Durable, flexible, and super-hydrophobic wood membrane with nanopore by molecular cross-linking for efficient separation of stabilized water/oil emulsions

Large amount of oily wastewater discharged from domestic sources and industrial has caused lots of pollution to our surrounding. Thus, searching effective and eco-friendly ways for separation of stabilized oil/water emulsions is urgent and highly desirable. Among various methods, membrane with special wettability is an ideal choice for the efficient treatment of oil/water emulsions owing to its low energy consumption and cost. However, it remains a great challenge to develop super-wettable membranes using green and inexpensive materials to realize durability, easy fabrication and scale-up. To address this issue, a highly flexible, durable, robust, and super-hydrophobic polydivinylbenzene (PDVB)-wood membrane with hydrophobic-nanopores is developed by the surface coating of cross-linked PDVB on the porous wood. The as-produced PDVB-wood membrane shows excellent flexibility, durability, chemical resistance and possesses above 99.98% separation efficiency for surfactant-stabilized water-in-oil emulsions. Furthermore, the PDVB-wood membrane also performs excellent recyclability with separation efficiency up to 99.98% after 20 separation cycles. The synergistic effect of the super-hydrophobicity and nanopores contributes to the high separation performance. With its excellent durability, easy scale up, easy fabrication, inexpensive, and green regeneration, we envision that this functional biomass-derived membrane could be used as a substitute for filter membrane in environmental restoration.

Automated summary

The discharge of large amounts of oily wastewater from domestic and industrial sources has led to significant pollution in the surrounding environment. To address this issue, a flexible, durable, and super-hydrophobic PDVB-wood membrane with hydrophobic nanopores was developed. This membrane demonstrated excellent separation efficiency of over 99.98% for surfactant-stabilized water-in-oil emulsions and showed great recyclability after 20 separation cycles.