Asay David B, Kim Seong H
Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
J Chem Phys. 2006 May 7;124(17):174712. doi: 10.1063/1.2192510.
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.
阐明了氧化硅表面单粗糙接触中粘附力对相对湿度（RH）强烈依赖的起源。随着RH的增加，用原子力显微镜（AFM）测量的粘附力最初增加，达到最大值，然后在高RH时降低。仅毛细力无法解释所观察到的RH依赖性的量级。这种对RH的强烈依赖性源于室温下吸附在氧化硅表面的冰状结构水的存在。建立了一个固体-吸附质-固体模型，计算毛细力、范德华相互作用以及接触区域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氧化硅纳米粗糙接触的粘附力。
Zotero 插件