@article { ISI:000228904900029, title = {Deposition of PTFE thin films by RF plasma sputtering on < 100 > silicon substrates}, journal = {Applied Surface Science}, volume = {245}, number = {1-4}, year = {2005}, month = {MAY}, pages = {202-207}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Polymers have been studied extensively due to the wonderful array of properties presented by them. Polymer materials can be coated/deposited by various techniques like sputtering (magnetron, ion beam, RF or dc), plasma polymerization, etc. and can be used in coatings, paint industries, etc. The present study deals with the RF sputter deposition of poly(tetrafluoro ethylene) (PTFE), commonly known as Teflon. Depositions were carried out on mirror polished silicon (1 0 0) substrates at different powers in the range of 100-200 W. The deposition time was kept constant at 60 min. The sputtered film shows lower contact angle of 50\&DEG; with water and 44\&DEG; with diiodomethane, a lower interfacial tension value of 0.76 dyne/cm, indicating hydrophilicity and good adhesion of the film with the substrate. FHR indicates presence of C-F, C-F-2 bonding groups in the deposited film. Further, XPS study shows presence of CF3 (292.2 eV), CF2 (290.8 eV), C-F (288.0 eV) and C-CF (286.4 eV) moieties indicating deposition of PTFE films at higher power levels of plasma. {\textcopyright} 2004 Elsevier B.V. All rights reserved.

}, keywords = {Contact angle measurement, FTIR, PTFE, RF plasma sputtering, XPS}, issn = {0169-4332}, doi = {10.1016/j.apsusc.2004.10.023}, author = {Bodas, Dhananjay S. and Mandale, A. B. and Gangal, S. A.} } @article { ISI:000235860500014, title = {Electron beam induced surface cross-linking of functional monomers coated on silicon substrate}, journal = {Materials Letters}, volume = {60}, number = {11}, year = {2006}, month = {MAY}, pages = {1360-1365}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A 3: 1 composition of functional monomer: multifunctional acrylate was spin coated and later cross-linked under the influence of keV electron irradiation on the surface of silicon to generate a surface-anchored cross-linked network bearing functional moieties. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) as well as wetting angle measurements were used for the analysis of functional monomer cross-linked surfaces. Results of the surface reconstruction of surfaces and electron irradiated on coated silicon wafers reveal that long-term hydrophilic surfaces can be achieved. Thus, the surface architecture can be favorably manipulated by using this remarkable technique with a Suitable combination of functional monomers and cross-linkers. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {electron beam irradiation, FTIR, Polymers, surface modification, XPS}, issn = {0167-577X}, doi = {10.1016/j.matlet.2005.11.029}, author = {Mahapatra, S. K. and Bodas, Dhananjay S. and Mandale, A. B. and Gangal, S. A. and Bhoraskar, Vasant N.} } @article { ISI:000238989300008, title = {Irradiation effects of 12 eV oxygen ions on polyimide and fluorinated ethylene propylene}, journal = {Radiation Effects and Defects in Solids}, volume = {161}, number = {8}, year = {2006}, month = {AUG}, pages = {495-504}, publisher = {TAYLOR \& FRANCIS LTD}, type = {Article}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

Polyimide (PI) and Fluorinated Ethylene Propylene (FEP) samples (15mm x 15mm x 50 mu m ) were exposed to atomic oxygen ions of average energy similar to 12 eV and flux similar to 5x10(13) ions cm(-2) s(-1) , produced in the Electron Cyclotron Resonance (ECR) plasma. The energy and the flux of the oxygen ions at different positions in the plasma were measured by a retarding field analyzer. The fluence of the oxygen ions was varied from sample to sample in the range of similar to 5x10(16) to 2x10(17) ions cm(-2) by changing the irradiation period. The pre- and the post-irradiated samples were characterized by the weight loss, Scanning Electron Microscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), and Fourier Transform Infrared (FTIR) techniques. The weight of the PI and FEP samples decreased with increasing the ion fluence. However, the erosion yield for the PI is found to be higher, by almost a factor five, when compared with that of FEP. On the surface region of irradiated samples, the concentrations of the carbon, fluorine, and oxygen and their corresponding chemical bonds have changed appreciably. Moreover, blisters and nanoglobules were also observed even at a fluence of similar to 10(17) ions cm(-2) . This oxygen ion fluence is almost two orders of magnitude lower than that of the 5 eV atomic oxygen, which a satellite encounters in the space, at the low Earth orbit, during its mission period of about 7 years.

}, keywords = {atomic oxygen, ECR plasma, FEP, FTIR, Polyimide, SEM, weight loss, XPS}, issn = {1042-0150}, doi = {10.1080/10420150600810224}, author = {Majeed, Riyadh M A Abdul and Purohit, V. S. and Bhoraskar, S. V. and Mandale, A. B. and Bhoraskar, Vasant N.} } @article { ISI:000255292000009, title = {Photocatalytic activity and characterization of sol-gel-derived Cr(III)-doped TiO(2)-coated active carbon composites}, journal = {Philosophical Magazine}, volume = {88}, number = {5}, year = {2008}, month = {APR}, pages = {767-779}, publisher = {TAYLOR \& FRANCIS LTD}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

Cr(III)-doped, TiO(2)-coated active carbon (Cr-TiO(2)/AC) were prepared by a sol-gel method. The effect of supports, including TiO(2) and active carbon (AC), on the molecular structure and photocatalytic activity of chromium oxide for complete decomposition of EDTA has been examined with respect to the content of Cr on the catalyst surface. The photocatalytic activity of the Cr-TiO(2)/AC composites was evaluated in the decomposition of EDTA solution under UV irradiation. The results indicate that Cr-TiO(2)/AC has a higher efficiency in decomposition of EDTA than TiO(2), TiO(2)/AC or active carbon. This was attributed to the different functions of active carbon and chromate species. (1) Nanosize TiO(2) particles on composites were not reunited, possible because active carbon retards transformation of anatase into rutile and decreases the crystallite size. (2) Production of high concentrations of organic compound near Cr-TiO(2). (3) Carbon in active carbon causes some of the TiO(2) to reduce to Ti(3+) ions, which prevents electron-hole pair recombination. (4) Formation of polychromate species, with a stronger redox capability, on the surface of TiO(2)/AC. It was found that the addition of Cr to TiO(2) sol could suppress the grain growth of TiO(2) crystals and increase the hydroxyl content on the surface of TiO(2)/AC. The photocatalytic efficiency and activity of the composites remained good, even after three cycles.

}, keywords = {EDTA, photoactive, sol-gel, Titanium dioxide, XPS}, issn = {1478-6435}, doi = {10.1080/14786430801955261}, author = {Gambhire, A. B. and Lande, Machhindra K. and Mandale, A. B. and Patil, K. R. and Arbad, B. R.} }