Synthesis and properties of self-doped polyaniline with polycationic templates via biocatalysis

摘要

The enzyme horseradish peroxidase (HRP) was used to polymerize acid-functionalized anilines to make self-doped polymer in the presence of a polycationic template. Anionic templates such as sulfonated polystyrene (SPS) could not function as a suitable template for the polymerization of acid-functionalized aniline derivatives. Several types of polyelectrolytes were used as templates to observe the structural effects and doping behavior of polyaniline/template complexes. The synthesis is straightforward and the conditions are mild in that the polymerization of conducting polyanilines may be carried out in buffered solutions as high as pH 6, with a stoichiometric amount of hydrogen peroxide and catalytic amount of enzyme. The conductivity of these enzymatically synthesized self-doped polymers was relatively high without additional doping due to the self-doping of the acid moieties. The conductivity did not decrease dramatically at pH 3 as is the usual case of unsubstituted HCl-doped polyaniline and maintained good conductivity even at pH 6. The measured conductivity at pH 4 similar to pH 6 is around 10(-4) S/cm to 10(-6) S/cm.