If I have understood well your question, based on experience of our research group, I will say that the melt-compounding approach is one key-technique that is mainly used to produce polymer nanocomposites and which allows also the quick extrapolation at larger scale. In this process, it is possible to mix micrometric or nanometric powders which finally will be distributed and dispersed at nanoscale within the different polymer matrices.
The literature is so large, thus I will recommend you only some aleatory sources of information.