01993nas a2200217 4500008004100000022001400041245009700055210006900152260000800221300001100229490000800240520125400248653001001502653002001512653002601532653002601558100002201584700002101606700002201627856012601649 2024 eng d a1944-399400aABPBI-based hollow fiber membranes for forward osmosis (FO) possessing low reverse salt flux0 aABPBIbased hollow fiber membranes for forward osmosis FO possess cOCT a1006410 v3203 a

The poly(2,5-Benzimidazole), known for its excellent thermochemical stability, was evaluated as a membrane material for forward osmosis. The dope in methane sulfonic acid was used to make hollow fiber membranes. The availability of bound MSA in HFMs was compared with its neutral form. Aqueous solutions of two common salts reported for FO (NaCl and MgCl2) were used as a draw solution at varying concentrations. The performance was determined in terms of water flux and reverse salt flux. The long-term performance of the membrane was assessed. The heat pretreatment of membranes was beneficial in offering low reverse salt flux, a crucial parameter in FO. The heat treatment at 350 degrees C exhibited excellent performance of low-RSF, irrespective of the draw solute used. The presence of MSA in the membrane matrix was found to be beneficial. Present HFMs exhibited reverse salt flux as low as 0.003 mol m-2 h-1 using 2 mol L-1 MgCl2 as a draw solution. The water flux of present membranes was lower than that of reported FO-membranes, which is attributable to the larger thickness of the present membranes. The findings will be used to make ABPBI-based membranes in thin form to elevate the fluxes and their practical applicability.

10aABPBI10aForward osmosis10aHollow fiber membrane10aLow reverse salt flux1 aThorat, Nitin, M.1 aLele, Ashish, K.1 aKharul, Ulhas, K. uhttps://library.ncl.res.in/content/abpbi-based-hollow-fiber-membranes-forward-osmosis-fo-possessing-low-reverse-salt-flux02426nas a2200241 4500008004100000022001400041245017000055210006900225260000800294300001600302490000700318520150000325653003101825653001701856653003101873653003501904653002701939100002601966700002201992700001702014700002202031856013102053 2024 eng d a1944-824400aScalable, interfacially synthesized, covalent-organic framework (COF)-based thin-film composite (TFC) hollow fiber membranes for organic solvent nanofiltration (OSN)0 aScalable interfacially synthesized covalentorganic framework COF cAPR a19463-194710 v163 a

Covalent organic frameworks have great potential for energy-efficient molecular sieving-based separation. However, it remains challenging to implement COFs as an alternative membrane material due to the lack of a scalable and cost-effective fabrication mechanism. This work depicts a new method for fabricating a scalable in situ COF hollow fiber (HF) membrane by an interfacial polymerization (IP) approach at room temperature. The 2D COF film was constructed on a polyacrylonitrile HF substrate using aldehyde (1,3,5-trimethylphloroglucinol, Tp) and amine (4,4 `-azodianiline (Azo) and 4,4 `,4 `'-(1,3,5-triazine- 2,4,6-triyl) trianiline (Tta)) as precursors. The COF membrane on the PAN substrate showed 99% rejection of Direct red-80 with remarkable solvent permeance. The rejection analysis revealed that the structural aspects of the solute molecule play a major role in rejection rather than the molecular weight. We further optimized the precursor concentrations to improve the permeation performance of the resulting membrane. The durability study reveals excellent stability of the membrane toward organic solvents. This study also demonstrated the easy scalability of the membrane fabrication approach. The approach was further extrapolated to fabricate a cation-based COF membrane. These charged membranes exhibited an enhanced rejection performance. Finally, this approach can facilitate industrially challenging molecular sieving applications using COF-based membranes.

10acovalent-organic framework10ahollow fiber10ainterfacial polymerization10aorganic solvent nanofiltration10aselective COF membrane1 aKunjattu, Shebeeb, H.1 aThorat, Nitin, M.1 aGawas, Saroj1 aKharul, Ulhas, K. uhttps://library.ncl.res.in/content/scalable-interfacially-synthesized-covalent-organic-framework-cof-based-thin-film-composite02201nas a2200205 4500008004100000022001400041245017400055210006900229260000900298490000800307520140700315653001701722653001401739653002601753100002401779700002201803700002201825700002201847856012601869 2026 eng d a0021-899500aPoly(2,5-Benzimidazole)-based flat sheet membranes: investigating effects of dope solvent and membrane heat treatment on forward osmosis and acid enrichment performances0 aPoly25Benzimidazolebased flat sheet membranes investigating effe cMAR 0 v1433 a

The present work investigates two methods for preparing defect-free, symmetric membranes of the thermochemically robust polymer, poly(2,5-benzimidazole) (commonly known as ABPBI) for forward osmosis (FO), a growing technology for niche separations. The obtained polymer and membranes were analyzed for physical properties of significance. The FO analysis was performed using three salt solutions, viz., sodium chloride (NaCl), magnesium chloride (MgCl2), and sodium sulfate (Na2SO4). The effects of casting methodology (solvents present in the dope), membrane heat treatment, draw solution concentration, long-duration analysis, and FO-assisted enrichment of organic acids were evaluated. Some of the membranes exhibited extremely low reverse salt flux (RSF), which conveys the novelty of these membranes. Some of these membranes were analyzed using a high draw solution (DS) concentration (4 mol L-1) to enhance water flux and further employed to enrich organic acids. The aqueous acetic and methacrylic acid concentrations were enriched from 4.89 and 2.93 mol L-1 to 11.88 and 10.01 mol L-1, respectively. These results demonstrate an unmet need of concentrating methacrylic acid (a temperature-sensitive compound possessing a double bond). The present work demonstrates the potentials of ABPBI-based symmetric, thin membranes for FO and their industrial applicability for the first time.

10aApplications10amembranes10aseparation techniques1 aSomkuwar, Nitin, C.1 aThorat, Nitin, M.1 aAmbade, Ashootosh1 aKharul, Ulhas, K. uhttps://library.ncl.res.in/content/poly25-benzimidazole-based-flat-sheet-membranes-investigating-effects-dope-solvent-and