Continuous electrodeposition of polypyrrole on carbon nanotube–carbon fiber hybrids as a protective treatment against nanotube dispersion

This paper describes the electrodeposition of nanometer size polypyrrole layers on carbon fibers coated with multi-wall carbon nanotubes. The obtained carbon nanotubes–carbon fiber hybrids are characterized by electrochemistry, electron microscopy, vibrational spectroscopy and thermogravimetry. The electrical properties are measured for various polymerization times and electrolytes. The conductivity is found decrease with increasing polypyrrole thickness, but all the carbon nanotube–carbon fiber hybrids remain more conductive than pristine carbon fibers having a sizing coating. Finally it is shown that polypyrrole acts as a protecting layer against carbon nanotube dispersion when sonicated in ethanol.