In order to improve the thermal conductivity of polyimide film and maintain its insulating properties, SiO2 was used to coat AgNWs to obtain AgNWs@SiO2 core-shell structure. At First, the AgNWs@SiO2 was dispersed in polyamide acid (PAA) discharge fiber by electrospinning technology, and the heat conduction path and the dispersity of AgNWs@SiO2 in PI matrix was planned and improved by electrospinning technology, respectively. Then the PAA glue containing AgNWs@SiO2 was used to impregnate PAA electrospun film, and an E-AgNWs@SiO2/PI composite film was obtained after thermal imidization. The effects of filler modification and content on the thermal conductivity and insulating properties of the composite films were studied. The results show that when the mass fraction of filler is 25%, the thermal conductivity of E-AgNWs/PI and E-AgNWs@SiO2/PI composite films is 2.92 W/(m·K) and 2.80 W/(m·K), which are 14.6 and 14 times higher than those of pure PI films, respectively. The dielectric constant of E-AgNWs@SiO2/PI composite film decreases to below 5, the dielectric loss factor maintains below 0.015, and the volume resistivity increases to 1.79×1013 Ω·m.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |