Cayer-Barrioz Juliette, Mazuyer Denis, Tonck André, Yamaguchi Elaine
Laboratoire de Tribologie et Dynamique des Systèmes-UMR 5513 CNRS/Ecole Centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully Cedex, France.
Langmuir. 2009 Sep 15;25(18):10802-10. doi: 10.1021/la9013398.
The sliding dynamics of a confined adsorbed polymer layer is investigated at the nanoscale. A combined mechanical and physical approach is used to model the rheology and structure of the adsorbed layer. The confinement at short distances governs the nanotribological behavior of the polymer layer formed close to the surface. It appears that the Amontons' proportionality between frictional and normal stresses does not hold here: the higher the contact pressure, the lower the friction. Besides, the sliding stress is strongly dependent on the velocity: it increases with the sliding velocity. Using a model based on the kinetics of formation and rupture of adhesive bonds between the two shearing surfaces theoretically accounts for the behavior of this system. This approach allows us to correlate the frictional properties to the molecular organization on the surfaces.
在纳米尺度下研究了受限吸附聚合物层的滑动动力学。采用机械和物理相结合的方法对吸附层的流变学和结构进行建模。短距离处的限制决定了靠近表面形成的聚合物层的纳米摩擦学行为。似乎阿蒙顿摩擦应力与法向应力之间的比例关系在此处并不成立:接触压力越高,摩擦力越低。此外,滑动应力强烈依赖于速度:它随滑动速度增加。使用基于两个剪切表面之间粘附键形成和断裂动力学的模型从理论上解释了该系统的行为。这种方法使我们能够将摩擦特性与表面上的分子组织联系起来。