Abstract Currently, porous polymeric membranes are mainly produced by the NIPS and TIPS techniques, but both have intrinsic technical limitations in terms of effective control of membrane structures. Recently, a novel Combined solvent Crystallisation and polymer Diffusion (CCD) method has been established to produce high-performance membranes with a unique asymmetric structure, where solvent nucleation and crystallisation in a binary polymer-solvent system are utilised to serve as the pore-forming mechanism. However, the membrane formation mechanism of the CCD method has yet been understood fully. In this work, the formation mechanism is proposed based on the widely acknowledged principles of nucleation and crystal growth. A typical and commonly used amorphous polymer, polyethersulfone (PES) is employed as a sample membrane material to prepare microfiltration/ultrafiltration membranes using the CCD method and the effect of cooling rate on the membrane structure is investigated. The structural features of the membranes can be well explained using the proposed membrane formation mechanism, where the effect of cooling rate is rationalised. Pristine PES membranes with pore sizes

中文翻译：

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结合结晶和扩散 (CCD) 方法制备的多孔膜：形成机制研究

摘要 目前，聚合物多孔膜主要采用NIPS和TIPS技术生产，但在有效控制膜结构方面均存在固有的技术局限性。最近，已经建立了一种新的组合溶剂结晶和聚合物扩散（CCD）方法来生产具有独特不对称结构的高性能膜，其中二元聚合物 - 溶剂系统中的溶剂成核和结晶被用作成孔机制。然而，CCD方法的成膜机制尚未完全了解。在这项工作中，基于广泛认可的成核和晶体生长原理提出了形成机制。一种典型且常用的无定形聚合物，以聚醚砜（PES）为样品膜材料，采用CCD方法制备微滤/超滤膜，研究了冷却速率对膜结构的影响。使用所提出的膜形成机制可以很好地解释膜的结构特征，其中冷却速率的影响被合理化。具有孔径的原始 PES 膜