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Item Modification of PSf/PIAM membrane for improved desalination applications using Chitosan coagulation media(2013) Kumar, R.; A.F., A.F.; Kassim, M.A.; Isloor, A.M.Polysulfone (PSf)/poly (isobutylene-alt-maleic anhydride) (PIAM) nanofiltration membranes were modified by changing the coagulation bath with various concentrations of glutaraldehyde cross-linked Chitosan solutions. Further the membranes were treated with 0.1N NaOH solution in order to achieve the hydrolysis of PIAM. The morphological changes of the membranes were determined using scanning electron microscope. The blending of PSf/PIAM membrane, the incorporation of Chitosan (CS) molecules in membrane matrix and the hydrolysis of PIAM in the membrane upon alkali treatment were studied by Attenuated Total Reflectance Infra Red (ATR-IR) spectroscopy. The hydrophilicity of modified membranes was measured using the contact angle analyzer. The pressure and time dependent pure water flux of modified PSf/PIAM/CS membranes were measured and compared with PSf/PIAM membranes (after alkali treatment). The antifouling property of membranes was determined using Bovine Serum Albumin (BSA) protein rejection studies. The modified membranes showed improved hydrophilicity and reduced pore size. The order of rejection of membranes for various electrolytes was Na2SO4>MgSO4>NaCl at minimum pressure of 0.2MPa TMP. The antifouling property of modified membranes increased with an increase in the composition of Chitosan in coagulation bath and membrane M-0.8 showed a maximum fouling resistance ratio of 74%. © 2013 Elsevier B.V.Item Performance improvement of polysulfone ultrafiltration membrane using N-succinyl chitosan as additive(2013) Kumar, R.; Isloor, A.M.; A.F., A.F.; Matsuura, T.A water soluble chitosan derivative, N-succinyl chitosan (NSCS), was blended with polysulfone (PSf) in three different compositions to fabricate PSf/NSCS blend membranes. The blending of polymers was confirmed by Attenuated Total Reflectance Infra-Red (ATR-IR) spectroscopy. The membranes were characterized by Scanning Electron Microscopy (SEM) images for their cross-sectional morphology. Pure water flux, water uptake and contact angle of the PSf/NSCS blend membranes were measured and compared with the pristine polysulfone membrane. The PSf/NSCS blend membranes showed enhanced hydrophilicity and permeation fluxes compared to the pristine polysulfone membrane. The membrane antifouling property was determined by filtering the bovine serum albumin (BSA) solution. The maximum flux recovery ratio (FRR) of 70% was observed by the PSf/NSCS blend membrane with 20% NSCS content. The PSf/NSCS membranes with the PSf:NSCS ratios of 80:20 and 90:10 showed nearly the same fluxes as those of polysulfone/polyethylene glycol (PSf/PEG) blend membranes with the same compositions. The hydrophilic derivative of chitosan NSCS acted as an excellent additive in improving PSf ultrafiltration properties. © 2013 Elsevier B.V.Item Antifouling and performance enhancement of polysulfone ultrafiltration membranes using CaCO3 nanoparticles(2013) Nair, A.K.; Isloor, A.M.; Kumar, R.; A.F., A.F.Calcium carbonate nanoparticles were synthesized from calcium nitrate via chemical precipitation method. The nanoparticles were characterized using scanning electron microscope (SEM), Attenuated total reflectance infra red (ATR-IR) spectrum and by X-ray diffraction (XRD). These nanoparticles were used as additive for polysulfone (PSf) ultrafiltration membrane along with polyethylene glycol (PEG) as pore forming agent. The PSf hybrid membranes were characterized by ATR-IR, XRD, and SEM studies. ATR-IR and XRD results indicated the successful incorporation of the nanoparticles in the membranes. Cross sectional images of the membranes along with the elemental mapping of calcium on the membrane surface were assessed using SEM. Hydrophilicity of the membranes was evaluated in terms of contact angle measurements. The permeability of the membranes was determined by measuring the pure water flux (PWF). Membranes were also subjected to antifouling studies using bovine serum albumin (BSA) as the standard protein for rejection. The membranes showed better permeability and antifouling property with the increased addition of CaCO3 nanoparticles. © 2013 Elsevier B.V.