Superhydrophobic Ether-Based Porous Organic Polymer-Coated Polyurethane Sponge for Highly Efficient Oil–Water Separation

Abstract

Oil/organic solvent spills can cause serious threats to environment and ecology, and high efficient oil–water separation has attracted much attention in recent years. Herein, we design a new superhydrophobic ether-based porous organic polymer (E-POP) by the condensation reaction between 4′,4‴,4‴″,4‴‴′''''-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1′-biphenyl]-4-carbaldehyde)) and pentaerythrotol monomers, and the resulting E-POP-1 exhibits superhydrophobicity on account of abundant ether groups. Meanwhile, the E-POP-1 has a rich porous structure and high stability, which are beneficial to the diffusion of organic solvents or oils, thereby improving adsorption capacity and efficiency. In addition, the E-POP-1 could be successfully coated on the skeleton of PU sponge, and thus, the obtained E-POP-1@PU sponge possesses superhydrophobicity, robust mechanical stability, and hierarchical porous structure. Based on the above, the superhydrophobic E-POP-1@PU sponge can rapidly and selectively adsorb various kinds of oils up to 82 times of its own weight, and the adsorbed oils can be collected by a simple squeezing process. Furthermore, the recovered sponge can maintain high adsorption capacity for oil–water separation even after 100 cycles. More interestingly, the superhydrophobic E-POP-1@PU sponge can continuously adsorb and expulse oils and organic solvents from water surfaces with vacuum assistance. The rapid and efficient adsorption capacity, excellent selectivity, high stability, high elasticity, and renewability make sure that E-POP-1@PU sponge is a promising candidate for large-scale industrial separation of oils/organic solvents and water in corrosive and turbulent conditions.