Growth from spherical to rod-like SiO2: Impact on microstructure and performance of nanocomposite

Abstract

The Structural design of rod-like SiO2 colloids and its effect on composites properties are of great significance. Here, sodium dodecyl sulfate (SDS) is used as a structure inducer for preparing rod-like SiO2, and rod-like SiO2/polyacrylate hybrid nanocomposite is obtained by in-situ polymerization. The difference in the amount of SDS and the amount of silicon source on the preparation of rod-like SiO2 is investigated. It turns out that the diameter of rod-like SiO2 about 50–100 nm is gained. The preparation principle of SiO2 nanoparticles with different morphologies was studied. It is found that micelles with different morphologies provide templates for the preparation of SiO2 nanoparticles. There is electrostatic repulsion between the SDS, which can promote unidirectional growth of SiO2 nanoparticles. Based on these results, formation mechanisms of rod-like SiO2/polyacrylate hybrid nanocomposite latexes and spherical SiO2/polyacrylate hybrid nanocomposite latexes are discussed in depth. Besides, physical and chemical properties, thermal performance and microscopic morphology of spherical SiO2/polyacrylate composite films and rod-like SiO2/polyacrylate composite films are dissussed. SEM and AFM analysis show that the rod-like SiO2 evenly intersperses in internal and surface of films. And, the composite film with uniformly distributed rod-like SiO2 has high mechanical properties, water resistance and thermal properties.