Fast layer-by-layer assembly of PDMS for boosting the gas separation of P84 membranes

Abstract

Herein, we report an fast layer-by-layer assembly strategy via spraying method using polydimethylsiloxane (PDMS) to heal the defects of P84 membranes which are easily formed by phase inversion preparation method. The viscous PDMS is spray-atomized and uniformly adhered on the surface of the P84 membrane. An ultra-short assembly time of 20–30 s is further achieved by the UV-induced polymerization of PDMS. It is one of the fast processing time for the defects healing to date of any polymer membranes, and this fast processing time for the defects healing is a major novelty for any polymer membranes. The results demonstrate that the P84 membrane sprayed by 3 wt% of PDMS concentration and 2 of spraying cycle times has the optimum H2 separation performance, where selectivities of 232 for H2/CH4 and 99 for H2/N2 are 2.4 and 2.7 times higher than these of P84 membranes without healing, respectively. This strategy opens a new avenue for healing the membrane defects and fitting the requirement of producing the defect-free membranes.