02149nas a2200217   4500008004100000022001400041245011100055210006900166260007300235300001200308490000800320520134100328653001401669653001901683653001901702653002201721653001301743100002801756700002201784856012501806       2010                        eng d  a0376-738800aInvestigation of gas permeation properties of systematically modified polybenzimidazoles by N-substitution0 aInvestigation of gas permeation properties of systematically mod  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a134-1420 v3573 a<p>Gas permeation behavior of a series of thermally stable N-substituted polybenzimidazoles by systematically varying bulk and flexibility of the substituent was investigated. Two different PBIs having variation in their acid moiety, viz., PBI-I (based on isophthalic acid) and PBI-BuI (based on 5-tert-butyl isophthalic acid) were selected for N-substitution by alkyl groups possessing different bulk and flexibility. These substituent groups were methyl, n-butyl, methylene trimethylsilane and 4-tert-butylbenzyl. Pure gas sorption and permeability using H(2), N(2), O(2), CH(4) and CO(2) were investigated and correlated with physical properties of formed polymers. Estimation of dual-mode sorption parameters, coefficients of sorption, permeability and diffusion for different gases provided an insight towards effects of nature of a substituent group and parent PBI on governing gas sorption and permeation properties. By changing the substituent group, diffusivity coefficients was found to vary to a larger extent than the solubility coefficient. This significantly enhanced gas permeability for different gases by 1.2-129 times than that of parent PBIs. The permselectivity P(O2)/P(N2) was increased (up to 237%), while for other gas pairs, it was decreased to a different extent. (C) 2010 Elsevier B.V. All rights reserved.</p>10aDiffusion10aGas permeation10aN-Substitution10aPolybenzimidazole10aSorption1 aKumbharkar, Santosh, C.1 aKharul, Ulhas, K.  uhttp://library.ncl.res.in/content/investigation-gas-permeation-properties-systematically-modified-polybenzimidazoles-n-002063nas a2200217   4500008004100000022001400041245012200055210006900177260007300246300001200319490000800331520120300339653001901542653003301561653002201594653002701616100002401643700002801667700002201695856012801717       2014                        eng d  a0376-738800aInvestigation of gas permeation properties of film forming polymeric ionic liquids (PILs) based on polybenzimidazoles0 aInvestigation of gas permeation properties of film forming polym  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a494-5030 v4703 a<p>Polymeric ionic liquids (PILs) are emerging as new generation membrane materials for CO2 separation. Gas permeation properties of a recently developed PIL family based on three structurally different polybenzimidazoles (PBIs) possessing excellent film forming characteristics are reported. Effects of cationic backbone and anions on gas permeation properties of PILs using pure gases (He, H-2, N-2, CH4, and CO2) were examined at 20 atm upstream pressure and correlated with their physical properties. In comparison to the parent PBIs, PILs exhibited generally higher CO2 permeability, without largely affecting CO2 based selectivity. Some of these PILs exhibiting high PCO2/PCH4, selectivity and P-H2/P-CO2, approaching similar to 1 indicated dominance of CO2 sorption over diffusion. The CO2 sorption specificity of these PILs was distinctly observed based on their improved S-CO2/S-N2, S-CO2/S-CH4 and S-CO2/S-H2 selectivity than their parent PBIs. A large variation in permeation properties of PILs based on a common polycation but different anions indicated that anions play a crucial role on governing gas permeation properties of these PILs. (C) 2014 Elsevier B.V. All rights reserved</p>10aGas permeation10aMembranes for CO2 separation10aPolybenzimidazole10aPolymeric ionic liquid1 aBhavsar, Rupesh, S.1 aKumbharkar, Santosh, C.1 aKharul, Ulhas, K.  uhttp://library.ncl.res.in/content/investigation-gas-permeation-properties-film-forming-polymeric-ionic-liquids-pils-based-0