Hierarchically porous sponge for oily water treatment: Facile fabrication by combination of particulate templates and thermally induced phase separation method

A polypropylene sponge with hierarchical structure was prepared from a polypropylene solution by combination of micro particle template and the phase separation technique. A simple procedure was proved to be able to fabricate a unique sponge in which both submillimeter-sized holes (approximate to 200 mu m) and small macrospores (approximate to 10 mu m) are formed. The unique structure was successfully confirmed by scanning electron microscopy measurement. In addition, the sponge showed low density, high hydrophobicity, and superoleophilicity. The sponge exhibited good compressibility, and high performance for the adsorption-release of oils. The adsorbability was proved to be improved in a large scale due to the existence of holes. Furthermore, the sponge demonstrated the ability to remove oil-in-water emulsion. Based on the properties, the present sponge has promising prospects for environmental applications in the treatment of oily water. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.