Structure and performance of polyamide-6 membranes prepared by thermally induced phase separation

The asymmetric polyamide-6 (PA6) membranes were prepared by thermally induced phase separation. From the scanning electron microscopy (SEM) images, it is observed that with the increase of silicon dioxide (SiO2) content the structure of obtained membranes gradually varied from cellular structure to large ball-shaped cluster aggregates. Subsequently, with the addition of SiO2, pure water flux increased first and then decreased, while rejection showed the opposite trend. Besides, raising the coagulation bath temperature was favorable to increase pure water flux. Consequently, different membrane morphologies and performance were obtained by changing SiO2 content and coagulation bath temperature.