9 results on '"Viswas Purohit"'
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2. Temperature-Responsive Polymer Brushes Switching from Bactericidal to Cell-Repellent
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Emilie Fautré, Xavier Laloyaux, Jérôme Leprince, Alain M. Jonas, Karine Glinel, Viswas Purohit, Thomas Blin, Thierry Jouenne, Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Neuroendocrinologie cellulaire et moléculaire, Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Différenciation et communication neuronale et neuroendocrine (DC2N), Polymères, biopolymères, membranes (PBM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Université Catholique de Louvain = Catholic University of Louvain (UCL), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)
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Materials science ,Surface Properties ,Xenopus ,[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,Nanotechnology ,[CHIM.THER]Chemical Sciences/Medicinal Chemistry ,02 engineering and technology ,Xenopus Proteins ,MESH: Ethylene Glycols ,010402 general chemistry ,01 natural sciences ,MESH: Transition Temperature ,Coated Materials, Biocompatible ,MESH: Coated Materials, Biocompatible ,MESH: Anti-Bacterial Agents ,[SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB] ,Animals ,Transition Temperature ,MESH: Animals ,MESH: Xenopus ,General Materials Science ,Thin film ,MESH: Xenopus Proteins ,ComputingMilieux_MISCELLANEOUS ,MESH: Surface Properties ,Bacteria ,Mechanical Engineering ,Transition temperature ,Temperature ,MESH: Antimicrobial Cationic Peptides ,021001 nanoscience & nanotechnology ,MESH: Methacrylates ,MESH: Temperature ,Anti-Bacterial Agents ,0104 chemical sciences ,MESH: Bacteria ,Mechanics of Materials ,[SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology ,Methacrylates ,Surface modification ,Ethylene Glycols ,0210 nano-technology ,Antimicrobial Cationic Peptides ,Temperature-responsive polymer - Abstract
International audience
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- 2010
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3. Synthesis of nanocrystalline diamonds by microwave plasma
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Vasant Sathe, Deepti Jain, Viswas Purohit, Sudha V. Bhoraskar, and V. Ganesan
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Materials science ,Acoustics and Ultrasonics ,Scanning electron microscope ,Nucleation ,Analytical chemistry ,Chemical vapor deposition ,Nanoindentation ,Condensed Matter Physics ,Nanocrystalline material ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,symbols ,Crystallite ,Raman spectroscopy ,Nanodiamond - Abstract
Nanocrystalline diamonds, varying in size from 40 to 400 nm, with random faceting were grown without the help of initial nucleation sites on nickel substrates as seen by scanning electron micrographs. These carbonaceous films were deposited in a microwave plasma reactor using hexane/nitrogen based chemical vapour deposition. The substrate temperatures during deposition were varied from 400 to 600 °C. The morphological investigations obtained by scanning electron micrographs and atomic force microscopy revealed the presence of nanocrystallites with multifaceted structures. Micro Raman investigations were carried out on the deposited films, which conclusively inferred that the growth of nanodiamond crystallites seen in the scanning electron micrographs correlate with clear Raman peaks appearing at 1120 and 1140 cm−1. Nanoindentation analysis with atomic force microscopy has revealed that the carbonaceous deposition identified by the Raman line at ~1140 cm−1, in fact, is related to nanodiamond on account of its hardness which was ~30 GPa. X-ray diffraction data supported this fact.
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- 2007
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4. Challenges in the study of Fe/MgO/Fe interfaces using 3D Atom Probe
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Baishakhi Mazumder, M. Gruber, François Vurpillot, Bernard Deconihout, Viswas Purohit, A. Vella, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC, Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
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[PHYS]Physics [physics] ,Materials science ,Field (physics) ,Metals and Alloys ,Oxide ,Analytical chemistry ,Surfaces and Interfaces ,Atom probe ,Laser ,Evaporation (deposition) ,Fluence ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,Wavelength ,chemistry ,law ,Materials Chemistry ,Mass spectrum ,ComputingMilieux_MISCELLANEOUS - Abstract
Detailed interface studies were conducted on two Fe/MgO/Fe systems having different thicknesses of MgO layers, using a laser assisted 3D atom probe. In conjunction with a detailed 3D reconstruction, the system exhibited an additional oxide formation at the interface between MgO and Fe of the multilayer structure. This oxide formation was found to be independent of the laser wavelength, laser fluence and the thickness of the intermediate layers. By using numerical simulations of field evaporation of two layers having two different evaporation fields, we discuss the possible oxidation mechanisms.
