[Angewandte Chemie International Edition] Electric-Field-Induced Alignment of Functionalized Carbon Nanotubes Inside Thermally Conductive Liquid Crystalline Polyimide Composite Films
作者：Kunpeng Ruan#, Xuetao Shi#, Yali Zhang, Yongqiang Guo*, Xiao Zhong and Junwei Gu*
關(guān)鍵字：Thermally Conductive
論文來源：期刊
具體來源：Angewandte Chemie International Edition
發(fā)表時(shí)間：2024年
Kunpeng Ruan#, Xuetao Shi#, Yali Zhang, Yongqiang Guo*, Xiao Zhong and Junwei Gu*. Electric-Field-Induced Alignment of Functionalized Carbon Nanotubes Inside Thermally Conductive Liquid Crystalline Polyimide Composite Films. Angewandte Chemie International Edition, 2023, 10.1002/anie.202309010. 2022IF=16.6.（1區(qū)化學(xué)Top期刊）
https://doi.org/10.1002/anie.202309010
Abstract
The positive liquid crystals, 4''-heptyl-4-biphenylcarbonitrile (7CB), are used to functionalize carbon nanotubes (LC-CNT), which can be aligned in the liquid crystalline polyimide (LC-PI) matrix under an alternating electric field to fabricate the thermally conductive LC-CNT/LC-PI composite films. The efficient establishment of thermal conduction pathways in thermally conductive LC-CNT/LC-PI composite films with a low amount of LC-CNT is achieved through the oriented alignment of LC-CNT within the LC-PI matrix. When the mass fraction of LC-CNT is 15 wt%, the in-plane thermal conductivity coefficient (λ∥) and the through-plane thermal conductivity coefficient (λ⊥) of the LC-CNT/LC-PI composite films reach 4.02 W/(m·K) and 0.55 W/(m·K), which are 90.5% and 71.9% higher than those of the intrinsically thermally conductive LC-PI films respectively, also 28.8% and 5.8% higher than those of the CNT/LC-PI composite films respectively. Meanwhile, the thermally conductive LC-CNT/LC-PI composite films also possess excellent mechanical and heat resistance properties. The Young''s modulus and the heat resistance index are 2.3 GPa and 297.7oC, respectively, which are higher than the intrinsically thermally conductive LC-PI films and the thermally conductive CNT/LC-PI composite films under the same amount of CNT.采用正性液晶分子4-氰基-4''-庚基聯(lián)苯（7CB）對碳納米管（CNT）進(jìn)行表面功能化改性（LC-CNT），進(jìn)而在交流電場作用下與本征導(dǎo)熱液晶聚酰亞胺（LC-PI）基體復(fù)合制備LC-CNT/LC-PI導(dǎo)熱復(fù)合膜。LC-CNT在LC-PI基體中的定向排列實(shí)現(xiàn)了低LC-CNT用量下LC-CNT/LC-PI導(dǎo)熱復(fù)合膜中導(dǎo)熱通路的高效構(gòu)筑。當(dāng)LC-CNT質(zhì)量分?jǐn)?shù)為15 wt%時(shí)，LC-CNT/LC-PI導(dǎo)熱復(fù)合膜室溫下的面內(nèi)導(dǎo)熱系數(shù)（λ∥）和面間導(dǎo)熱系數(shù)（λ⊥）分別達(dá)到4.02 W/(m·K)和0.55 W/(m·K)，較本征導(dǎo)熱LC-PI膜的λ∥（2.11 W/(m·K)）和λ⊥（0.32 W/(m·K)）提升了90.5%和71.9%，也明顯高于相同CNT用量下CNT/LC-PI導(dǎo)熱復(fù)合膜（λ∥=3.12 W/(m·K)，λ⊥=0.52 W/(m·K)）。此時(shí)，LC-CNT/LC-PI導(dǎo)熱復(fù)合膜還兼具優(yōu)異的力學(xué)性能和耐熱性能，楊氏模量和耐熱指數(shù)分別為2.3 GPa和297.7oC，高于本征導(dǎo)熱LC-PI膜（2.1 GPa和262.4oC）和相同CNT用量下CNT/LC-PI導(dǎo)熱復(fù)合膜（2.2 GPa和291.3oC）。