Faculty Publications

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Subject: search.filters.subject.Membrane performance

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    Synthesis and desalination performance of Ar+-N+ irradiated polysulfone based new NF membrane
    (2011) Hegde, C.; Isloor, A.M.; Padaki, M.; Wanichapichart, P.; Liangdeng, Y.
    In the last few years, membrane technology has gained more attention from polymer chemists throughout the globe. Nowadays, surface modification of membrane is very useful in biotechnology and food science. In the present investigation, we have synthesized polysulfone based composite nanofiltration (NF) membranes, and characterized these membranes by FT-IR, SEM and membrane performance studies. Surface plasma treatment was carried out by irradiation with argon and nitrogen beams in suitable conditions. It was observed that nitrogen beam caused surface roughness that was more severe than the Ar beam. After irradiation, water contact angle was slightly increased. For pure water permeability, flux increased linearly with the operating pressure. However, for the salt solution, the flux was decreased marginally and salt rejection increased after irradiation due to surface modification. The modification effect was characterized in terms of contact angle, AFM employed roughness measurement and dielectric property. It revealed that irradiated NF membranes showed higher salt rejection and lower flux as compared to the nonmodified membranes. Accordingly, the roughness of the membrane surface intensively affected the performance of RO membrane. © 2010 Elsevier B.V.
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    New CPS-PPEES blend membranes for CaCl2 and NaCl rejection
    (Techno Press technop2@chollian.net, 2012) Hegde, C.; Isloor, A.M.; Padaki, M.; A.F., A.F.; Lau, L.W.
    Carboxylated polysulfone (CPS), poly (1,4-phenylene ether ethersulfone) (PPEES), membranes were prepared and used for the separation of NaCl and CaCl2 in efficient way with less energy consumption. In this work, nanofiltration and reverse osmosis membranes were employed to the salt rejection behavior of the different salt solutions. The influence of applied pressure (1-12 bar), on the membrane performance was assessed. In CM series of membranes, CM1 showed maximum of 97% water uptake and 36% water swelling, whereas, CM4 showed 75% water uptake and 28% water swelling. In RCM series, RCM1 showed 85% water uptake and 32% water swelling whereas, in RCM4 it was 68% for water uptake and 20% for water swelling. Conclusively reverse osmosis membranes gave better rejection whereas nanofiltration membrane showed enhanced flux. CM1 showed 58% of rejection with 12L/(m2h) flux and RCM1 showed 55% of rejection with 15L/(m2h) flux for 0.1wt.% NaCl solution. Whereas, in 0.1wt.% CaCl22 solution, membrane CM11 showed 78% of rejection with 12L/(m2h) flux and RCM1 showed 63% rejection with flux of 9L/(m2h).
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    Synthesis and performance characterization of PS-PPEES nanoporous membranes with nonwoven porous support
    (2013) Hegde, C.; Isloor, A.M.; Padaki, M.; Fun, H.-K.
    The present work describes about the synthesis and characterization of Polysulfone blend nanoporous membrane with nonwoven support. This Nonwoven support provides mechanical strength to membrane while filtration process and minimizes membrane fouling. Hence it helps in better membrane performance in terms of salt rejection, improved flux, thermal stability and fairly increases in proton conductivity. In this work we have used K.C.270 nonwoven material consisting of fine polyester fibers and has a thickness of below 110. ?m. © 2011.
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    Synthesis and characterization of novel sulfanilic acid-polyvinyl chloride-polysulfone blend membranes for metal ion rejection
    (Royal Society of Chemistry, 2016) Nayak, V.; Jyothi, M.S.; Balakrishna, R.G.; Padaki, M.; Isloor, A.M.
    Near-complete removal of heavy metals, namely Cd(ii), Cr(vi) and Pb(ii), has been attempted by a membrane purification process using a blend of modified polyvinyl chloride (PVC) and polysulfone (PSf), prepared by the diffusion induced phase separation (DIPS) method. The prepared novel material was characterized by NMR, ATR-IR spectroscopy and DSC. The sulphonyl groups incorporated into PVC enhance the hydrophilicity and are substantiated by water uptake, contact angle (CA) and flux studies. The obtained properties of the blend membrane like increased surface roughness and porosity are observed from AFM and SEM analysis. An enhanced rejection of ?95% which is about 1.15, 1.41 and 1.37 times better than the commercially available NF 270 membrane was observed, for Cd(ii), Cr(vi) and Pb(ii) respectively. The work was further extended to study the antifouling property and the interference of other existing metal ions on the performance. An improved antifouling property with 98.5% rejection for bovine serum albumin (BSA) and a 75.6% flux recovery ratio (FRR) was achieved. The study gains significance in exploring the incorporation of sulphonyl groups in to polymers, to enhance membrane performance. © The Royal Society of Chemistry 2016.
