Pervaporation of benzene/cyclohexane mixtures through poly(vinyl alcohol) membranes with and without β-cyclodextrin Original Research Article

β-cyclodextrin (β-CD)-filled cross-linked poly(vinyl alcohol) (PVA) membranes (β-CD/PVA/GA) were prepared using glutaraldehyde as the cross-linker, and these membranes showed strong benzene permselectivity. The permeation flux of β-CD/PVA/GA membranes increased when the β-CD content was 0–8 wt%, but permeation flux decreased slightly when the β-CD content was 8–20 wt%. The separation factor towards benzene increased when β-CD content was in the range 0–10 wt% and decreased slightly when the β-CD content was 10–20 wt%. Compared with the β-CDfree PVA/GA membrane, the separation factor of the β-CD/PVA/GA membrane for benzene to cyclohexane considerably increased from 16.7 to 27.0, and the permeation flux of benzene increased from 23.1 to 30.9 g/(m2 h) for benzene/cyclohexane (50/50, wt) mixtures at 323 K. The analysis based on the solution–diffusion model and β-cyclodextrin inclusion phenomena (complex stabilities) revealed that β-CD in PVA membranes played an important role as a carrier to partition benzene selectively from benzene/cyclohexane mixtures.