Time–space synchronized cross‐linked polydimethylsiloxane membranes for organophilic pervaporation

The preparation of versatile polydimethylsiloxane (PDMS) membrane largely relies on the pre‐crosslinking of the casting solution, while membrane structural defects caused by its elevated viscosity over time pose a major challenge. Herein, we employ the time–space synchronized cross‐linking (TSSC) strategy utilizing a vapor–liquid interface‐confined cross‐linking reaction method to ensure all cross‐linking reaction sites initiate and complete simultaneously across the entire membrane surface, resulting in a remarkably consistent reaction degree at any location on the membrane. The TSSC PDMS membranes possess larger free volume, more uniformly sized pores, and higher cross‐linking degree, exhibiting a flux of 3400 g m −2 h −1 and a separation factor of 8.8 in separating a 5 wt% ethanol–water solution, showing a 36% increase in flux than conventional premixed stepwise cross‐linked PDMS membrane. This strategy successfully the large‐scale fabrication of a 2500 cm 2 TSSC PDMS membrane with stable performance, exhibiting significant potential for organic recovery.