NMR study of a bimesogenic liquid crystal with two nematic phases

Burnell, E. E.; Dong, R. Y.; Kohlmeier, A.; Tamba, M. G.; Welch, C.; Mehl, G. H.

Abstract

Recent interest in bimesogenic liquid crystals showing two nematic phases has led us to investigate the nematic mean-field interactions in these nematic phases by using rigid solutes as probes. The nematic potential that is modelled by two independent Maier-Saupe terms is successful in fitting the observed dipolar couplings (order parameters) of para-, meta- and ortho-dichlorobenzene solutes in both the nematic phases of 39 wt% of 4-n-pentyl-4′-cyanobiphenyl (5CB) in α,ω-bis(4-4′-cyanobiphenyl)nonane (CB_C9_CB) to better than the 5% level. The derived liquid-crystal potential parameters G₁ and G₂ for each solute in the N and Ntb phases will be discussed. The most interesting observation is that G1 (associated with size and shape interactions) is almost constant in the Ntb phase, whereas G₂ (associated with longer-range electrostatic interactions) has large variation, even changing sign.

Citation

Burnell, E. E., Dong, R. Y., Kohlmeier, A., Tamba, M. G., Welch, C., & Mehl, G. H. (2015). NMR study of a bimesogenic liquid crystal with two nematic phases. Molecular crystals and liquid crystals, 610(1), 100-107. https://doi.org/10.1080/15421406.2015.1025211

• Acceptance Date: Jul 1, 2014
• Online Publication Date: Jul 6, 2015
• Publication Date: Mar 24, 2015
• Deposit Date: Sep 2, 2015
• Publicly Available Date: Nov 23, 2017
• Journal: Molecular crystals and liquid crystals
• Print ISSN: 1542-1406
• Electronic ISSN: 1563-5287
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 610
• Issue: 1
• Pages: 100-107
• DOI: https://doi.org/10.1080/15421406.2015.1025211
• Keywords: General Materials Science; General Chemistry; Condensed Matter Physics
• Public URL: https://hull-repository.worktribe.com/output/378599
• Publisher URL: http://www.tandfonline.com/doi/full/10.1080/15421406.2015.1025211#.VebPJyVVhBc
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Molecular Crystals and Liquid Crystals on 6 July 2015, available online: http://wwww.tandfonline.com/10.1080/15421406.2015.1025211.