Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of the Ministry of Education, Beijing Key Laboratory of Bio-inspired Energy Materials and Devices, School of Chemistry and Environment, Beihang University , Beijing 100191, P. R. China.
ACS Appl Mater Interfaces. 2015 Feb 25;7(7):4336-43. doi: 10.1021/am508814g. Epub 2015 Feb 10.
Oily wastewater is always a threat to biological and human safety, and it is a worldwide challenge to solve the problem of disposing of it. The development of interface science brings hope of solving this serious problem, however. Inspired by the capacity for capturing water of natural fabrics and by the underwater superoleophobic self-cleaning property of fish scales, a strategy is proposed to design and fabricate micro/nanoscale hierarchical-structured fabric membranes with superhydrophilicity and underwater superoleophobicity, by coating scaly titanium oxide nanostructures onto fabric microstructures, which can separate oil/water mixtures efficiently. The microstructures of the fabrics are beneficial for achieving high water-holding capacity of the membranes. More importantly, the special scaly titanium oxide nanostructures are critical for achieving the desired superwetting property toward water of the membranes, which means that air bubbles cannot exist on them in water and there is ultralow underwater-oil adhesion. The cooperative effects of the microscale and nanoscale structures result in the formation of a stable oil/water/solid triphase interface with a robust underwater superoleophobic self-cleaning property. Furthermore, the fabrics are common, commercially cheap, and environmentally friendly materials with flexible but robust mechanical properties, which make the fabric membranes a good candidate for oil/water separation even under strong water flow. This work would also be helpful for developing new underwater superoleophobic self-cleaning materials and related devices.
含油废水一直对生物和人类安全构成威胁，如何处理含油废水是一个全球性的难题。界面科学的发展为此带来了新的希望。受天然织物吸水和鱼鳞水下超疏油自清洁特性的启发，提出了一种通过在织物微结构上涂覆具有鳞片结构的二氧化钛纳米结构来设计和制备具有超亲水和水下超疏油性的微纳分级结构织物膜的策略，可高效分离油水混合物。织物的微结构有利于实现膜的高持水能力。更重要的是，特殊的鳞片结构对于实现膜对水的理想超润湿性至关重要，这意味着在水下，气泡无法存在于膜表面，水下油的附着极低。微观和纳米结构的协同作用形成了稳定的油/水/固三相界面，具有强大的水下超疏油自清洁性能。此外，这些织物是通用的、商业上廉价的、环境友好的材料，具有灵活但坚固的机械性能，这使得织物膜成为即使在强水流条件下也能进行油水分离的良好候选材料。这项工作还有助于开发新型水下超疏油自清洁材料和相关器件。
