Pickering emulsion strategy to control surface wettability of polymer microspheres for oil-water separation

Surface wettability, one of the most important parameters for oil-water separation, depends on the chemical composition and surface roughness of a material. Herein, the Pickering emulsion template method is proposed to control the surface wettability of polymer microspheres. Upon the dispersion of modified diatomite particles in the aqueous phase, a superhydrophobic surface was formed on the polymer microspheres via Pickering emulsion polymerization, with a water contact angle of 152 degrees. When the initial dispersion location of the modified diatomite particles changed from water to oil, a hydrophilic/underwater superoleophilic surface with micro/ nanoscale hierarchical structures formed on the polymer microspheres. This special wettability enabled the microsphere layer to serve as an adsorbent with underwater superoleophilicity, achieving efficient oil separation from various oil-in-water emulsions with high separation efficiency of >99.8%. Hence, this study provides a valuable strategy based on the Pickering emulsion template method to design materials with special wettability for realizing promising emulsion separation.

Automated summary

This study effectively controlled the surface wettability of polymer microspheres using the Pickering emulsion template method, achieving efficient oil-water separation with a valuable strategy for designing materials with special wettability.