Enhanced Thermal Stability of Polystyrene by Interfacial Noncovalent Interactions
Enhanced Thermal Stability of Polystyrene by Interfacial Noncovalent Interactions
复制标题
通过界面非共价相互作用增强聚苯乙烯的热稳定性
DOI：
10.1021/acs.macromol.8b01012
复制
发表时间：
2018-08-14
期刊：
影响因子：
5.5
通讯作者：
Tanaka, Keiji
中科院分区：
文献类型：
--
作者：
Hong, Yongming;Li, Yawei;Tanaka, Keiji
通过和频发生光谱法检查了在不同条件下使用苯基三甲氧基硅烷 (PTS) 覆盖苯基的聚苯乙烯 (PS) 和氘代 PS 在与石英基底界面处的局部构象。正如苯基 v2 振动模式的波数红移所证明的那样，据称，与石英表面垂直的 PTS 苯基通过界面处能量上有利的平行位移 π-π 相互作用诱导了 PS 苯环的垂直取向。即使在比本体玻璃化转变温度高 60 K 的温度下，通过 π-π 相互作用牢固锚定在基底上的 PS 链的局部构象在 48 小时内几乎保持不变。也就是说，界面π-π相互作用促进了PS链在基材上的吸附，以获得较大的焓增益，导致界面处PS链的动力学显着减慢。我们的结果说明了重要的...
The local conformation of polystyrene (PS) and deuterated PS at the interface with quartz substrates, which were covered with phenyl groups using phenyltrimethoxysilane (PTS) under various conditions, was examined by sum frequency generation spectroscopy. As evidenced by the red-shift of the wavenumber of the v2 vibration mode for phenyl groups, it was claimed that PTS phenyl groups standing vertically from the quartz surface induced the perpendicular orientation of PS phenyl rings by energetically favorable parallel-displaced π–π interactions at the interface. The local conformation of PS chains strongly anchored onto the substrate by the π–π interactions remained almost unchanged for 48 h even at a temperature 60 K higher than the bulk glass transition temperature. That is, the interfacial π–π interactions facilitated the adsorption of PS chains on the substrate to attain a large enthalpic gain, resulting in significantly slower dynamics of PS chains at the interface. Our results illustrate the importan...