Xu Dewei, Liechti Kenneth M, Ravi-Chandar K
Research Center for the Mechanics of Solids Structures and Materials, Department of Aerospace Engineering and Engineering Mechanics, The University of Texas at Austin, Austin, TX 78712-0235, USA.
J Colloid Interface Sci. 2007 Nov 15;315(2):772-85. doi: 10.1016/j.jcis.2007.07.048. Epub 2007 Jul 27.
The JKR, DMT, Maugis models and Tabor parameter for contact under normal loading have been developed based mainly on solid-solid (van der Waals) interactions. In this case, the characteristic length scale for the adhesive forces in the Tabor parameter is the equilibrium interatomic spacing. However, for contact in humid environments, where a liquid meniscus may be present, capillary forces with a longer force range related to the Kelvin radius dominate. Fogden and White [J. Colloid Interface Sci. 138 (1990) 414] introduced a parameter that includes the Kelvin radius for the JKR-DMT transition. This topic was also addressed by Maugis and Gauthier-Manuel [J. Adhes. Sci. Technol. 8 (1994) 1311] who included capillary effects within the frame work that Maugis had previously established. The parameters introduced by Fogden and White and Maugis and Gauthier-Manuel can be viewed as a modified Tabor parameter for the JKR-DMT transition. In the present work, the Kelvin equation linking the Kelvin radius and the relative humidity was explicitly included in the modified Tabor parameter. This provided a quantitative description of the JKR-DMT transition in terms of the relative humidity. This parameter was examined via load and contact radius measurements, where the latter were obtained from Bowden and Tabor's assumption that the friction force f=tauA. The friction experiments were conducted at two different humidity levels using a newly-developed mesoscale friction tester (MFT), which provides a very wide range of contact radii. The modified Tabor parameter was used to reexamine data from pull-off experiments in water and cyclohexane vapor environments [L.R. Fisher, J.N. Israelachvili, Colloids Surf. 3 (1981) 303 and H.K. Christenson, J. Colloid Interface Sci. 121 (1988) 170]. Finally, guidelines are presented for the appropriate choice of contact mechanics models to be used in interpreting data from SFA and AFM experiments in humid environments.
JKR模型、DMT模型、Maugis模型以及法向载荷下接触的泰伯参数主要是基于固-固（范德华）相互作用而建立的。在这种情况下，泰伯参数中粘附力的特征长度尺度是平衡原子间距。然而，对于在潮湿环境中的接触，可能会存在液体弯月面，与开尔文半径相关的具有更长力程的毛细力起主导作用。Fogden和White[《胶体与界面科学杂志》138(1990)414]引入了一个参数，该参数包含了JKR-DMT转变的开尔文半径。Maugis和Gauthier-Manuel[《粘接科学与技术杂志》8(1994)1311]也探讨了这个主题，他们将毛细效应纳入了Maugis之前建立的框架内。Fogden和White以及Maugis和Gauthier-Manuel引入的参数可以看作是JKR-DMT转变的修正泰伯参数。在本工作中，将联系开尔文半径和相对湿度的开尔文方程明确纳入修正泰伯参数中。这就从相对湿度的角度对JKR-DMT转变进行了定量描述。通过载荷和接触半径测量来检验这个参数，其中接触半径是根据Bowden和泰伯的假设f=τA得到的。摩擦实验是在两种不同湿度水平下使用新开发的中尺度摩擦测试仪（MFT）进行的，该测试仪能提供非常广泛的接触半径范围。修正泰伯参数被用于重新审视在水和环己烷蒸汽环境中拉脱实验的数据[L.R. Fisher，J.N. Israelachvili，《胶体表面》3(1981)303以及H.K. Christenson，《胶体与界面科学杂志》121(1988)170]。最后，给出了在解释潮湿环境中表面力仪（SFA）和原子力显微镜（AFM）实验数据时，关于合适的接触力学模型选择的指导原则。
Zotero 插件