Faculty Publications
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Item 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.Item 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.Item Synthesis, and antitubercular and antimicrobial activity of 1?-(4-chlorophenyl)pyrazole containing 3,5-disubstituted pyrazoline derivatives(Royal Society of Chemistry, 2016) Harikrishna, N.; Isloor, A.M.; Kulal, K.; AlObaid, A.; Fun, H.-K.A new series of 1?-(4-chlorophenyl)-5-(substituted aryl)-3?-(substituted aryl)-3,4-dihydro-2H,1?H-[3,4?]bipyrazolyl derivatives (6a-e, 8a-e, 10a-e) have been synthesized, characterized and screened for antimicrobial and antitubercular activity. Among the synthesized compounds, the minimum inhibition concentration of 10e was found to be as low as 1.56 ?g ml-1 and that of 10c was 6.25 ?g ml-1 as compared to the standard anti-tb drugs pyrazinamide and streptomycin. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2016.Item Favorable influence of mPIAM on PSf blend membranes for ion rejection(Elsevier B.V., 2017) Jyothi, M.S.; Soontarapa, K.; Padaki, M.; Balakrishna, R.G.; Isloor, A.M.The study reports the use of a novel membrane for heavy metal removal and salt rejection. Poly isobutylene alt maleic anhydride (PIAM) modified by sulfanilic acid is blended with polysulfone (PSf) in different concentrations. This induces surface charge and hydrophillicity in the otherwise hydrophobic PSf membranes. The so modified polymers and their blends are characterized by spectroscopic and microscopic techniques. Blend membranes show drastically enhanced performance with respect to water flux, water uptake and ion exchange capacity. SEM micrographs indicate the hydrophilic domains, –SO3H groups in the polymer to have formed cavities during phase inversion process, thus enhancing permeability. 100% rejection of PEG 2000 and 59% of NaCl rejection substantiated the nature of the membrane to be nanofiltration (NF) type. The prepared membranes were further evaluated for Cr (VI) removal, with removal efficiency reaching above 92%. The electronic coupling that occurs between SO3H? and Na+ and the electrostatic interaction between metal ions and the charge on membrane facilitates NaCl and Cr (VI) rejection respectively. The study gains significance in use of such modified PIAM as blend material with any other polymer to enhance the native properties of the blend membrane. © 2017 Elsevier B.V.Item Antitubercular and antimicrobial activity of nh4vo3 promoted 1,4-dihydropyridine incorporated 1,3,4-Trisubstituted pyrazole(Bentham Science Publishers B.V. P.O. Box 294 Bussum 1400 AG, 2017) Harikrishna, N.; Isloor, A.M.; Kulal, K.; Parish, T.; Jamalis, J.; Ghabbour, H.A.; Fun, H.-K.Background: A new series of pyrazole containing 1,4-dihydropyridine derivatives 5a-i and 6a-i were synthesized from substituted acetylated aryls and substituted phenylhydrazine by the multistep reaction. Method: The target compounds 1,4-dihydropyridine derivatives were obtained from green synthesis of 1,3-disubstituted phenyl-1H-pyrazole-4-carbaldehydes 4a-i with ethyl acetoacetate and methyl acetoacetate at higher temperatures in the presence of ammonium acetate and the catalytic amount of ammonium metavanadate (NH4VO3). The role of ammonium metavanadate was increases rate of the reaction and obtained high yields. Result: Structures of newly synthesized 1,4-dihydropyridine moiety containing pyrazole derivatives were confirmed by FT-IR, NMR and Mass spectral studies. The structure of compound 5b was confirmed by S-XRD study. Further, these compounds were tested for in-vitro antitubercular and antimicrobial studies. Compounds 5a, 5b, 5i, 6a, 6b, 6g, 6h, and 6i were found to be active against all the bacterial microorganisms. Conclusion: The above mentioned compounds have shown lowest MIC ranging between 3.12-12.5 ?g/ml against Mycobacterium tuberculosis and MIC values ranging between 7.8- 15.6 ?g/ml for Mycobacterium smegmatis, Staphylococcus aureus and Pseudomonas aeruginosa. For the control of life threatening diseases such as tuberculosis, these eight compounds may be strongly promising synthetic compounds. © 2017 Bentham Science Publishers.Item 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.Item 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.Item 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.Item 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.Item Efficient multi-pollutant removal: The role of Keggin polyoxometalates in polysulfone-chitosan blend membranes(Elsevier B.V., 2025) Fashapoyeh, M.A.; Shokrollahzadeh, S.; Isloor, A.M.; Streb, C.Membrane filtration is a vital area in separation science, providing an effective method for water purification due to the unique properties of membranes. This study presents the development of blend membranes composed of polysulfone (PS), chitosan (CS), and polyvinyl alcohol (PVA), incorporating two types of Keggin polyoxometalates: K?[?-SiW??O??] ({SiW11}) and K?[?-SiW??O??] ({SiW12}) at a concentration of 0.05 to 1.0 wt% each. Our findings reveal that the incorporation of 0.1 wt% {SiW11} results in an optimum membrane exhibiting high porosity, a finger-like pore structure, and enhanced hydrophilicity. This membrane achieves a water flux of 34.8 L/m2h and significantly enhances the simultaneous removal of multiple pollutants. Specifically, this membrane achieved rejection rates of >88 % for heavy metal ions (Ni2+, Cu2+, and Pb2+) and > 98 % for organic dyes (Congo Red and Methylene Blue). The improved rejection rates and water fluxes observed with the optimal amounts of polyoxometalates (POMs) can be attributed to the combined effects of surface charge (Donnan effect), size exclusion, and adsorption at the binding sites of the POMs. Notably, the nanofiltration membrane containing {SiW11} outperformed the one with {SiW12} in filtering multi-contaminant solutions, underscoring its superior effectiveness. © 2025 Elsevier B.V.