Abstract
With increasing environmental awareness, novel strategies to effectively separate oil from industrial wastewaters and polluted oceanic water are highly desired. Using special wettability to design new materials for oil/water separation is an effective and facile way. Herein, polyimide (PI) aerogel is designed and prepared by freeze-drying PI precursor poly(amic acid) ammonium salt (PAS) water solution followed by imidization. With high hydrophobicity, the PI aerogel can be used for the absorption and separation of oil and water. 30–195 times weight of organic pollutants and oils can be absorbed by PI aerogel. To demonstrate the cyclic distillation test, cyclohexane was absorbed by the PI aerogel. As the size and the porosity structures of PI aerogel stayed the same during the separation/distillation cycles, no obvious change in absorption capacity was found after five cycles, indicating the highly stable recycling performance. During separation, water quickly permeated through the PI aerogel and dropped into the beaker below, while oil was retained above it and no external force was employed. Additionally, PI aerogel is also usable under harsh conditions. This research paved the way for fabricating high efficient and recyclable oil/water separation PI aerogel which can be used in the petroleum industry in the future.
