Conducting Polymers on Paper Fibres

Various composite paper - conducting polymer products have been prepared by polymerizing polypyrrole and polyaniline directly onto the paper sheet using ferric chloride as the oxidant. Electronmicroscopy shows that the polymers comprise spheres of about 50-150 nanometers in size fused together such that they fully encapsulate the individual cellulose fibres in the paper sheet. The open matrix of fibres characteristic of the original paper sheet is maintained and hence provides a much greater specific surface area for the conducting polymer than that of a continuous flat sheet which would be the case if the polymer simply formed a laminar coating on the paper surface. In the case of polyaniline, it was also possible to form a different morphology of the polymer comprising a mix of nano-size spheres, rods and plates using ammonium persulfate as the oxidant. Conductivities of up to 6 S cm−1 have been measured for paper-polypyrrole composites and up to 2x10−3 S cm−1 for paper-polyaniline composites.