Institute of Chemistry, University of Campinas, Campinas, SP, Brazil.
Sci Rep. 2013;3:2384. doi: 10.1038/srep02384.
Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers.
在电介质表面之间的摩擦会产生固定的稳定电荷图案，这些电荷反过来会为接触固体之间的表面相互作用贡献静电分量。文献中提供了大量关于金属和半导体中摩擦的电子贡献的信息，但摩擦电对电介质摩擦系数的影响至今仍未得到很好的定义和理解。在这项工作中，使用三种不同的技术测量了在摩擦带电聚四氟乙烯（PTFE）上的摩擦系数。结果表明，当 PTFE 表面发生摩擦带电时，宏观和纳米尺度上的摩擦系数会增加许多倍，但通过在 PTFE 上滚动的玻璃球进行硅烷化处理，可以消除这种效应。总之，摩擦带电可能会取代 PTFE 及其他绝缘聚合物的宏观和纳米尺度摩擦系数的所有其他贡献。
