Mousavi Seyedeh Mohaddeseh, Raveshiyan Saba, Amini Younes, Zadhoush Ali
Department of Textile Engineering, Isfahan University of Technology, Isfahan 8415683111, Iran.
Department of Chemical Engineering, Tarbiat Modares University, Tehran, Iran.
Adv Colloid Interface Sci. 2023 Sep;319:102986. doi: 10.1016/j.cis.2023.102986. Epub 2023 Aug 23.
Considering the importance of asymmetric membrane morphology in controlling the performance of various membrane systems as well as the rapid development of membrane technologies in different industries, the control of membrane manufacturing processes and effective parameters is considered an outstanding subject. Therefore, it seems that investigating the rheological properties of polymer solutions, including gelation behavior, viscoelasticity, and their effect on membrane formation, as well as the morphological structure of membranes, such as hollow fiber and flat sheet membranes, is a requirement for the production of asymmetric membranes with desirable properties. One of the most widely used techniques for the preparation of asymmetric membranes is phase separation. Its two main mechanisms are liquid-liquid demixing and solid-liquid demixing, which can affect the morphology of the membranes in the membrane formation process. Therefore, the membrane morphology can be greatly influenced by controlling the phase separation in the early stages. In this study, an attempt has been made to investigate the rheological behavior of polymer solutions and other factors during the membrane fabrication process, affecting the morphological structure of membranes. The principles governing the rheology of polymer solutions, such as shear, elongation, viscosity, and viscoelasticity have a vital role in determining the membrane morphology and separation performance. Due to the interaction of the rheology of polymer solutions and phase separation, the effects of changes in the rheological properties of the phase separation and the formation of membranes with different structures and morphologies are studied. Furthermore, in addition to the analysis of the effect of the relaxation time and gelation mechanisms, discussions are provided for the determination of the final membrane morphology considering the competition between the domain growth and gelation rates. Finally, the effect of controlling the rheological behavior and phase separation on the membrane structure and performance was investigated in several membrane applications.
考虑到不对称膜形态在控制各种膜系统性能方面的重要性以及膜技术在不同行业的快速发展，膜制造过程和有效参数的控制被视为一个突出的课题。因此，研究聚合物溶液的流变特性，包括凝胶化行为、粘弹性及其对膜形成的影响，以及膜的形态结构，如中空纤维和平板膜，似乎是制备具有理想性能的不对称膜的必要条件。制备不对称膜最广泛使用的技术之一是相分离。其两个主要机制是液-液分层和固-液分层，这在膜形成过程中会影响膜的形态。因此，在早期阶段控制相分离可以极大地影响膜的形态。在本研究中，已尝试研究膜制造过程中聚合物溶液的流变行为和其他影响膜形态结构的因素。控制聚合物溶液流变学的原理，如剪切、拉伸、粘度和粘弹性，在决定膜的形态和分离性能方面起着至关重要的作用。由于聚合物溶液流变学与相分离的相互作用，研究了相分离流变特性变化对具有不同结构和形态的膜形成的影响。此外，除了分析弛豫时间和凝胶化机制的影响外，还讨论了考虑域生长和凝胶化速率之间的竞争来确定最终膜形态的问题。最后，在几种膜应用中研究了控制流变行为和相分离对膜结构和性能的影响。
