@article { ISI:000228435300001, title = {Zirconia-supported 12-tungstophosphoric acid as a solid catalyst for the synthesis of linear alkyl benzenes}, journal = {Journal of Catalysis}, volume = {231}, number = {1}, year = {2005}, month = {APR}, pages = {1-10}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The liquid-phase alkylation of benzene with 1-octene and 1-dodecene was investigated with zirconia-supported 12-tungstophosphoric acid (TPA) as catalysts. We prepared the catalysts, with different TPA loading (5-20 wt\% calcined at 750 degrees C) and calcination temperatures (15 wt\% calcined from 650 to 850 degrees C), by suspending hydrous zirconia in a methanol solution of TPA, followed by drying and calcination. These catalysts were characterized by X-ray diffraction, DTG-DTA, FTIR pyridine adsorption, NH3-TPD, and P-31, MAS NMR spectroscopy measurements. The catalyst with optimum TPA loading (15\%) and calcination temperature (750 degrees C) was prepared in different solvents and characterized by P-31 MAS NMR spectroscopy. The XRD results indicate that TPA stabilizes the tetragonal phase of zirconia. The catalysts show both Bronsted and Lewis acidity, and 15\% TPA on zirconia calcined at 750 degrees C shows the highest acidity. P-31 MAS NMR spectra show two types of phosphorous species: one is the Keggin unit and the other is the decomposition product of TPA. The relative amount of each depends on TPA loading, calcination temperature, and the solvent used for the catalyst preparation. Under reaction conditions of 84 degrees C and a benzene/1-olefin molar ratio of 10 (time 1 h), the most active catalyst, 15\% TPA, calcined at 750 degrees C, gave more than 98\% olefin conversion with selectivity for 2-phenyl octane (53.5\%) and 2-phenyl dodecane (47\%). (c) 2004 Elsevier Inc. All rights reserved.

}, keywords = {12-tungstophosphoric acid, linear alkyl benzene, solvent effect, Zirconia}, issn = {0021-9517}, doi = {10.1016/j.jcat.2004.09.024}, author = {Devassy, Biju M. and Lefebvre, F. and Halligudi, Shivaraj B.} } @article { ISI:000271812000007, title = {Studies of anion transport through supported liquid membrane}, journal = {Analytical Letters}, volume = {42}, number = {18}, year = {2009}, month = {NOV}, pages = {PII 916769949}, publisher = {TAYLOR \& FRANCIS INC}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

Transport studies of anions were investigated through cellulose triacetate supported liquid membrane. The experimental variables explored were concentration of anions, sodium hydroxide, and stirring speed. The two-channel membrane system has been explored for the transport of carbonate ions from source to receiving phases. Carbonate ions are selectively transported through the cellulose triacetate supported liquid membrane in comparison with that of nitrate and sulfate. Sulfate and nitrate anions are strongly held in the cellulose triacetate membrane, and then stripped out later. Carbonate ions are loosely bound to the cellulose triacetate membrane and stripped out earlier.

}, keywords = {Anions, cellulose triacetate membrane, solvent effect, stability of supported liquid membrane, two-channel membrane system}, issn = {0003-2719}, doi = {10.1080/00032710903202063}, author = {Gaikwad, Abaji G.} } @article { ISI:000278112200007, title = {Effect of solvents having different dielectric constants on reactivity: a conceptual DFT approach}, journal = {International Journal of Quantum Chemistry}, volume = {110}, number = {9}, year = {2010}, month = {AUG}, pages = {1642-1647}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

Conceptual density functional theory is exploited to understand the reactivity in a medium of solvents with increasing dielectric constants. Aprotic as well as protic solvents are used for this study. It is found that the global parameters, such as chemical potential and hardness, decrease from gas phase to solvent phase with increasing dielectric constant. However, it is observed that the Fukui functions of the reactive atoms increase significantly with the dielectric constants of the aprotic solvents while for the protic solvents the variation of the reactivity indices is insignificant. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 110: 1642-1647, 2010

}, keywords = {COSMO, DFT, dielectric constant, Reactivity descriptors, solvent effect}, issn = {0020-7608}, doi = {10.1002/qua.22333}, author = {Kar, Rahul and Pal, Sourav} }