Polymers 2017, 9(7), 295; https://doi.org/10.3390/polym9070295
Light-Driven Rotation and Pitch Tuning of Self-Organized Cholesteric Gratings Formed in a Semi-Free Film
Ling-Ling Ma 1, Wei Duan 1, Ming-Jie Tang 1, Lu-Jian Chen 2, Xiao Liang 3, Yan-Qing Lu 1 and Wei Hu 1,*
1
National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures and College of Engineering and Applied Sciences, Nanjing University, Nanjing 210093, China
2
Department of Electronic Engineering, School of Information Science and Engineering, Xiamen University, Xiamen 361005, China
3
Department of Chemistry, Tsinghua University, Beijing 100084, China
*
Author to whom correspondence should be addressed.
Received: 29 June 2017 / Revised: 18 July 2017 / Accepted: 19 July 2017 / Published: 21 July 2017
(This article belongs to the Special Issue Photo-Responsive Polymers)
Abstract
Cholesteric liquid crystal (CLC) has attracted intensive attention due to its ability to form a periodic helical structure with broad tunability. CLC gratings in open systems are especially promising in sensing and micromanipulation. However, there is still much to learn about the inherent mechanism of such gratings. We investigate the light-driven rotation and pitch-tuning behaviors of CLC gratings in semi-free films which are formed by spin-coating the CLC mixtures onto planarly photoaligned substrates. The doped azobenzene chiral molecular switch supplies great flexibility to realize the continuous grating rotation. The maximum continuous rotational angle reaches 987.8°. Moreover, dependencies of light-driven rotation and pitch tuning on the dopant concentration and exposure are studied. The model of director configuration in the semi-free film is constructed. Precise beam steering and synchronous micromanipulation are also demonstrated. Our work may provide new opportunities for the CLC grating in applications of beam steering, micromanipulation, and sensing. View Full-TextKeywords:
cholesteric liquid crystal; photoalignment; light-driven; isomerization; beam steering; micromanipulation; self-assembly; semi-free film
▼
Figures
Graphical abstract
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
Share & Cite This Article
MDPI and ACS Style
Ma, L.-L.; Duan, W.; Tang, M.-J.; Chen, L.-J.; Liang, X.; Lu, Y.-Q.; Hu, W. Light-Driven Rotation and Pitch Tuning of Self-Organized Cholesteric Gratings Formed in a Semi-Free Film. Polymers 2017, 9, 295.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.
Related Articles
Article Metrics
Comments
[Return to top]
Polymers
EISSN 2073-4360
Published by MDPI AG, Basel, Switzerland
RSS
E-Mail Table of Contents Alert