What is the role of the interfacial interaction in the slow relaxation of nanometer-thick polymer melts on a solid surface?
What is the role of the interfacial interaction in the slow relaxation of nanometer-thick polymer melts on a solid surface?
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DOI：
10.1021/la3002674
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发表时间：
2012-03
期刊：
影响因子：
--
通讯作者：
Yongjin Wang;Jianing Sun;Lei Li
中科院分区：
文献类型：
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作者：
Yongjin Wang;Jianing Sun;Lei Li
在纳米尺度和界面处，聚合物熔体的弛豫行为与本体中的弛豫行为有很大的不同，这影响了聚合物在许多重要应用中的长期性能。聚合物-基底界面相互作用的作用，它没有一个大的对应物，至今尚未完全理解。在这项研究中，纳米厚的全氟聚醚熔体在硅片上的弛豫已经通过水接触角测量进行了研究。聚合物-基底相互作用已经通过定制聚合物结构而系统地改变，以澄清界面相互作用的影响。实验结果表明：（1）当界面上存在吸引力时，聚合物部分锚定在基体上，部分则处于自由状态;（2）界面吸引力驱使自由聚合物在界面处弛豫;（3）弛豫比在本体中慢得多，这归因于纳米厚膜中锚定聚合物链的低迁移率以及锚定聚合物链和自由聚合物链之间的运动协同性。
At the nanoscale and interfaces, the relaxation behavior of polymer melts, which affects the polymer's long-term performance in many important applications, is very different from that in the bulk. The role of polymer-substrate interfacial interaction, which does not have a bulk counterpart, has not been fully understood to date. In this study, the relaxation of nanometer-thick perfluoropolyether melts on a silicon wafer has been investigated by water contact angle measurement. The polymer-substrate interactions have been systematically changed by tailoring the polymer structure to clarify the effect of the interfacial interaction. The experimental results show that (1) when there is attractive interaction at the interface, some polymers are anchored to the substrate and others are free, (2) the attractive interfacial interaction drives the free polymers to relax at the interface, and (3) the relaxation is much slower than in the bulk, which has been attributed to the low mobility of the anchored polymer chains and the motional cooperativity between anchored and free polymer chains in the nanometer-thick films.