02284nas a2200229   4500008004100000022001400041245008300055210006900138260007300207300001200280490000800292520149100300653002101791653001401812653001901826653001901845653001101864653001301875100002801888700002201916856011601938       2010                        eng d  a0376-738800aNew N-substituted ABPBI: synthesis and evaluation of gas permeation properties0 aNew Nsubstituted ABPBI synthesis and evaluation of gas permeatio  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP  a418-4250 v3603 a<p>Aromatic poly(2,5-benzimidazole), ABPBI was post-modified for the first time to produce organosoluble N-substituted ABPBI. This modification was carried out by N-substitution of ABPBI with bulky alkyl groups, viz., 4-tert-butylbenzyl and methylene trimethylsilyl in an attempt to utilize high rigidity of ABPBI towards gas permeation. These substituted polymers exhibited solubility in common organic solvents, enhancing their processability than ABPBI, which is soluble only in acidic solvents. Considerable decrease in chain packing density led to increase in gas sorption as that of unsubstituted ABPBI. The permeability of pure gases of commercial significance (He, H(2), N(2), O(2), CH(4) and CO(2)) were high, coupled with attractive selectivities. In comparison to conventional PBI, methylene trimethylsilyl substituted ABPBI led to considerably high (33 folds) CO(2) permeability with almost similar selectivity (P(CO2)/P(N2) approximate to 33). Feasibility of these N-substituted ABPBIs to be converted in to required membrane form along with its considerably higher permeation properties depicted the potential of this polymer to be used as gas separation material. Gas diffusion coefficients were estimated from solubility and permeability coefficient. These, along with dual-mode sorption parameters estimated from sorption isotherms provided an insight towards variations in permeation behavior caused by the substitution. (C) 2010 Elsevier B.V. All rights reserved.</p>10a5-benzimidazole)10aDiffusion10aGas permeation10aN-Substitution10aPoly(210aSorption1 aKumbharkar, Santosh, C.1 aKharul, Ulhas, K.  uhttps://library.ncl.res.in/content/new-n-substituted-abpbi-synthesis-and-evaluation-gas-permeation-properties-002288nas a2200241   4500008004100000022001400041245007600055210006900131260000800200300001100208490000800219520153700227653002101764653002001785653001801805653002701823653001801850653001101868100001701879700002001896700002201916856010801938       2024                        eng d  a0376-738800aChemodialysis of organic acids using ABPBI-based hollow fiber membranes0 aChemodialysis of organic acids using ABPBIbased hollow fiber mem  cJAN  a1221530 v6893 a<p>
	Organic acids are a class of essential commodity chemicals used in various industries. Their production methods are shifting from conventional chemicals to fermentation, driven by green process strategies, environmental regulations, cost feasibility, etc. Separating formed acid from the fermentation broth is a primary technological barrier. Conventional methods are complex and impose environmental issues. A promising approach, `Chemodialysis,' capable of transforming the techno-economical feasibility of acid recovery scenario by reducing the number of steps, needs further investigation. This work evaluates scalable hollow fiber membranes based on poly(2,5-benzimidazole) (ABPBI) for chemically assisted dialysis, viz., Chemodialysis. Sorption analyses of commercially significant organic acids (acetic, lactic, and glycolic acid) and nonacidic solutes (NaCl and glucose) were performed using conventional flat sheet samples to assess their role in governing permeation characteristics. The transport properties of acids in the presence of NaCl and glucose as co-solutes were analyzed using hollow fiber membranes. The high selectivity of acid over nonacidic solutes ranges from 400-22,400, coupled with high acid permeability, enhances the applicability of Chemodialysis for the separation of acids using hollow fiber membranes. The fluxes of acids (acetic, glycolic, and lactic) through dense, similar to 100 mu m thick, scalable hollow fiber membranes ranging from 10.9 to 13.12 g/m(2)h are highly appreciable.</p>
10a5-benzimidazole)10aAcid separation10aChemodialysis10aHollow fiber membranes10aOrganic acids10aPoly(21 aGawas, Saroj1 aAlladi, Lavanya1 aKharul, Ulhas, K.  uhttps://library.ncl.res.in/content/chemodialysis-organic-acids-using-abpbi-based-hollow-fiber-membranes