(180e) Multilayer Assemblies of Polyaniline Nanofibers and Carbon Nanotubes for Electrochemical Applications

Polyaniline nanofibers (PANi) and acid functionalized multiwalled carbon nanotubes (MWNT) are used to fabricate nanostructured thin films for electrochemical capacitors using by layer-by-layer (LbL) assembly. The pH dependent surface charge of these components allow the system to grow in a linear but pH dependent fashion, much like weak polyelectrolytes, with controllable  film thickness and morphology. The physicochemical properties and electrochemical behavior of the LbL films have been investigated by a variety of techniques including surface profilometry, infrared (IR) and Raman spectroscopy, scanning electron and atomic force microscopy and cyclic voltammetry. The experimental results reveal an interpenetrating network of PANi and MWNTs with a highly nanoporous morphology.  The combination of the electrochemical redox behavior of PANi and the functionalized graphene surfaces of the MWNTs lead to high capacitance of 248 F/cm3 that are stable over 1000 cycles. Electrochemical measurements confirm the PANi/MWNT LbL film could be ideal for use in supercapacitor, fuel cell and battery electrode materials.