Electric-field-directed growth of gold nanorods in aqueous surfactant solutions

Abstract

The factors affecting the nucleation and growth of gold nanorods, (Jana et al., Adv. Mater. 2001, 13, 1389) have been investigated. It is shown that the size and aspect ratio can be controlled through the use of different sized seed particles. The length of the rods can be tuned from 25-170 nm, while the width remains almost constant at 22-25 nm. The formation of rods requires the presence of the cationic surfactant cetyltrimethylammonium bromide (CTAB). Lower temperature favors rod formation, although this reduces CTAB solubility. The addition of chloride ions or the use of dodecyltrimethylammonium bromide (DTAB) leads to shorter-aspect rods. AIII and AuI are shown to be quantitatively boun..