Stabilization of colloidal metallic nanoparticles using polymers and hexa-substituted compounds with 1,3,4-oxadiazole pendant groups

Abstract

Stabilization of metallic nanoparticles in colloidal solutions has been realized by different capping agents. Heterocyclic compounds can interact with metallic surfaces, and some authors have reported the use of heterocyclic compounds for the stabilization of colloidal nanoparticles. In this work, we report stabilization of Au and Ag nanoparticles using polymers and hexa-substituted compounds with 1,3,4-oxadiazole pendant groups. Using a polyelectrolyte with 2-amino-1,3,4-oxadiazole groups was possible to reduce Au3+ and Ag+ ions and stabilize Au and Ag nanoparticles in colloidal solution. With polymers and hexa-substituted compounds containing 1,3,4-oxadiazoles substituted with methyl, phenyl, or acetyl groups, stabilize Au and Ag nanoparticles in a water-DMF medium was possible. Characterization by TEM revealed the obtaining of Au and Ag nanoparticles with control over the size and the shape. The lowest average size for Au and Ag nanoparticles was 4 and 10 nm, respectively, using the hexa-substituted compound with 2-acetamido-4-acetyl-1H-1,3,4-oxadiazole groups.