A rapid two-step process to prepare a high-throughput, efficient, reusable superhydrophobic–superoleophilic stainless steel mesh for oil/water separation

Currently, due to the industrial development, the direct discharge of large amounts of oil-containing wastewater has led to serious water pollution. It is necessary to develop an efficient, durable, and high-throughput material for oil–water separation. To achieve this, we prepared a nickel (Ni) coating with a loose leaf-like micro/nanostructure on the surface of stainless steel mesh (SSM), imparting it with superhydrophobic and superoleophilic properties. The deposition of ions onto the substrate was carefully controlled by adjusting the deposition parameters. Subsequently, the as-prepared Ni coating was further modified using a solution of perfluorooctyltriethoxysilane (PFOTS) in ethanol to obtain a PFOTS/Ni mesh (PNM) with excellent superhydrophobic–superoleophilic properties. Wettability tests revealed that the water contact angle (WCA) and oil contact angle (OCA) of the PNM, prepared under the optimized deposition conditions, were 161 ± 1° and 0°, respectively, with a water sliding angle (WSA) of less than 10°. Importantly, the PNM demonstrated remarkable mechanical stability in blade scratch and tape peel tests, as well as excellent chemical stability in acid-alkali resistance and electrochemical corrosion tests. And, the PNM exhibited remarkable self-cleaning capability. Additionally, PNMit filters displayed outstanding efficiency in separating oil and water (reaching 91.5%) and remarkable durability. The results indicate that the well-designed superhydrophobic–superoleophilic SSM exhibits advantages such as simple fabrication, low cost, high reusability, and strong robustness. It holds great potential for practical applications in the treatment of oily wastewater and oil spill remediation.

当前，随着工业发展，大量含油废水直接排放已造成严重的水体污染，开发高效、耐用且高通量的油水分离材料迫在眉睫。为此，我们在不锈钢网(SSM)表面制备了具有疏松叶状微纳结构的镍(Ni)涂层，赋予其超疏水与超亲油特性。通过调控沉积参数，可精准控制离子在基底上的沉积过程。随后，我们采用乙醇中的全氟辛基三乙氧基硅烷(PFOTS)溶液对所制备的镍涂层进行后改性，得到兼具优异超疏水-超亲油性能的PFOTS/镍网(PNM)。润湿性能测试结果表明，在优化沉积条件下制备的PFOTS/镍网，其水接触角(WCA)为161±1°，油接触角(OCA)为0°，水滑动角(WSA)小于10°。重要的是，PFOTS/镍网在刀片刮擦与胶带剥离测试中展现出优异的机械稳定性，同时在耐酸碱与电化学腐蚀测试中表现出良好的化学稳定性。此外，该材料还具备出色的自清洁能力。PFOTS/镍网滤膜在油水分离中展现出高达91.5%的分离效率与优异的耐用性。研究结果表明，这款精心设计的超疏水-超亲油不锈钢网具备制备工艺简便、成本低廉、可重复使用率高、鲁棒性强等优势，在含油废水处理与溢油修复领域具有良好的实际应用潜力。