How linear molecules resist to shear:the origin of nanoscale friction

查看全文 作　　者：Linmao [1,2]QIAN;[1]G.Luengo;[1]E.Perez 机构地区：[1]Laboratoire de Physique Statistique de I’Ecole Normale Superieure,associee au CNRS et aux Univer-sites Paris Vl et Paris Vll,24,rue Lhomond,75231 Paris Cedex 05,France;[2]Key Laboratory of Advanced Technologies of Materials(Ministry of Education),Tribology Research Institute,Southwest Jiaotong University,Chengdu 610031,China 出　　处：《Science China(Physics,Mechanics & Astronomy)》索引2004年第47卷第z1期,共6页 基　　金：This work was supported by the National Natural Science Foundation of China (Grant No.50305029). 摘　　要：Friction force measurements between smooth surfaces across two layers of linear alkanes over five decades of speeds are presented. A maximum friction dissipation is observed at a characteristic speed. The behaviour is described by a new approach: the formation and destruction of molecular bridges between confined alkane layers. The bridges interdigitated between the layers exhibit a thermally activated resistance to shear.An analytical model involving activation barriers accounts for the overall behaviour of the forces over four decades of speed. This first simple semi-quantitative description sheds new light on the subtle mechanisms of friction at the nanoscale level and shows how the molecular length influences the tribological properties of the liquid. 关 键 词：nanotribology, friction, surface force apparatus, interface molecular films, linear alkanes.