Well-dispersed hollow silica microspheres synthesis with silica sol as precursor by template method

• Well-dispersed hollow silica microspheres were obtained.
• Hollow silica microspheres synthesized with silica sol as precursor.
• Some “bowl shaped” new structures were detected in the samples.

In this paper, an operative water-in-oil micro-emulsion method for the preparation of well-dispersed templates and the preparation of hollow spheres from the templates were presented. The hollow spheres were obtained via the cross-linking of acidic SiO2 sol on the surface of cross-linked polyvinyl alcohol (CPVA) templates under base condition and the following calcinations process at 800 °C. The XRD results indicated that the hollow silica spheres were composed of amorphous phase. Well-dispersed templates and silica hollow spheres were characterized by scanning electron microscope (SEM) and field emission scanning electron microscope (FESEM) respectively. The results showed that the as-synthesized hollow silica microspheres were hollow spheres with diameter of 1–20 μm, wall thickness of 0.2–3 μm. The thickness of the hollow microspheres could be controlled by the parameter of the reaction condition. Moreover, some “bowl shaped” new structures were detected in the samples with the low ratio of silica sol and CPVA microspheres.