Preparation and properties of PANI/PI composite fabrics with conductive nanofiber network structure

Electrically conductive polyaniline (PANI)/polyimide (PI) composite fabric was prepared by in situ polymerized aniline on PI fabric in the acid solution using ammonium persulfate as the oxidant. PANI nanoflowers and nanofibers was obtained on the surface of PI fabric by controlling the molar ratio of aniline/oxidant and the acidity of the polymerization solution. Field Emission Scanning Electron Microscope (FESEM) results demonstrated that a continuous PANI nanofiber network with an average fiber diameter of 80–100 nm was successfully constructed on PI fabric when the doping acid was HNO3, the aniline to oxidant molar ratio was 4:5, and the pH value was 2.32. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis indicated that the PANI nanofibers was combined on PI fabric through hydrogen bonding. The conductivity of the composite fabric was 0.53 S/m, the contact angle of the composite fabric was increased from 50.6° to 84.7° due to the uniform nanofiber network structure, and the decomposition temperature (Td) of the composite fabrics was beyond 580.0 °C. Remarkably, the prepared PANI/PI composite fabric exhibited excellent electromagnetic wave absorption features (reflection loss of −57.99 dB), which implied it could be a good candidate for the electromagnetic wave absorbing materials.