Wood-Inspired Fabrication of Polyacrylonitrile Solid Foam with Superfast and High Absorption Capacity for Liquid Without Selectivity.

Inspired by the principles of natural capillary action, unidirectional freeze and low-temperature freeze-extraction methods are employed to replicate natural wood structure into aligned vertically oriented porous polyacryonitrile (PAN) foam (APPF), which show superfast absorption speed and high-efficiency absorption capacities for liquids, including organic pollutants (chloroform, soybean oil, and toluene). Foams with different absorption capacity and speed are prepared by adjusting the PAN concentration in the preparation. The mechanical properties of the APPFs with vertically oriented pores indicate that they have excellent strength and Young's modulus, which can help maintain the integrity of micropores. The prepared APPFs with aligned vertically oriented pores have immense potential in numerous applications, including wastewater treatment, cleaning, drug delivery, and hygiene products.