-1
$\begingroup$

I have synthesized gold nanoparticles in water through the seed-mediated thermal method by cationic additive $\ce{Ag+}$ as an assisted growth procedure [article]. The pH of the nanoparticles solution is about 2. I would like to reach the pH of the solution to 5.I found that when I use NaCl solution or buffer (such as sodium acetate) for adjasting pH, it cause the aggregation of nanoparticles.
How to increase the pH without any aggregation in the nanoparticles solution?

$\endgroup$
1
$\begingroup$

It should have, because with pH you change the electostatic forces between particles. I guess you would increase pH adding more electrolytes and this might decrease double-layer thickness of the NPs, so repulsive forces would decrease and the NPs might agglomerate. It strongly depends on electrolyte conc.

Therefore I think you should rather try to synthesize them in pH5 then increase pH from 2 to 5.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.