One-pot solvothermal synthesis of robust ambient-dried polyimide aerogels with morphology-enhanced superhydrophobicity for highly efficient continuous oil/water separation

In this study, using a sequential polyamic acid (PAA) gelation and solvothermal imidization, we demonstrate a scalable one-pot solvothermal approach for the preparation of polyimide (PI) aerogels having a three-dimensional network composed of uniform microspheres. PI aerogels prepared by this approach were mechanically robust can be directly dried in oven without considerable contraction. More importantly, the PI aerogels showed morphology-enhanced water droplet contact angles from 98 degrees to as high as 146 degrees, which makes them nearly superhydrophobic. Such hydrophobic/oleophilic monolithic aerogels could rapidly and continuously separate oil from oil/water mixtures and even from water-in-oil emulsions.