I've produced my first nanoparticles of gold using the Turkevich process. I tried to concentrate them down because I need to fit about 500 miligrams into 20 - 50 ml of space, perhaps even dry them out. Sound easy? Well, I boiled my one liter reaction solution down to about 100 ml in a two liter beaker. The solution at that point turned from red to grey with black powder and gold flake like layers floating on top. I think it's no longer 20 nm size range particles at all.
Can these Turkevich process size range nano-particles (20nm) be centrifuged to the bottom of a test tube? I read a patent refering to a process for making the same size and also spherical nanoparticles using monosodium glutamate instead of trisodium citrate. To concentrate the nanoparticles for analysis, they put the solution into a freezer and froze them to destabilize the nanoparticles and make them more or less fall to the bottom of the beaker so that they could be retrieved for centrifuging. Could nanoparticles made using the Turkevich process be frozen to make them fall out of solution in the same way? And then centrifuged out, if simply centrifuging is impossible?
Yes I know, I've yet arrived and ask so many questions =-) Is there any Turkevich nanoparticle concentration specialists here?