Bi-directional high thermal conductive epoxy composites with radially aligned boron nitride nanosheets lamellae. (29th September 2020)

• Record Type: Journal Article
• Authors: Huang, Taoqing; Li, Yongwei; Chen, Min; Wu, Limin
• Is Part Of: Composites science and technology. Volume 198(2020)
• Publication Date: 2020-09-29
• Subjects: A. Boron nitride -- B. Thermal properties -- C. Anisotropy -- E. Casting; Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2020.108322
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: Hexagonal boron nitride (h-BN), as a high thermal conductive filler, has been widely used to construct thermal transport network in polymers. However, anisotropic thermal property of BN and its conventional thermal conductive network usually lead to high thermal conductivity in one direction that limits the overall heat dissipation effect. Herein, we report a novel radially aligned three-dimensional boron nitride nanosheets/epoxy composite for thermal interface materials via radial freeze-casting method. The as-prepared composite with radially aligned boron nitride nanosheets lamellae exhibits bidirectional high thermal conductivity, with 4.02 W m −1 K −1 in the through-plane direction and 3.87 W m −1 K −1 in the in-plane direction even at low BNNS loading (e.g., 15 vol%), respectively. Besides, excellent electronic insulation property and shape stability can also meet the requirements of isotropic TIM in thermal management. Graphical abstract: We investigated the fabrication of radially aligned 3D boron nitride nanosheets (BNNS)/epoxy composite for TIM via radial freeze-casting method. The as-prepared composite with radially aligned lamellae structure provides effective thermal transport pathways in both through-plane and in-plane directions, endowing bidirectional high thermal conductive property, 4.02 W m −1 K −1 in the through-plane direction and 3.87 W m −1 K −1 in the in-plane direction at low loading ratio of BN (15 vol%), respectively. Image 1 Highlights: Polymer/BN composites prepared via freeze-casting method commonly show anisotropic thermal conductive properties. Thermal interface materials present high thermal conductivities at low BN ratio. Bidirectional high thermal conductive composites are obtained from radial freeze-casting method. Bidirectional orientation of BN increases thermal conductivity. Radially aligned lamellae structure provides bidirectional phonon transport pathways.