Li Mengxiong, Liu Jiangwei, Pan Shaoxue, Zhang Jiajia, Liu Ya, Liu Johan, Lu Hongbin
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Collaborative Innovation Center of Polymers and Polymer Composites, Fudan University, 2005 Songhu Road, Shanghai 200438, P. R. China.
Department of Chemistry, Merkert Chemistry Center, Boston College, 2609 Beacon Street, Chestnut Hill, Massachusetts 02467, United States.
ACS Appl Mater Interfaces. 2020 Jun 17;12(24):27476-27484. doi: 10.1021/acsami.0c02151. Epub 2020 Jun 2.
Graphene-based thermally conductive polymer composites are of great importance for the removal of the excess heat generated by electronic devices. However, due to the orientation of graphene sheets in the polymer matrix, the through-plane thermal conductivity of polymer/graphene composites remains far from satisfactory. We here demonstrate a confined liquid-phase expansion strategy to fabricate highly oriented confined expanded graphite (CEG) aerogels. After being incorporated into epoxy resin (EP), the resulting EP/CEG composites exhibit a high through-plane thermal conductivity (4.14 ± 0.21 W m K) at a quite low filler loading of 1.75 wt % (0.91 vol %), nearly 10 times higher than that of neat EP resin and 7.5 times higher than the in-plane thermal conductivity of the composite, indicating that the CEG aerogel has a high through-plane thermal conductivity enhancement efficiency that outperforms those of many graphite/graphene-based fillers. The facile preparation method holds great industrial application potential in fabricating anisotropic thermally conductive polymer composites.
基于石墨烯的导热聚合物复合材料对于去除电子设备产生的多余热量非常重要。然而，由于石墨烯片在聚合物基体中的取向，聚合物/石墨烯复合材料的面内热导率仍远不能令人满意。我们在此展示了一种受限液相膨胀策略，以制备高度取向的受限膨胀石墨（CEG）气凝胶。将其掺入环氧树脂（EP）后，所得的EP/CEG复合材料在仅1.75 wt%（0.91 vol%）的低填料负载下就表现出高的面内热导率（4.14±0.21 W m K），几乎是纯EP树脂的10倍，比复合材料的面内热导率高7.5倍，这表明CEG气凝胶具有高的面内热导率增强效率，优于许多基于石墨/石墨烯的填料。这种简便的制备方法在制造各向异性导热聚合物复合材料方面具有巨大的工业应用潜力。
