3D-printed controllable gradient pore superwetting structures for high temperature efficient oil-water separation

Superwetting surfaces have the potential to address oil pollution in water, through their ability to separate the two. However, it remains a great challenge to fabricate stable and efficient separation structures using conventional manufacturing techniques. Furthermore, the materials traditionally used for oil-water separation are not stable at high temperature. Therefore, there is a need to develop stable, customizable structures to improve the performance of oil-water separation devices. In recent years, 3D printing technology has developed rapidly, and breakthroughs have been made in the fabrication of complicated ceramic structures using this technology. Here, a ceramic material with a gradient pore structure and superhydrophobic/superoleophilic properties was prepared using 3D printing for high-efficiency oil-water separation. The gradient pore structure developed here can support a flux of up to 25434 L/m²h, which is nearly 40% higher than that an analogous structure with straight pores. At 200 °C, the oil-water separation performance was maintained at 97.4%. Furthermore, samples of the material exhibited outstanding mechanical properties, and chemical stability in a variety of harsh environments. This study provides an efficient, simple, and reliable method for manufacturing oil-water separation materials using 3D printing, and may have broader implications for both fundamental research and industrial applications.