基于多巴胺亲水改性下Janus膜的制备及其油水乳液分离

目前用于处理含油废水的特殊润湿材料通常分为去油型和去水型，其仅局限分离单一乳液。本文基于多巴胺改性的聚偏氟乙烯(PVDF)膜，通过交替浸渍工艺和无纺布剥离，制备了具有不对称润湿性的Janus膜。通过调整交替次数以及剥离无纺布，可分别获得超亲水/水下超疏油的表面以及超疏水/超亲油的底面，水/水下油接触角(CA)差异高达150°。基于Janus膜的非对称润湿性，仅通过切换跨膜方向，对表面活性剂稳定的水包油(O/W)和油包水(W/O)乳液渗透通量高达367L/(m²·h)和1729L/(m²·h)，其中水包油渗透液化学需氧量(COD)符合石油化工排放标准，油包水渗透液中水含量小于80mg/L，实现了对O/W和W/O乳液的高效分离。此外，Janus膜在牛血清蛋白(BSA)溶液分离过程中表现出理想的防污性能和可重复使用性。

Asymmetric Janus membranes based on hydrophilic modification of dopamine for efficient oil/water separation

Current special wetting materials used for treating oily wastewater are usually divided into the oil-removing type or the water-removing type, which are limited to separating single emulsion. In this paper, Janus membranes with asymmetric wettability were fabricated by alternating soaking process and non-woven peeling upon dopamine-modified PVDF membranes. By facilely adjusting the number of alternating soaking and peeling the nonwoven fabric, superhydrophilic/underwater superoleophobic surface and superhydrophobic/superoleophobic bottom surface could be respectively obtained, where the discrepancy in water contact angle between these two surfaces water contact angle was up to 150°. Based on the asymmetric wettability of Janus membranes, high permeate flux of 367L/(m²·h) and 1729L/(m²·h) were achieved for surfactant-stabilized oil-in-water (O/W) and water-in-oil (W/O) emulsions by simply switching the transmembrane direction, where the COD in the permeate of oil-in-water fulfilled the petrochemical discharge standard and the water content in the permeate of water-in-oil was less than 80mg/L, achieving efficient separation of O/W and W/O emulsions. Moreover, Janus membranes exhibited ideal antifouling property and reusability during BSA solution separation process.