Abstract Recent development of omniphobic membranes shows promise in scaling/fouling mitigation in membrane distillation (MD), however, the fundamental understanding is still under dispute. In this paper, we report a novel omniphobic micropillared membrane coated by silica nanoparticles (SiNPs) (SiNPs-MP-PVDF) with dual-scale roughness prepared by a micromolding phase separation (μPS) and electrostatic attraction. This membrane was used as a model for analysis of scaling behavior by calcium sulfate (CaSO4) scaling and fouling behavior by protein casein in comparison with commercial (C-PVDF) and micropillared (MP-PVDF) membranes. Unprecedented scaling/fouling resistance to CaSO4 and casein was observed in direct contact membrane distillation (DCMD) for SiNPs-MP-PVDF membrane. Similar scaling and fouling occurred for commercial PVDF and micropillared PVDF membranes. The observation corresponds well to the wetting state of all membranes as SiNPs-MP-PVDF shows suspended wetting, but MP-PVDF shows pinned wetting. From a hydrodynamic view, the suspended wetting attributes a slippery surface which reduces the direct contact of foulants to solid membrane part and leads to significantly reduced fouling and scaling. However, a pinned (or metastable) wetting state leads to a stagnant interfacial layer that is prone to severe fouling and scaling. This work highlights that both scaling and fouling resistance are indeed of suspended wetting state and slippage origin.

中文翻译：

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具有二氧化硅纳米颗粒涂层微柱的全疏水性聚偏二氟乙烯膜在直接接触膜蒸馏中具有前所未有的抗结垢/抗污染性

摘要 全疏水膜的最新发展显示出在膜蒸馏 (MD) 中减少结垢/污染的前景，然而，基本理解仍存在争议。在本文中，我们报告了一种由二氧化硅纳米粒子 (SiNPs) (SiNPs-MP-PVDF) 涂覆的新型全疏水微柱膜，该膜具有通过微成型相分离 (μPS) 和静电吸引制备的双尺度粗糙度。与商业 (C-PVDF) 和微柱 (MP-PVDF) 膜相比，该膜用作分析硫酸钙 (CaSO4) 结垢和蛋白质酪蛋白结垢行为的模型。在 SiNPs-MP-PVDF 膜的直接接触膜蒸馏 (DCMD) 中，观察到了对 CaSO4 和酪蛋白的前所未有的结垢/结垢抗性。商业 PVDF 和微柱 PVDF 膜也发生了类似的结垢和结垢。观察结果与所有膜的润湿状态非常吻合，因为 SiNPs-MP-PVDF 显示悬浮润湿，但 MP-PVDF 显示固定润湿。从流体动力学的角度来看，悬浮润湿归因于光滑的表面，这减少了污垢与固体膜部分的直接接触，并显着减少了污垢和结垢。然而，钉扎（或亚稳态）润湿状态会导致界面层停滞，易于严重结垢和结垢。这项工作强调了结垢和污垢阻力确实是悬浮润湿状态和滑移起源。从流体动力学的角度来看，悬浮润湿归因于光滑的表面，这减少了污垢与固体膜部分的直接接触，并显着减少了污垢和结垢。然而，钉扎（或亚稳态）润湿状态会导致界面层停滞，易于严重结垢和结垢。这项工作强调了结垢和污垢阻力确实是悬浮润湿状态和滑移起源。从流体动力学的角度来看，悬浮润湿归因于光滑的表面，这减少了污垢与固体膜部分的直接接触，并显着减少了污垢和结垢。然而，钉扎（或亚稳态）润湿状态会导致界面层停滞，易于严重结垢和结垢。这项工作强调了结垢和污垢阻力确实是悬浮润湿状态和滑移起源。