Polyelectrolytes with tetrazole pendant groups useful in the stabilization of Au and Ag nanoparticles

Stabilization of metallic nanoparticles is a challenge of enormous dimensions because the nanosize nanoparticles are not stable by themselves and therefore they tend to coalesce, forming large agglomerates causing the loss of the properties of individual nanoparticles. In this work, we report the synthesis of polyelectrolytes with tetrazole groups useful as stabilizing agents of Au and Ag nanoparticles. The polyelectrolytes with tetrazole groups were synthetized from the appropriate starting materials with nitrile groups, which were successfully converted to the corresponding 1H-tetrazole rings using 1,3-dipolar cycloaddition with ammonium azide. These new materials were characterized by NMR and FT-IR techniques and they were used for the stabilization of Au and Ag colloidal nanoparticles at room temperature, using sodium borohydride as reducing agent. Formation and stabilization processes of the nanoparticles were monitored by UV-vis spectroscopy. Shape and size of nanoparticles were studied by TEM. The polyelectrolytes with tetrazole pendant group are suitable materials for synthesis and stabilization of gold nanoparticles, obtaining average sizes lower than 10 nm. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43773.