Faculty Publications
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Publications by NITK Faculty
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Item Antifouling and performance enhancement of polysulfone ultrafiltration membranes using CaCO3 nanoparticles(2013) Nair, A.K.; Isloor, A.M.; Kumar, R.; A.F., A.F.Calcium carbonate nanoparticles were synthesized from calcium nitrate via chemical precipitation method. The nanoparticles were characterized using scanning electron microscope (SEM), Attenuated total reflectance infra red (ATR-IR) spectrum and by X-ray diffraction (XRD). These nanoparticles were used as additive for polysulfone (PSf) ultrafiltration membrane along with polyethylene glycol (PEG) as pore forming agent. The PSf hybrid membranes were characterized by ATR-IR, XRD, and SEM studies. ATR-IR and XRD results indicated the successful incorporation of the nanoparticles in the membranes. Cross sectional images of the membranes along with the elemental mapping of calcium on the membrane surface were assessed using SEM. Hydrophilicity of the membranes was evaluated in terms of contact angle measurements. The permeability of the membranes was determined by measuring the pure water flux (PWF). Membranes were also subjected to antifouling studies using bovine serum albumin (BSA) as the standard protein for rejection. The membranes showed better permeability and antifouling property with the increased addition of CaCO3 nanoparticles. © 2013 Elsevier B.V.Item Performance enhancement of polysulfone ultrafiltration membrane using TiO2 nanofibers(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2016) Nair, A.K.; Shalin, P.M.; JagadeeshBabu, P.E.Titanium dioxide nanofibers were synthesized via alkaline hydrothermal method using TiO2 nanopowder. The hydrothermal method was optimized by studying the operating variables to obtain nanosized TiO2 fibers. These nanofibers were used to make composite polysulfone ultrafiltration membranes along with polyethylene glycol as pore forming agent. The obtained samples were characterized using scanning electron microscope, X-ray diffraction, and attenuated total reflectance infrared spectroscopy. Contact angle measurements were used to estimate hydrophilicity of the membrane. Performance of the membrane was analyzed using pure water flux studies and antifouling studies with bovine serum albumin as the standard protein for rejection. The composite membranes exhibited better performance in both permeability and antifouling property. © 2015 Balaban Desalination Publications. All rights reserved.Item Synthesis and characterisation of TiO2 nanofibre/cellulose acetate nanocomposite ultrafiltration membrane(Taylor and Francis Ltd. michael.wagreich@univie.ac.at, 2017) Neelapala, S.D.; Nair, A.K.; JagadeeshBabu, J.Nanofibres of TiO2 were synthesised by hydrothermal routine. Cellulose acetate/TiO2 nanofibre composite membranes were synthesised via blending TiO2 nanofibre in cellulose acetate solutions in 1-methyl-2-pyrrolidone. In order to study the effect of addition of nanofibre, membranes with various composition were synthesised, first by keeping cellulose acetate to 1-methyl-2-pyrrolidone ratio constant and second by decreasing cellulose acetate concentration with increasing addition of TiO2 nanofibre. The membranes were characterised using scanning electron microscope and X-ray diffraction. Hydrophilicity of the membranes was evaluated in terms of contact angle measurements and water uptake study. Permeation characteristics were determined in terms of pure water flux and bovine serum albumin rejection. Antifouling property was studied in terms of flux recovery after rejection. Remarkable improvement in membrane flux and antifouling properties is achieved by the addition of TiO2 nanofibres. © 2017 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.Item Synthesis and characterization of silver decorated polysulfone/cellulose acetate hybrid ultrafiltration membranes using functionalized TiO2 nanoparticles(Desalination Publications dwt@deswater.com, 2017) Sri, K.S.; Nair, A.K.; JagadeeshBabu, J.Amine functionalized TiO2 nanoparticles were synthesized via surface reaction with 3-Aminopropyl triethoxysilane. These nanoparticles were added to polysulfone and cellulose acetate blend casting solutions in 1-Methyl-2-pyrrolidone to form hybrid membranes by phase inversion. The amine groups on the surface of the membranes were used as absorption sites for silver nanoparticles. The obtained membranes were characterized using Fourier Transform Infra Red spectroscopy, Scanning electron microscope and X-ray diffraction. Water uptake studies and contact angle measurements were done to evaluate hydrophilicity of the membranes. Pure water flux studies of the membrane were carried out in a dead end filtration unit. Rejection and antifouling studies were carried out using bovine serum albumin as a model protein. The hybrid membranes exhibited better permeability and fouling resistance. The hybrid membranes with silver decoration on the surface showed microbial resistance. © 2017 Desalination Publications. All rights reserved.Item 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.Item Ag-TiO2 nanosheet embedded photocatalytic membrane for solar water treatment(Elsevier Ltd, 2017) Nair, A.K.; JagadeeshBabu, P.E.Solar photocatalytic degradation of contaminants in waste water using nanocatalysts is potentially sustainable water treatment. The major challenges in using nano size photocatalysts is catalyst recovery and its toxic effect. In the present work, the problem of catalyst recovery is mitigated by immobilising the photocatalyst on the surface of a membrane by pressurized ultrafiltration method. The membrane thus synthesised is capable of simultaneously degrading and filtering the pollutants. The photocatalyst employed in this work is silver doped TiO2 nanosheets, their thin structure and larger size favoured stable film formation on the membrane surface. The nanosheets were synthesised via hydrothermal route and their photocatalytic efficiency was future enhanced by doping with silver. The nanosheets were characterised using scanning electron microscopy, X-ray diffraction and energy dispersive X-ray spectroscopy. Photocatalytic degradation studies were conducted using Congo red dye as the model pollutant. The effect of catalyst loading on permeation properties and dye removal were studied under ultra violet irradiation. M-200 membrane with Ag-TNS loading of 136.98 gm-2 was found optimum for superior flux and dye removal. M-200 membrane also showed good performance under solar radiation. © 2017 Elsevier Ltd.Item TiO2 nanosheet incorporated polysulfone ultrafiltration membranes for dye removal(Desalination Publications dwt@deswater.com, 2018) Nair, A.K.; Kumar, B.V.; Kalaiarasan, G.; JagadeeshBabu, J.B.Incorporation of nanomaterials in polymeric membranes is an effective means to improve membrane performance. In the present work, a novel additive TiO2 nanosheet was incorporated in polysulfone membrane. TiO2 nanosheets were synthesised by hydro-thermal method and blended with polysulfone to give nanocomposite membranes. The membranes performance was evaluated via pure water flux, bovine serum albumin rejection and anti fouling studies. Further the membranes were subjected to dye rejection application using Congo red and Rhodamine-B dyes. The membranes were characterised using scanning electron microscopy; X-ray diffraction and contact angle measurement. The nanocomposite membranes exhibited superior permeation, anti fouling and dye rejection traits. © 2018 Desalination Publications. All rights reserved.