Polylactide aerogel with excellent comprehensive performances imparted by stereocomplex crystallization for efficient oil-water separation

Recently, polylactide (PLA) aerogel has been considered as an ideal oil-water separation and oil absorption material due to its renewability, biodegradability , considerable mechanical and processing performance. However, the practical application of PLA aerogel still faces some obstacles like inferior heat resistance, poor durability, and unsatisfactory oil-water separation and oil absorption performances. In this work, a promising strategy of constructing different amounts of stereocomplex (SC) crystallites in PLA aerogels via blending poly(L-lactide) (PLLA) with various amounts of poly(D-lactide) (PDLA) is devised to simultaneously overcome these obstacles. The results reveal that the formation of SC crystallites can not only improve the heat resistance and degradation resistance of the SC-type PLA (SC-PLA) aerogels, but also result in many nanopores on the pore walls of SC-PLA aerogels upon freeze-drying. SC-PLA aerogels with such special porous structures exhibit good hydrophobicity , excellent oil-water separation capability, and high absorption capacity for various oils and organic solvents . Specifically, the absorption capacity of SC-PLA50 aerogel can reach 42 times to its own weight, and good cycling stability of SC-PLA50 aerogel is confirmed by the absorption/evaporation cycling experiments. We believe this high-performanced SC-PLA aerogel can be applied in oil spill accidents and industrial wastewater pollution treatments.