Nanoconfined Ultrathin Polymer Membrane for Ultrafast Separation of Biobutanol from Water

Efficient recovery of biobutanol, a next-generation biofuel, from fermentation liquor remains challenging due to its low concentration and volatility. This study introduces ultrathin rubbery polymer membranes developed through an interfacial dissolution-crosslinking method, with cross-linked polysiloxane confined within the permanent nanovoids of ceramic alumina substrates. The resulting membranes, which are less than 10 nm thick, achieve unparalleled performance: concentrating 1.0 wt% aqueous n-butanol 14.2-fold with a record-high liquid flux of 110 kg m^-2 h^-1-one to two orders of magnitude greater than those of previously reported membranes. These advancements suggest significant reductions in the membrane area and operational costs for large-scale biobutanol separation, establishing a sustainable and economical solution for biofuel production.