Weichold Oliver, Tigges Britta, Bertmer Marko, Möller Martin
DWI an der RWTH Aachen e. V. und Institut für Technische und Makromolekulare Chemie der RWTH Aachen, Pauwelsstr. 8, D-52056 Aachen, Germany.
J Colloid Interface Sci. 2008 Aug;324(1-2):105-9. doi: 10.1016/j.jcis.2008.04.060. Epub 2008 May 1.
A method to prevent the irreversible agglomeration of silica nanoparticles prepared from sodium silicate, which occurs upon treatment with trialkoxy silanes, is presented. Electrostatic stabilisation is maintained by using mixtures of 3-aminopropyltrimethoxysilane and the cationic derivative N-trimethoxysilylpropyl-N,N,N-trimethylammoniumchloride (TMAPS), which gives rise to stable dispersions of aminofunctionalised particles with unusually high amine content. The particles can be isolated and redispersed without significant increase in particle size. However, an increase in the dispersed particle-size was observed on increasing the APS content in the reaction mixture. This was least pronounced for the 9 nm particles prepared from sodium silicate and more pronounced for the 30 nm particles, for which gel and/or precipitate formation occurred at high APS contents.
本文提出了一种防止由硅酸钠制备的二氧化硅纳米颗粒在经三烷氧基硅烷处理时发生不可逆团聚的方法。通过使用3-氨丙基三甲氧基硅烷和阳离子衍生物N-三甲氧基甲硅烷基丙基-N,N,N-三甲基氯化铵（TMAPS）的混合物来维持静电稳定，这会产生具有异常高胺含量的氨基官能化颗粒的稳定分散体。这些颗粒可以被分离并重新分散，而粒径不会显著增加。然而，观察到随着反应混合物中APS含量的增加，分散颗粒的尺寸会增大。对于由硅酸钠制备的9nm颗粒，这种情况最不明显；而对于30nm颗粒则更明显，在高APS含量下会发生凝胶和/或沉淀形成。
