高热导率的聚偏氟乙烯/石墨烯复合材料  

High Thermal Conductivity of Polyvinylidene Fluoride/Graphene Composites

作　　者：胡济珠 董岚 卢婷玉 徐象繁[1] 周俊[1] HU Jizhu;DONG Lan;LU Tingyu;XU Xiangfan;ZHOU Jun(Center for Phononics and Thermal Energy Science,School of Physics Science and Engineering,Tongji University, Shanghai 200092,China)

机构地区：[1]同济大学物理科学与工程学院声子学与热能中心,上海200092

出　　处：《集成技术》2019年第1期15-23,共9页Journal of Integration Technology

基　　金：国家重点研发计划项目(2017YFB0406000)

摘　　要：芯片散热问题限制了芯片技术的进一步发展,寻求高热导率的热界面材料成为突破该瓶颈的重要手段之一。有机-无机复合材料由于其柔软性以及热导率可调控,有望取代常规材料——硅脂,成为新一代热界面材料。实验上,有机-无机复合材料的制备方法包括物理混合、分相析出和原位氧化。该文采用物理混合方法制备聚偏氟乙烯/石墨烯复合材料,并使用非稳态测量方法得到其热导率高达83 W/(m·K)(温度T=360 K、体积分数f=76 vol%)。此外,复合材料的热导率与填料的体积分数、颗粒大小形状以及填料与基体之间的相互作用等因素密切相关,利用改进的有效介质理论Bruggeman模型和Agari模型来解释复合材料热导率的物理机制时发现,改进的有效介质理论Bruggeman模型并不能很好地解释该复合材料的高热导率。由Agari模型可知,当填料含量较高时,填料之间更容易形成导热通道,从而提高了复合材料的热导率。Heat dissipation problems have limited the further development of the chip technique, therefore, searching for thermal interfacial materials with high thermal conductivity becomes one of the most important methods to break through the bottlenecks. Among these thermal interfacial materials, organic-inorganic composites are believed to be a promising alternative of the traditional silicon grease, due to their flexibility and controllable thermal conductivity. The fabrication methods of organic-inorganic composites, such as physical blending, phase precipitation, in-situ oxidation have been widely adopted on experiment. In this paper, we fabricated the polyvinylidene fluoride/graphene composites by using physical blending method, and their thermal conductivities could achieve as high as 83 W/(m·K) by using non-steady measurements with temperature T=360 K and volume ratio f=76 vol%. Furthermore, the thermal conductivity of the organicinorganic composites is highly depends on factors including the volume ratio of the fillers, grain sizes and shapes, and the interactions between the organic and inorganic materials. We adopted the improved Bruggeman model and Agarimodel based on the effective medium theory to explain the thermal transport mechanism. Investigation results showed that, improved Bruggeman model cannot interpret the reason of high thermal conductivity of composites. The larger the fraction of the fillers, according to Agari model, the easier could the thermal conductive channels form among the fillers, thus the higher the thermal conductivities of these composites.

关 键 词：聚偏氟乙烯/石墨烯复合材料 有效介质理论 热导率 

分 类 号：TB333[一般工业技术—材料科学与工程] V258[航空宇航科学与技术—航空宇航制造工程]