超亲水/水下超疏油膜的制备及油水分离性能

工业生产和频繁的溢油事故产生大量的含油废水，其高效分离依然面临全球性的挑战。具有仿生浸润特性的膜可以选择性透过水或油，分离效率高且操作简单而广泛应用于油水分离。本文通过一步浸渍法将TiO₂纳米颗粒和聚乙烯吡咯烷酮（PVP）原位固化到不锈钢网上制备了具有微/纳米层级结构的超亲水/水下超疏油油水分离膜。重点考察了TiO₂/PVP涂覆液浓度（质量分数1%、3%、5%、7%、9%）对膜的浸润特性和油水分离性能的影响。实验结果表明，不同TiO₂/PVP浓度改性的膜具有超亲水/水下超疏油特性，水的接触角均为0°，在水中油的接触角达160°，油水分离效率大于99.5%。膜通量随浓度的增大先减小后增加，当质量分数为3%时膜通量最大为8422.5L/（m²·h）。经过30次连续油水分离后，其分离效率仍大于99.5%，表明TiO₂/PVP-SS （stainless steel）膜有良好的耐久性和稳定性。因此，TiO₂/PVP-SS仿生特殊浸润膜材料在油水分离领域具有经济、高效、环境友好的潜在优势。

Fabrication of superhydrophilic/underwater superoleophobic mesh for oil-water separation

The rapid development of industry activities and the frequently oil leakage accidents have produced large amount of oily wastewater and high efficient separation is still a worldwide challenge. Bio-inspired membranes with special wettability have highly selectivity on oil or water and have been extensively used for oil/water separation because of the advantages of easy operation, high efficiency. A one-step fabrication of micro/nano scale hierarchical structure superhydrophilic and underwater superoleophobic oil/water separation membrane was developed through impregnation of TiO₂ nanoparticles and polyvinyl pyrrolidone(PVP) into stainless steel mesh. The effects of TiO₂/PVP concentration on wetting properties and oil-water separation performances were investigated. The results indicated that water contact angle of the modified membrane was 0°, underwater oil contact angle was 160°, and the oil-water separation efficiency was above 99.5% under varied coating concentrations. The flux of these as-prepared membranes undergone a trend of going up and drop down, the maximum flux of 8422.5L/(m²·h) was reached at the TiO₂/PVP concentration of 3%. The mesh still maintained separation efficiency above 99.5% after 30 separation cycles, indicating that the TiO₂/PVP-SS(stainless steel) modified membrane has good durability and stability. Therefore, the TiO₂/PVP modified bionic special wettability membrane has the potential advantages of economy, high efficiency and environmental friendliness in the oil-water separation.