Dispersion of Inorganic Nanoparticles in Polymer Matrices: Challenges and Solutions

Recently, nanoparticles with remarkable physical and chemical properties have attracted intense attention. Many techniques have been developed to synthesize nanoparticles. The introduction of nanoparticles into organic polymers offers an effective way to improve properties such as electrical conductivity, mechanical properties, thermal stability, flame retardancy, and resistance to chemical reagents. The properties of polymer composites depend on the nanoparticles that are incorporated, including their size, shape, concentration, and interactions with the polymer matrix. However, the lack of compatibility between inorganic particles and polymer matrix limits the applications of nanoparticles in composites. As a result of incompatibility, the dispersion of synthesized inorganic nanoparticles in polymer matrices is very difficult, and particles with specific surface area and volume effects can form aggregates. Therefore, it is necessary to modify the particles to overcome their tendency to aggregate and improve their dispersion in polymer matrices. Two ways are used to modify the surface of inorganic particles: modification of the surface by chemical treatment and the grafting of functional polymeric molecules to the hydroxyl groups existing on the particles. By surface modification of nanoparticles the dispersion of inorganic nanoparticles in organic solvents and polymer matrices is improved.