Yaoqi Wang, Yunpeng Tan, Ping Song*, Yongqiang Guo, Junwei Gu*. Highly thermally conductive polydimethylsiloxane composites with bidirectional thermal conduction pathways. Composites Science and Technology, 2026, 284: 111786. 2025IF=9.9.

https://www.sciencedirect.com/science/article/pii/S026635382600271X

  Constructing ordered thermally conductive pathways within polymer-based composites can optimize heat transfer routes, thereby significantly enhancing the thermal conductivity of the composites. In this work, polydimethylsiloxane (PDMS) was employed as the matrix, while magnetically responsive boron nitride nanosheets (BNNS@Ni) and surface-functionalized gallium-indium liquid metal (Constructing ordered thermally conductive pathways within polymer-based composites can optimize heat transfer routes, thereby significantly enhancing the thermal conductivity of the composites. In this work, polydimethylsiloxane (PDMS) was employed as the matrix, while magnetically responsive boron nitride nanosheets (BNNS@Ni) and surface-functionalized gallium-indium liquid metal (f-LM) were utilized as hybrid thermally conductive fillers to fabricate H-BNNS@Ni/f-LM/PDMS composites with bidirectional thermally conductive pathways in both the in-plane and through-plane directions via magnetic field orientation. At a H-BNNS@Ni to f-LM mass ratio of 4:1 and a total filler loading of 50 wt%, the in-plane thermal conductivity (λ_∥) and through-plane thermal conductivity (λ_⊥) of the H-BNNS@Ni/f-LM/PDMS composites reached 6.31 W/(m·K) and 0.98 W/(m·K), corresponding to 33.2 and 9.8 times those of pure PDMS , respectively. The H-BNNS@Ni/f-LM/PDMS composites also exhibited outstanding thermal stability (thermal resistance index of 261.8℃), photothermal conversion capability (surface temperature reaching 161.4℃ after 30 seconds of near-infrared light irradiation at 0.95 W·cm^-2), and hydrophobicity (water contact angle of 120.0°), indicating their considerable potential for applications in next-generation flexible electronic devices.

  在聚合物基复合材料中构筑填料有序导热通路，可以优化热量传输路径，从而大幅提升其导热性能。本工作以聚二甲基硅氧烷（PDMS）为基体、磁响应氮化硼纳米片（BNNS@Ni）和表面功能化改性镓铟液态金属（f-LM）为二元导热填料，经磁场取向制备具有面内/面间双向导热通路的H-BNNS@Ni/f-LM/PDMS导热复合材料。当H-BNNS@Ni和f-LM质量比为4：1且总质量分数为50 wt%时，H-BNNS@Ni/f-LM/PDMS导热复合材料的面内导热系数（λ_∥）和面间导热系数（λ_⊥）分别为6.31 W/(m·K)和0.98 W/(m·K)，约为纯PDMS λ_∥（0.19 W/(m·K)）和λ_⊥（0.10 W/(m·K)）的33.2和9.8倍。H-BNNS@Ni/f-LM/PDMS复合材料还兼具优异的耐热性能（耐热指数为261.8℃）、光热转换性能（在0.95 W·cm^-2的近红外光照射30秒后表面温度达到161.4℃）和疏水性（水接触角120.0°），使其在新一代柔性电子器件领域具有良好的应用前景。