The effects of citrate’s counterions and pH are examined in gold nanoparticle growth kinetics. The growth of gold nanoparticles from citrate reduction is a common method used for creating particles from 10-120 nm with a well-defined size distribution. TEM observation of the seed-mediated growth shows an intermediate aggregation phase that has been shown by researchers to exist in other solution-phase nanocrystal growth. We have shown that this intermediate agglomeration phase within particle growth may be avoided with certain pairings of counterion and pH. This aggregation phase has no noticeable effects on the formation of the particles at a smaller scale but may be cause for concern when the seed-mediated growth process is used at higher particle concentration and larger volumes. The ability to get rid of this aggregation phase at a small scale may help avoid unwanted particle characteristics at an industrial scale which includes increased volume and concentration of production.
Closson, Andrew B., "Citrate’s Counter Ions and pH Effect on Gold Nanoparticle Growth Kinetics" (2016). Honors College. 374.