Slot-die coating of vinyl-PDMS composite membranes for alcohol perm-selective pervaporation

The use of pervaporation membranes has shown great potential in the extraction of bioethanol. However, a simple, continuous, and controllable alcohol perm-selective membrane manufacturing process is needed for practical applications. In this study, the slot-die coating technique was utilized to deposit low-viscosity vinyl-polydimethylsiloxane (vinyl-PDMS) and crosslinker onto a porous substrate. A defect-free separation layer could be created within just 20 min, which includes the membrane forming and drying process, due to the rapid hydrosilylation reaction between vinyl-PDMS and the crosslinker. Therefore, the efficient fabrication process is suitable for continuous roll-to-roll industrial production. Additionally, by optimizing the slot-die parameters, the thickness of the separation layer could be regulated from 0.4 to 15 μm. The obtained vinyl-PDMS composite membrane demonstrated a total flux of 2.8 kg m−2 h−1 and a separation factor of 10.3 for 5 wt% ethanol/water mixture at 60 °C. [Display omitted] •Slot-die coating was used to prepare an alcohol-selective pervaporation membrane.•The thickness of the separation layer could be regulated between 0.4 μm and 15 μm.•A defect-free separation layer could be formed within just 20 min.