Understanding the graphene-polymer interfacial mechanical behavior via coarse-grained modeling
Understanding the graphene-polymer interfacial mechanical behavior via coarse-grained modeling
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DOI：
10.1016/j.commatsci.2023.112109
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发表时间：
2023-04
影响因子：
3.3
通讯作者：
Yang Wang-;W. Nie;Liang-zhi Wang;Dawei Zhang;K. Niu;W. Xia
中科院分区：
文献类型：
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作者：
Yang Wang-;W. Nie;Liang-zhi Wang;Dawei Zhang;K. Niu;W. Xia
了解石墨烯-聚合物纳米复合材料的界面行为是深入了解工程结构材料力学性能的长期努力。在这项研究中，我们实施了“硬”截止方案，开发了一个4-1映射粗粒石墨烯（CGGr）模型和相应的CG势tersofffcg(4-1)，与实验结果相比，该模型忠实地再现了石墨烯片的蜂窝结构（键长和角度）和力学性能。以聚甲基丙烯酸甲酯（PMMA）和石墨烯片为代表的复合体系，建立了预测CG建模框架，在分子水平上研究其界面行为。通过速率相关的界面分离模拟，我们的研究结果表明，较低的分离速度和较厚的柔性层可以促进裂纹原纤维的形成，并进一步提高复合材料的韧性，这归因于聚合物在较低的分离速度下对石墨烯的充分响应，以及在较厚的柔性层下更多的聚合物可能形成原纤维。我们的工作证明了TersoffCG（4-1）在理解石墨烯-聚合物纳米复合材料界面力学行为方面的有效性，为通过设计界面来提高性能提供了有效的建模策略。
Understanding the interfacial behavior of graphene-polymer nanocomposite is a long-standing endeavor to gain deep insight into the mechanical properties of engineered structural materials. In this study, we implement the ‘hard’ cutoff scheme to develop a 4-1 mapping coarse-grained graphene (CGGr) model and the corresponding CG potential TersoffCG(4-1), which faithfully reproduces the honeycomb structure (bond length and angle) and mechanical properties of the graphene sheet compared to experimental results. Taking the poly(methyl methacrylate) (PMMA) and graphene sheet as a representative composite system, we establish a predictive CG modeling framework to study the interfacial behavior at a molecular level. By performing the rate-dependent interfacial separation simulations, our results reveal that lower separation velocity and thicker flexible layer can facilitate the craze fibrils formation and further enhance the toughness of the composite, which attribute to the adequate response of polymer to the graphene under lower velocity and more polymers that potentially to form fibrils under thicker flexible layer. Our work demonstrates the efficacy of TersoffCG(4-1) potential in understanding the interfacial mechanical behavior of graphene-polymer nanocomposite, offering an effective modeling strategy for performance improvement by designing the interfaces.