Structure effect on transition mechanism of UV-visible absorption spectrum in polyimides: A density functional theory study

doi:10.1016/j.polymer.2018.06.049

	Structure effect on transition mechanism of UV-visible absorption spectrum in polyimides: A density functional theory study
	Ma, YP ; Hu, CC ; Guo, HX ; Fan, L ; Yang, SY ; Sun, WH
刊名	POLYMER
	2018-07-18
卷号	148 页码:356-369
关键词	Transition mechanism DFT and TDDFT Transparent polyimide
ISSN号	0032-3861
DOI	10.1016/j.polymer.2018.06.049
英文摘要	Understanding of the nature of the transition mechanism in UV-visible absorption spectrum may contribute to the designing of highly transparent polyimide (PI) materials. In the present work, structure effect (alicyclic ring, flexible -O- linkage, and -CF3) on the intra- and inter-molecular transition mechanism of optical absorptions in PI model molecules is investigated by the Density functional theory (DFT) in combination with the time dependent DFT calculations. Six pyromelliticdianhydride (PMDA) derived aromatic and six 1,2,4,5-cyclohexanetetracarboxylic dianhydride (CHDA) derived semi-aromatic polyimide (PI) species are considered and their intermolecular transitions are analyzed by designing typical dimers with classical face-to-face Pi-Pi stacking orientation. The natural bond orbital method (NBO) is employed to analyze the delocalization degree in the PI species. By calculating the energies of the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) as well as the transition characters between them, the electron excitation nature concerning on the structural variations in the monomers and the dimers are clarified. These theoretical results agree well with the related experimental observations and provide a deep understanding into the transition mechanism of optical absorptions in the PI species. (C) 2018 Elsevier Ltd. All rights reserved.
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000437378000037
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/41966]
专题	化学研究所_工程塑料实验室
作者单位	1.Fan, L (reprint author), Chinese Acad Sci, Inst Chem, Lab Adv Polymer Mat, Beijing 100190, Peoples R China. 2.Guo, HX (reprint author), State Key Lab Polymer Phys & Chem, Beijing 100190, Peoples R China. 3.Sun, WH (reprint author), Key Lab Engn Plast, Beijing 100190, Peoples R China.
推荐引用方式 GB/T 7714	Ma, YP,Hu, CC,Guo, HX,et al. Structure effect on transition mechanism of UV-visible absorption spectrum in polyimides: A density functional theory study[J]. POLYMER,2018,148:356-369.
APA	Ma, YP,Hu, CC,Guo, HX,Fan, L,Yang, SY,&Sun, WH.(2018).Structure effect on transition mechanism of UV-visible absorption spectrum in polyimides: A density functional theory study.POLYMER,148,356-369.
MLA	Ma, YP,et al."Structure effect on transition mechanism of UV-visible absorption spectrum in polyimides: A density functional theory study".POLYMER 148(2018):356-369.