A Particle-Driven, Ultrafast-Cured Strategy for Tuning the Network Cavity Size of Membranes with Outstanding...

Poly(dimethylsiloxane) (PDMS) membranes are widely used for bioethanol separation. However, the network cavity size r₃ of PDMS membranes is generally smaller than the ethanol kinetic radius (0.225 nm), which limits the transport of ethanol molecules and weakens the pervaporation performance. Herein, we proposed a particle-driven, ultrafast-cured strategy to overcome the above key issue: (1) Incorporating particles into PDMS for preventing polymer chains from packing tightly, (2) freezing particles within a PDMS layer by the ultrafast UV-cross-linking for improving its distribution and increasing the chain extension of the polymer, and (3) covalently bonding particles with PDMS to enhance their compatibility. Consequently, r₃ was increased to 0.262 nm, and an extremely high loading membrane (50 wt %) with an ultrashort curing time (20 s) was prepared, which is difficult to be realized by the conventional thermally driven approach. As a result, a separation factor of 13.4 with a total flux of 2207 g m^-2 h^-1 for separating ethanol from a 5 wt % aqueous solution at 60 °C was obtained. This strategy shows the feasibility of recovery of different bioalcohols and the large-scale continuous membrane preparation.