Ghai Viney, Mishra Ases Akas, Huang Enling, Ngaloy Roselle, Dash Saroj P, Matic Aleksandar, Kádár Roland
Department of Industrial and Materials Science, Chalmers University of Technology, Göteborg, 41296, Sweden.
Department of Microtechnology and Nanoscience, Chalmers University of Technology, Göteborg, 41296, Sweden.
Adv Sci (Weinh). 2025 Feb;12(6):e2408532. doi: 10.1002/advs.202408532. Epub 2024 Dec 23.
Thermal conductivity enhancement in polymers is vital for advanced applications. This study introduces a novel method to align hexagonal boron nitride (hBN) nanosheets within polydimethylsiloxane (PDMS) matrices using a Halbach array to create a highly uniform magnetic field. This technique achieves significant improvements in thermal conductivity by effectively aligning hBN nanosheets. This research shows that hBN nanosheets, when aligned, can drastically enhance thermal conductivity in PDMS composites. Specifically, 10 wt.% vertically aligned hBN nanosheets in a rotating magnetic field achieve a thermal conductivity of 3.58 W mK, an impressive 1950% increase over pure PDMS. Additionally, the study explores the effects of orientation on dielectric properties, finding that the orientation of hBN nanosheets also improves electrical insulation and increases the dielectric constant while maintaining extremely low dielectric losses. For a vertically oriented sample, the dielectric constant reaches ≈14, and dielectric losses are as low as 0.0049 at 100 Hz, highlighting their potential for energy storage capacitors. This approach not only enhances thermal management but also maintains or improves electrical insulation, offering promising advances for polymer composites in various technological applications.
提高聚合物的热导率对于先进应用至关重要。本研究介绍了一种使用哈尔巴赫阵列在聚二甲基硅氧烷（PDMS）基质中排列六方氮化硼（hBN）纳米片的新方法，以创建高度均匀的磁场。该技术通过有效排列hBN纳米片，实现了热导率的显著提高。这项研究表明，hBN纳米片排列后，可大幅提高PDMS复合材料的热导率。具体而言，在旋转磁场中10 wt.%垂直排列的hBN纳米片实现了3.58 W mK的热导率，比纯PDMS提高了令人印象深刻的1950%。此外，该研究还探讨了取向对介电性能的影响，发现hBN纳米片的取向还可改善电绝缘性并提高介电常数，同时保持极低的介电损耗。对于垂直取向的样品，介电常数达到≈14，在100 Hz时介电损耗低至0.0049，突出了它们在储能电容器方面的潜力。这种方法不仅增强了热管理能力，还保持或改善了电绝缘性，为聚合物复合材料在各种技术应用中提供了有前景的进展。
