Fractal and dendritic growth of metallic Ag aggregated from different kinds of gamma-irradiated solutions

With gamma-irradiation on AgNO3 dissolved in deionized water, ethanol, and 0.01 M C12H25NaSO4, metallic Ag with different dispersed states and particl e sizes was obtained. In the former two solvents, metallic Ag particles pre cipitated From the solutions and the Ag particle size was about 100 and 20 nm, respectively. In the latter solvent, Ag colloid was produced. The morph ology of structures formed during two-dimensional aggregation of Ag particl es in three different solvents was studied by transmission electron microso copy (TEM). The patterns were dendrite, fractal (with center), and fractal (no center) with the fractal dimension of 1.81, 1.73, and 1.70 correspondin g to the aggregating structure from deionized water, ethanol, and 0.01 M C1 2H25NaSO4 solutions, respectively. The formation mechanism of different pat terns was illustrated from different aspects.