Akbulut Mustafa, Godfrey Alig Anna R, Israelachvili Jacob
Department of Chemical Engineering , and the Materials Research Laboratory, University of California, Santa Barbara, CA, USA.
J Phys Chem B. 2006 Nov 9;110(44):22271-8. doi: 10.1021/jp063161j.
Using a modified surface forces apparatus, we have simultaneously measured the friction and triboelectrification between both similar and dissimilar molecularly smooth hexadecanethiol-coated metal surfaces on mica substrates. On shearing dissimilar surfaces, the tribocurrent increases dramatically as the load or pressure is increased, with large fluctuations about the mean. Neither charge transfer nor fluctuations are observed when the symmetric surfaces are sheared against each other. We also find that the type of friction, i.e., stick-slip or smooth sliding, the load and friction force, the sliding distance, and recent previous history have additional fine influences on the triboelectrification. Our results suggest that frictional dissipation induces electron-hole formation and charge transfer between two shearing surfaces due to molecular-level roughness and defects and local dielectric constant changes, giving rise to the observed tribocurrents.
我们使用改进的表面力装置，同时测量了云母基底上相似和不同的分子光滑的十六烷硫醇涂层金属表面之间的摩擦力和摩擦起电。在剪切不同表面时，摩擦电流会随着负载或压力的增加而急剧增加，且围绕平均值有较大波动。当对称表面相互剪切时，既未观察到电荷转移也未观察到波动。我们还发现，摩擦类型（即粘滑或平滑滑动）、负载和摩擦力、滑动距离以及最近的历史对摩擦起电有额外的细微影响。我们的结果表明，由于分子水平的粗糙度、缺陷以及局部介电常数的变化，摩擦耗散会在两个剪切表面之间诱导电子 - 空穴的形成和电荷转移，从而产生观察到的摩擦电流。
