A thermoplastic polyurethane-based composite aerogel with low shrinkage and high specific surface area enhanced by activated carbon for highly efficient oil/water separation

Abstract

Aerogels are attractive candidates in the field of oily wastewater treatment. Nevertheless, some disadvantages like sharp shrinkage, massive expense of drying process, and weak mechanical properties pose an obstacle to their wide practical applications. Herein, an activated carbon (AC) enhanced thermoplastic polyurethane (TPU-AC) composite aerogel was successfully prepared by simple thermally induced phase separation (TIPS) method followed by ambient pressure drying. The average drying shrinkage rate of TPU-AC was controlled to < 10% due to the AC-enhanced skeleton. With an optimal addition of AC, the resultant composite aerogel exhibited low density, reasonable porosity, and significantly improved specific surface area (105.86 m2/g). Good hydrophobicity endowed TPU-AC with superior oil/water selectivity. Therefore, an adequate oil adsorption capacity of up to 38.64 g/g was gained by TPU-AC with a fast adsorption rate. Thanks to the marvelous mechanical flexibility of TPU-AC, especially, the absorption and recovery of oil can be realized by facile adsorption-extrusion method as well as pump-assisted oil/water separation device with satisfactory separation efficiency and excellent recyclability. Along with the admirable cost effectiveness, the current study is expected to pave a facile way for aerogel preparation, providing a scalable and effective strategy for oily wastewater treatment.