Controlling synthesis of silver nanowires and dendrites in mixed surfactant solutions

Using a simple wet chemical route, high-yield silver nanowires with an average diameter of 25 +/- 15 nm and length up to several pm and dendrites with a long central backbone and symmetrically ramified secondary branches have been successfully obtained by reducing AgNO3 with L-ascorbic acid (AsA) in the mixed surfactant solutions of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). It was found that the architecture of silver nanocrystals was drastically influenced by the concentrations of ascorbic acid. At a given high concentration, a nonequilibrium system was easily built, which favored the formation of fractals. When the concentration was lowered, one-dimensional silver nanowires were successfully obtained. In addition, the presence of electrolyte (NaCl) plays an important role in the preparation of silver nanowires, influencing the silver crystallization process in surprising ways. (C) 2003 Elsevier Inc. All rights reserved.