Construction of sustainable, fireproof and superhydrophobic wood template for efficient oil/water separation

Three-dimensional wood structure derived from nature has emerged as a promising template for oil/water separation due to their high tubular porosity, inexpensive, exceptional absorption capacity, and sustainability. However, wood is naturally inflammable and thus expected to increase the risk of fire and explosion when being used as an absorbent for many oils and organic compounds. Herein, a robust strategy for fabricating bio-based fireproof and superhydrophobic wood template as an oil/water separation membrane via a layer-by-layer assembly technique is proposed. The resulting wood template exhibits highly flame retardant and excellent oil/water separation properties (> 97%), self-cleaning capability, and mechanical durability. The limiting oxygen index (LOI) of the wood-layer-15 sample increased to 60.5% and showed very strong self-extinguishing behavior in the UL-94 test. The surface of the treated wood template possessed superhydrophobicity with the water contact angle of 168° and showed stable super-repellency toward corrosive liquids, including acidic, basic and other commonly fluids. More importantly, the video capture system indicated that falling water droplet was able to bounce off the surface several times. This work takes full advantage of raw materials from nature, which has a great potential for cleaning up the oil spills and chemical leakage in the actual large-scale production. Graphical abstract