3D-printed porous Al₂O₃ membrane coated with hydrophilic modified titanium dioxide particles for large-flux oil/water separation

A viable material to address oil pollution in water is the super wetting surface, which is accessible to realise the separation of oil and water. According to Young’s equation, hydrophobic/oleophilic materials are theoretically simple to realise and have a wide range of applications. The hydrophobic/oleophilic membrane, however, has a poor separating effect on the mixture in which the oil has a lower density than water. Hence, to optimise the oil/water separation performance, hydrophilic modified titanium dioxide particles were introduced to a novel porous superhydrophilic/oleophobic substrate fabricated by 3D printing technology in this work. The contact angle of n-hexadecane on the membrane surface was about 130°, which was an oleophobic surface. The oil/water separation efficiency of the 0.7 mm thick oleophobic membrane was over 98% and the penetration flux was up to 11,191 L m⁻² h⁻¹, indicating that the membranes prepared in this work might be used in high-flux oil/water separation applications. This study provides an efficient, simple, and reliable method for preparing oil/water separation materials with 3D printing technology, and may have broader significance among the academic and industry communities.