Hydrophilic–Oleophobic, Macroporous Polymers Enabled by In-Situ Polymerization and Foaming for Removing Water from Oils

Abstract

Porous polymers with hydrophilicity and oleophobicity are promising for removing water from various oil–water mixtures (including emulsions), but the preparation of such polymers is usually complicated and time-consuming. Herein, a novel stragey, in situ polymerization and foaming, has been developed to fabricate hydrophilic–oleophobic porous polymers in a facile manner within seconds. The porous polymers from pentaerythritol tetra­(3-mercaptopropionate) and poly­(ethylene glycol) diacrylate showed hydrophilicity and underwater oleophobicity, enabling the removal of water from oil–water mixtures and surfactant-stabilized, water-in-oil (w/o) emulsions, with a high efficiency of 99.9% and excellent reusability, without obvious deterioation after 10 cycles. With incorporatin of 1H,1H,2H,2H-perfluorooctyl methacrylate, the resulting porous polymers showed hydrophilicity and oleophobicty in air, providing an additional function of antioil-fouling ability both in dry state and in the process of oil–water separation. Moreover, both the two types of the porous polymers showed robust compression, without fracture and changes in wetting property after cycles of compression at 70% strain and high fatigue-resistant elasticity, without obvious plastic deformation after 1000 compression-release cycles. The facile and rapid preparation, hydrophiclity–oleophobicity, and robustness in compression and elasticity enabled the porous polymers to be good candidates for removing water from various oil–water mixtures.

Asymmetric Wettability Janus Mesh via Electrostatic Printing for Selective Oil–Water and Emulsion Separation

“…Oil–water mixture separation has become an increasingly important global issue for the protection of Earth’s ecosystems. − For example, in 2019, a crude oil spill off the coast of Brazil and attacks on more than 40 marine protected areas impacted the livelihoods and food security of millions. Near the oil-slick-covered waters, carcasses of fishes and birds have been washed up on beaches, causing serious ecological disasters. , Therefore, many researchers worked on developing practical methods to solve the oil–water separation problem in a timely manner. − Zhang et al prepared microscale MnCo 2 O 4 -coated stainless-steel mesh (SSM) using a simple and effective hydrothermal annealing process. The MnCo 2 O 4 –SSM has excellent superhydrophilicity and underwater superoleophobicity for efficient oil–water separation.…”