Yu Cuiping, Gong Wenbin, Zhang Jun, Lv Weibang, Tian Wei, Fan Xiaodong, Yao Yagang
The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education and Shaanxi Key Laboratory of Macromolecular Science and Technology, School of Science, Northwestern Polytechnical University Xi'an 710072 PR China
Division of Advanced Nanomaterials, Key Laboratory of Nanodevices and Applications, Joint Key Laboratory of Functional Nanomaterials and Devices, CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences Suzhou 215123 PR China
RSC Adv. 2018 Jul 18;8(45):25835-25845. doi: 10.1039/c8ra04700f. eCollection 2018 Jul 16.
Styrene-ethylene-butylene-styrene (SEBS) composite films containing well-dispersed and highly aligned hexagonal boron nitride (hBN) platelets were achieved by a ball milling process followed by hot-pressing treatment. An ultrahigh in-plane thermal conductivity of 45 W m K was achievable in the SEBS composite film with 95 wt% hBN. The corresponding out-of-plane thermal conductivity was also as high as 4.4 W m K. The hBN/SEBS composite film was further used to cool a CPU connected to a computer, resulting in a decrease by about 4 °C in the stable temperature. Percolation thresholds over 40 wt% and 60 wt% in the hBN/SEBS composites were obtained in the in-plane and out-of-plane directions, respectively. This phenomenon has rarely been reported in polymer composites. Molecular dynamics simulations were also conducted to support this percolation threshold. The linear coefficients of the thermal expansion value of the hBN/SEBS composite with 95 wt% hBN was as low as 16 ppm K. This was a significant decrease compared to that of pure SEBS (149 ppm K). The proposed strategy provides valuable advice about the heat-transfer mechanism in polymer composites containing oriented two-dimensional materials.
通过球磨工艺然后进行热压处理，制备出了含有分散良好且高度取向的六方氮化硼（hBN）薄片的苯乙烯-乙烯-丁烯-苯乙烯（SEBS）复合薄膜。在含有95 wt% hBN的SEBS复合薄膜中，可实现高达45 W m⁻¹ K⁻¹的超高面内热导率。相应的面外热导率也高达4.4 W m⁻¹ K⁻¹。hBN/SEBS复合薄膜进一步用于冷却连接到计算机的CPU，使稳定温度降低了约4°C。在hBN/SEBS复合材料中，面内和面外方向的渗流阈值分别超过40 wt%和60 wt%。这种现象在聚合物复合材料中鲜有报道。还进行了分子动力学模拟以支持这一渗流阈值。含有95 wt% hBN的hBN/SEBS复合材料的热膨胀值线性系数低至16 ppm K⁻¹。与纯SEBS（149 ppm K⁻¹）相比，这是一个显著的降低。所提出的策略为含取向二维材料的聚合物复合材料中的传热机制提供了有价值的建议。
