Abstract Surface roughness enhancement by fabricating multi-scale nano/microstructure is an effective strategy to prepare superhydrophobic membranes. Here we report a novel solvent-thermal induced roughening (STIR) method. The method involves the swelling of a polymer surface to create a soft shell/hard core structure under the combined action of solvent and heating, followed by a controllable surface roughening as a result of mismatched thermal expansion between the shell and the core. We show a significant increase of surface roughness for a STIR-treated polyvinylidene fluoride nanofibrous membrane, whose nanofibers were covered with densely-packed nanofins. The treated membrane had greatly enhanced hydrophobicity, resulting in improved anti-wetting performance to low-surface-tension feed water in a membrane distillation process. The STIR method was capable of treating membranes with various pore structures. The novel surface roughening strategy opens up new directions to fabricate superhydrophobic surfaces and membranes, which can greatly benefit a wide range of applications such as membrane distillation, oil/water separation.

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溶剂热诱导粗糙化：一种制备超疏水膜的新型通用方法

摘要 通过制造多尺度纳米/微结构来增强表面粗糙度是制备超疏水膜的有效策略。在这里，我们报告了一种新的溶剂热诱导粗糙化 (STIR) 方法。该方法涉及在溶剂和加热的共同作用下，聚合物表面溶胀以产生软壳/硬核结构，然后由于壳和核之间的热膨胀不匹配导致可控的表面粗糙化。我们展示了经过 STIR 处理的聚偏二氟乙烯纳米纤维膜的表面粗糙度显着增加，其纳米纤维被密集堆积的纳米鳍覆盖。处理后的膜具有大大增强的疏水性，从而提高了膜蒸馏过程中对低表面张力给水的抗湿性能。STIR 方法能够处理具有各种孔结构的膜。新颖的表面粗糙化策略为制造超疏水表面和膜开辟了新的方向，可以极大地有益于广泛的应用，如膜蒸馏、油/水分离。