Robust Polylactide Aerogel with Oriented Pore Structure for Oil–Water Separation and Directional Transportation

Although polylactide (PLA) aerogel has been developed as a highly promising biodegradable aerogel for realizing carbon neutrality and sustainable development, there remains significant room for research in precisely regulating its pore structure and expanding its application fields. In this study, PLA aerogels with oriented pore structures have been developed by directional freeze-drying technology, and the oriented pore structures of PLA aerogels have been precisely controlled by regulating the proportion of deionized water in the 1,4-dioxane/deionized water binary solvent system during the directional freezing process. The resultant PLA aerogels not only have regular vertically oriented pore structures and excellent three-dimensional connectivity but also have the advantages of high porosity (94.74–95.44%) and superior compressive strength (maximum of 340 kPa). PLA aerogels exhibit excellent hydrophobicity and oil adsorption performances, which can achieve efficient oil–water separation and emulsion separation. Moreover, PLA aerogels also exhibit outstanding anisotropic liquid and thermal transport properties. Specifically, the liquid transport rate parallel to the pore direction can reach 0.135 mm/s, which is 3.65 times that perpendicular to the pore direction. This work can broaden the applications of PLA aerogels in oil–water separation and the directional transport of liquids and heat fields.