Hello everyone, I'm looking to embed hollow nano plastic or ceramic spheres into an epoxy or polyurethane matrix. It is for my dissertation and I would like to carry out tests on the finished materials. Can anyone suggest any suitable resins that could be used as a matrix?

Any of the laminating resins will suit your purpose.  The challenge you may face is that the resins have their own properties.  You may not get a direct correlation between nanoparticle proportion with different resin types.