Monolayers of silver nanoparticles obtained by green synthesis on macrocation modified substrates

Abstract

Abstract Formation of silver nanoparticle monolayers on polydiallyldimethylammonium chloride (PDADMAC), modified mica was studied in situ by the streaming potential measurements, ex situ atomic force microscopy (AFM), and scanning electron microscopy (SEM). The silver nanoparticles were obtained in a green synthesis involving AgNO3 precursor, using glucose and sucrose serving as both reducing and stabilizing agents. The average size of the nanoparticles was 48 nm. The dynamic light scattering measurements showed that the silver nanoparticle suspension was stable for the time period up to 60 days. The electrophoretic mobility measurements revealed that the nanoparticles were negatively charged, with zeta potential increasing with the ionic strength from −75 mV at 10−5 M to −42 mV at 2 × 10−2 M. The effect of ionic strength on the nanoparticle deposition kinetics on PDADMAC monolayer was also quantitatively determined. A significant increase of the nanoparticle coverage with macrocation coverage suggested that the deposition of the nanoparticles occurred only on local adsorption sites, consisting of a few macrocation molecules exhibiting large positive charge. The obtained results can find practical applications in constructing biocompatible materials serving for bioparticle immobilization and biofilm formation.