Experiment and modeling of hydrophobic membranes for removal of organics from aqueous solution by pervaporation

Abstract

Pervaporation(PV) has the advantages of high efficiency, low consumption and cleanliness, and it is widely used in the separation of organic-water or organic-organic systems. In this paper, the separation of five azeotropic systems with different molecular weights was discussed by simulation and experiment. First, a hydrophobic and alcohol-loving PDMS/ PVDF-PTFE membranes with stable mechanical properties were prepared by scraping polydimethylsiloxane (PDMS) onto the support layer of PPTFE-PVDF membranes. The relatively better membrane preparation conditions were established by SEM, FTIR and water contact angle. Then, the dissolution and diffusion processes of five azeotropic systems were simulated by Materials Studio (MS). The simulated permselectivity of order: ethyl acetate/water > 1-butanol/water > pentanol/water > isobutanol/water > ethanol/water. Finally, corresponding to the simulation, the separation performance of PDMS/PVDF-PTFE membrane for five azeotropic systems was investigated. The order of pervaporation separation index(PSI) of five azeotropic systems in the membrane as ethyl acetate/water > 1-butanol/water > pentanol/water > isobutanol/water > ethanol/water. The experimental separation results of five azeotrope systems were consistent with the MS simulation results. It shows that the MS simulation can provide some theoretical guidance for the experiment, and realize the possibility of reducing the experimental cost and workload through cheap computer resources.