CHARACTERISTICS OF PERMEATION AND SEPARATION FOR PROPANOL ISOMERS THROUGH POLY(VINYL ALCOHOL) MEMBRANES CONTAINING CYCLODEXTRIN

Poly (vinyl alcohol) membranes containing cyclodextrin (CD-PVA membrane) were prepared and characteristics of permeation and separation for propanol (PrOH) isomers through the CD-PVA membranes were investigated by pervaporation and evapomeation. Evapomeation was more effective for the separation of PrOH isomers through the CD-PVA membrane than was pervaporation. The CD-PVA membrane more preferentially permeated n-PrOH than i-PrOH from their mixtures. In particular, the mixture of 10 wt % n-PrOH concentration was concentrated to about 45 wt % through the CD-PVA membrane. Both permeability and selectivity for n-PrOH were improved with an increase of CD content in the membrane. The results were supported by the fact that the affinity of CD for n-PrOH was stronger than that for i-PrOH. The permeation mechanism of PrOH isomers through the CD-PVA membrane is discussed based on the solution-diffusion theory. (C) 1994 John Wiley & Sons, inc.