Faculty Publications
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Item Preparation and evaluation of heavy metal rejection properties of polysulfone/chitosan, polysulfone/N-succinyl chitosan and polysulfone/N-propylphosphonyl chitosan blend ultrafiltration membranes(Elsevier, 2014) Kumar, R.; Isloor, A.M.; A.F., A.F.Heavy metal rejection properties of chitosan based polysulfone/chitosan (PSf/CS), polysulfonef/N-succinyl chitosan (PSf/NSCS) and polysulfone/N-propylphosphonyl chitosan (PSf/NPPCS) ultrfiltration (UF) membranes were evaluated. The rejection of membranes towards the copper, cadmium and nickel ions was studied during ultrafiltration (UF) by polymer enhanced ultrafiltration (PEUF) processes. The flux change during the UF process and the effect of pH on the rejection were determined. The membrane recycling property was studied during PEUF process by filtering chelated CuSO4 solution. A maximum of 78% of Cu, 73% of Ni and 68% of Cd rejection for M-5 membrane, 75% of Cu, 71% of Ni and 66% of Cd rejection for M-8 membrane and 76% of Cu, 69% of Ni and 66% of Cd rejection for M-2 membrane with reasonably good flux was observed. Further improvement in heavy metal ion rejection was achieved by PEUF process. Membrane M-5 showed a maximum of 98%, 95% and 92% rejection for Cu, Ni and Cd respectively with steady state flux of 117L/m2h. An increase in membrane recycling property after the metal ion rejection was mainly attributed to the hydrophilicity of CS, NSCS and NPPCS. © 2014 Elsevier B.V.Item Preparation and antifouling properties of PVDF ultrafiltration membranes with polyaniline (PANI) nanofibers and hydrolysed PSMA (H-PSMA) as additives(Elsevier, 2014) Pereira, V.R.; Isloor, A.M.; Bhat, K.U.; A.F., A.F.Polyaniline (PANI) nanofibers were used as hydrophilic additives to study their effect on the performance of polyvinylidene fluoride (PVDF) ultrafiltration (UF) membranes. PVDF UF membranes were prepared by the phase inversion method with hydrolyzed polystyrene-co-maleic anhydride (H-PSMA) and PANI nanofibers as additives. PANI nanofibers were synthesized by rapid mixing reaction and were used as a hydrophilic modifying agent with varying concentrations (0-1.5 wt.%) in the membranes. The synthesized PANI nanofibers were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis. Hydrolyzed PSMA was prepared by the hydrolysis of PSMA and was used as a novel pore forming additive. The addition of PANI nanofibers into the membranes increased the membrane hydrophilicity, porosity, water uptake and permeability. The membranes also showed good antifouling nature during BSA (bovine serum albumin) filtration when compared to the pristine membrane without PANI nanofibers. Membrane with 1.0 wt.% PANI content showed highest permeability among the synthesized membranes. The membrane having highest permeability was subjected to heavy metal ion rejection which showed high rejection of 98.52% and 97.38% for heavy metal ions Pb2+ and Cd2+ respectively. © 2014 Elsevier B.V.Item Fabrication of polydopamine functionalized halloysite nanotube/polyetherimide membranes for heavy metal removal(Royal Society of Chemistry, 2016) Hebbar, R.S.; Isloor, A.M.; Kulal, K.; A.F., A.F.Polydopamine modified halloysite nanotubes (HNTs) were synthesised through a one step facile procedure and employed as a well dispersed hydrophilic additive to enhance the filtration properties of polyetherimide (PEI) membranes. The nanocomposite membranes were prepared by an immersion precipitation method with different amounts of modified HNTs (MHNTs) in the casting solution. The good dispersion of MHNTs throughout the membrane matrix was confirmed by elemental mapping analysis. The prepared nanocomposite membranes were extensively studied in terms of their porosity, morphology, membrane hydraulic resistance and hydrophilicity. The permeation experiments showed that the modified membranes exhibited higher water flux than a pristine PEI membrane. The antifouling and anti-biofouling behaviour of the modified membranes was investigated in detail. The results revealed that a membrane with a 3 wt% MHNT dosage showed a higher Fouling Resistance Ratio (FRR) of 74.5% with reversible membrane fouling of 64.3%. Moreover, the membrane showed excellent resistance to microbial growth on the membrane surface. The well performing membrane was subjected to heavy metal ion rejection. Results indicated that membranes had the capacity to adsorb Pb2+ and Cd2+. Overall, PEI-MHNTs nanocomposite membranes could have great potential to improve antifouling, anti-biofouling and filtration properties. © The Royal Society of Chemistry 2016.Item Performance intensification of the polysulfone ultrafiltration membrane by blending with copolymer encompassing novel derivative of poly(styrene-co-maleic anhydride) for heavy metal removal from wastewater(Elsevier B.V., 2018) Gnani Peer Mohamed, G.P.S.; Isloor, A.M.; Siddique, I.; Asiri, A.M.; A.F., A.F.; Kumar, R.; Ahamed, M.I.A simple, scalable, novel polymer was synthesized by the aminolysis of poly(styrene-co-maleic anhydride) cumene terminated (PSMAC) using p-aminohippuric acid. The main