3D-printed porous Al 2 O 3 membrane coated with hydrophilic modified titanium dioxide particles for large-flux oil/water separation

ABSTRACTA 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.KEYWORDS: 3D printingsuperhydrophilic/oleophobic membraneoil/water separationhydrophilic modificationporous structure AcknowledgementsWe would like to thank the Analytical & Testing Center of Northwestern Polytechnical University for SEM and TEM.Disclosure statementNo potential conflict of interest was reported by the author(s).Declaration of competing interestThe authors declare that they have no known competing financial interests or personal relations that could have appeared to influence the work reported in this paper.Additional informationFundingThis work was financially supported by the Fundamental Research Funds for the Central Universities [grant number 3102019PJ008 and 3102018JCC002]; National Key Research and Development Program of China [grant number 2021YFB3701500]; National Natural Science Foundation of China [grant number 52072306].