SORPTION AND PERMEATION OF BINARY WATER-ALCOHOL SYSTEMS THROUGH PVA MEMBRANES CROSS-LINKED WITH MULTIFUNCTIONAL CROSS-LINKING AGENTS

Sorption and permeation of aqueous alcohol (C-1-C-4) through PVA membr ane cross-linked with a multifunctional cross-linker is reported. The effect of temperature, feed concentration, cross-linker loading and th e shape and size of the permeating species on pervaporation characteri stics is investigated. Sorption isotherms of cross-linked PVA are obta ined for the aqueous alcohol systems namely water-methanol, +ethanol, +n-propanol, +isopropanol, +n-butanol and +isobutanol. Values of activ ation energy for permeation (Delta E-p), diffusion (Delta E-d) and hea t of sorption (Delta H-s) for water through cross-linked PVA are estim ated. The value of Delta E-d for water was found to vary for all the w ater-alcohol systems (20-50 kJ mole(-1)) covered in this work. (C) 199 7 Elsevier Science B.V.