An efficient method allowing for continuous preparation of PDMS/PVDF composite membrane

摘要

Polydimethylsiloxane (PDMS) membranes are widely applied in biofuel production, gasoline desulfurization, and wastewater treatment because of its excellent organophilic nature. However, curing of PDMS membrane usually lasts for hours to days. In this study, effects of temperature, catalyst, water, and ethanol on viscoelasticity of PDMS before and after coating were investigated. A mathematical model was proposed to describe the relationships between viscosity of coating mixture and time. The time window to coat PDMS coating mixture could be predicted by this model with errors below 2.7 min. Moreover, we proposed an imprint method to determine the time for membrane winding-up. Finally, a continuous fabrication procedure was established by controlling compositions of coating mixture and crosslinking conditions where the time window to coat PDMS and duration of winding up were 88.3 min and 11 min, respectively. The fast and continuous preparation procedure fits the requirement of producing large amounts of PDMS membranes.