title: Preparation of spherical silica particles by Stöber process with high concentration of tetra-ethyl-orthosilicate.
abstract: In this paper, Stöber process with high concentration of tetra-ethyl-orthosilicate (TEOS) up to 1.24 M is used to prepare monodisperse and uniform-size silica particles. The reactions are carried out at [TEOS]=0.22-1.24 M, low concentrations of ammonia ([NH(3)]=0.81[TEOS]), and [H(2)O]=6.25[TEOS] in isopropanol. The solids content in the resulting suspension achieves a maximum value of 7.45% at 1.24 M TEOS. Various-sized particles in the range of 30-1000 nm are synthesized. The influences of TEOS, NH(3), and H(2)O on the size and size distribution of the particles are discussed. A modified monomer addition model combined with aggregation model is proposed to analyze the formation mechanism of silica particles.
authors.affiliation: Institute of Precision Optical Engineering, Department of Physics, Tongji University, Shanghai 200092, China.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Wang
authors.forename: Zheng-Xiang
authors.initials: ZX
authors.lastname: Shen
authors.forename: Tian
authors.initials: T
authors.lastname: Sang
authors.forename: Xin-Bin
authors.initials: XB
authors.lastname: Cheng
authors.forename: Ming-Fang
authors.initials: MF
authors.lastname: Li
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Chen
authors.forename: Zhan-Shan
authors.initials: ZS
authors.lastname: Wang