Dispersion of nanoparticles in polymer matrices with well-designed ligands as dispersant/emulsifier/comonomer.

Dispersing nanoparticles in polymers is a key requirement for the development of polymer-matrix composites. In this study, cationic ligand and anionic ligand were designed to serve as dispersant, emulsifier and comonomer in different stages of nanocomposites preparation. Commercial BaTiO 3 , TiO 2 , Ag and Al 2 O 3 nanoparticles were incorporated and dispersed uniformly in polystyrene (PS) and polymethyl methacrylate (PMMA) matrices by designed cationic/anionic ligand. As dispersants, the sizes of nanoparticles aggregates were reduced from thousands of nanometers to dozens of nanometers by cationic/anionic ligand. Then ligands served as emulsifiers to prepare polymer nanocomposites. At the end of emulsion polymerization, the ligands copolymerized with polymer matrices. At this stage, the sizes of nanoparticles in polymer matrices fell to several nanometers. After hot-pressing, nanoparticles maintained the stable dispersion state in polymer matrices. The tensile strength of P(MMA-co-VDAC)/BaTiO 3 increased by 77% compared with PMMA. The thermal decomposition temperature of P(St-co-MAMS)/Al 2 O 3 was improved by 24 °C compared with PS. A facile and efficient approach was exhibited for preparing polymer nanocomposites with a large variety of chemically different nanoparticles in diversified polymer matrices. [ABSTRACT FROM AUTHOR]