journal article·2019-10-30

Cholesteric Flakes in Motion Driven by the Elastic Force from Nematic Liquid Crystals

Wei Liu, Yong Zhou, Sunqian Liu, Wan Shao, Dirk J. Broer, Guofu Zhou, Dong Yuan, Danqing Liu

ACS Applied Materials & Interfaces· Volume 11· Issue 43
Publisher page

Abstract

The paper presents a methodology to control the motion and orientation of suspended reflective cholesteric flakes in a nematic liquid crystal (LC) matrix. The flakes exhibit a dielectric anisotropy which controls their alignment with their in-plane axes parallel to an external electrical dc field. The elastic forces imposed by the LC host affect the switching behavior of the flakes and take care of the realignment to the planar state as soon as the dc field is switched off. When the LC host has a positive dielectric anisotropy, the switching voltage of the flakes is reduced by a factor of 2 in comparison with a LC host with negative dielectric anisotropy or in comparison with an isotropic host. We discovered that the LC host further regulates the back relaxation of cholesteric to return to the planar state upon retrieving the electric field. Whereas, in the isotropic fluid, flakes do not exhibit a preferred orientation when relaxed. Based on this newly proposed principle, we demonstrated its application as an optical switch for smart windows. Depending on the pitch of the cholesteric helix of the flakes, the light of a preset wavelength is reflected. Upon application of an electric field, the embedded flakes rotate their planes perpendicular to the substrate and consequently the incident light becomes fully transmitted without reflection or scattering of light.
Source: openalex_inverted_index · Quality: baseline

Research context

OpenAlex topics: Post-Soviet Geopolitical Dynamics

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

SCNU-TUE Joint Lab of Device Integrated Responsive Materials (DIRM), National Center for International Research on Green Optoelectronics, Guangzhou Higher Education Mega Center, South China Normal University, No 378, West Waihuan Road, Guangzhou 510006, China

Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute of Electronic Paper Displays, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, P. R. China

Stimuli-responsive Functional Materials and Devices (SFD), Eindhoven University of Technology, Groene Loper 5, Eindhoven 5612 AE, The Netherlands

Funding

Guangdong Province Introduction of Innovative R&D Team · State Administration of Foreign Experts Affairs · Ministry of Education of the People's Republic of China · National Natural Science Foundation of China · H2020 European Research Council · Nederlandse Organisatie voor Wetenschappelijk Onderzoek · Guangdong Province · International Laboratory for Optical Information Technologies, South China Academy of Advanced Optoelectronics, South China Normal University · Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Acadamy of Advanced Optoelectronics, South China Normal University

References (36)

Show source-provided references
1. 10.1016/j.enbuild.2013.06.00610.1016/j.enbuild.2013.06.006 ↗
2. Atkinson, J. W. Window Greenhouse. U.S. Patent 4,038,791A, Aug 2, 1977.
3. 10.1049/ir:2005040410.1049/ir:20050404 ↗
4. 10.1016/j.solmat.2016.08.02610.1016/j.solmat.2016.08.026 ↗
5. 10.1016/j.solmat.2009.08.02110.1016/j.solmat.2009.08.021 ↗
6. 10.1002/pssr.20080218610.1002/pssr.200802186 ↗
7. 10.1039/c5ra08172f10.1039/c5ra08172f ↗
8. 10.1039/c3ra44397c10.1039/c3ra44397c ↗
9. 10.1021/jp804490b10.1021/jp804490b ↗
10. 10.1080/02678292.2016.126206910.1080/02678292.2016.1262069 ↗
11. 10.1364/ome.5.00121710.1364/ome.5.001217 ↗
12. 10.1103/physreve.58.459410.1103/physreve.58.4594 ↗
13. 10.1080/1058725960803876610.1080/10587259608038766 ↗
14. 10.1063/1.10676510.1063/1.106765 ↗
15. 10.1143/apex.3.02170210.1143/apex.3.021702 ↗
16. 10.1063/1.35851810.1063/1.358518 ↗
17. 10.1016/j.optmat.2015.12.03310.1016/j.optmat.2015.12.033 ↗
18. 10.1364/oe.18.00017310.1364/oe.18.000173 ↗
19. 10.1002/adfm.20170743610.1002/adfm.201707436 ↗
20. 10.1364/ao.55.00850610.1364/ao.55.008506 ↗
21. 10.1021/acs.jpcb.6b0508010.1021/acs.jpcb.6b05080 ↗
22. Taheri B. · 2010 · 7618 · 76180W
23. 10.1023/a:101844840724210.1023/a:1018448407242 ↗
24. 10.1016/j.enbuild.2006.03.01110.1016/j.enbuild.2006.03.011 ↗
25. Kosc, T. Z. Motion of Polymer Cholesteric Liquid Crystal Flakes in an Electric Field. Ph.D. Dissertation, University of Rochester, Rochester, NY, 2003.
26. Cox, G. P. Microencapsulation Effects on the Electro-Optical Behavior of Polymer Cholesteric Liquid Crystal Flakes. Ph.D. Dissertation, University of Rochester, Rochester, NY, 2009.10.1063/1.3272106 ↗
27. 10.1063/1.194422110.1063/1.1944221 ↗
28. 10.1063/1.508398010.1063/1.5083980 ↗
29. 10.1107/s0365110x5100075110.1107/s0365110x51000751 ↗
30. 10.1080/1058725980804711610.1080/10587259808047116 ↗
31. 10.1039/c2sm26228b10.1039/c2sm26228b ↗
32. 10.1002/adma.20030619610.1002/adma.200306196 ↗
33. 10.1364/oe.21.01986710.1364/oe.21.019867 ↗
34. 10.3390/nano709025010.3390/nano7090250 ↗
35. 10.1039/c7sm00535k10.1039/c7sm00535k ↗
36. 10.1002/adfm.20040028610.1002/adfm.200400286 ↗