This paper conducts theoretical study on the mechanical, thermal and electrical properties of graphene reinforced composites by effective medium theory (EMT). Considering the imperfect bonding between the reinforcing fillers and the matrix, an interphase surrounding the graphene fillers is introduced during the EMT modeling. The coated graphene fillers are homogenized as effective reinforcements dispersed in a matrix. The EMT model is validated by comparing the predicted material properties with previously reported results. Parametric study is carried out to investigate the influences of several parameters, including concentration and geometry of graphene fillers, the attributes of the introduced an interphase and the alternating current (AC) frequency, upon the effective material properties of the reinforced composites. The results demonstrate that the increase of the thickness of the interphase results in the decrease of Young’s modulus, thermal conductivity and electrical conductivity of the composites while it is favorable to enhance the dielectric properties of the composites. The increase in the aspect ratio of the graphene filler enhances all material properties involved. Percolation behaviors are observed for the dielectric properties of the composites. Moreover, the dielectric properties of the composites are very sensitive to the change of the AC frequency within a certain range, which suggests the achievement of active tuning of material properties.

中文翻译：

---

有效介质理论对石墨烯增强复合材料力学、热学和电学性能的参数化研究

本文采用有效介质理论（EMT）对石墨烯增强复合材料的力学、热学和电学性能进行理论研究。考虑到增强填料和基体之间的不完美结合，在 EMT 建模过程中引入了围绕石墨烯填料的界面。涂覆的石墨烯填料作为分散在基体中的有效增强物被均质化。通过将预测的材料特性与先前报告的结果进行比较来验证 EMT 模型。进行参数研究以研究几个参数对增强复合材料有效材料性能的影响，包括石墨烯填料的浓度和几何形状、引入的界面属性和交流电 (AC) 频率。结果表明，界面层厚度的增加导致复合材料的杨氏模量、热导率和电导率降低，但有利于提高复合材料的介电性能。石墨烯填料纵横比的增加增强了所涉及的所有材料特性。观察了复合材料介电性能的渗流行为。此外，复合材料的介电性能对一定范围内交流频率的变化非常敏感，这表明实现了材料性能的主动调谐。复合材料的导热性和导电性，同时有利于提高复合材料的介电性能。石墨烯填料纵横比的增加增强了所涉及的所有材料特性。观察了复合材料介电性能的渗流行为。此外，复合材料的介电性能对一定范围内交流频率的变化非常敏感，这表明实现了材料性能的主动调谐。复合材料的导热性和导电性，同时有利于提高复合材料的介电性能。石墨烯填料纵横比的增加增强了所涉及的所有材料特性。观察了复合材料介电性能的渗流行为。此外，复合材料的介电性能对一定范围内交流频率的变化非常敏感，这表明实现了材料性能的主动调谐。