Polymer brushes in restricted geometries
Polymer brushes in restricted geometries
复制标题
DOI：
10.1039/c0sm00444h
复制
发表时间：
2010-01-01
期刊：
影响因子：
3.4
通讯作者：
Kuhl, Tonya Lynn
中科院分区：
文献类型：
--
作者：
Mulder, Dennis John;Kuhl, Tonya Lynn
聚合物刷的结构一直是相当多的理论和实验活动的主题。接枝刷和单刷结构在固溶界面处的立体力的实验测量结果与理论预测相吻合。然而，电刷层在约束条件下的物理结构仍然是难以捉摸的。在这里，我们报告的测量聚合物刷密度分布在良好的溶剂作为压缩的功能。利用中子反射率和对比匹配技术明确地确定了电刷的延伸和穿透。测量结果表明，接枝表面的电刷浓度随着压缩而显著增加。这与聚合物刷被压缩时均匀密度分布的理论预测相反。锚固表面的低穿透性和刷压实性为我们提供了新的见解，为什么这些层在减少表面之间的摩擦和磨损方面如此有效。
The structure of polymer brushes has been the subject of considerable theoretical and experimental activity. Experimental measurements of the steric forces between grafted brushes and the structure of a single brush at the solid-solution interface are in good agreement with theoretical predictions. However, the physical structure brush layers adopt under confinement has remained elusive. Here, we report measurements of polymer brush density distributions in good solvent as a function of compression. The extension and interpenetration of the brushes are unambiguously determined using neutron reflectivity and contrast matching techniques. The measurements reveal a significant increase in brush concentration at the grafting surface with compression. This is in contrast to theoretical predictions of uniform density distributions as polymer brushes are compressed. The low interpenetration and brush compaction at the anchor surface provides new insight into why such layers are so effective at reducing friction and wear between surfaces.