Effects of adsorbed water layer structure on adhesion force of silicon oxide nanoasperity contact in humid ambient
Effects of adsorbed water layer structure on adhesion force of silicon oxide nanoasperity contact in humid ambient
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DOI：
10.1063/1.2192510
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发表时间：
2006-05-07
影响因子：
4.4
通讯作者：
Kim, SH
中科院分区：
文献类型：
--
作者：
Asay, DB;Kim, SH
阐明了氧化硅表面单表面粗糙接触时粘附力对相对湿度(RH)的大依赖性的原因。随着RH的增加，原子力显微镜(AFM)测得的附着力最初增加，达到最大值，然后在高RH时减小。毛细管力本身不能解释观测到的相对湿度依赖性的大小。RH依赖性大的原因是室温下硅氧化物表面吸附了冰状的结构水。建立了一个固体-吸附-固体模型，计算了毛细作用力、范德华相互作用和接触区中心冰-冰桥破裂的贡献。该模型说明了吸附水层的结构、厚度和粘弹性行为如何影响二氧化硅纳米微凸体接触的粘附力。
The origin of the large relative-humidity (RH) dependence of the adhesion force in the single-asperity contact between silicon oxide surfaces is elucidated. As RH increases, the adhesion force measured with an atomic force microscopy (AFM) initially increases, reaches a maximum, and then decreases at high RH. The capillary force alone cannot explain the observed magnitude of the RH dependence. The origin of the large RH dependence is due to the presence of an icelike structured water adsorbed at the silicon oxide surface at room temperature. A solid-adsorbate-solid model is developed calculating the contributions from capillary forces, van der Waals interactions, and the rupture of an ice-ice bridge at the center of the contact region. This model illustrates how the structure, thickness, and viscoelastic behavior of the adsorbed water layer influence the adhesion force of the silicon oxide nanoasperity contact.