Conductive polyaniline composite films from aqueous dispersion: Performance enhancement by multi-walled carbon nanotube

The intractable multi-walled carbon nanotube (MWNT) was dispersed in aqueous solutions of conductive polyaniline (cPANI) by externally doping of MWNT/polyaniline (PAN!) employing an organic polymeric phosphate acid as the dopant Free-standing composite films were obtained from the MWNT/ cPANI aqueous dispersion after drying. In comparison with the cPANI, the conductivity of MWNT/cPANI composites showed a 2 order of magnitude increase with the maximum value 1.2 S cm(-1), at the MWNT loading of 1.0 wt% because of the doping effect of MWNT on PANT. Under the strong 9-pi-pi interactions between PANI and MWNT which were discussed by FT-IR and UV-vis analysis, the redox performance of the MWNT/cPANI composites was significantly modified compared with the pure cPANI. In addition, the capacitive behaviors of the MWNT/cPANI films varied with the difference of the MWNT loading due to the morphology variation resulted from the established interactions. The enhanced specific capacitance with the highest value of 371 F g(-1) at a current loading of 0.5 A g(-1) was obtained for the MWNT/cPANI films containing MWNT content of 1.0 wt%, as well as the better cyclability. (C) 2014 Elsevier B.V. All rights reserved.