Durable and Recyclable Superhydrophilic–Superoleophobic Materials for Efficient Oil/Water Separation and Water-Soluble Dyes Removal

Superhydrophilic/superoleophobic materials with specific wetting properties have attracted extensive attention during the recent years because of their extraordinary performance in oil/water separation. In this work, we developed a facile process to fabricate the superhydrophilic–superoleophobic material from kaolin nanoparticles. The obtained material performs universal oil repellency both in air and under water, and exhibits general applicability which can be extended to various relevant substrates, irrespective of their chemical composition. Furthermore, the as-prepared material is efficient to separate varieties of oil/water mixtures, even surfactant-stabilized oil-in-water emulsions, showing the high separation efficiency above 92%. What’s particularly attractive is that during the separation process, the water-soluble dye contaminants could be removed simultaneously, resulting in colorless and transparent filtered water. These results further confirm that the as-prepared materials could be good candidates for efficient oil/water separation and wastewater purification. Simple and scalable design of the fabrication process is also very desirable to obtain the specific wetting surfaces, making both materials and their fabrication methods attractive for scalability, which will offer variety of promising application in various fields.