Preparation and characterization of siloxane composite membranes for n-butanol concentration from ABE solution by pervaporation

A poly(vinylidenefluoride) (PVDF) layer was obtained by casting PVDF/N-methylpyrrolidone solution on a poly(ethylene terephthalate) non-woven sheet using phase inversion. Polydimethylsiloxane (PDMS) and phenyltrimethoxysilane (PhTMS) were cured on PVDF layer surfaces to obtain composite membranes. Multilayer polyphenylsiloxane (PPhS)/PDMS/PVDF composite membranes were prepared for butanol separation in acetone/butanol/ethanol (ABE). The composite membranes were characterized by using field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, and contact angle analysis. Membrane performances were examined using pervaporation with feed solutions of ABE and water. The permeate flux and separation factor for PPhS/PDMS/PVDF were 261.4 g/m2 h and 46.82 in pervaporation separation of 1 wt% butanol in ABE solution at 30 °C. The permeation mechanism was explained by the solubility parameters of the permeating components and membrane surfaces.