表面绝缘兼具高导热和电磁屏蔽的复合多层膜的制备与性能研究

Preparation and properties of multilayer composite film with surface insulation, high thermal conductivity and electromagnetic shielding

以环境友好型材料纳米纤维素为基体,与多壁碳纳米管和六方氮化硼复合制备兼具高导热和电磁屏蔽且表面绝缘的复合薄膜材料,并对其性能进行研究。结果表明,碳纳米管和纤维素组成的复合薄膜在碳纳米管填充量为40%时,电磁屏蔽效能、厚度、密度达到最佳平衡;其单位厚度比屏蔽性能(SSE/t)显著提高,达到5 465.28 dB·cm^(2)/g;叠层复合薄膜的面内热导率最高达到5.56 W/(m·K),较纯CNF薄膜提高了近400%;叠层复合薄膜具有很好的柔韧性,可以完全对折而不产生裂痕;叠层复合薄膜的表面电导率均在10-9数量级,表明薄膜具有很好的绝缘性能。

A composite film with high thermal conductivity, electromagnetic shielding and surface insulation is prepared by using nanocelluloses as substrate, multi-walled carbon nanotubes and hexagonal boron nitride as fillers, and its properties is studied.The results indicate that there is a best balance reached among the electromagnetic shielding efficiency, thickness and density of the composite film when the filling amount of carbon nanotubes is 40 wt%.Its specific shielding effectiveness per unit thickness(SSE/t) reaches 5 465.28 dB·cm^(2)·g^(-1).The highest value for in-plane thermal conductivity of the laminated composite film is 5.56 W/(m·K),which is nearly 400% higher than that of pure carbon nanotubes film.Laminated composite film maintains a good flexibility, which can be completely folded without any cracks.The surface conductivity of the laminated composite film attains in the order of 10-9,indicating a good insulation performance.