Investigation into glutaraldehyde crosslinked chitosan/cardo-poly-etherketone composite membrane for pervaporation separation of methanol and dimethyl carbonate mixtures

Separations of methanol and dimethyl carbonate mixtures were performed by a pervaporation process using chitosan-based composite membrane GA–STA–CS/PEK-C, which was prepared using silicotungstic acid hydrate (STA) filled chitosan (CS) as active layer and cardo-polyetherketone (PEK-C) as substrate, then crosslinked with glutaraldehyde (GA). To optimize the pervaporation performance of active layer of the composite membrane, the homogeneous membranes GA–STA–CS were also prepared and investigated. The membranes were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and contact angle meter methods. Sorption experiments indicated that the glutaraldehyde content, feed methanol concentration and temperature greatly affected swelling degree, solubility selectivity and diffusion selectivity of the homogeneous membranes GA–STA–CS. The pervaporation results showed that the GA–STA–CS had the highest permselectivity when glutaraldehyde content was 0.3 wt%. Feed methanol concentration significantly affected the pervaporation performance of the membranes. The prepared GA–STA–CS/PEK-C had excellent separation performance with a flux of 910.2 g m−2 h−1 and separation factor of 120.3 at 10 wt% feed methanol concentration at 30 °C.