Shear Induced Alignment of Low Aspect Ratio Gold Nanorods in Newtonian Fluids
Donglin Xie, Marco Lista, Greg G Qiao, Dave E Dunstan
The Journal of Physical Chemistry Letters | AMER CHEMICAL SOC | Published : 2015
The flow-induced alignment of small gold nanorods ranging in aspect ratio from 2.4 to 4.2 in aqueous sucrose solutions is reported. Optical absorption spectra have been measured over a range of shear rates using polarized incident light in an optically transparent quartz Couette cell. The measured spectral changes are directly attributed to the shear-induced anisotropy in the suspension due to particle alignment that saturates at Péclet number of around 200. The measured optical changes are reversible, indicating that the nanorods do not undergo aggregation during measurement. Numerical simulations show that the spectral shifts are consistent with the rods flipping between extreme orientatio..View full abstract
Awarded by ARC
The authors thank Paul Mulvaney, Sean Collins and Sarah Jaber for the synthesis of the gold nanorods, and ARC for support through grant LF100100117. Additionally, M.L. acknowledges the Science Faculty for support through a McKenzie Fellowship.