Distinct differences in the nanoscale behaviors of the twist-bend liquid crystal phase of a flexible linear trimer and homologous dimer

Autor: Tuchband, MR, Paterson, DA, Salamończyk, M, Norman, VA, Scarbrough, AN, Forsyth, E, Garcia, E, Wang, C, Storey, JMD, Walba, DM, Sprunt, S, Jákli, A, Zhu, C, Imrie, CT, Clark, NA
Rok vydání: 2019
Předmět:
Zdroj: Proceedings of the National Academy of Sciences of the United States of America, vol 116, iss 22
Tuchband, Michael R; Paterson, Daniel A; Salamończyk, Mirosław; Norman, Victoria A; Scarbrough, Alyssa N; Forsyth, Ewan; et al.(2019). Distinct differences in the nanoscale behaviors of the twist-bend liquid crystal phase of a flexible linear trimer and homologous dimer.. Proceedings of the National Academy of Sciences of the United States of America, 116(22), 10698-10704. doi: 10.1073/pnas.1821372116. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/7q1632g2
ISSN: 0027-8424
DOI: 10.1073/pnas.1821372116.
Popis: We synthesized the liquid crystal dimer and trimer members of a series of flexible linear oligomers and characterized their microscopic and nanoscopic properties using resonant soft x-ray scattering and a number of other experimental techniques. On the microscopic scale, the twist-bend phases of the dimer and trimer appear essentially identical. However, while the liquid crystal dimer exhibits a temperature-dependent variation of its twist-bend helical pitch varying from 100 - 170 {\AA} on heating, the trimer exhibits an essentially temperature-independent pitch of 66 {\AA}, significantly shorter than those reported for other twist-bend forming materials in the literature. We attribute this to a specific combination of intrinsic conformational bend of the trimer molecules and a sterically favorable intercalation of the trimers over a commensurate fraction (two-thirds) of the molecular length. We develop a geometric model of the twist-bend phase for these materials with the molecules arranging into helical chain structures, and we fully determine their respective geometric parameters.
Comment: supplemental information included
Databáze: OpenAIRE