Chemical and Enzymatic Polymerization of Polyaniline/Ag Nanocomposites

Polyaniline (PANI)/Ag nanocomposites were successfully synthesized via in situ chemical oxidative and enzymatic polymerization of aniline based on 2-aminothiophenol (2-ATP)-capped Ag nanoparticles. The approach to the fabrication included three steps: (i) the preparation of silver nanoparticles; (ii) the formation of an ATP monolayer on the silver particle surface, which serves as a binder; and (iii) the polymerization of aniline monomers joined to ATP by using ammonium persulfate in the chemical method, and horseradish peroxidase in the presence of sulfonated polystyrene as a polyanionic template and H₂O₂ as an oxidized agent in the enzymatic method. Comparison of the results revealed that the enzymatic method is more suitable because not only the size of the nanocomposites was smaller but also their thermal stability was more improved with the enzymatic method than with chemical one.