Investigation of sorption properties and pervaporation behaviors under different operating conditions for trimesoyl chloride-crosslinked PVA membranes

Trimesoyl chloride (TMC)-crosslinked PVA membranes were prepared and their pervaporation and sorption properties were investigated. Temperature and concentration dependencies of sorption properties were studied by equilibrium water uptake and preferential sorption tests. The effects of water/IPA on the PVA-TMC matrix and the possible change of the degree of crystallinity induced by the sorbed water are believed to account for the differences of sorption properties at different temperatures and feed compositions. Permeation flux did not change significantly in the heating-cooling cycle when conducting water permeation and performing pseudo-steady-state pervaporation dehydration of IPA. However, the formation of crystallites during the heating run could improve the membrane selectivity. At a given feed concentration, the permeation flux and separation factor did not change in the diluting and concentrating runs at 60 °C. Permeate concentrations remained unchanged with time in the batch pervaporation process, and verified the independence of permeate water contents on feed concentrations.