Entanglement density and particle dynamics in rigid interfacial layers of polymer nanocomposites
Entanglement density and particle dynamics in rigid interfacial layers of polymer nanocomposites
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DOI：
10.1063/5.0060139
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发表时间：
2021-08
影响因子：
3.2
通讯作者：
Di Wu;Yi Feng;Ruhao Li;R. Ozisik;Pinar Akcora
中科院分区：
文献类型：
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作者：
Di Wu;Yi Feng;Ruhao Li;R. Ozisik;Pinar Akcora
在纳米颗粒周围化学上不同的聚合物之间的混合产生化学上不均匀的层，由于聚合物纳米复合材料中的动态限制和耦合现象而表现出不寻常的动态异常。当吸附的链在其玻璃化转变温度以上是移动的时，链的界面混合是可能的，导致在界面处的缠结密度增强。线性流变数据的聚合物纳米复合材料的化学非均匀的界面周围的纳米粒子进行了分析，在一个很宽的频率范围内，调查矩阵链松弛和颗粒扩散的作用链刚性。我们的研究结果表明，纳米粒子吸附刚性较低的聚合物移动在一个亚扩散模式。柔性聚合物吸附纳米粒子可以减缓基体聚合物动力学和粒子扩散，这种界面效应增强了整个聚合物纳米复合材料的粘弹性能。
Intermixing between chemically different polymers around nanoparticles creates chemically heterogeneous layers, exhibiting unusual dynamic anomalies due to dynamic confinement and coupling phenomena in polymer nanocomposites. Interfacial mixing of chains is possible when adsorbed chains are mobile above their glass-transition temperature, leading to enhanced entanglement density at the interphase. Linear rheology data of polymer nanocomposites with chemically heterogeneous interphases around nanoparticles were analyzed over a wide frequency range to investigate the role of chain rigidity on matrix chain relaxations and particle diffusion. Our findings show that nanoparticles adsorbed with less rigid polymer move in a sub-diffusive mode. Nanoparticles adsorbed by flexible polymers can slow down the matrix polymer dynamics and particle diffusion, and this interphase effect enhances the viscoelastic properties of the whole polymer nanocomposite.