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. © 1994 John Wiley & Sons, Inc.