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- 2015
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5. Irradiation effects of 12 eV oxygen ions on polyimide and fluorinated ethylene propylene
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Viswas Purohit, A.B. Mandale, R.M.A. Abdul Majeed, Sudha V. Bhoraskar, and Vasant N. Bhoraskar
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chemistry.chemical_classification ,Nuclear and High Energy Physics ,Radiation ,Plasma ,Polymer ,Condensed Matter Physics ,Photochemistry ,Ion ,chemistry.chemical_compound ,Fluorinated ethylene propylene ,X-ray photoelectron spectroscopy ,chemistry ,General Materials Science ,Irradiation ,Fourier transform infrared spectroscopy ,Polyimide - Abstract
Polyimide (PI) and Fluorinated Ethylene Propylene (FEP) samples (15 mm×15 mm×50 μm ) were exposed to atomic oxygen ions of average energy ∼12 eV and flux ∼5×1013 ions cm −2 s −1, produced in the El...
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- 2006
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6. Evidence of coexistence of micro and nanoporosity of organo-silica polymeric films deposited on silicon by plasma deposition
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Laurent Akesso, Viswas Purohit, Jerzy A. Mielczarski, E. Mielczarski, Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Teer Coatings Ltd, Droitwich WR9 9AS, Worcs, England
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Hexamethyldisiloxane ,Materials science ,Silicon ,Polymers ,Analytical chemistry ,chemistry.chemical_element ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,02 engineering and technology ,01 natural sciences ,chemistry.chemical_compound ,X-ray photoelectron spectroscopy ,0103 physical sciences ,XPS ,General Materials Science ,Fourier transform infrared spectroscopy ,Spectroscopy ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,010302 applied physics ,Argon ,Nanoporous ,technology, industry, and agriculture ,Microporous materials ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Carbon film ,chemistry ,FTIR ,[SDU]Sciences of the Universe [physics] ,[SDE]Environmental Sciences ,Plasma deposition ,0210 nano-technology ,[SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy - Abstract
International audience; A range of hybrid, SiOCH films were deposited on silicon substrates within a radio frequency plasma reactor using hexamethyldisiloxane (HMDSO) as a precursor. The plasma polymerized films were deposited at various HMDSO/argon/oxygen ratios. The composition and structure, at microscopic and nanoscopic levels, of the deposited films were determined by external reflection and transmission Fourier Transform Infrared (FTIR) spectroscopy as well as by X-Ray Photoelectron Spectroscopy (XPS). The content of carbon and oxygen in films were found to be inversely proportional to each other. XPS results showed that the outermost surface of the deposited films are nanoporous and coexist with microporosity which was revealed by electron microscopy. The structure of deposited coatings is anisotropic as was documented by polarized external reflection FTIR spectroscopy. Several correlations between the film chemical composition, surface structure, and macroscopic properties of the films such as: hydrophobicity and hydrophilicity were established.
