Electrospun nylon nanofibers as effective reinforcement to polyaniline membranes

This research demonstrates that a nylon nanofiber (NNF) mat can be an effective mechanical reinforcement to polyaniline (PANI) thin films. Nanofibers of ca. 250 nm diameter were produced by electrospinning of a nylon 6 solution in formic acid. Scanning electron microscopy showed that the solution impregnation method utilized was effective to embed the nanofibers into the PANI matrix. The effectiveness of NNFs as a mechanical reinforcement of a PANI thin film was assessed via dynamic mechanical analysis in tension mode. The as-cast PANI films displayed a tensile dynamic modulus, E', of ca. 0.65 GPa at room temperature. Scanning in the temperature showed that the PANI film has a usage temperature of up to about 80 degrees C, with this being limited by its glass transition temperature, and over this temperature range, the elastic modulus was nearly independent of the temperature. On the other hand, the PANI-NNF composite displayed a significantly higher tensile modulus at room temperature (1.1 GPa) and its usage temperature was extended up to just over 200 degrees C, with this being limited by the melting transition of nylon 6 (at 220 degrees C). The results therefore showed that the NNF mat increased the usage temperature of PANI films over 100 degrees C, opening up applications for PANI membranes.