Faculty Publications

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    Probing the morphology and anti-organic fouling behaviour of a polyetherimide membrane modified with hydrophilic organic acids as additives
    (Royal Society of Chemistry, 2015) Hebbar, R.S.; Isloor, A.M.; A.F., A.F.; Shilton, S.J.; AlObaid, A.; Fun, H.-K.
    A facile approach for the preparation of an organic antifouling polymer membrane has been developed using low molecular weight organic acids as additives. The presence of these additives in the membrane was analysed by FTIR spectroscopy. The properties of the modified membranes were investigated in terms of contact angle, water uptake capacity, SEM and AFM analysis. These additives exerted a strong impact on the rheological properties of the casting solution, thereby altering the membrane morphology, surface roughness, water flux and the hydrophilicity of the membranes, as compared to those of the pristine polyetherimide (PEI) membrane. The organic antifouling properties of the modified membrane were analysed by filtering both bovine serum albumin (BSA) and humic acid solutions. The results showed that the additives exhibited a remarkable improvement in the antifouling properties (FRR of 72%) and a humic acid rejection of up to 86%. These outcomes offer new insights into the use of cheaper and readily available organic acids as additives, compared to the traditional, synthetic polymer materials as additives in membrane preparation. ©2015 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
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    Fabrication of a novel hollow fiber membrane decorated with functionalized Fe2O3 nanoparticles: Towards sustainable water treatment and biofouling control
    (Royal Society of Chemistry, 2017) Hebbar, R.S.; Isloor, A.M.; Kulal, K.; Abdullah, M.S.; A.F., A.F.
    The development of sustainable, surface-functionalized hollow fiber membranes with advanced nanomaterials has enabled the tailoring and targeted control of their physicochemical properties. This provides the material with improved features of hydrophilicity and permeability, excellent selectivity, and superior antifouling and antimicrobial activity. We explored a new strategy using well dispersed functionalized Fe2O3 nanoparticles to fabricate a polyetherimide nanocomposite hollow fiber membrane with enhanced surface and anti-biofouling properties. To confirm the membrane modification, a series of characterizations such as contact angle, surface energy, water uptake capacity, porosity, zeta potential, and morphological analysis were performed. The permeation experiment indicated superior hydrodynamic permeability and antifouling properties with more than 95% rejection of BSA protein molecules after inclusion of a 1.5 wt% additive dosage. Moreover, the nanocomposite membrane exhibited a relatively higher normalized flux and rejection up to 94% during the filtration of hazardous natural organic matter (NOM) with differing parameters such as the feed solution pH and ionic strength. The presence of modified Fe2O3 nanoparticles in the membrane significantly inhibits the growth of bacteria and other microorganisms on the membrane surface, resulting in an enhanced anti-biofouling property. In particular, the demonstrated method illustrates a fast, facile strategy for the functionalization of Fe2O3 nanoparticles to improve the membrane properties and anti-biofouling activity, giving them great potential for effective and sustainable water treatment applications. © 2017 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
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    Improvement in performance of polysulfone membranes through the incorporation of chitosan-(3-phenyl-1h-pyrazole-4-carbaldehyde)
    (Cogent OA info@CogentOA.com, 2017) Balakrishna Prabhu, K.; Saidutta, M.B.; Isloor, A.M.; Hebbar, R.S.
    Pure polysulfone membranes are known to exhibit poor permeability, and high fouling. This study was conducted to explore the possibility of improving the permeation characteristics of polysulfone membranes by using a chitosan derivative as an additive. Polysulfone membranes blended with chitosan derivative 3-phenyl-1H-pyrazole-4-carbaldehyde (ChD) were prepared by the method of wet coagulation. The hydroxyl, amine and the imine functional groups present in the ChD evidently increased the hydrophilicity of the surface of the blended membranes which was confirmed by contact angle measurements. The contact angle of the blended membrane having 2 wt.% ChD was 62 ± 1 as compared to 70 ± 1 of neat polysulfone membrane. The SEM analysis of the blended membranes revealed a highly porous structure with a very thin surface skin layer, finger like projections in the sub-layer with a macro void structure at the base. The blended membranes also showed significant improvement in pure water flux of 351 L m?2 h?1 at 0.8 MPa trans membrane pressure (TMP) as compared to 24 L m?2 h?1 of neat polysulfone membrane at the same TMP. The anti-fouling test using bovine serum albumin exhibited improved anti-fouling characteristic of blended membranes with a maximum flux recovery ratio (FRR) of 57%. The heavy metal rejection study revealed that membrane P-1 showed maximum 36 and 29% rejection for Pb and Cu respectively. © 2017 The Author(s). This open access article is distributed under a Creative Commons Attribution (CC-BY) 4.0 license.