The modified polydimethysiloxane (PDMS) hybrid membranes with hydrophobic nano SiO2 as filler and using PVDF film as support layer were prepared for pervaporation of n-butyl acetate from aqueous solution. The physciochemical properties of membranes were characterized by SEM

FTIR

XRD

tensile testing

contact angle and positron annihilation lifetime spectroscopy(PALS). The effects of the loading of SiO2

feed concentration

feed temperature on swelling behavior and pervaporation performance were studied. The results indicated that SiO2 particles dispersed uniformly in the membrane material and no chemical change occurred between SiO2 and PDMS polymer chain. The mechanical strength and hydrophobic properties of the filled film were obviously improved by incorporation of SiO2. With the increase of SiO2 content

the adsorption capacity of n-butyl acetate increased and then decreased

while the permeation flux decreased and the separation factor increased initially and then decreased. When SiO2 content was 4%(mass)

the permeation flux increased while the separation factor increased initially and then decreased with the rise of the feed concentration. The permeation flux increased with increase of the feed temperature

however

the separation factor decreased. The maximum values of the permeation flux and the separation factor were 240 g·m-2·h-1 and 542 respectively.