Synthesis and characterization of hollow silica particles from tetraethyl orthosilicate and sodium silicate.

We herein introduce an effective method to synthesize hollow silica particles (HSPs) from tetraethyl orthosilicate (TEOS) and sodium silicate (Na2SiO3) as silica sources using a sacrificial template method with a simple modification. The advantage of the method is that it can be applied to synthesize HSPs from not only TEOS but also Na2SiO3 silica sources without changing the method adopted to obtain the sacrificial polymeric templates. Polystyrene particles are adopted as sacrificial templates to synthesize the HSPs, and a conventional dispersion polymerization method is used to synthesis polystyrene particles in an oil medium. Size control of HSPs is enabled by modulation of the polymerization initiator content (2,2'-Azoisobutyronitrile). The particle size, shell thickness, and morphology are analyzed. Light reflection spectra are measured to obtain the light reflection properties of the HSPs. The results indicate that the hollow architecture is the most important factor in determining the light reflection properties of the particles. Such particles are potential candidates for use in light reflectors and heat insulators, as they may reduce energy consumption in heating and cooling applications.