I want to use nano particles as filler in GFRP.. Many researcher used to mix the nano particles into resin by stirring arrangement and changing the temperature of resin while mixing..
Shear mixing using a Speedmixer (or equivalent - there are other similar brands) may be a good option - equipment with various capacities (1 g to > 5 kg) are available. Gives good mixing in a short time for a range of formulations.
Nanoparticles can be best incorporated to a polymer matrix by melt blending technique. I think you better choose an internal mixer (like Brabender) for better dispersion. The method may also depend on the nature of the filler and polymer in your study.Anyway you have to adopt the technique which gives maximum dispersion so that your material possess enhanced properties.