Growth Mechanism of Gold Nanorods in Binary Surfactant System

In order to reveal the growth mechanism of gold nanorods ( GNRs ) in a binary surfactant system, we synthesized various GNRs by changing the concentration of the surfactants, AgNO 3 , and HBr in the growth solution. We found that the benzyldimethylhexadecylammoniumchloride surfactant had weak interaction with the gold ions, but it could reduce the membrane fluidity. In addition, we could dramatically decrease the cetyltrimethylammonium bromide concentration required for GNR growth by adding an HBr solution. Notably, Ag + ions were necessary to break the symmetry of the seed crystals for GNR growth, but increasing the concentration of Ag + and Br − ions caused a decrease in the template size.