B Tripathi
Articles written in Bulletin of Materials Science
Volume 29 Issue 3 June 2006 pp 261-264 Biomaterials
Transport through track etched polymeric blend membrane
Kamlendra Awasthi Vaibhav Kulshreshtha B Tripathi N K Acharya M Singh Y K Vijay
Polymer blends of polycarbonate (PC) and polysulphone (PSF) having thickness, 27 𝜇m, are prepared by solution cast method. The transport properties of pores in a blend membrane are examined. The pores were produced in this membrane by a track etching technique. For this purpose, a thin polymer membrane was penetrated by a single heavy ion of Ni7+ of 100 MeV, followed by preferential chemical etching of the ion track. Ion permeation measurements show that pores in polymeric membrane are charged or neutralized, which depends upon the variation in concentration of the solvent. The 𝑉–𝐼 curve at concentration, N/10, shows that the pores are negatively charged, whereas at concentration, N/20, the linear nature of 𝑉–𝐼 curve indicates that the pores approach towards neutralized state and on further concentration, N/40, the pores become fully neutralized, consequently the rectifier behaviour of pores has been omitted.
The gas permeability of hydrogen and carbon dioxide of this membrane was measured with increasing etching time. The permeability was measured from both the sides. Permeability at the front was larger than the permeability at the back which shows asymmetric behaviour of membranes.
Volume 30 Issue 1 February 2007 pp 5-7 Thin Films
Study of annealing effects in Al–Sb bilayer thin films
R K Mangal B Tripathi M Singh Y K Vijay
In this paper, we present preparation and characterization of Al–Sb bilayer thin films. Thin films of thicknesses, 3000/1000 Å and 3000/1500 Å, were obtained by the thermal evaporation (resistive heating) method. Vacuum annealing and rapid thermal annealing methods were used to mix bilayer thin film structure. Results obtained from optical band gap data and Rutherford back scattering spectrometry showed mixing of Al–Sb bilayer system.
Volume 32 Issue 6 December 2009 pp 569-573 Thin Films and Nanomatter
Swift heavy ion irradiation effect on Cu-doped CdS nanocrystals embedded in PMMA
Shweta Agrawal Subodh Srivastava Sumit Kumar S S Sharma B Tripathi M Singh Y K Vijay
Semiconductor nanocrystals (NCs) have received much interest for their optical and electronic properties. When these NCs dispersed in polymer matrix, brightness of the light emission is enhanced due to their quantum dot size. The CdCuS NCs have been synthesized by chemical route method and then dispersed in PMMA matrix. These nanocomposite polymer films were irradiated by swift heavy ion (SHI) (100 MeV, Si+7 ions beam) at different fluences of 1 × 1010 and 1 × 1012 ions/cm2 and then compared their structural and optical properties by XRD, atomic force microscopy, photoluminescence, and UV-Vis spectroscopy before and after irradiation. The XRD spectra showed a broad hump around 2𝜃 ≈ 11.83° due to amorphous PMMA and other peaks corresponding to hexagonal structure of CdS nanocrystals in PMMA matrix. The photoluminescence spectra shows a broad peak at 530 nm corresponding to green emission due to Cu impurities in CdS. The UV-Vis measurement showed red shift in optical absorption and bandgap changed from 4.38–3.60 eV as the irradiation fluency increased with respect to pristine CdCuS nanocomposite polymer film.
Volume 46, 2023
All articles
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Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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