Hydrophobic tuning of PDMS-PVDF hollow fiber membranes for enhanced isopropanol recovery in pentane diol production process via pervaporation

Abstract

BackgroundsThis study explores a use of crosslinked polydimethylsiloxane (PDMS) membranes for the selective pervaporation separation of isopropanol (IPA) from a mixture of 1,2 and 1,5 pentanediols (PeD). MethodsTwo crosslinkers, tetraethyl orthosilicate (TEOS) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FDTS), were used to prepare PDMS coating on inside of polyvinylidene fluoride (PVDF) hollowfiber membrane. Significant findingsSeparation performance of PDMS-FDTS membrane outperformed to that of PDMS-TEOS membrane. Both of the PDMS membrane systems resulted a high IPA selectivity, was attributed to the nonpolar nature of IPA and its strong interaction with hydrophobic PDMS chain. An operating conditions influenced the pervaporation performance, with higher feed temperature increasing flux but reducing IPA content in permeate. An increasing IPA content in the feed mixture increased flux while slightly decreasing the separation factor. Overall, PDMS-FDTS membranes demonstrated promising performance for selective IPA removal and yielded a flux in the range of 173 ± 15 g/m2h while maintaining the IPA content in permeate higher than 99.7% at 60 °C, which showed potential for industrial-scale applications due to its high flux and selectivity.