Enhanced Entanglement Density and Its Implication on Chain Diffusion Dynamics at the Air/Polyethylene Melt Interface

IF 5.1 1区化学 Q1 POLYMER SCIENCE

Macromolecules Pub Date : 2024-10-29 DOI:10.1021/acs.macromol.4c01588

Natsumi Kyoda, Tatsuya Ishiyama

引用次数: 0

Abstract

All-atom molecular dynamics (MD) simulations at the air/polyethylene (PE) melt interface are performed to investigate the entanglement of polymer chains specific to the interfacial region. Before analyzing the entanglement, certain properties of the PE melt such as density, melting point, and glass transition temperature are examined, and the present model accurately reproduces these properties. The MD simulations reveal an enhancement of kink (entanglement) density in the subsurface region of the PE melt. Additionally, it is observed that the enhanced entanglement density exhibits temperature dependence, decreasing as the temperature increases. The influence of the enhanced entanglement density on the diffusion dynamics (mean square displacement) of the polymer chains is examined in the time scale of several tens of nanoseconds. The results confirm that the chain dynamics at the interfacial region are affected by the interface-specific entanglement in the time scale of a reptation-like regime.

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增强的纠缠密度及其对空气/聚乙烯熔体界面链扩散动力学的影响

对空气/聚乙烯（PE）熔体界面进行了全原子分子动力学（MD）模拟，以研究界面区域特有的聚合物链缠结。在分析缠结之前，先检查了聚乙烯熔体的某些特性，如密度、熔点和玻璃化转变温度，本模型准确地再现了这些特性。MD 模拟显示，聚乙烯熔体次表层区域的扭结（缠结）密度增加。此外，还观察到增强的缠结密度与温度有关，随着温度的升高而降低。在几十纳秒的时间范围内，研究了增强的纠缠密度对聚合物链扩散动力学（均方位移）的影响。结果证实，界面区域的链动力学在类似于爬行机制的时间尺度内受到界面特定纠缠的影响。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Macromolecules 工程技术-高分子科学

CiteScore

9.30

自引率

16.40%

发文量

942

审稿时长

2 months

期刊介绍： Macromolecules publishes original, fundamental, and impactful research on all aspects of polymer science. Topics of interest include synthesis (e.g., controlled polymerizations, polymerization catalysis, post polymerization modification, new monomer structures and polymer architectures, and polymerization mechanisms/kinetics analysis); phase behavior, thermodynamics, dynamic, and ordering/disordering phenomena (e.g., self-assembly, gelation, crystallization, solution/melt/solid-state characteristics); structure and properties (e.g., mechanical and rheological properties, surface/interfacial characteristics, electronic and transport properties); new state of the art characterization (e.g., spectroscopy, scattering, microscopy, rheology), simulation (e.g., Monte Carlo, molecular dynamics, multi-scale/coarse-grained modeling), and theoretical methods. Renewable/sustainable polymers, polymer networks, responsive polymers, electro-, magneto- and opto-active macromolecules, inorganic polymers, charge-transporting polymers (ion-containing, semiconducting, and conducting), nanostructured polymers, and polymer composites are also of interest. Typical papers published in Macromolecules showcase important and innovative concepts, experimental methods/observations, and theoretical/computational approaches that demonstrate a fundamental advance in the understanding of polymers.