A biodegradable poly-L-lactic acid (PLLA)/polybutylene adipate-co-terephthalate (PBAT) composite aerogel for continuous oil-water separation

In the context of sustainable development, the exploration of renewable, biodegradable, and environmentally friendly polymer aerogels have emerged as a significant area of research. Herein, we report a facile synthesis of fully degradable polylactic acid (PLLA)/poly (butylene adipate- co -terephthalate) (PBAT) composite aerogels via 1,4-dioxane-assisted co-dissolution, followed by freeze-drying and phase separation techniques. The resulting aerogels feature a hierarchically porous structure with 98.6% porosity and vertically aligned channels, formed by controlled solvent crystallization during the freezing process. This unique architectural configuration integrates PLLA's oil-retention capability with PBAT's elasticity, yielding adsorption capacities of 13.6 g/g for n-hexane and 31.5 g/g for carbon tetrachloride. Notably, the aerogel retains ~97.5% stress and height recovery after 100 cycles of 50% strain compression, overcoming pure PLLA's inherent brittleness. It also maintains 96.5% the oil-water separation efficiency after 20 c centrifugal desorption cycles. 1,4-Dioxane promotes the compatibility of PLLA and PBAT, improving the interfacial compatibility and effectively avoiding the structural defects usually caused by phase separation. This research provides a scalable, filler-free approach to fabricate the high-performance biodegradable aerogels, bridging environmental sustainability and practical functionality for oily wastewater remediation.