Dynamic Heterogeneity of Filler-Associated Interphases in Polymer Nanocomposites.
Dynamic Heterogeneity of Filler-Associated Interphases in Polymer Nanocomposites.
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聚合物纳米复合材料中填料相关界面的动态异质性
DOI：
10.1002/marc.202100061
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发表时间：
2021
影响因子：
4.6
通讯作者：
K. Saalwächter
中科院分区：
文献类型：
--
作者：
H. Schneider;M. Roos;Y. Golitsyn;K. Steiner;K. Saalwächter
动态不均匀聚合物体系表现出具有迁移率梯度的界面。这些被认为在材料的性能中起着关键作用。一个突出的例子是颗粒填充橡胶，这是交联聚合物纳米复合材料的一种特殊情况，其中有利的橡胶-填料相互作用可以在填料周围产生纳米级固定层，包括中等流动性的区域。这样的中间域可以形成单独的壳状层或者是动态不均匀性的表现，在这种情况下，中间移动的材料将以纳米尺寸的子域的形式分散。在这篇文章中，应用于二氧化硅填充丙烯酸酯橡胶的双向质子NMR自旋扩散（SD）实验与数值模拟相结合，以提供对这个问题的微观见解。虽然不同情景的模型计算与给定数据在较长SD混合时间内的拟合效果相似，但短时间数据确实支持动态非均匀性的存在。
Dynamically inhomogeneous polymer systems exhibit interphases with mobility gradients. These are believed to play key roles in the material's performance. A prominent example is particle‐filled rubber, a special case of a crosslinked polymer nanocomposite, where favorable rubber‐filler interactions may give rise to a nanoscale immobilized layer around the filler, including regions of intermediate mobility. Such intermediate domains may either form a separate shell‐like layer or be a manifestation of dynamic heterogeneities, in which case the intermediately mobile material would be dispersed in the form of nanometer‐sized subdomains. In this contribution, bidirectional proton NMR spin diffusion (SD) experiments applied to silica‐filled acrylate rubber are combined with numerical simulations to provide microscopic insights into this question. While model calculations for different scenarios fit the given data similarly well for longer SD mixing time, the short‐time data do support the presence of dynamic heterogeneities.