09-11T00:00:00) Raval, Bhargav; Srivastav, Amit Kumar; Gupta, Sanjeev K.; Kumar, Umesh; Mahapatra, S.K.; Gajjar, P.N.; Banerjee, I.
Our work investigates the interaction of synthesized graphene with the SARS-CoV-2 virus using molecular docking and molecular dynamics (MD) simulation method. The layer dependent inhibitory effect of graphene nanosheets on spike receptor-binding domain of 6LZG, complexed with host receptor i.e. angiotensin-converting enzyme 2 (ACE2) of SARS-CoV-2 was investigated through computational study. Graphene sample was synthesized using mechanical exfoliation with shear stress and its mechanism of inhibition towards the SARS-CoV-2 virus was explored by molecular docking and molecular dynamics (MD) simulation method. The thermodynamics study for the free binding energy of graphene towards the SARS-CoV-2 virus was analyzed. The binding energy of graphene towards the virus increased with an increasing number of layers. It shows the highest affinity of ?17.5 Kcal/mol in molecular docking while ?Gbinding is in the order of ?28.01 � 0.04 5 Kcal/mol for the seven-layers structure. The increase in carbon layers is associated with an increasing number of edge sp3 �type carbon, providing greater curvature, further increase the surface reactivity responsible for high binding efficiency. The MD simulation data reveals the high inhibition efficiency of the synthesized graphene towards SARS-CoV-2 virus which would help to design future in-vitro studies. The graphene system could find potential applications in personal protective equipment and diagnostic kits. Communicated by Ramaswamy H. Sarma. � 2020 Informa UK Limited, trading as Taylor & Francis Group.
Synthesis of gadolinium oxide nanocuboids for in vitro bioimaging applications
(Institute of Physics Publishing, 2019) Chawda, N; Mishra, S; Basu, M; Chander, H; Podder, R; Mahapatra, S.K; Banerjee, I.
Undoped and Eu-doped gadolinium oxide (GGNCs and EGNCs) nanocuboids functionalized with D-gluconic acid (GA) were synthesised by a simple yet unique scheme using all the benign solvents and temperature. Samples were characterized and presented with properties like good dispersity, biocompatibility, and stability required for standard contrast agent used in magnetic resonance imaging (MRI) and optical coherence tomography (OCT). Biological assays such as 3-(4, 5-dimethyl-2-yl)-2, 5-diphenyltetrazoliumbromide (MTT) assay, flow cytometry and confocal microscopy were used to determine its biocompatibility, cellular internalization and optical cellular imaging using A549 and H1299 lung cancer cell lines. EGNCs treated with cell lines emitted red fluorescence which was used to track the internalization of EGNCs within the cells. GGNCs sample showed ?20% enhanced MRI relaxivity as compared to EGNCs; whereas EGNCs revealed better contrast in doctor scans of OCT. Samples could be used as promising candidate for other biomedical applications such as drug delivery when equipped with well functionalised drug molecules.