Poly(amino acid)-Facilitated Electrochemical Growth of Metal Nanoparticles

Abstract

Poly(amino acids) are natural chelating agents for various metal ions. Zinc ions were encapsulated in situ in a conductive polypyrrole film using polyglutamic acid as a localized complexing agent within the film. The subsequent electrochemical reduction of the metal ions to zero-valent metal leads to the formation of the nanoparticles. The electrochemical approach demonstrated in this report provides facile regeneration of the particles and also prevents aggregation of nanoparticles in the conductive polymeric film. The correlation of the amount of zinc with the thickness of the film indicates that the zinc resides largely in the outer layer of the film. TEM and EDS data show that the nanoparticles formed are composed of zinc and are 18 +/- 7 nm in diameter. The nanoparticle/ polymer composite was used to reduce halogenated organics, indicating its potential usefulness in remediation applications.

Reductive dechlorination of 3,3′,4,4′-tetrachlorobiphenyl (PCB77) using palladium or palladium/iron nanoparticles and assessment of the reduction in toxic potency in vascular endothelial cells

“…Nanoparticles have been incorporated into polypyrrole using both electrochemical and chemical methods [32][33][34][35][36][37][38][39]. Polypyrrole has positive charges in its fully oxidized form for every 3-4 pyrrole units and can be doped with anions to compensate this charge [40].…”

Electrosynthesis and catalytic activity of polymer-nickel particles composite electrode materials

“…16,17 It should be emphasized that electrochemical syntheses of metal-polymer composites have essentially been reported with noble metal-based materials. 3,14,16,17 In contrast, examples of electrodeposition in conducting polymers of transition metals such as copper, [18][19][20][21][22][23] nickel, [24][25][26][27] or zinc 28 are more scarce, in spite of the potential interest of transition metal-based electrode materials in electrosynthesis. 26,29,30 As demonstrated in the case of the deposition of copper 20,31 and cadmium 31 by direct electroreduction of metal salts onto conducting polymer film-modified electrodes, the main problems for the electrosynthesis of transition metals-polymer composites concern the poor polymer conductibility in the potential domain usually required for the reduction of metal species, and the morphology of the metal deposit obtained, i.e.…”