Amino-functionalized poly(vinyl alcohol) membranes for enhanced water permselectivity

The surfaces of poly(vinyl alcohol) (PVA) membranes are treated using γ-aminopropyl triethoxysilane (APTEOS) to prepare PVA/APTEOS hybrid membranes. The as-prepared membranes are characterized by wide-angle X-ray diffraction (WXRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), contact angle meter and X-ray photoelectron (XPS). The performance of the membranes is investigated for pervaporation separation of ethanol/water (85/15) mixtures. The effect of surface treating time and feed temperature is studied. The surface-treated membranes exhibit good water permselectivity. The separation factor increases with increasing the APTEOS content, and first increases with increasing treating time below 120 min then slightly decreases afterwards. However, the separation factor is found to demonstrate a unique temperature dependence in a range 50–70 °C.