From hydrogel to aerogel: A green fabrication of multifunctional polyimide absorbents

Developing advanced absorbent materials with multifunctional properties has always been one of hotspots in the research. Here, multifunctional polyimide (PI) aerogels absorbents were prepared from poly(amic acid) ammonium salt (PAS) hydrogels via facile and environment friendly method. By tuning the micro- and nano-structures and surface modification with fluoroalkylsilane, the polyimide/fluoroalkylsilane (HPI/F) aerogels fabricated from hydrogels exhibit superhydrophobic and superoleophilic attributes. Moreover, the HPI/F aerogels show excellent mechanical flexibility, fire-resistance and high thermostability, which enable them to be a highly efficient and recyclable sorbent material useable at extremely high or low temperatures. They also exhibit chemical durability in strong acidic solutions. This work opens up the use of polymer hydrogels for the fabrication of 3D aerogel materials and shows the possibility for the application in diverse work conditions.