AIEgen containing side-chain liquid crystalline polymers: Photoluminecence or photothermal, which dominate?  

作　　者：Lei Tao He-Lou Xie Xin Qi Jun Song Hong Xin Zhen-Qiang Yu 

机构地区：[1]College of Chemistry and Environmental Engineering,Institute of Low-dimensional Materials Genome Initiative,Shenzhen University,Shenzhen 518060,China [2]Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,College of Optoelectronic Engineering,Shenzhen University,Shenzhen 518071,China [3]Key Lab of Environment-friendly Chemistry and Application in Ministry of Education,College of Chemistry,Xiangtan University,Xiangtan 411105,China

出　　处：《Nano Research》2022年第10期9334-9340,共7页纳米研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)(Nos.21875143,21674065,and 21975215);the Innovation Research Foundation of Shenzhen(Nos.SGG20190222175202275,JCYJ20180507182229597,and JCYJ20180305125649693);the Natural Science Foundation of Guangdong Province(No.2016A030312002)。

摘　　要：Why many luminescent liquid crystalline polymers(LLCPs)containing aggregation-induced emission luminogen(AIEgen)show weak emission is a question still to be answered.Herein,a series of LLCPs(α-Pns,n=4,8,and 12)with polynorbornene as main chain and twoα-dicyanodistyrylbenzene(α-DCS)as side chain are successfully synthesized to solve this issue.Differential scanning calorimetry(DSC),polarized light microscopy(PLM),one-dimentional(1D),two-dimentional(2D)middle-angle and wide-angle X-ray scattering(MAXS and WAXS)results demonstrate that the polymers form smectic A(SmA)phase with the side chains interdigitated packed within the smectic layers.Meanwhile,the photophysical properties ofα-Pns were investigated by ultraviolet-visible(UV-vis)absorption,steady state and time-resolved spectroscopy,and photothermal effect.Results show that the polymers are AIE active,but emit weak emission.The emission peak ofα-Pns film red-shift from 473 to 531 nm,the quantum yield gradually increases from around 1.6%to 14.7%,and the photothermal conversion efficiency decreases from 39%to 19%with the alkyl tail length increased.The photothermal effect,but not photoluminescence,dominates the excited state relaxation.

关 键 词：luminescent liquid crystalline polymers dicyanodistyrylbenzene smectic A structure alkyl tail dependence photothermal conversion 

分 类 号：O63[理学—高分子化学]