Effect of a biphenyl side chain of polyimide on the pretilt angle of liquid crystal molecules: molecular simulation and experimental studies

Autor:	Yi Gu, Ming Li, Boxun Chen, Xiangyang Liu, Hua Lai
Rok vydání:	2010
Předmět:	Biphenyl Materials science General Chemistry Condensed Matter Physics BPDA Surface energy End-group chemistry.chemical_compound Crystallography chemistry Liquid crystal Diamine Side chain Organic chemistry General Materials Science Polyimide
Zdroj:	Liquid Crystals. 37:149-158
ISSN:	1366-5855 0267-8292
DOI:	10.1080/02678290903420234
Popis:	The side chain structure of polyimides (PIs) exerts an important effect on the pretilt angle of liquid crystal molecules. Three PIs with different side chain structures were prepared based on 3,3′,4,4′-biphenyl dianhydride (BPDA) and 1,3-phenylene diamine (m-PDA), 3,5-diaminobenzoic-4′-biphenyl ester (DABBE) and 4′-(tert-butyldimethylsiloxy) biphenyl-4-yl 3,5-diaminobenzoate (DPA). The surface properties of the PI films and the pretilt angles of the liquid crystal molecules on them were examined with experimental and molecular simulation methods, showing a good agreement between two methods. Molecular simulation showed that the BPDA-DPA system had the lowest surface energy for its side chain enriched on the PI surface, which was driven by the low polar silyl end group of side chain. The phenyl ring in the PI backbone tended to be arranged parallel with the surface, while the phenyl ring in the side chain inclined to align vertical to surface. By incorporation of the biphenyl group and the silyl end group,...
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8686d5a06dc82576ac583aba67c40643 https://doi.org/10.1080/02678290903420234 Zobrazit plný text záznamu