Gun'ko V M, Zarko V I, Sheeran D J, Blitz J P, Leboda R, Janusz W, Chibowski S
Institute of Surface Chemistry, 17 General Naumov Street, Kiev, 03164, Ukraine.
J Colloid Interface Sci. 2002 Aug 1;252(1):109-18. doi: 10.1006/jcis.2002.8460.
Fumed silica Cab-O-Sil HS-5 grafted with 3-aminopropyldimethylsilyl (APDMS), butyldimethylsilyl (BDMS), octadecyldimethylsilyl (ODDMS), and trimethylsilyl (TMS) groups of different concentrations were studied using photon correlation spectroscopy, electrophoresis, potentiometric titration, and nitrogen adsorption methods. Calculations of both electrophoretic mobility and zeta potential were performed taking into consideration the topological structure of "porous" aggregates of primary particles of fumed silica using two different approaches. Changes in surface charge density and the textural, aggregative, and electrophoretic characteristics of modified silicas depend on the type of grafted OSC, its chain length, polarity, and surface concentration. Particle swarms of initial and modified silicas in aqueous suspension are typically characterized by bimodal size distributions between 20 and 300 nm (aggregates) and 1-3 microm (agglomerates of aggregates). The difference between parameter values computed according to the Smoluchowski theory and improved approaches increases with increasing pH and is concordant for both mobility and zeta potential.
使用光子相关光谱法、电泳法、电位滴定法和氮吸附法研究了接枝有不同浓度的3-氨丙基二甲基硅烷基（APDMS）、丁基二甲基硅烷基（BDMS）、十八烷基二甲基硅烷基（ODDMS）和三甲基硅烷基（TMS）基团的气相二氧化硅Cab-O-Sil HS-5。考虑到气相二氧化硅一次颗粒“多孔”聚集体的拓扑结构，采用两种不同方法进行了电泳迁移率和zeta电位的计算。改性二氧化硅的表面电荷密度以及结构、聚集和电泳特性的变化取决于接枝的有机硅化合物（OSC）的类型、其链长、极性和表面浓度。水悬浮液中初始二氧化硅和改性二氧化硅的颗粒群通常具有20至300纳米（聚集体）和1至3微米（聚集体的团聚体）之间的双峰尺寸分布。根据斯莫卢霍夫斯基理论计算的参数值与改进方法之间的差异随pH值的增加而增大，并且迁移率和zeta电位的结果一致。
