Membrane wetting and fouling issues are two major obstacles which hinder the practical application of membrane distillation (MD). In this study, a sequential electrospray method was introduced to impart a dual-layered superhydrophilic/superhydrophobic Janus skin onto a commercial polyvinylidene fluoride (PVDF) substrate. The bottom superhydrophobic layer was obtained by incorporating octaphenylsilsesquioxane (POSS) nanoparticles into PVDF carriers to construct a POSS@PVDF multiscale rough surface via electrospraying. At the same time, the top hierarchical-structured hydrophilic coating was composed of PAN beaded nanofilaments, rendering an intriguing in-air hydrophilicity and underwater superoleophobicity which benefited from the loose packing state of the interconnected beads and nanofibers. Further, this Janus skin exhibited good integrity and strong adhesion with the substrate, and due to its underlying superhydrophobicity and slightly decreased pore size, the hierarchical Janus membrane possessed a greatly enhanced liquid entry pressure of water (LEPw). Once applied in the MD process, with soybean-oil-in-saline-water emulsions as feed, this Janus membrane exhibited stable and excellent desalination performance with a high flux and nearly perfect salt rejection, whereas both the commercial and superhydrophobic membranes failed from oil contaminating. This suggests the remarkable simultaneous anti-wetting and anti-fouling property of Janus membranes, which possess great potential in water reclamation for challenging hypersaline oily wastewaters.

膜润湿和污染问题是阻碍膜蒸馏 (MD) 实际应用的两大障碍。在这项研究中，引入了连续电喷雾方法，将双层超亲水/超疏水 Janus 皮肤赋予商业聚偏二氟乙烯 (PVDF) 基材。通过将八苯基倍半硅氧烷（POSS）纳米颗粒掺入 PVDF 载体中，通过电喷涂构建 POSS@PVDF 多尺度粗糙表面，从而获得底部超疏水层。同时，顶部分层结构的亲水涂层由PAN珠状纳米丝组成，得益于相互连接的珠粒和纳米纤维的松散堆积状态，呈现出有趣的空气中亲水性和水下超疏油性。更远，这种Janus皮肤表现出良好的完整性和与基材的强粘附性，并且由于其潜在的超疏水性和略微减小的孔径，分级Janus膜具有大大增强的水的液体进入压力（LEPw）。一旦应用于 MD 工艺，以大豆-盐水-包油乳液为原料，这种 Janus 膜表现出稳定和出色的脱盐性能，具有高通量和近乎完美的脱盐率，而商业化和超疏水性膜均因油而失效污染。这表明 Janus 膜具有显着的同时抗湿和防污性能，在应对高盐含油废水的水回收方面具有巨大潜力。并且由于其潜在的超疏水性和略微减小的孔径，分级 Janus 膜具有大大增强的水的液体进入压力（LEPw）。一旦应用于 MD 工艺，以大豆-盐水-包油乳液为原料，这种 Janus 膜表现出稳定和出色的脱盐性能，具有高通量和近乎完美的脱盐率，而商业化和超疏水性膜均因油而失效污染。这表明 Janus 膜具有显着的同时抗湿和防污性能，在应对高盐含油废水的水回收方面具有巨大潜力。并且由于其潜在的超疏水性和略微减小的孔径，分级 Janus 膜具有大大增强的水的液体进入压力（LEPw）。一旦应用于 MD 工艺，以大豆-盐水-包油乳液为原料，这种 Janus 膜表现出稳定和出色的脱盐性能，具有高通量和近乎完美的脱盐率，而商业化和超疏水性膜均因油而失效污染。这表明 Janus 膜具有显着的同时抗湿和防污性能，在应对高盐含油废水的水回收方面具有巨大潜力。以大豆盐水包油乳液为原料，这种 Janus 膜表现出稳定和出色的脱盐性能，具有高通量和近乎完美的脱盐率，而商用膜和超疏水膜均因油污染而失败。这表明 Janus 膜具有显着的同时抗湿和防污性能，在应对高盐含油废水的水回收方面具有巨大潜力。以大豆盐水包油乳液为原料，这种 Janus 膜表现出稳定和出色的脱盐性能，具有高通量和近乎完美的脱盐率，而商用膜和超疏水膜均因油污染而失败。这表明 Janus 膜具有显着的同时抗湿和防污性能，在应对高盐含油废水的水回收方面具有巨大潜力。