Highly thermally conductive, ductile biomimetic boron nitride/aramid nanofiber composite film. (22nd March 2020)

• Record Type: Journal Article
• Authors: Xiao, Guang; Di, Jiangtao; Li, Hao; Wang, Jianfeng
• Is Part Of: Composites science and technology. Volume 189(2020)
• Publication Date: 2020-03-22
• Subjects: Aramid nanofiber -- Boron nitride -- Layered structure -- Mechanical property -- Thermal conductivity; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2020.108021
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: Combining a large volume of boron nitride platelets with a little polymer to fabricate ductile, thermally conductive composite materials for the thermal management of flexible electronic devices is a challenge. Herein, we imitate the hierarchical layered architecture of mollusk nacre to design high-loading boron nitride composite film. Boron nitride/aramid nanofiber composite films are prepared by a sol-gel-film transformation approach and show nacre-like hierarchical layered composite structure. High-strength aramid nanofibers form a three-dimensional framework as matrix, which hosts 40–70 wt% oriented BN platelets. Thanks to the high interconnectivity of aramid nanofiber in the three-dimensional framework, the composite films have large ductility, up to 18.3–49.4%. Meanwhile, the composite films have high thermal conductivity (47.4–122.5 W m −1 K −1 ) because high-loading boron nitride platelets form a percolative, oriented heat conduction path. Moreover, the outstanding ductility and thermal conductivity are integrated with high volume resistivity (10 14 –10 16 Ω cm) and thermal decomposition temperature (515 °C), enabling the structured boron nitride/aramid nanofiber composite films to be promising as flexible substrate for cooling electronic components.