Abstract Phase separation micromolding (PSμM) is an effective technique for fabricating porous membranes with micropatterned structures. However, reports on procedures to control the size and number of open pores on the patterned surface are scarce, which often limits the use of the surface-patterned membranes. This work presents a systematic study on tailoring open pores on the patterned surface of polyethersulfone (PES) membranes prepared by the PSμM procedure. The composition of the solvent and the concentration of PES in the casting solution were optimized to tune the size and number of pores on the membrane surfaces formed on a flat substrate during the nonsolvent-induced phase separation (NIPS) process. The surface porosity changed significantly and macrovoids appeared when the flat substrate was replaced by a micropatterned substrate. The vapor-induced phase separation process was applied prior to the NIPS process to prevent the formation of macrovoids. The composition of the casting solution was tuned again to prepare micropatterned porous PES membranes with open pores on the patterned surface. We observed that the size and number of pores were different depending on the pore locations on the patterned surface, which was caused by different solvent/nonsolvent demixing dynamics resulting from the physical discontinuity of micro-patterned membranes. This work presents a method on tailoring open pores on the patterned surface of polyethersulfone membrane prepared by the phase separation micromolding. By modifying both the thermodynamics of the casting solution and the dynamics of solvent/nonsolvent demixing, micropatterned membrane with average surface open pores in the diameter of 1095 nm and porosity as high as 31.4% was achieved. The size and number of pores were different depending on their locations on the patterned surface, which was caused by different solvent/nonsolvent demixing dynamics resulting from the physical discontinuity of micro-patterned membranes.

中文翻译：

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微调相分离微成型制备的微图案聚醚砜膜的表面孔隙率

摘要 相分离微成型 (PSμM) 是制造具有微图案结构的多孔膜的有效技术。然而，关于控制图案表面开孔大小和数量的程序的报道很少，这通常限制了表面图案膜的使用。这项工作提出了一项关于在由 PSμM 程序制备的聚醚砜 (PES) 膜的图案化表面上定制开孔的系统研究。溶剂的组成和浇铸溶液中 PES 的浓度经过优化，以调整在非溶剂诱导相分离 (NIPS) 过程中在平坦基材上形成的膜表面上的孔的大小和数量。当平面基材被微图案基材取代时，表面孔隙率发生显着变化，并出现大孔。在 NIPS 工艺之前应用蒸汽诱导相分离工艺以防止形成大孔洞。再次调整浇铸溶液的组成以制备在图案化表面上具有开孔的微图案化多孔 PES 膜。我们观察到孔的大小和数量根据图案表面上的孔位置而不同，这是由微图案膜的物理不连续性导致的不同溶剂/非溶剂分层动力学引起的。这项工作提出了一种在通过相分离微成型制备的聚醚砜膜的图案化表面上定制开孔的方法。通过修改浇铸溶液的热力学和溶剂/非溶剂分层的动力学，微图案膜的平均表面开孔直径为 1095 nm，孔隙率高达 31.4%。孔的大小和数量根据它们在图案表面上的位置而不同，这是由微图案膜的物理不连续性导致的不同溶剂/非溶剂分层动力学引起的。