Membranes of Amphiphilic Polyamide 1012 Prepared via Mixed ‘Non-solvents’ Evaporation Induced Phase Separation

Long-chain polyamides (LCPAs) are a class of bio-based polymers that can bridge conventional polyolefins and polycondensates. In this work, taking the advantage of the amphiphilic nature of polyamide 1012 (PA1012), membranes were prepared by using a non-conventional phase separation approach, namely, mixed ‘non-solvents’ evaporation induced phase separation (MNEIPS). PA1012 can be dissolved in a mixture of polar and non-polar solvents, both of which are non-solvents of PA1012. During the sequential evaporation of the two solvents, the phase separation of PA1012 occurred, inducing the formation of porous structures. We investigated the process of membrane formation in detail, with a specific focus on the liquid-liquid and liquid-solid phase transitions involved. Moreover, we studied the influence of critical factors, such as polymer concentration and mixed-solvent ratio, on the morphologies and properties of PA1012 membranes. This study provides new insights into the development of porous materials based on long-chain polycondensates.