Effect of macromolecule poly(vinyl alcohol) on the growth of cetyltrimethylammonium bromide stabilized Ag-nanoparticles

The kinetics of cetyltrimethylammonium bromide stabilized silver nanoparticles was studied spectrophotometrically in the absence and presence of poly(vinyl alcohol) (PVA). Silver nanoparticles were prepared in aqueous solution using silver nitrate and cysteine as oxidant and reductant, respectively. Size and the distribution of the particles were determined by transmission electron microscopy. Silver nanoparticles were spherical, aggregated, cross-linking and of uniform particle size (the average particle size was about 30 and 7 nm in absence and presence of PVA, respectively). At higher concentration of PVA, the formation of silver sol was not observed for a certain reaction time, i.e., 200 min. Silver sol formation follows zero-order kinetics with respect to [Ag+]. Viscosity of the CTAB-PVA mixture was also determined. A mechanism that involves simultaneous formation of cysteine–Ag complex has been proposed.