A facile method combining micro-molding with thermally-induced phase separation (TIPS) to prepare superhydrophobic isotacticpolypropylene (iPP) microporous membranes with micron-submicron hierarchical structures is proposed in this paper. In this study, the hydrophobicity of the membrane was controlled by changing the size of micro-structures on the micro-structured mold and the temperature of the cooling bath. The best superhydrophobicity was achieved with a high water contact angle (WCA) of 161° and roll-off angle of 2°, which was similar to the lotus effect. The permeability of the membrane was greatly improved and the mechanical properties were maintained. The membrane prepared by the new method and subjected to 60h vacuum membrane distillation (VMD) was compared with a conventional iPP membrane prepared via the TIPS process. The flux of the former membrane was 31.2 kg/m2·h, and salt rejection was always higher than 99.95%, which was obviously higher than that of the latter membrane. The deposition of surface fouling on the former membrane was less and loose, and that of the latter membrane was greater and steady, which was attributed to the micron-submicron hierarchical structure of the former and the single submicron-structure of the latter. Additionally, the new method is expected to become a feasible and economical method for producing an ideal membrane for membrane distillation (MD) on a large scale.

中文翻译：

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微米级-亚微米级膜结构的超疏水iPP微孔膜的简便制备

提出了一种微成型与热诱导相分离（TIPS）相结合的方法，以制备具有微米-亚微米级结构的超疏水等规聚丙烯（iPP）微孔膜。在这项研究中，通过改变微结构模具上微结构的尺寸和冷却浴的温度来控制膜的疏水性。最佳的超疏水性是在161°的高水接触角（WCA）和2°的滚落角下实现的，这与荷叶效应相似。膜的渗透性大大提高，并保持了机械性能。将通过新方法制备并经过60h真空膜蒸馏（VMD）的膜与通过TIPS工艺制备的常规iPP膜进行了比较。前一种膜的通量为31.2 kg / m2·h，脱盐率始终高于99.95％，明显高于后一种膜。前者膜上的表面污垢沉积少而疏松，后者膜则更大且稳定，这归因于前者的微米-亚微米分层结构和后者的单一亚微米结构。另外，预期该新方法将成为大规模生产用于膜蒸馏（MD）的理想膜的可行且经济的方法。后者的膜更大，更稳定，这归因于前者的微米-亚微米层次结构和后者的单一亚微米结构。另外，预期该新方法将成为大规模生产用于膜蒸馏（MD）的理想膜的可行且经济的方法。后者的膜更大，更稳定，这归因于前者的微米-亚微米层次结构和后者的单一亚微米结构。另外，预期该新方法将成为大规模生产用于膜蒸馏（MD）的理想膜的可行且经济的方法。