Strong Reduction in Amplitude of the Interfacial Segmental Dynamics in Polymer Nanocomposites
Strong Reduction in Amplitude of the Interfacial Segmental Dynamics in Polymer Nanocomposites
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DOI：
10.1021/acs.macromol.0c00496
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发表时间：
2020-05
期刊：
影响因子：
5.5
通讯作者：
I. Popov;B. Carroll;V. Bocharova;A. Genix;Shiwang Cheng;A. Khamzin;A. Kisliuk;A. Sokolov
中科院分区：
文献类型：
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作者：
I. Popov;B. Carroll;V. Bocharova;A. Genix;Shiwang Cheng;A. Khamzin;A. Kisliuk;A. Sokolov
尽管聚合物纳米复合材料（PNC）在各种应用中得到了广泛的应用，但我们对控制其宏观性能的微观参数的理解仍然有限。在这项研究中，我们研究了介电强度的分段动力学，ΔeIL（T）在界面聚合物层周围的纳米粒子在PNC。所提出的分析揭示了在吸附到纳米颗粒的聚合物层中ΔeIL（T）的显著下降及其异常的温度依赖性。在所有样品中观察到ΔeIL（T）的下降，无论界面层中的链段弛豫时间比本体聚合物中的链段弛豫时间慢还是快，排除“死”层的解释。我们归因于所观察到的介电强度的减少，在界面/吸附层的节段性弛豫的限制幅度。我们的研究结果提供了一个新的视角，在PNCs和薄聚合物膜的界面层的动力学讨论，表明不仅节段弛豫时间，但其幅度可以强烈地受界面。
Despite the wide use of polymer nanocomposites (PNCs) in various applications, our understanding of the microscopic parameters controlling their macroscopic properties remains limited. In this study, we examine the dielectric strength of segmental dynamics, ΔeIL(T) in the interfacial polymer layer surrounding the nanoparticles in PNCs. The presented analysis reveals a significant drop in ΔeIL(T) and its anomalous temperature dependence in the polymer layer adsorbed to nanoparticles. The drop in ΔeIL(T) was observed in all samples regardless of whether segmental relaxation time in the interfacial layer was slower or faster than in the bulk polymer, excluding interpretation of the “dead” layer. We ascribe the observed decrease in the dielectric strength to the restricted amplitude of segmental relaxation in the interfacial/adsorbed layer. Our results provide a new perspective on discussion of dynamics in the interfacial layer in PNCs and thin polymer films, demonstrating that not only segmental relaxation time but also its amplitude can be strongly affected by the interface.