Facile Synthesis of Silver Nanoparticles Using a Novel Benzenethiol Derivative: Addition Effect of Cationic Surfactants

Abstract

We propose a new type of preparation method of silver nanoparticles (AgNps) by using a triazine benzenethiol derivative such as (4,6-dimethoxy-1,3,5-triazin-2-yl)-4-mercaptobenzoate (TBSH) as a reductant in the presence of a cationic surfactant such as cetyltrimethylammonium chloride (CTAC) or cetyltrimethylammonium bromide (CTAB). The formation amount and stability of AgNps in the presence of CTAC is compared with those in CTAB system; the addition of CTAC play important roles for the formation of AgNps. The optical properties of as prepared AgNps were characterized by using UV-vis, FTIR, and X-ray photoelectron (XPS). Transmission electron microscopy (TEM) images of as-prepared AgNps distinctly show the morphology of AgNps with average size of 30 nm. CTAC-concentration dependence of FTIR spectra indicates that the combination of rigid and compact network of TBSH and CTAC capped on AgNps significantly affects the size and shape of AgNps and also exhibit the presence of enhanced gauche conformers below the critical micellar concentration (cmc ∼ 0.6 mM) and trans conformers at cmc and above cmc of CTAC. Based on the present results, we propose a model of molecular structure and stability of AgNps.