Gold nanoparticle protected with poly(2-methyl
aniline) were synthesized and characterized by
various spectroscopic techniques. The process of
reduction of the auric precursor and subsequent
capping of the nanoparticles by the amines is elucidated.
The reduction of the auric ions and the
oxidation of the aromatic amine occur simultaneously,
suggesting that they behave as a redox
couple. It is found that the oxidative polymerization
of the aromatic amines goes in step with the
formation of gold nanoparticles from the reduced
gold atoms. Finally the polymerized amine
encapsulates the gold nanoparticle forming a robust
shell. The polymer-protected nanoparticles
were found to be inert towards mineralizing agents
such as chloroform, bromoform, sodium cyanide
and benzylchloride, which have been known to
react with naked and monolayer-protected gold
core