Ojas Mahapatra

Ultrafine dispersed CuO nanoparticles and their antibacterial activity

Copper oxide nanoparticles with a particle size ranging from 80 to 160 nm were prepared by a wet chemical procedure. Copper carbonate hydroxide and sodium hydroxide were used as raw materials. Copper hydroxide was generated as a precursor which was thermally decomposed to CuO nanoparticles. The nanoparticles were characterised using atomic force microscopy, X-ray diffraction and UV-visible spectrometry. The nanoparticles were tested for antibacterial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella paratyphi and Shigella strains.

Influence Of Plasma Pretreatment In The Formation Of Diamond-Like Carbon Thin Films

Plasma-enhanced chemical vapor deposition has been used to synthesize diamond-like carbon (DLC) thin films. High purity argon and methane gases were used as precursors for the fabrication of the DLC films. The influence of plasma pretreatment on the growth of the DLC films has been studied by subjecting one of the substrates to plasma pretreatment prior to deposition of the DLC films, while maintaining the other substrate as the control. The structural properties of the DLC films have been characterized using atomic force microscopy and Raman spectroscopy. The film grown on the pretreated substrate shows a more uniform coating as compared to the film grown on non-pretreated silicon substrate. The results are discussed based on diffusivity of carbon on silicon and the effect of the plasma pretreatment.

Low Temperature Growth of Carbon Nanostructures by Radio Frequency‐Plasma Enhanced Chemical Vapor Deposition (Low Temperature Growth of Carbon Nanostructures by RF‐PECVD)

This paper reports the growth of carbon nanostructures on Si (100) substrate in the absence of catalyst using radio‐frequency plasma enhanced chemical vapor deposition (RF‐PECVD). A variety of carbon nanostructures have been grown by low pressure high density plasma process at 400°C using a methane/argon mixture. Various shapes and structures including novel carbon nanoparticles have been found. The surface morphology was studied by Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM) while the chemical composition was studied using Energy Dispersive Spectroscopy (EDS). The AFM images show that the nanostructures are predominantly either particulate (spherical) in nature or have a sheet‐like morphology. SEM images are in good correspondence to the AFM results and indicate formation of either individual islands or two‐dimensional nanosheet‐like structures. The crux of this work is in the synthesis of the carbon nanostructures at comparatively low fabrication temperature (400°C) as compared to other techniques.

Effects of quenching on the morphology and crystal structure of ZnO nanostructures

Zinc oxide nanostructures were prepared by a simple wet chemical procedure using zinc acetate and sodium hydroxide as precursors. The process was subjected to quenching treatment and the effect of the treatment on the formation of the nanostructures was studied using atomic force and scanning electron microscopies. The change in crystal structure of the nanostructures due to quenching was studied using an X-ray diffractometry that established that physical and structural properties of the nanostructures were largely influenced by the quenching treatment.

Effect Of Temperature On Self-Assembly Of Diamond-Like Carbon (Dlc) Grown By Plasma Enhanced Chemical Vapor Deposition (Pecvd)

Diamond-like carbon nanostructures were prepared using Plasma enhanced chemical vapor deposition (PECVD). Temperature dependence of self-assembly of carbon nanostructures is noted. Carbon and silicon exhibit significant lattice mismatch and during the self-assembly, stacking of carbon atoms takes place which results in conic projections. The carbon nanostructures were prepared at 600°C and 100 W RF power and were subjected to a cooling treatment. Argon and Methane were used as reactant gases. The formation of nanostructures did not use any catalyst. The surface morphology and roughness analysis was carried by Atomic Force microscopy. The nanocones were characterized by X Ray Diffractometer and Raman Spectroscopy.