The electrospun polyamide 6 nanofiber membranes used as high efficiency filter materials: Filtration potential, thermal treatment, and their continuous production

AbstractIn this article, polyamide (PA) 6 was dissolved in 98 wt % formic acids with a concentration of 13 wt %, and then the electrospun PA 6 nanofiber membranes were prepared. The filtration potential of the nanofiber membranes were firstly analyzed based on the scanning electron microscope images and pore size measurements, and then the effects of thermal treatment on the dimensional stability were studied. Subsequently, the continuous production process based on the above experiments and the deposition areas of the nanofibers on the collecting meshes was designed. Finally, the mechanical properties and the filtration performances of the electrospun PA 6 nanofiber membranes were assessed. The results showed the membranes with a thickness of 71 μm (electrospinning for 15 min) had good filtration potential for the microparticles with 0.3 μm diameter. After being treated by tension and relaxation heat setting, the membranes demonstrated excellent dimensional stability, the breaking tenacity, and the elongation reached 4.71 ± 1.66 MPa and (69.97 ± 6.56)%, respectively. The permeability decreased with the increase of the membranes thickness. However, the permeability of membranes with (72.9 ± 1.04) μm thickness still maintained 516 L/m2 s, and the actual filtration efficiency of 0.3 μm particles reached 99.98%. The above results showed that the membranes fabricated by the continuous production process could meet the demands of high efficiency filtration and provide a reference for the industrial use of electrospun nanofiber membranes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013