Faculty Publications

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Publications by NITK Faculty

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Author: search.filters.author.Isloor, A.M.Subject: search.filters.subject.contact angle

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Now showing 1 - 7 of 7
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    Synthesis and characterization of novel water soluble derivative of Chitosan as an additive for polysulfone ultrafiltration membrane
    (2013) Kumar, R.; Isloor, A.M.; A.F., A.F.; Matsuura, T.
    A novel water soluble Chitosan derivative N-propylphosphonic Chitosan (NPPCS) having a terminal phosphonic acid group was synthesized by reacting Chitosan with Hydroxybenzotriazole (HOBt) and propylphosphonic anhydride (T3P)® via one pot reaction. The novel derivative was characterized by 1H NMR, Attenuated Total Reflectance Infra Red (ATR-IR) spectroscopy and XRD. Due to insolubility of NPPCS in organic solvents, a new process was demonstrated for blending of NPPCS with Polysulfone. The proper blending of NPPCS with Polysulfone was confirmed by ATR-IR spectroscopy. The improved hydrophilicity of PSf/NPPCS membranes was confirmed by contact angle measurement. The permeation studies showed increased flux of PSf/NPPCS membranes as compared to the pristine Polysulfone membrane. The antifouling property of PSf/NPPCS membrane was determined by Bovine Serum Albumin (BSA) protein rejection studies. The membranes showed the enhanced antifouling property as compared to pristine Polysulfone membranes with a maximum of 74% flux recovery ratio (FRR) value. © 2013 Elsevier B.V.
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    Preparation, characterization and the effect of PANI coated TiO2 nanocomposites on the performance of polysulfone ultrafiltration membranes
    (Royal Society of Chemistry, 2015) Pereira, V.R.; Isloor, A.M.; Ahmed, A.A.; A.F., A.F.
    Polysulfone ultrafiltration (UF) membranes with PANI-TiO2 (polyaniline-titania) nanocomposites and PEG 1000 (Polyethylene Glycol 1000) as additives were prepared by the phase inversion method. PANI-TiO2 nanocomposites were synthesized by coating TiO2 nanotubes with PANI via chemical oxidative polymerization. The synthesized PANI-TiO2 nanocomposite was characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD) and Transmission Electron Microscope (TEM) analysis. PANI-TiO2 nanocomposites with varying concentrations (0-1.5 wt%) were dispersed in the polysulfone membrane matrix with N-methyl-2-pyrrolidone (NMP) as solvent along with PEG 1000 as the pore former. The effect of addition of PANI-TiO2 nanocomposites with different concentrations (0-1.5 wt%) on the membrane structure, performance, hydrophilicity and the antifouling nature of the membranes was analyzed. PANI-TiO2 nanocomposite membranes showed better hydrophilicity, improved permeability, enhanced porosity, water uptake and good antifouling ability when compared with neat polysulfone membranes. The performance of the membranes improved with the increase in the addition of the PANI-TiO2 nanocomposite. However, the membrane performance decreased slightly at 1.5 wt% addition of PANI-TiO2 due to the agglomeration of PANI-TiO2 at higher concentration. The well performed membranes were also subjected to heavy metal ion rejection. The membranes showed a rejection of 83.75% and 73.41% during the polymer enhanced ultrafiltration (PEUF) process and a rejection of 68% and 53.78% during the UF process for Pb2+ and Cd2+ respectively. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2015.
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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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    Use of cellulose acetate/polyphenylsulfone derivatives to fabricate ultrafiltration hollow fiber membranes for the removal of arsenic from drinking water
    (Elsevier B.V., 2019) Kumar, M.; Todeti, S.; Isloor, A.M.; Gnani Peer Mohamed, G.P.S.; Siddique, I.; Ismail, N.I.; A.F., A.F.; Asiri, A.M.
