Trabecular bone-inspired tung oil-derived spongy cellular networks with intelligent pH-responsive wettability and superelasticity for efficient multitasking separation

Development of new biomass sponges with controllable wettability and excellent resilience is urgent while challenging for multitasking and effective oil–water separation because incorporating these performances into conventional biomass sponges is complicated and even contradictory. Herein, a hypersalinity-confined thermopolymerization strategy is presented for fabricating the tung oil-derived spongy cellular network (TSN), during which its interconnected porous skeleton with ionizable carboxyl groups is formed due to the self-initiated thermal polymerization and crosslinking of tung oil precursors enclosed in the stacking space of sodium chloride (NaCl) particles. By mimicking trabecular bone architecture with good energy transfer/dissipation, high porosity and strong capillary absorption, the resultant TSN with carboxylic acid groups exhibits reversible pH-responsive wettability (transition from hydrophobicity/lipophilicity to hydrophilicity/oleophobicity), superelasticity (nearly 100 % stress and height retention after 1000 cycles), good thermal/chemical stability and efficient oil–water separation performance (>99.4 % separation efficiency) in multitasking situations. This study provides an encouraging insight for the tailored fabrication of smart sponge materials derived from renewable vegetable oils for oil–water separation in multitasking and complex situations.