纳米二氧化硅水分散体的制备及复配

Preparation of Aqueous Nanometer Silica Dispersions Made from Silica Sols with Well-defined Particle Size

通过粒子紧密堆积数学模型计算得到不同粒径硅溶胶粒子间的最优配比,在此基础上合成了3种不同单分散粒径的硅溶胶。将不同粒径硅溶胶按数学模型计算的比例加入到钾水玻璃中,复配制备了不同纳米二氧化硅水分散体。与由单一粒径硅溶胶形成的膜相比,由不同粒径硅溶胶复配后形成的膜,呈现出较高的结构致密性和憎水性,与由粒子紧密堆积模型推导结果吻合。

Three monodispersed silica sols with welldefined particle size were synthesized and characterized by means of transmission electron microscopy. Two kinds of aqueous nanometer silica dispersions were prepared by adding silica sols with different sizes into potassium silicate according to the mass ratios calculated from the closely packed model of particles. The coating films formed by these composite silica sols show higher structure density and less porosity as well as better hydrophobicity than that formed by silica sol with uniform particle size distribution. All these experimental data are consistent with the results derived from the closely packed model.