title: Ionic liquid crystalline phases in 3-hexadecylimidazolium bromide and binary mixtures with 1-decanol.
abstract: 3-Hexadecylimidazolium bromide was synthesized and characterized showing formation of thermotropic smectic liquid crystals at temperatures above its melting point from 48.5 to 150.9°C. With decreasing temperature, the peak intensities in XRD patterns increase and full widths at half-maximum decrease, suggesting structural order increases with decreasing temperature. Compared with 1,2-dimethyl-3-hexadecyl-imidazolium bromide and hexafluorophosphate, the IL shows a lower melting point and less degree of chain interdigitation. The main reason is due to a more symmetrical structure and denser assembly of the IL molecules, which results in more steric resistance for the alkyl chain to interdigitate. The self-assembly behavior of the hydrophobic IL in an organic solvent was investigated showing SmA(2) lyotropic liquid crystalline phases. The first-order scattering peak shifts to lower q values with increasing IL content, which is opposite to the shift directions of the binary mixtures of the soluble imidazolium IL and water, indicating a different packing behavior of the hydrophobic IL in 1-decanol.
authors.affiliation: College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen, China. licuihuasz@163.com
authors.forename: Cuihua
authors.initials: C
authors.lastname: Li
authors.forename: Jinhua
authors.initials: J
authors.lastname: He
authors.forename: Jiahui
authors.initials: J
authors.lastname: Chen
authors.forename: Jianhong
authors.initials: J
authors.lastname: Liu
authors.forename: Qianling
authors.initials: Q
authors.lastname: Zhang
authors.forename: Zhenqiang
authors.initials: Z
authors.lastname: Yu