High-/Low-Molecular-Weight PDMS Photo-Copolymerized Membranes for Ethanol Recovery

Poly(dimethylsiloxane) (PDMS) is the benchmark of alcohol-selective membranes. The low-molecular-weight PDMS easily causes pore penetration and nonuniform coverage, thus PDMS membrane is generally fabricated by the high-molecular-weight chains (Mw >= 50,000). However, there are inevitably excessive chain entanglements in longer polymeric chains, limiting the transport of penetrating molecules. In this work, we proposed a high-/low-molecular-weight PDMS photo-copolymerized strategy to prepare a high-performance pervaporation membrane for ethanol recovery, which combines the advantages of high-/low-molecular-weight PDMS chains. The fluidity and polymerization efficiency are improved, while the excessive pore penetration is prevented. The result showed that the high-/low-molecular-weight PDMS mixed membranes display a superior comprehensive pervaporation performance for ethanol recovery in comparison with the other polymeric membranes. The copolymerized strategy is facile and shows a promising prospect for ethanol recovery.