School of Process, Environmental and Materials Engineering, Institute of Particle Science and Engineering, University of Leeds, Leeds, UK LS2 9JT.
Langmuir. 2010 Jun 1;26(11):8366-72. doi: 10.1021/la904784a.
The adsorption of colloidal laponite at the solid/liquid interface on various substrates and over a range of laponite concentrations (10-1000 ppm) has been investigated. Although a wide range of surfaces were studied, only on a positively charged poly(diallyldimethylammonium chloride) (PDADMAC) surface was any adsorption of the laponite observed. This shows that when fully wetted, laponite adsorption depends primarily on the surface charge rather than the degree of hydrophobicity of the surface. The adsorption of spherical Ludox silica nanoparticles on PDADMAC surfaces was also examined for comparison with the disklike laponite. The QCM data for both laponite and Ludox show strong adsorption on PDADMAC surfaces; however, larger frequency shifts were seen for Ludox than laponite at all concentrations tested. Within the concentration range examined in this work, the dissipation data from the QCM suggested a simple monolayer formation for Ludox but a monolayer to multilayer transition for laponite as the concentration increases.
已研究了胶体锂蒙脱石在各种基底上的固/液界面的吸附作用，以及在一系列锂蒙脱石浓度（10-1000ppm）下的吸附作用。尽管研究了广泛的表面，但仅在带正电荷的聚二烯丙基二甲基氯化铵（PDADMAC）表面上观察到了锂蒙脱石的任何吸附作用。这表明，当完全润湿时，锂蒙脱石的吸附作用主要取决于表面电荷，而不是表面的疏水性程度。还研究了球形 Ludox 硅纳米粒子在 PDADMAC 表面上的吸附作用，以与盘状锂蒙脱石进行比较。QCM 数据表明，锂蒙脱石和 Ludox 都强烈吸附在 PDADMAC 表面上；然而，在所有测试浓度下，Ludox 比锂蒙脱石的频率偏移都更大。在所研究的浓度范围内，QCM 的耗散数据表明，对于 Ludox，简单的单层形成，但对于锂蒙脱石，随着浓度的增加，从单层到多层的转变。
