Preparation of high concentration of silver colloidal nanoparticles in layered laponite sol

The synthesis and characterization of silver colloidal nanoparticles by chemical reduction of silver ions in the presence of laponite using sodium borohydride (NaBH4) as the reducing agent are described. Laponite is used to prevent the growth and aggregation of particles to give stable high concentration of silver colloidal particles with a narrow size distribution. The optimum experimental condition for preparing silver colloidal particles is described in terms of concentrations of initial concentration of AgNO3 and NaBH4. The silver nanoparticles synthesized are characterized on UV–vis spectrophotometer, transmission electron microscopy (TEM) and the results show that silver nanoparticle is spherical and the mean size is below 10 nm.