Pore structure design and optimization of electrospun PMIA nanofiber membrane

Poly (m-phenylene isophthalamide) (PMIA) has been widely used in many applications due to its excellent thermal stability, flame resistance and mechanical properties. In this study, PMIA nanofiber membranes were fabricated by electrospinning method, and then, the solvent welding was used to optimize the pore structure and mechanical strength. Effects of solvent concentration (volume fraction of solvent) and welding temperature on the PMIA nanofiber membranes' morphology, pore structure and mechanical properties were investigated, respectively. The mechanical strength and pore size was simply controlled by solvent welding and heat pressing. And the process of solvent welding and heat pressing was classifiable regulation. In addition, the separation accuracy of nanofiber membrane was controllable in the range of ultrafiltration. The mechanical strength of PMIA nanofiber membrane raised from 5.5 MPa to 99.0 MPa, while the mean pore size decreased from 459.1 nm to 33.6 nm after post-treatment. The Congo red rejection rate of PMIA nanofiber membrane after heat pressing increased from 4.9% to 94.7%, which showed excellent ultrafiltration performance.