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- 2013
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7. Eco-friendly Synthesis, Characterization of Poly(N-Ethyl Aniline)-ZnO nanocomposite and its Application as Alcohol Gas Sensor
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Rathod, Vikas D, Vasant V Chabukswar, Bhavsar, Sanjay, Horne, Amit, Vijaysinha S Patil, Hondore, Kalpana, Shisodia, Suresh U, Kumar, Vineet, Nishigandh S Pande, Viswas Purohit, and Dipika Kaur
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- 2013
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8. Characterization and modeling of hot carrier injection in LDMOS for L-band radar application
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Jean Pierre Sipma, Karine Mourgues, Loïc Lachèze, Philippe Eudeline, Pascal Dherbécourt, Olivier Latry, Viswas Purohit, Hichame Maanane, F. Cornu, Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), and Normandie Université (NU)
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LDMOS ,Materials science ,Hardware_PERFORMANCEANDRELIABILITY ,02 engineering and technology ,01 natural sciences ,law.invention ,[SPI]Engineering Sciences [physics] ,law ,0103 physical sciences ,Hardware_INTEGRATEDCIRCUITS ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Figure of merit ,Electrical and Electronic Engineering ,Safety, Risk, Reliability and Quality ,ComputingMilieux_MISCELLANEOUS ,Hot-carrier injection ,010302 applied physics ,Equivalent series resistance ,business.industry ,Transistor ,High voltage ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,020202 computer hardware & architecture ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,Optoelectronics ,business ,Microwave ,Voltage - Abstract
This paper reports a methodology to correlate Hot Carrier Injection (HCI) degradation mechanism and electrical figures of merit on Lateral-Diffused Metal–Oxide-Semiconductor (LDMOS) transistor. This method is based on RF life test in radar operating conditions coupled to a high drain voltage in order to make visible HCI degradation. We propose drain current modeling vs. time based on a simple extraction procedure. The electron density trapped in the oxide is extracted from hot carrier induced series resistance enhancement model (HISREM – i.e. Δ R d model). From this methodology, the degradation of RF-LDMOS due to HCI is quantified and could be simulated with EDA.
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- 2011
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9. Bactericidal Microparticles Decorated by an Antimicrobial Peptide for the Easy Disinfection of Sensitive Aqueous Solutions
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Thomas Blin, Thierry Jouenne, Karine Glinel, Viswas Purohit, Jérôme Leprince, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Polymères, biopolymères, membranes (PBM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université Catholique de Louvain = Catholic University of Louvain (UCL), Différenciation et communication neuronale et neuroendocrine (DC2N), Normandie Université (NU)-Normandie Université (NU)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)
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Polymers and Plastics ,[SDV.NEU.NB]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Neurobiology ,Bioengineering ,Peptide ,MESH: Microscopy, Fluorescence ,02 engineering and technology ,Microbial Sensitivity Tests ,[CHIM.THER]Chemical Sciences/Medicinal Chemistry ,MESH: Solutions ,010402 general chemistry ,Methacrylate ,01 natural sciences ,Biomaterials ,chemistry.chemical_compound ,Microscopy, Electron, Transmission ,MESH: Disinfection ,MESH: Anti-Bacterial Agents ,[SDV.BC.IC]Life Sciences [q-bio]/Cellular Biology/Cell Behavior [q-bio.CB] ,Materials Chemistry ,Copolymer ,MESH: Water ,Organic chemistry ,chemistry.chemical_classification ,MESH: Microbial Sensitivity Tests ,Aqueous solution ,Chemistry ,MESH: Peptides ,Water ,021001 nanoscience & nanotechnology ,Grafting ,Antimicrobial ,0104 chemical sciences ,Anti-Bacterial Agents ,Disinfection ,Solutions ,Chemical engineering ,Microscopy, Fluorescence ,MESH: Microscopy, Electron, Transmission ,[SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology ,Particle ,0210 nano-technology ,Peptides ,Ethylene glycol - Abstract
International audience; Silica and paramagnetic silica microparticles are surface-modified by an antibacterial macromolecular coating. For this, a hydrophilic copolymer brush based on oligo(ethylene glycol) methacrylates is grown on the particle surface by surface-initiated ATRP. Then, Magainin-I, a natural antimicrobial peptide, is grafted onto the hydroxyl groups of the brush through a heterolinker. The grafting of the peptide is evidenced by fluorescence microscopy and X-ray photoelectron spectroscopy. Moreover, culturability and viability assays performed in the presence of the magainin-grafted particles prove their bactericidal properties. The rapid recovery of the bactericidal particles based on paramagnetic silica and suspended in solution is shown under magnetization. Such particles offer the advantage to treat efficiently various sensitive aqueous solutions while avoiding any dissemination of bactericidal substances in the environment. As a consequence, they are of a great interest for various applications in medical, cosmetic, or biomedical fields.
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- 2011
- Full Text
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