Surface Modification of Colloidal Silica Nanoparticles: Controlling the size and Grafting Process

作者：Wentao He, Wu Danhua, Juan Li, Kai Zhang, Yushu Xiang, Lijuan Long, Shuhao Qin, Jie Yu, Qin Zhang · 发表于：Bulletin of the Korean Chemical Society · 年份：2013 · DOI：10.5012/bkcs.2013.34.9.2747 · 被引用次数：56 · 研究领域：Mesoporous Materials and Catalysis、Surfactants and Colloidal Systems、Polymer Surface Interaction Studies

Surface modification of colloidal silica nanoparticles without disrupting the electric double layer of nanoparticles is a major challenge. In the work, silane was employed to modify colloidal silica nanoparticles without inducing bridge flocculation obviously. The effect of pH value of the silica sol, the amount of silane in feed, and reaction temperature on the graft amount and the final size of modified particles was investigated. The increased weight loss by TG and the appearance of $T_2$ and $T_3$ except for $Q_2$ and $Q_3$ signals by CP/MAS $^{29}Si$ NMR of the modified samples verified the successful grafting of silane. The graft amount reached 0.57 mmol/g, which was slightly lower than theory value, and the particle size remained nearly the same as unmodified particles for acidic silica sol at the optimum condition. For alkaline silica sol after modification, aggregates composed of several nanoparticles connected together with silane moleculars as the bridge appeared.