Direct observation of liquid crystals using cryo-TEM : specimen preparation and low-dose imaging
Gao, Min (Electron microscopist) ; Kim, Young-Ki; Zhang, Cuiyu; Borshch, Volodymyr; Zhou, Shuang; Park, Heung-Shik; Jákli, A. (Antal); Lavrentovich, Oleg D.; Tamba, Maria-Gabriela; Kohlmeier, Alexandra, 1978-; Mehl, Georg H.; Weissflog, Wolfgang; Studer, Daniel Franz; Zuber, Benoît; Gnägi, Helmut; Lin, Fang (Chemist)
Department of Chemistry; Department of Chemistry; Department of Chemistry
Freeze fracture; High-pressure freezing; CEMOVIS; Thermotropic; Lyotropic
2014
Journal article
- Rights
- ©2016 University of Hull
- Abstract
Liquid crystals (LCs) represent a challenging group of materials for direct transmission electron microscopy (TEM) studies due to the complications in specimen preparation and the severe radiation damage. In this paper, we summarize a series of specimen preparation methods, including thin film and cryo-sectioning approaches, as a comprehensive toolset enabling high-resolution direct cryo-TEM observation of a broad range of LCs. We also present comparative analysis using cryo-TEM and replica freeze-fracture TEM on both thermotropic and lyotropic LCs. In addition to the revisits of previous practices, some new concepts are introduced, e.g., suspended thermotropic LC thin films, combined high-pressure freezing and cryo-sectioning of lyotropic LCs, and the complementary applications of direct TEM and indirect replica TEM techniques. The significance of subnanometer resolution cryo-TEM observation is demonstrated in a few important issues in LC studies, including providing direct evidences for the existence of nanoscale smectic domains in nematic bent-core thermotropic LCs, comprehensive understanding of the twist-bend nematic phase, and probing the packing of columnar aggregates in lyotropic chromonic LCs. Direct TEM observation opens ways to a variety of TEM techniques, suggesting that TEM (replica, cryo, and in situ techniques), in general, may be a promising part of the solution to the lack of effective structural probe at the molecular scale in LC studies. Microsc. Res. Tech. 77:754–772, 2014. © 2014 Wiley Periodicals, Inc.
- Publisher
- The University of Hull
- Peer reviewed
- Yes
- Language
- English
- Extent
- 2 MB
- Identifier
- hull:12823
Journal
- Journal title
- Microscopy research and technique
- Publication date
- 2014
- Publisher
- Wiley
- DOI
- 10.1002/jemt.22397
- ISSN (Print)
- 1059-910X
- ISSN (Electronic)
- 1097-0029
- Volume
- 77
- Issue
- 10
- Start page
- 754
- End page
- 772
- Notes
Author's accepted manuscript of article: Gao, M., Kim, Y.-K., Zhang, C., Borshch, V., Zhou, S., Park, H.-S., Jákli, A., Lavrentovich, O. D., Tamba, M.-G., Kohlmeier, A., Mehl, G. H., Weissflog, W., Studer, D., Zuber, B., Gnägi, H. and Lin, F. (2014), Direct observation of liquid crystals using cryo-TEM: Specimen preparation and low-dose imaging. Microsc. Res. Tech., 77: 754–772.
- Link
- Published article