Hi, I am trying to construct a 15 nm diameter SiO2 reinforced polyurethane nanocomposite. How can I make a larger nanoparticle like this? Is there a way to make a smaller nanocluster and group multiple nanoclusters together to imitate the larger nanoparticle I need? And how can I mix these nanoparticles into the polyurethane, with amorphous cell builder or something else? I am very new so not sure how to do this. Thanks!