Abstract
Frequent oil spills and the discharge of industrial oily wastewaters cause serious threats to environments, ecosystems, and human beings. Herein, a non-fluorinated and photothermal superhydrophobic polyurethane sponge has been successfully obtained by decorating lignin microspheres (LMs)/candle soots (CSs) with the assistance of polydimethylsiloxane. The as-prepared superhydrophobic sponge shows excellent chemical stability and mechanical durability in terms of being immersed in various liquids and being performed under different conditions (i.e., abrased by sandpapers, rinsed in water, bended, compressed, and teared by tapes). The superhydrophobic sponge possesses adsorption capacities for oils and organic solvents ranging from 29.1 to 129.3 g/g, shows separation efficiencies of CCl4 and crude oil up to 99.2 % and 95.2 %, and maintains separation efficiencies of CCl4-in-water and crude oil-in-water emulsions for 98.2 % and 94.9 % even after 10 cyclic adsorption tests. Due to the synergistic photothermal effect between LMs and CSs, the superhydrophobic sponge shows a maximum surface temperature of 79.3 °C and rapidly adsorbs a droplet of crude oil (500 μL) in 16 s under solar irradiation (1 sun). Thus, the superhydrophobic sponge as a promising material provides a new solution for the treatments of daily oil/water separation and crude oil recovery in serious marine oil spill accidents.
