http://nopr.niscair.res.in/handle/123456789/10831 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/13109 Title: Synthesis and application of cross-linked graft copolymer from poly(vinyl alcohol) and malic acid <br/> <br/>Authors: Chowdhury, P; Singha, B; Mukherjee, A <br/> <br/>Abstract: A novel polymeric sorbent has been synthesized by graft copolymerization of crosslinked polyvinyl alcohol with malic acid, and characterized by FTIR, TGA and swelling studies. A suitable and interesting method has been developed for the extraction and separation of lead ion with the graft copolymer. The lead ion uptake capacity of the polymer has been evaluated vis-a-vis varying <i style="">p</i>H and metal ion concentration. Pb(II) ion has been isolated quantitatively from various synthetic mixture containing metal ions (Cd(II), Zn(II), Ni(II), Hg(II)) commonly found in battery and electroplating waste. The synthesized material has also been tested for analyzing real samples such as solder, lead concentrate and electroplating waste. <br/> <br/>Page(s): 1730-1734 http://nopr.niscair.res.in/handle/123456789/13108 Title: Preparation, characterization and catalytic application of some polyoxometalates with Keggin, Wells-Dawson and Preyssler structures <br/> <br/>Authors: Sheshmani, Shabnam; Fashapoyeh, Marzieh Arab; Mirzaei, Masoud; Rad, Bita Abedi; Ghortolmesh, Somayeh Nouri; Yousefi, Mohammad <br/> <br/>Abstract: Dibutylphthalate has been prepared<i> </i>via esterification reaction in the presence of some solid acidic catalysts. Transition metal polyoxometalates with Keggin (K₃[PMo₆W₆O₄₀], K₃[PMo₁₂O₄₀], K₄[SiMo₁₂O₄₀], K₄[SiW₁₂O₄₀], Na₇[PW₁₁O₃₉]), Wells-Dawson (K₆[P₂W₁₈O₆₂]), and Preyssler structures (K₁₄[NaP₅W₃₀O₁₁₀]) have been synthesized and characterized. The reactivity of these catalysts has been studied for the preparation of dibutylphtalate by esterification reaction of phthalic anhydride and 1-butanol. Among the various acidic catalyst used, K₃[PMo₆W₆O₄₀] showed the best reactivity and efficiency compared to other catalysts. <br/> <br/>Page(s): 1725-1729 http://nopr.niscair.res.in/handle/123456789/13107 Title: Vapor phase fluorination of 1,1,1-trifluoro-2-chloroethane over CrO_x-Y₂O₃ catalysts: Effects of calcination atmosphere and chromium content <br/> <br/>Authors: Pu, Zhi-Ying; Yu, Hong-Bo; Jia, Wen-Zhi; Zhou, Huan; Wang, Yue-Juan; Luo, Meng-Fei <br/> <br/>Abstract: CrO_x-Y₂O₃ catalysts (CrYO) prepared by a coprecipitation method transformed to Cr₂O₃-YF₃(CrYF) catalysts after being fluorinated with HF. The effects of calcination atmosphere and chromium content on its catalytic activity for the vapor phase fluorination of 1,1,1-trifluoro-2-chloroethane have been investigated. The CrYF catalysts calcined in nitrogen atmosphere show higher catalytic activity than those calcined in air. In addition, the CrYF-20 and CrF catalysts (calcined in nitrogen or air) show higher catalytic activity than CrYF-50 and CrYF-80 catalysts. Characterization results indicate that the CrYO and CrYF catalysts calcined in nitrogen atmosphere are amorphous and much easier to fluorinate with HF than those calcined in air, while CrO-N and CrF-N exist mainly as crystalline phase and difficult to be fluorinated. It is also observed that the surface acidity plays an important role in the catalyst activity for the vapor phase fluorination of HCFC-133a. <br/> <br/>Page(s): 1719-1724 http://nopr.niscair.res.in/handle/123456789/13106 Title: Studies on volumetric properties of triethylamine in organic solvents with varying polarity <br/> <br/>Authors: Ijardar, S P; Malek, N I; Oswal, S L <br/> <br/>Abstract: Apparent molar volumes (<img src='http://www.niscair.res.in/jinfo/V phi-B.gif' border=0>) of dilute solutions of triethylamine in heptane, 2-butanone, ethyl ethanoate, butyl ethanoate, 1,4-dimethylbenzene, ethylbenzene, chlorobenzene, and nitrobenzene, at 303.15 K have been calculated from the densities determined. The limiting partial molar volumes (<img src='http://www.niscair.res.in/jinfo/V B-infinity.gif' border=0>), limiting excess partial molar volumes (<img src='http://www.niscair.res.in/jinfo/V B-E-infinity.gif' border=0>) and volumes of transference (<img src='http://www.niscair.res.in/jinfo/del V-B-tr-infinity.gif' border=0>) from heptane to the other investigated solvents of varying polarity have been analysed in terms of solute-solute-solvent interactions and structural effects of the molecules. Using the Terasawa model, an attempt has been made to find a measure of the contribution of specific interactions in terms of void volumes of triethylamine in the investigated solvents over a range of polarity. The Flory theory/ERAS model has also been applied to estimate the apparent molar volumes, excess apparent molar volumes and limiting excess partial molar volumes of triethylamine in investigated systems. <br/> <br/>Page(s): 1709-1718