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    Preparation of polysulfone-based PANI-TiO2 nanocomposite hollow fiber membranes for industrial dye rejection applications
    (Royal Society of Chemistry, 2016) Pereira, V.R.; Isloor, A.M.; Zulhairun, A.K.; Subramaniam, M.N.; Lau, W.J.; A.F., A.F.
    Polysulfone-based polyaniline-TiO2 containing hollow fiber membranes were prepared via a dry wet spinning method. Polyaniline (PANI) coated TiO2 nanotubes were prepared via chemical oxidative polymerisation and were incorporated into the hollow fiber membranes at different compositions. The hollow fibers were fabricated by varying the air gap distance during the spinning process. The effects of the addition of PANI coated TiO2 and the variation in the air gap distance on membrane performance, such as morphology and the permeability of the membranes, were analysed. The addition of the PANI-TiO2 nanocomposite enhanced the hydrophilicity and antifouling ability of the prepared membranes. The polysulfone hollow fiber membranes were examined for their dye rejection of Reactive Black 5 and Reactive Orange 16. The results indicated that the polysulfone hollow fibers containing 1.0 wt% of PANI-TiO2 fabricated using a 5 cm air gap can be used as a potential candidate for industrial dye rejection and showed a maximum rejection of 81.5% and 96.5% for Reactive Black 5 and Reactive Orange 16, respectively. © 2016 Royal Society of Chemistry.
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    TiO2 nanosheet-graphene oxide based photocatalytic hierarchical membrane for water purification
    (Elsevier B.V., 2017) Nair, A.K.; JagadeeshBabu, J.
    There is a rising concern over the toxicity of nanomaterials which emphasizes the need for reforms in application of nanomaterials in water treatment. A hierarchical membrane with a thin layer of photocatalyst coated on top of the membrane surface has emerged as a better alternate for immobilization of photocatalyst. Studies have revealed that nanoparticles are not pliable for synthesis of hierarchical membranes due to their smaller size and low stability after deposition. TiO2 nanosheets serve as better alternate due their thin structure which enables stable layer formation. Integrating the nanosheets with modifiers like graphene oxide can further enhance the photocatalytic activity. The sheet structure of graphene oxide enhances stable film formation and also acts as support for interconnecting TiO2 nanosheets. In the present work, TiO2 nanosheets are modified with graphene oxide and used to develop a hierarchical membrane by depositing a catalyst coating on a support membrane. The hierarchical membrane performance was studied using Congo red dye as model pollutant and the effect of catalyst loading on the permeate flux and dye removal were analyzed. © 2017 Elsevier B.V.
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    Polyimide-graphene oxide nanofiltration membrane: Characterizations and application in enhanced high concentration salt removal
    (Elsevier Ltd, 2018) Khairul Zaman, N.K.; Rohani, R.; Mohammad, A.W.; Isloor, A.M.
    A membrane usually suffers from a reduction in membrane rejection performance when exposed to a concentrated salt solution. A fabricated polyimide (PI)/graphene oxide (GO) mixed matrix membrane (MMM) was prepared at different GO/PI concentrations (ranging from 0 to 3.5 wt%) to investigate membrane performance in diluted and concentrated salt solutions. Results showed that the MMM possess nanofiltration (NF) properties with high water permeability and excellent salt rejection (99%) in diluted conditions regardless of the applied filtration pressure. The water and permeate permeability increased with the increase in GO content. Interestingly, for concentrated salt solutions, PI/GO MMM only showed at most 4% reduction in rejection, unlike in pure PI membrane, which experienced 16% reduction. A higher amorphous region of the MMM compared to the pure PI in salt solutions was found through XRD. The ionization of GO increases the amorphous structure thus enhances the effective thickness of membrane maintaining the MMM rejection performance. 0.9 wt% GO/PI in MMM showed the highest rejection (98%) in 0.15 M Na2SO4. The presence of GO with its unique properties and highly porous structure was found to retain the membrane rejection properties, especially in concentrated solution. © 2017 Elsevier Ltd