论文标题
通过分子动力学验证的自折叠石墨烯膜中结构依赖性热传输行为的预测
Prediction of structure-dependent thermal transport behavior in self-folded graphene film validated by molecular dynamics simulation
论文作者
论文摘要
了解微观结构与整体属性之间的关系是材料设计和应用的基本问题之一。作为自然界中普遍存在的结构构型,在基于石墨烯的纳米材料中,折叠的形态也被广泛观察到。最近,通过嫁接和展示有希望的热管理应用程序,已成功制造了一种自折叠的石墨烯膜(SF-GF)材料。然而,SF-GF的热性能依赖于Grafold的结构特征尚不清楚。我们在这里开发了一个分析模型来描述SF-GF中的热传输行为。我们的模型证明了植被的几何形状与SF-GF的热性能之间的关系。通过分子动力学模拟,可以很好地验证温度轮廓和热导率的预测。使用该模型,我们进一步研究了SF-GF的导热率的演变,并在拉伸过程中发生了变形。此外,发现了谷物的几何不规则性的影响。有趣的是,在拉伸下,SF-GF的预测运输行为适合基于石墨烯的应变传感器中报道的一些类似的实验观察。我们的结果不仅揭示了基于石墨烯的设备应用中某些物理现象背后的机制,而且还为SF-GF和其他具有折叠微结构的SF-GF和其他石墨烯组件的属性设计提供了实用的指南。
Understanding the relationship between the microstructures and overall properties is one of the basic concerns for the material design and applications. As a ubiquitous structural configuration in nature, the folded morphology is also widely observed in graphene-based nanomaterials, namely grafold. Recently, a self-folded graphene film (SF-GF) material has been successfully fabricated by the assembly of grafolds and exhibits promising applications in thermal management. However, the dependence of thermal properties of SF-GF on the structural features of grafold has still remained unclear. We here develop an analytical model to describe the thermal transport behavior in SF-GF. Our model demonstrates the relationship between the geometry of grafolds and thermal properties of SF-GF. The predictions of temperature profile and thermal conductivity are well validated by molecular dynamics simulations. Using this model, we further study the evolution of thermal conductivity of SF-GF with the unfolding deformation during stretch. Moreover, the effect of geometrical irregularity of grafolds is uncovered. Interestingly, the predicted transport behaviors of SF-GF under stretch fit some analogous experimental observations reported in graphene-based strain sensor. Our results not only reveal the mechanisms behind some physical phenomenon in the applications of graphene-based devices, but also provide practical guidelines for the property design of SF-GF and other graphene assemblies with folded microstructure.