Strategies for dispersing nanoparticles in polymers

Controlling the dispersion of nanoparticles in polymeric matrices is the most significant impediment in the development of high-performance polymer nanocomposite materials and results primarily from the strong interparticle interactions between the nanoparticles. This review examines the theoretical and experimental strategies employed in developing appropriate chemical and physical methods to achieve controlled dispersion of nanoparticles. Methods to characterize the state of dispersion, including force and electron microscopy, and scattering, electrical, and mechanical spectroscopy, are considered with special emphasis on achieving quantitative measures of the dispersion. Some of the outstanding issues, such as long-term aging and the implication for the dispersion of nanoparticles, development of high-throughput methods for rapid screening, and methods for in-line monitoring, are also discussed.