James Antony Prince; Sowrirajalu Bhuvana; Vanangamudi Anbharasi; K.V. Kamelia Boodhoo; Gurdev Singh
Abstract
Bio-fouling is a major issue in all membrane-based water treatment systems and there are several cleaning methods available to address this problem. Current membrane modification methods are focused on improving the hydrophilicity of membranes by blending hydrophilic additives or blending antibacterial ...
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Bio-fouling is a major issue in all membrane-based water treatment systems and there are several cleaning methods available to address this problem. Current membrane modification methods are focused on improving the hydrophilicity of membranes by blending hydrophilic additives or blending antibacterial compounds with the dope solution. In this study, we demonstrate a new method to impart bio-fouling resistance to a membrane surface by developing a water-insoluble unique copolymer additive, namely poly (acrylonitrile co maleic acid co di-amino maleio-nitrile) (PANCMACDAMN) with highly hydrophilic carboxylic and amine functional groups. Hydrophilic polyethylene glycol functionalized with silver (Ag) was grafted to the copolymer backbone to further improve the hydrophilicity. The final additive PEG-Ag attached PANCMACDAMN was used to modify polyethersulfone (PES) ultrafiltration (UF) membrane. Characterization tests indicate that the innovative surface chemistry increases the hydrophilicity of the membrane by reducing the water contact angle (CAw) by 78.1% and increases its permeability by 120% compared to the control membrane. More importantly, the innovative surface chemistry prevents protein attachment and exhibits inhibition to microbes even after 720 min of continuous protein solution filtration.
Ana Flávia R. Silva; Nelcy D. S. Mohallem; Marcelo M. Viana
Abstract
In this work, TiO2 and Ag/TiO2 thin films were synthesized on glass by combination of sol-gel method and dip-coating deposition technique. Thermal treatment in temperatures ranging from 100 °C to 500 °C was used to evaluate changes in structure, morphology and texture of these materials. Adherent ...
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In this work, TiO2 and Ag/TiO2 thin films were synthesized on glass by combination of sol-gel method and dip-coating deposition technique. Thermal treatment in temperatures ranging from 100 °C to 500 °C was used to evaluate changes in structure, morphology and texture of these materials. Adherent and microcrack-free films were obtained. The structural and morphological evolution with temperature was studied by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Average particle size and roughness were determined by atomic force microscopy (AFM). The films were tested for wettability by measuring the contact angle between a drop of distilled water and the material surface. Results of hydrophobic/hydrophilic tests using UV-C irradiation showed that the films change their hydrophobic character to hydrophilic reaching even the superhydrophilic character which indicates their potential application as self-cleaning coatings.