Development and performance characteristics of silane crosslinked poly(vinyl alcohol)/chitosan membranes for reverse osmosis

Abstract Novel thin film poly(vinyl alcohol)/chitosan (PVA/CS) based reverse osmosis membranes infused with silane crosslinked tetraethylorthosilicate (TEOS) were prepared by dissolution casting methodology. The performance characteristics and the scope of the reverse osmosis membranes were explicated by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyzer (TGA), differential scanning calorimetery (DSC), scanning electron microscopy (SEM), contact angle, X-ray diffraction (XRD) and reverse osmosis (RO) permeation tests which determined the functional groups and network of covalent crosslinks, thermal properties, morphology, hydrophilicity, structural investigation and RO properties, respectively. It was found that the membrane surface became smoother, more hydrophilic, with improved thermal stability, increased salt rejection and good permeation flux after the appropriate infusion of TEOS. The crosslinked membranes showed more hydrophilicity compared to the uncrosslinked PVCS membrane. The SEM micrographs of membranes revealed dense structure with no mottled surfaces. PVCS-4 showed an optimal flux of 1.84 L/m 2 h and 80% salt rejection that confirmed the selective interaction of TEOS molecules with PVA/CS polymer backbone compared to the pristine (PVCS) membrane. The antibacterial properties of the membranes showed the inhibition of the growth of Escherichia coli successfully.