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Polysulfone (psf)/nanoclay mixed matrix ultrafiltration membranes with N-methyl pyrrolidone as a solvent and polyvinylpyrrolidone (PVP) as porogen were prepared using phase inversion techniques. Unlike the other nanocomposites membranes prepared using nanoclays, the present work deals with the incorporation of montmorillonite clay (MMT) and MMT modified with methyl dihydroxy ethyl hydrogenated tallow ammonium (mMMT) to psf matrix as nanoparticle to improve the performance of the membrane. The amount of PVP is optimised by analysing porosity and equilibrium water content. The thermal, chemical and morphological characterisation is carried out using X-ray diffractometer, thermal gravimetric analyser, FTIR and scanning electron microscopy. From the studies, it is found that membrane with 0.6% PVP has higher porosity with a lower contact angle. The water flux and chromium (VI) ion rejection were studied using a crossflow filtration unit. The MMT and mMMT concentration was varied from 1 to 5% and found that polymer nanocomposite membrane (psf/mMMT) with 3% mMMT is having higher rejection and flux. Antifouling performance of the pristine membrane, psf/MMT and psf/mMMT membrane was conducted using bovine serum albumin as organic foulant. The flux recovery ratio of psf/mMMT membrane with 3% mMMT increased to 83%, which is higher than the pristine polysulfone membrane, and the total fouling is reduced to 39%. [ABSTRACT FROM AUTHOR]

The biodegradability of polycaprolactone (PCL) and the anti-fouling property of TiO2 are utilized for the preparation of membranes for water treatment. Polyethylene glycol (PEG) is added to the polymeric solution to increase the pore formation in the membranes. The composition of PEG and TiO2 nanoparticles was optimized using the central composite design and response surface methodology. Quadratic models were developed for the responses porosity and contact angle, and the optimum compositions obtained for PEG and TiO2 were 6.24 and 1 wt%, respectively. The competency of the membrane for water treatment is studied using different characterization techniques such as TG analysis, FTIR to determine the chemical interactions, UTM to examine the mechanical strength, AFM for membrane roughness determination and morphological analysis using FESEM. A twofold increase in the overall porosity and a twentyfold reduction (approx.) in pore size were observed for the composite membrane from FESEM images. The anti-fouling ability of TiO2 resulted in a flux recovery of about 90% for the composite membrane compared to the PCL–PEG membrane after bovine serum albumin filtration. Also, the presence of TiO2 increased the reversible fouling component, which can be easily removed by cleaning/backwashing. Thus, the PCL–TiO2 combination would be a better alternative for the membranes used in water treatment applications. [ABSTRACT FROM AUTHOR]