Partic. vol. 10 no. 3 pp. 352-358 (June 2012)
doi: 10.1016/j.partic.2011.04.009

Preparation of nanosized hollow silica spheres from Na₂SiO₃ using Fe₃O₄ nanoparticles as templates

Chun Liu, Aili Wang, Hengbo Yin^*, Yutang Shen, Tingshun Jiang

yin@ujs.edu.cn

Abstract

Nanosized hollow silica spheres with average diameters from 43 to 70 nm were prepared by removal of Fe₃O₄ templates with hydrochloric acid from silica-coated Fe₃O₄ core–shell composites. The shells of the hollow silica spheres had nanopores with average diameters of 0.92–1.25 nm. When the silica-coated Fe₃O₄ core–shell composites were prepared at a high pH value or with a low mole ratio of Na₂SiO₃ to Fe₃O₄, the resulting hollow silica spheres consisted of highly porous shells. When the silica-coated Fe₃O₄ core–shell composites were prepared with a high mole ratio of Na₂SiO₃ to Fe₃O₄, the resulting hollow silica spheres had large diameters and thick shells. The release rate of herbicide, ammonium glyphosate, could be tuned by using hollow silica spheres with different shell thicknesses.

Graphical abstract

Keywords

Hollow silica spheres; Sodium silicate; Fe₃O₄ nanoparticles; Herbicide release