objective was to perceive the effect of blend ratio of polysulfone (PSF) and poly[styrene-alt-(N-4-benzoylglycine-maleamic acid)] cumene terminated (PAH) on morphology and permeation properties of the membranes. The PSF/PAH blend membranes unveiled enriched hydrophilicity, porosity, zeta potential, water uptake and permeability owing to the existence of the hydrophilic PAH. However, the contact angle was not diminished over 20% of PAH ratio as there was an increase of hydrophobic alkyl group density. Differential scanning calorimetry (DSC) was employed for the determination of the glass transition temperature of the blends and the results revealed that the polymer blend is miscible in nature. Moreover, the M-3 membrane was screened for the heavy metal ion removal and achieved removal of 91.5% of Pb2+ and 72.3% of Cd2+ ions, respectively. The adsorption parameters indicated that the Langmuir isotherm model fits well for both Pb2+ and Cd2+ ions adsorption on M-3 membrane. The adsorption capacity attained from Langmuir isotherm model was 19.35 and 9.88 mg/g for Pb2+ and Cd2+ ions correspondingly. © 2018 Elsevier B.V.Item A chicken egg white-based amyloid–graphitic carbon nitride composite-incorporated hollow fiber membrane for efficient removal of dyes and heavy metal ions present in water(Royal Society of Chemistry, 2025) Nayak, S.S.; Isloor, A.M.; A.F., A.F.Severe water pollution due to excessive industrialization is resulting in a pure water crisis for humans and other living beings. This growing crisis emphasizes the urgent need for advanced and efficient water purification technologies to mitigate pollution and ensure the availability of pure water. To address this issue, the current study focuses on the synthesis of a chicken egg white amyloid–graphitic carbon nitride composite (AM–CN) using graphitic carbon nitride (g-C3N4) and egg whites through environment friendly and simple techniques. These composites were further characterized using different analytical techniques such as BET, FTIR, XRD, SEM, and TEM to understand the structure of the composite. Furthermore, these composites were embedded into hollow fiber membranes, and later, these membranes were analyzed through AFM, SEM, and hydrophilicity studies to understand the character and structure of the membrane. The filtration performance of the membrane revealed that the membrane with the AM–CN composite demonstrated enhanced performance in both pure water permeability and pollutant removal capacity. Among the fabricated membranes, the neat membrane exhibited a pure water permeability of 81 L m?2 h?1 bar?1. In contrast, the highest permeability of 203 L m?2 h?1 bar?1 was exhibited by the M II membrane, therefore considering it as an optimized membrane. This optimized membrane also displayed the highest pollutant removal capacity of >99% for Congo red dye, >98% for Reactive black 5 and 88% for Reactive orange 16 dye. In the case of heavy metal ion removal, the same membrane displayed an impressive 99% removal of lead ions and 75% removal of mercury ions in the presence of humic acid. © 2025 The Royal Society of Chemistry.Item Sustainable waste water purification via integration of novel COF@UiO-66 dual-layer PVDF/PEI hollow fiber membranes(Elsevier B.V., 2025) Prabhakar, N.; Isloor, A.M.; Othman, M.H.D.; A.F., A.F.In the present study, dual-layer (polyvinylidene fluoride (PVDF)/ polyether imide (PEI) blend membranes were fabricated by coextrusion technique, with varying loadings (0–1.5 wt%) of covalent organic framework (COF) grafted UiO-66, for dye and heavy metal ion removal. UiO-66-NH2 was chosen for its excellent surface area and water stability, which can enhance the water permeability through the membrane without getting degraded over a period of time. The structures of the synthesized UiO-66-NH2 and COF@UiO-66 were confirmed by characterizations like scanning electron microscopy (SEM), FTIR (Fourier Transform Infrared Spectroscopy), and XRD (X-ray Diffraction). The membrane fabricated with the synthesized additive in the outer layer, was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM) for the surface topography and morphology. The incorporation of the additive significantly affected the hydrophilicity, porosity, and surface area of the membrane, resulting in improved permeability and rejection, along with imparting relatively good antifouling nature to the membrane. Membrane with outer dope flow rate of 2 mL/min and an optimized loading of the additive (1.0 wt.%) displayed a water permeability of 117.5 Lm?2 h?1 bar?1, whereas the neat membrane showed only 60 Lm?2 h?1 bar?1. The dyes, Congo red and reactive black-5, showed rejections of 99.1 %, and 97.96 % respectively. Whereas, the heavy metal ions mercury and lead showed 69.58 %, and > 99.9 % in the complexed state with humic acid for the optimized membrane, along with a bovine serum albumin (BSA) fouling rejection ratio of 74.22 %. Whereas the neat membrane without the MOF additive showed 89 %, 79 %, 75 %, and 43 % rejections for reactive black 5, congo red, lead, and mercury ions, respectively, with an FRR of only 57 %. © 2025 Elsevier B.V.