Kunpeng Ruan^#, Han Yan^#, Sijie Zhang, Xuetao Shi^*, Yongqiang Guo and Junwei Gu^*. In-situ fabrication of hetero-structured fillers to significantly enhance thermal conductivities of silicone rubber composite films. Composites Science and Technology, 2021, 210: 108799. 2019IF=7.094.（1区材料科学Top期刊）

https://doi.org/10.1016/j.compscitech.2021.108799

Abstract

With the method of precipitation followed by high temperature calcination, hetero-structured fillers boron nitride nanosheets@alumina (BNNS@Al₂O₃) were in-situ fabricated. Thereafter, thermally conductive & insulating BNNS@Al₂O₃/silicone rubber (SR) composite films were then prepared. The “point-surface” hetero-structured fillers BNNS@Al₂O₃ had more significant thermal conductivity coefficient (λ) improvement than single Al₂O₃, BNNS and directly blending BNNS/Al₂O₃ fillers. With the mass fraction of BNNS@Al₂O₃ to be 30 wt% (BNNS/Al₂O₃, 1:1, wt:wt), the in-plane λ (λ_∥) and through-plane λ (λ_⊥) of the BNNS@Al₂O₃/SR composite films attained 2.78 W/mK and 0.84 W/mK, 1.75 times higher than λ_∥ (1.01 W/mK) and 3.0 times higher than λ_⊥ (0.21 W/mK) of pure SR, also more excellent than BNNS/SR (λ_∥=2.46 W/mK, λ_⊥=0.76 W/mK), Al₂O₃/SR (λ_∥=1.58 W/mK, λ_⊥=0.50 W/mK) and directly blending (BNNS/Al₂O₃)/SR (λ_∥=2.04 W/mK, λ_⊥=0.62 W/mK) composite films under the same mass fraction of fillers. Also, BNNS@Al₂O₃/SR composite films presented wonderful mechanical, insulation as well as thermal properties.

采用“沉淀-高温煅烧”法原位制备了具有“点-面”异质结构的氮化硼纳米片@氧化铝（BNNS@Al₂O₃）导热填料，进而制备了BNNS@Al₂O₃/硅橡胶（SR）导热绝缘复合膜。“点-面”异质结构导热填料BNNS@Al₂O₃具有较单一Al₂O₃、BNNS和BNNS/Al₂O₃简单共混填料更显著的导热系数（λ）提升效果。当BNNS@Al₂O₃用量为30 wt%（BNNS/Al₂O₃，1：1，wt：wt）时，BNNS@Al₂O₃/SR复合膜的面内λ（λ_∥）和面间λ（λ_⊥）分别达到2.78 W/mK和0.84 W/mK，较纯SR的λ_∥（1.01 W/mK）和λ_⊥（0.21 W/mK）高出1.75倍和3.0倍，且优于相同填料用量下的BNNS/SR（λ_∥=2.46 W/mK，λ_⊥=0.76 W/mK）、Al₂O₃/SR（λ_∥=1.58 W/mK，λ_⊥=0.50 W/mK）和（BNNS/Al₂O₃）/SR（BNNS/Al₂O₃简单共混，1：1，wt：wt，λ_∥=2.04 W/mK，λ_⊥=0.62 W/mK）复合膜。此外，BNNS@Al₂O₃/SR复合膜还兼具良好的力学性能、电绝缘性能和热性能。