拓本
聚合物
润滑
聚电解质
反离子
胶体
材料科学
水溶液
化学工程
复合材料
化学物理
离子
化学
有机化学
工程类
作者
Uri Raviv,Suzanne Giasson,Nir Kampf,Jean‐François Gohy,Robert Jérôme,Jacob Klein
出处
期刊:Nature
[Springer Nature]
日期:2003-09-01
卷期号:425 (6954): 163-165
被引量:843
摘要
Long-ranged forces between surfaces in a liquid control effects from colloid stability to biolubrication, and can be modified either by steric factors due to flexible polymers, or by surface charge effects. In particular, neutral polymer 'brushes' may lead to a massive reduction in sliding friction between the surfaces to which they are attached, whereas hydrated ions can act as extremely efficient lubricants between sliding charged surfaces. Here we show that brushes of charged polymers (polyelectrolytes) attached to surfaces rubbing across an aqueous medium result in superior lubrication compared to other polymeric surfactants. Effective friction coefficients with polyelectrolyte brushes in water are lower than about 0.0006-0.001 even at low sliding velocities and at pressures of up to several atmospheres (typical of those in living systems). We attribute this to the exceptional resistance to mutual interpenetration displayed by the compressed, counterion-swollen brushes, together with the fluidity of the hydration layers surrounding the charged, rubbing polymer segments. Our findings may have implications for biolubrication effects, which are important in the design of lubricated surfaces in artificial implants, and in understanding frictional processes in biological systems.
科研通智能强力驱动
Strongly Powered by AbleSci AI