You can only ensure good dispersion if the nanoparticles are well dispersed. Therefore ideal 'solution' would be to mix with a liquid dispersion of nanoparticles. In case you dose in dry form, you will only disperse the already strongly aggregated/agglomerated particles.

Dear Dr Sobisch,

Thanks for the insight. I really appreciate that.

In my study, the nanoparticle sets and hardens in the presence of water. I need to find some way to mix them quickly if I were to conduct in form of liquid.

maybe you can use a dispersion dispersed e.g. in isopropanol.