    Cellulose acetate (CA) and cellulose acetate phthalate (CAP) were used as additives (1 wt%, 3 wt%, and 5 wt%) to prepare polyphenylsulfone (PPSU) hollow fiber membranes. Prepared hollow fiber membranes were characterized by surface morphology using scanning electron microscopy (SEM), surface roughness by atomic force microscopy (AFM), the surface charge of the membrane was analyzed by zeta potential measurement, hydrophilicity by contact angle measurement and the functional groups by fourier transform infrared spectroscopy (FTIR). Fouling resistant nature of the prepared hollow fiber membranes was evaluated by bovine serum albumin (BSA) and molecular weight cutoff was investigated using polyethylene glycol (PEG). By total organic carbon (TOC), the percentage rejection of PEG was found to be 14,489 Da. It was found that the hollow fiber membrane prepared by the addition of 5 wt% of CAP in PPSU confirmed increased arsenic removal from water as compared to hollow fiber membrane prepared by 5 wt% of CA in PPSU. The removal percentages of arsenic with CA-5 and CAP-5 hollow fiber membrane was 34% and 41% with arsenic removal permeability was 44.42 L/m2h bar and 40.11 L/m2h bar respectively. The increased pure water permeability for CA-5 and CAP-5 hollow fiber membrane was 61.47 L/m2h bar and 69.60 L/m2 h bar, respectively. © 2019 Elsevier B.V.
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    Biological and Physical Characterization of Surface-Modified Grade v Titanium Alloy
    (Hindawi Limited, 2024) Kakunje, M.; Nambiar, S.; Isloor, A.M.; Kabekkodu, S.; Bhat K, U.
    Surface modification and biomimetic approaches have been widely used to enhance bioinert substances. It is not very clear whether surface alterations and polymer coatings on titanium make it more biologically active and enhance cell adhesion. We tried to focus on the physical and biological characterization of surface-modified titanium disks. Four different surface modifications were done for the titanium disks, ranging from acid etching, sandblasting, polydopamine coating, and polydopamine-based chitosan coating, and were compared with disks without any surface modification. The disks were studied for physical characteristics like surface roughness and contact angle. Human gingival fibroblasts were used to investigate the biological effects of surface modification of titanium alloy surfaces. The wettability of chitosan-coated, acid-etched, and polydopamine-coated titanium was much better than that of the sandblasted surface, indicating that surface energy was higher for acid-etched and coated surfaces than others. The cell seeding with fibroblasts showed increased adhesion to the smoother surfaces as compared to the rougher surfaces. Polydopamine coatings on titanium disks showed the most favorable physical and biological properties compared to others and can be a good surface coating for in vivo implants. © 2024 Mahesh Kakunje et al.
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    Development of polymeric ionic poly(VBC-co-VI) nanoparticle incorporated thin film nanocomposite membranes for dye and salt rejection
    (Royal Society of Chemistry, 2025) Mendonca, N.R.; Isloor, A.M.; Farnood, R.
    Water is an important life-sustaining liquid. However, due to the current anthropogenic activities, this resource is diminishing. This work explores a method for the potential reuse of textile wastewater containing salts by utilization of thin film composite (TFC) membranes fabricated by means of interfacial polymerization on a macroporous membrane substrate composed of 15% polysulfone (PSf). A relatively lesser known variety of nanoparticles termed ionic polymeric nanoparticles were integrated into the dense polyamide (PA) layer. The ionic poly(VBC-co-VI) nanoparticles were synthesized in the laboratory via quaternary precipitation polymerization (QPP) of the monomers 1-vinyl imidazole (VI) and 4-vinybenzyl chloride (VBC) by the utilization of 2,2?-azobis(2-methylpropionitrile) (AIBN) as the free radical initiator in the solvent acetonitrile (ACN) in a single step. The synthesized nanoparticles existing in the PA layer improved the water permeability as well as the rejection capacity of the membranes. The fabricated membranes showed a dye rejection of 98% for Reactive Black 5 and >95% for Sunset Yellow FCF having a concentration of 100 ppm. The salt rejection for NaCl, MgCl, Na2SO4 and MgSO4 at 1000 ppm concentration was found to be 36%, >50%, 85% and 85%, respectively. © 2025 The Royal Society of Chemistry.