Kind Lucy, Plamper Felix A, Göbel Ronald, Mantion Alexandre, Müller Axel H E, Pieles Uwe, Taubert Andreas, Meier Wolfgang
Department of Chemistry, University of Basel, CH-4056 Basel.
Langmuir. 2009 Jun 16;25(12):7109-15. doi: 10.1021/la900229n.
Silica is an important mineral in biology and technology, and many protocols have been developed for the synthesis of complex silica architectures. The current report shows that silsesquioxane nanoparticles carrying polymer arms on their surface are efficient templates for the fabrication of silica particles with a star- or raspberry-like morphology. The shape of the resulting particles depends on the chemistry of the polymer arms. With poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) arms, spherical particles with a less electron dense core form. With poly{[2-(methacryloyloxy)ethyl] trimethylammonium iodide} (PMETAI), star- or raspberry-like particles form. Electron microscopy, electron tomography, and small-angle X-ray scattering show that the resulting silica particles have a complex structure, where a silsequioxane nanoparticle carrying the polymer arms is in the center. Next is a region that is polymer-rich. The outermost region of the particle is a silica layer, where the outer parts of the polymer arms are embedded. Time-resolved zeta-potential and pH measurements, dynamic light scattering, and electron microscopy reveal that silica formation proceeds differently if PDMAEMA is exchanged for PMETAI.
二氧化硅是生物学和技术领域中的一种重要矿物，人们已经开发出许多用于合成复杂二氧化硅结构的方法。当前报告表明，表面带有聚合物臂的倍半硅氧烷纳米颗粒是制备具有星形或树莓状形态的二氧化硅颗粒的有效模板。所得颗粒的形状取决于聚合物臂的化学性质。对于带有聚（N，N-二甲基氨基乙基甲基丙烯酸酯）（PDMAEMA）臂的情况，会形成具有电子密度较低核心的球形颗粒。对于聚{[2-（甲基丙烯酰氧基）乙基]三甲基碘化铵}（PMETAI），则会形成星形或树莓状颗粒。电子显微镜、电子断层扫描和小角X射线散射表明，所得二氧化硅颗粒具有复杂的结构，其中带有聚合物臂的倍半硅氧烷纳米颗粒位于中心。接下来是富含聚合物的区域。颗粒的最外层是二氧化硅层，聚合物臂的外部嵌入其中。时间分辨的zeta电位和pH测量、动态光散射以及电子显微镜显示，如果将PDMAEMA换成PMETAI，二氧化硅的形成过程会有所不同。
