2013 Volume 49 Issue 1 Pages 4-10
The surface treatment of spherical silica particles using glycidoxy or amino functional silane coupling agent was conducted and the effect of the alkoxy group number on the molecular mobility of the silane chain with multilayer coverage was investigated by 1H pulse nuclear magnetic resonance.The silica particles were treated with 2-propanol solution and heated at 120℃ for 24h after solvent evaporation. For multilayer coverage, the linear chain and network structures were expected to form on the surface by polycondensation reaction using the di-and trialkoxy structures, respectively. However, the rigid network structure was formed from both the di-and trialkoxy structures for both glycidoxy and amino functional silanes. Fourier transform infrared spectroscopic analysis revealed that ring opening of the epoxy group occurred, followed by reaction to form the network structure, even with the dialkoxy structure for the glycidoxy functional. Ring opening of the epoxy group could be reduced by setting the heating temperature at 80℃, and the linear chain structure was formed by di-alkoxy structure. In the case of amino group, it was seemed to be caused by the formation of hydrogenbond between the aminogroup and the silanolgroup on silica surface.
