Smart carbon foams with switchable wettability for fast oil recovery

The adsorption and recovery of crude-oil from oily water using oil-selective adsorbents is a highly promising solution for the increasing worldwide oil pollution, but remain a challenge. Herein, we reported a carbon foam (CF) with switchable wettability as smart materials for fast oil adsorption and recovery. By grafting poly(4-vinylpyridine) (P4VP) onto the surface of CF, the obtained smart foam presented a pH responsiveness and could change superhydrophilic and superhydrophobic surface according to the pH value. Thus, the smart responsive carbon foam could fast adsorb the oil in neutral solution (pH = 7) with high oil adsorption capacity of 62-120 g g(-1) and desorb all the adsorbed oil in acidic solution (pH = 1) within 1.5 min. In addition, only 3% loss was observed for oil (chloroform) adsorption and recovery after successive reuses of up to 15 cycles, which demonstrated great recyclability of the materials. (C) 2019 Elsevier Ltd. All rights reserved.