Capillary against adhesion forces during drying of particle submonolayers on a solid substrate
Capillary against adhesion forces during drying of particle submonolayers on a solid substrate
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固体基质上颗粒亚单层干燥过程中毛细管抵抗粘附力的作用
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
O. Spalla
中科院分区：
文献类型：
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作者：
A. Thill;O. Spalla
这项工作涉及到常见的原子力显微镜观察，即附着在底物上的小颗粒往往会形成聚集体，至少在空气中成像时是这样。我们证明了用静态光散射的方法原位测量α-Al_2O_3胶体在云母表面的覆盖率是可能的。从该层获得的散斑图案的动态特性也被用来探测粒子的动态。然后得出结论，即使是最弱的颗粒粘附性也不允许原位聚集和表面流动性(至少在实验室实验的时间尺度上)。由于横向毛细管力的作用，只有在干燥阶段，附着颗粒才会聚集。考虑了干燥过程中颗粒间的作用力平衡，建立了颗粒的聚集机理模型。
This work deals with the common atomic force microscopy observation that small particles weakly adhering to a substrate tend to form aggregates at least when imaged under air. We show that it is possible to measure the coverage of mica surfaces with α-Al2O3 colloids in situ by means of static light scattering. The dynamic properties of the speckled pattern obtained from the layer are also used to probe the dynamic of the particles. It is then concluded that even the weakest adhesion of the particles does not allow in situ aggregation and surface mobility (at least, on the time scale of the laboratory experiment). The adhering particles aggregate only during the drying stage, due to the action of lateral capillary forces. A model for the aggregation mechanism is introduced taking into account the balance of forces acting on the particles during the drying stage.