Glass Formation in Mechanically Interlocked Ring Polymers: The Role of Induced Chain Stiffness
Glass Formation in Mechanically Interlocked Ring Polymers: The Role of Induced Chain Stiffness
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机械互锁环聚合物中的玻璃形成：诱导链刚度的作用
DOI：
10.1021/acs.macromol.2c01368
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发表时间：
2023-01
期刊：
影响因子：
5.5
通讯作者：
Yushan Li
中科院分区：
文献类型：
--
作者：
Jian Li;Bokai Zhang;Yushan Li
聚合物材料由于其分子结构和拓扑结构的不同，在不同的尺度下表现出丰富的玻璃化行为。最近的研究已经确定了瞬时的互穿的长链环上的质量中心水平的动态逮捕。环的互穿被提出作为促进聚合物熔体中玻璃形成的一种方法。在这项工作中，受到机械联锁聚合物合成的最新进展的启发，我们使用分子动力学模拟研究了受环的永久互穿影响的纳米级片段的玻璃化转变。我们发现，减少链长度的机械联锁系统是等效的诱导一个有效的链刚度的子环。诱导刚度提供了一个统一的解释，这些独特的结构特征和瞬态动力制动系统的联锁环，而短链。此外，在冷却后的本地化和玻璃化深度之间的缩放关系中观察到交叉。我们的工作揭示了一个动态的转变，从弱到强笼在交叉温度。根据局域化模型，我们表明，链刚度增加的临界温度和振荡距离，从而导致更脆弱的动力学和更深的玻璃态。这些发现与分子模拟和理论预测的聚合物具有真实的局部刚度是一致的。我们的工作加深了对诱导刚度在玻璃化转变中作用的理解，并为通过机械键控制刚度来设计富玻璃材料开辟了新的方向。
Polymer-related materials exhibit rich glassy behaviors at different length scales due to their various molecular structures and topological constraints. Recent studies have identified transient interpenetration of the long-chain rings contributing to dynamic arrest on the center-of-mass level. Interpenetration of rings is proposed as an approach to facilitate glass formation in polymer melts. In this work, inspired by recent advances in the synthesis of mechanically interlocked polymers, we investigate glass transition on the nanometer-scale segments influenced by permanent interpenetration of rings using molecular dynamics simulations. We find that decreasing chain length in the mechanically interlocked system is equivalent to inducing an effective chain stiffness on the subrings. The induced stiffness provides a unified explanation for these unique structural features and transient dynamic arrest in the system of interlocked rings with rather short chains. Further, a crossover is observed in the scaling relation between localization and glassy depth upon cooling. Our work reveals a dynamic transition from weak to strong caging at the crossover temperature. According to the localization model, we demonstrate that the chain stiffness increases the critical temperature and oscillation distance, which therefore leads to more fragile dynamics and a deeper glassy state. These findings are consistent with the predictions of molecular simulations and theories for polymers with real local stiffness. Our work deepens the understanding of the role of induced stiffness on glass transition, and it opens up a new direction to design rich glass materials by manipulating stiffness through mechanical bonds.
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影响因子：
5.5
作者：
Qiang Zhou;R. Larson
通讯作者：
Qiang Zhou;R. Larson
DOI：
10.1209/0295-5075/130/56001
发表时间：
2020
期刊：
Europhysics Letters
影响因子：
--
作者：
李健;张博凯
通讯作者：
张博凯
DOI：
10.1063/1.5052153
发表时间：
2018-12
期刊：
The Journal of chemical physics
影响因子：
--
作者：
Deng Pan;Zhao‐Yan Sun
通讯作者：
Deng Pan;Zhao‐Yan Sun
影响因子：
4.3
作者：
Rosa, Angelo;Everaers, Ralf
通讯作者：
Everaers, Ralf
影响因子：
56.9
作者：
Marcos, Vanesa;Stephens, Alexander J.;Leigh, David A.
通讯作者：
Leigh, David A.