Journal article
EPR Study of Order and Dynamics of the 5CB Liquid Crystal in an H-PDLC Device
Molecular crystals and liquid crystals (Philadelphia, Pa. : 2003), v 558(1)
30 May 2012
Abstract
We have studied the effects of confinement on the order and dynamics of the 5CB liquid crystal (LC) inside nanosized droplets of a reflection-mode holographic-polymer dispersed LC (H-PDLC) device, consisting of alternating LC nanodroplets and polymer layers, forming a diffraction grating. Here we have investigated, taking advantage of the high sensitivity of the EPR spin probe technique, a series of temperatures spanning the nematic and isotropic phase of the LC. The occurrence of phase separation and the consequent formation of a diffraction grating was revealed by SEM images of the H-PDLC cross section and by the presence of a reflection peak around 565 nm. Differently from the case of BL038 LC based H-PDLCs, the results here indicate the absence of an ordered fraction of mesogens throughout the analysed temperature range. Taking into account a previous model of LC molecules arrangement in the same kind of device [Bacchiocchi, C., et al. (2009). J. Phys. Chem. B 113, 5391], we postulate the presence of very small droplets in which the surface anchoring constraints represent the dominant effect. This results in the hindrance of the LC uniform macroscopic alignment, providing a plausible explanation for the malfunctioning of these devices.
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Details
- Title
- EPR Study of Order and Dynamics of the 5CB Liquid Crystal in an H-PDLC Device
- Creators
- Corrado Bacchiocchi - University of CamerinoIsabella Miglioli - University of BolognaAlberto Arcioni - University of BolognaKashma Rai - Drexel UniversityAdam Fontecchio - Drexel UniversityClaudio Zannoni - University of Bologna
- Publication Details
- Molecular crystals and liquid crystals (Philadelphia, Pa. : 2003), v 558(1)
- Publisher
- Taylor & Francis Group
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Electrical and Computer Engineering
- Web of Science ID
- WOS:000303232600016
- Scopus ID
- 2-s2.0-84860494012
- Other Identifier
- 991019168898804721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- International collaboration
- Web of Science research areas
- Chemistry, Multidisciplinary
- Crystallography
- Materials Science, Multidisciplinary