Shuangshuang Wang, Dianying Feng, Zhiming Zhang, Xia Liu, Kunpeng Ruan, Yongqiang Guo* and Junwei Gu. Highly thermally conductive polydimethylsiloxane composites with controllable 3D GO@f-CNTs networks via self-sacrificing template method. Chinese Journal of Polymer Science, 2024, 10.1007/s10118-024-3098-4. 2022IF=4.3.（2区化学期刊，中国科技期刊卓越行动计划-梯队期刊类项目）

Abstract

Constructing controllable thermal conduction networks is the key to efficiently improve thermal conductivities of polymer composites. In this work, graphite oxide (GO) and functionalized carbon nanotubes (f-CNTs) are combined to prepare “Line-Plane”-like hetero-structured thermally conductive GO@f-CNTs fillers, which are then performed to construct controllable 3D GO@f-CNTs thermal conduction networks via self-sacrificing template method based on oxalic acid. Subsequently, thermally conductive GO@f-CNTs/polydimethylsiloxane (PDMS) composites are fabricated via casting method. When the size of oxalic acid is 0.24 mm and the volume fraction of GO@f-CNTs is 60 vol%, GO@f-CNTs/PDMS composites present the optimal thermal conductivity coefficient (λ, 4.00 W/(m·K)), about 20 times that of the λ of pure PDMS (0.20 W/(m·K)), also much higher than the λ (2.44 W/(m·K)) of GO/f-CNTs/PDMS composites with the same amount of randomly dispersed fillers. Meanwhile, the obtained GO@f-CNTs/PDMS composites have excellent thermal stability, whose λ deviation is onlyabout 3% after 500 thermal cycles (20~200^oC).

可控导热网络的构筑是高效提升导热填料/高分子复合材料导热性能的关键。本文以氧化石墨（GO）和改性碳纳米管（f-CNTs）构筑的“线-面”状异质结构GO@f-CNTs为导热填料，借助草酸为自牺牲模板构筑结构完整、形貌可控的GO@f-CNTs导热网络，经浇注聚二甲基硅氧烷（PDMS）制备GO@f-CNTs/PDMS导热复合材料。结果表明，当草酸粒径为0.24 mm且GO@f-CNTs体积分数为60 vol%时，GO@f-CNTs/PDMS导热复合材料具有最优的导热系数（λ，4.00 W/(m·K)），约为纯PDMS的λ（0.20 W/(m·K)）的20倍，也远高于同等GO和f-CNTs用量随机分散的GO/f-CNTs/PDMS导热复合材料的λ（2.44 W/(m·K)）。GO@f-CNTs/PDMS导热复合材料兼具优异的导热稳定性，经500次热循环（20~200^oC）后其λ的偏差约为3%。

论文亮点

1. 以草酸为自牺牲模板将化学接枝法制备的GO@f-CNTs异质结构导热填料构筑成结构完整、形貌可控的三维GO@f-CNTs导热网络。

2. 当草酸粒径为0.24 mm且GO@f-CNTs体积分数为60 vol%时，GO@f-CNTs/PDMS导热复合材料具有最优的导热系数（λ，4.00 W/(m·K)），远高于同等GO和f-CNTs用量随机分散的GO/f-CNTs/PDMS导热复合材料的λ（2.44 W/(m·K)）。

3. GO@f-CNTs/PDMS导热复合材料的微观热传导有限元模拟揭示了粒径为0.24 mm的草酸构筑的GO@f-CNTs导热网络具有最佳的热传导效率。

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