High-hydrophobic ZIF-67@PLA honeycomb aerogel for efficient oil–water separation

Abstract

The ZIF-67 @PLA honeycomb aerogel was formulated by using the metal–organic frame (MOF) ZIF-67 through physical mixing and heat-induced phase separation interaction. Changing the mass fraction ratio of ZIF-67 in aerogels can effectively adjust the pore size, pore surface unevenness, and specific surface area of pure polylactic acid (PLA) aerogels. In comparison to PLA aerogels, the ZIF-67 @PLA honeycomb aerogels showed greater oil wettability combined with a notable increase in mechanical characteristics. In this paper, the morphology, oil adsorption capacity, oil wettability, oil–water separation ability and sample reuse of composite aerogels were studied in depth. The ZIF-67 @PLA aerogel with 3 wt% ZIF-67 has the highest oil wettability, highest oil–water separation function, maximum specific area and good reusability. Compared to pure PLA, which has a tensile strength and elongation at break of 0.1424 MPa and 13%, ZIF-67 @PLA has a tensile strength and elongation at break of 0.3344 MPa and 15%, respectively. After 20 cycles, the separation flux of ZIF-67 @PLA is still 98% of the initial flux. The experimental results show that the use of MOF as a nanofiller-filled pure PLA aerogel exhibits high oil wettability and has been demonstrated to be an ideal material for high-efficiency oil–water separation.