Silica hollow spheres-based superhydrophobic PDMS composite membrane for enhanced acetone permselective pervaporation

Superhydrophobic mixed matrix membranes (SMMMs) are very desirable for efficient separation of biofuel recovery from the fermentation broth via pervaporation. In this work, hydrophobic silica hollow spheres (SHSs) were elaborately prepared by template method and subsequent silane modification. The resulting SHSs were incorporated into polydimethylsiloxane (PDMS) matrix to construct superhydrophobic SHSs/PDMS MMMs. The superhydrophobic composite membrane with 15 wt% SHS contents showed a water contact angle of up to 160°, with low sliding angle of less than 5°. As a result, for the permselective pervaporation of 1 wt% acetone aqueous solution at 35 °C, the optimized composite membrane with separation factor of 46 increased by 256%, and maintained a comparable total flux compared with the pure PDMS membrane. The slight decrease of the total flux was mainly attributed to the reduced water partial flux resulting from water repellency of the superhydrophobic membrane surface. Thus, our proposed strategy of constructing superhydrophobic composite membranes may provide new insights into the development of high-performance pervaporation membrane for biofuel recovery.