摘要
Black polyimides(BPIs)have attracted increasing attention owing to their growing demand in optoelectronics.However,commonly used black polyimides doped with black fillers suffer from poor mechanical and electrical properties.To address these issues,a new diamine(2,5-bis(4′-amino-[1,1′-biphenyl]-4-yl)-3,4-bis(4-fluorophenyl)cyclopenta-2,4-dien-1-one,TPCPFPDA)bearing a tetraphenylcyclopentadienone(TPCP)moiety bonded with benzene and fluorine units was synthesized.The diamine was reacted with 4,4′-(hexafluoroisopropylidene)diphthalic anhydride(6FDA)to yield a soluble intrinsic black polyimide(TPCPFPPI).Bonding fluorine(auxochrome group)and benzene units to TPCP can increase the conjugation ofπ-electrons systems and facilitate the movement of electron throughout the bigπbond,respectively.Owing to the structural features,the synthesized TPCPFPPI exhibited complete visible-light absorption with high blackness and opacity.Its cutoff wavelength(λ_(cut))and CIE(Commission Internationale de I′Eclairage)parameter L^(*)were 684 nm and 1.33,respectively.Moreover,TPCPFPPI displayed exceptional electrical,mechanical,and thermal properties as well as excellent solubility.A detailed theoretical calculation was conducted to gain better insight into the electronic properties of the TPCPFPPI.Results showed that the blackness of TPCPFPPI was chiefly attributed to the electron transition from highest occupied molecular orbital(HOMO)to lowest unoccupied molecular orbital(LUMO)in the diamines,where the charges primarily migrated from the aryl groups in the 2-and 5-positions to the cyclopentadienone center.The as-obtained intrinsic BPI(TPCPFPPI),exhibiting both high solubility and outstanding overall properties,has important applications in photo-electronics.
基金
supported by the National Natural Science Foundation of China (Grant Nos.51973055&52103004)
the Natural Science Foundation of Hunan Province (Grant No.2021JJ50004)
the Science Research Project of Hunan Provincial Department of Education (Grant No.21A0364)
the Student Innovation and Entrepreneurship Training Program of Hunan Province (Grant No.S202211535096)。
作者简介
Corresponding authors:HUANG Jie,email:huangjie3@alumni.sjtu.edu.cn;Corresponding authors:LIU YiWu,email:liuyiwu@hut.edu.cn。
