Abstract:The nano-silver flake with about 30 nm, was prepared by a chemical reduction method. Cetyltrimethyl ammonium bromide (CTAB) was used to prevent agglomeration of the nanoparticles by its steric hindrance. However, an excessive amount of CTAB will impede the growth of silver nanoparticles, and thus it is not beneficial to the formation of the desired morphology. When the mass ratio of CTAB to silver nitrate is 0.8, the nano-silver with flaky structure can be obtained. At temperature of 20 oC, the solubility of CTAB is low, and it is difficult to retard the agglomeration effectively. At the same time, the low reaction rate will lead to large and nonuniform nanoparticles. When the temperature is 40 oC, the increased solubility of CTAB promotes the forming of nanoparticle. Nevertheless, when the temperature reaches 60 oC, the reaction is so fast that the nucleation rate increases and thus tiny particles are formed eventually. High pH value will lead to promote the reaction and ensure the complete consumption of Ag+, but too high pH may cause damage to the double-layer electronic structure of silver particles, resulting in collapse and agglomeration of the formed particles. When the pH value is around 6, stable nano-silver flakes can be obtained in a uniform dispersed form.