Tunable Slow Dynamics of Three-Dimensional Polymer Melts through Architecture Engineering
Tunable Slow Dynamics of Three-Dimensional Polymer Melts through Architecture Engineering
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DOI：
10.1021/acs.macromol.3c02337
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发表时间：
2024-01
期刊：
影响因子：
5.5
通讯作者：
Qingzhi Zou;Yifu Ruan;Rui Zhang;Gengxin Liu
中科院分区：
文献类型：
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作者：
Qingzhi Zou;Yifu Ruan;Rui Zhang;Gengxin Liu
粗粒三维（3D）结构的聚合物，即软簇，即使在比它们的玻璃化转变温度高得多的温度下也表现出玻璃化但熔融的状态。在这项研究中，我们系统地调节了珠子的数量，并操纵了这些软簇的3D结构。我们揭示了平移和旋转松弛的独特解耦，并确定了三种不同类型的粘弹性。值得注意的是，软集群的质心动力学对压力和密度不太敏感，关键的决定因素是结构的紧凑性和珠子的数量，它们共同决定了预定义的合作水平。我们建立了发散弛豫时间，增长的动态异质性，和激活能的质心之间的直接相关性。我们的研究结果强调了通过化学键（弹簧）引入的预定义的合作性在软簇行为中的重要作用。这种玻璃化的新实现表明了3D结构聚合物的富有成效的未来。
Coarse-grained three-dimensional (3D) architectured polymers, namely, soft-clusters, exhibit a glassy yet melt state even at temperatures much higher than their glass transition temperature. In this study, we systematically modulated the number of beads and manipulated the 3D architectures of these soft-clusters. We unveiled the distinct decoupling of translational and rotational relaxation and identified three distinct types of viscoelasticity. Remarkably, the center-of-mass dynamics of soft-clusters are less sensitive to pressure and density, with the critical determinants being the compactness of the architecture and the number of beads, which collectively dictate a predefined level of cooperation. We established direct correlations between the divergent relaxation time, growth of dynamic heterogeneity, and the activation energy of the center of mass. Our findings underscore the essential role of predefined cooperativeness, introduced via chemical bonds (springs), in the behavior of soft-clusters. This novel realization of glassiness suggests a fruitful future for 3D-architectured polymers.