Version 2 2022-02-04, 15:06Version 2 2022-02-04, 15:06
Version 1 2022-02-03, 16:15Version 1 2022-02-03, 16:15
journal contribution
posted on 2022-02-04, 15:06authored byLucien Roach, P. Louise Coletta, Kevin Critchley, Stephen D. Evans
We
present the characterization of the CTAB-oleate controlled synthesis
of gold nanorods (AuNRs). Concentrations of key compounds in the synthetic
system were varied in the presence of oleate, including HCl, borohydride,
silver nitrate, and ascorbic acid. The longitudinal surface plasmon
resonance peak was sensitive to changes in all concentrations. Reducing
the concentration of Ag ions below 66 μM led to slower reaction
kinetics and incomplete Au reduction. Variation of the ascorbic acid
concentration revealed that oleate is responsible for around 44% of
reduction of Au3+ to Au+ before nucleation in
these experiments. Increasing the oleate concentration significantly
slows the growth kinetics and leads to much longer synthesis times
of above 12 h for reaction completion. These observations will enable
the design of better methods of synthesizing of AuNRs using binary
surfactants.