Light-Driven Reversible Transformation between Self-Organized Simple Cubic Lattice and Helical Superstructure Enabled by a Molecular Switch Functionalized Nanocage

Kang Zhou; Hari Krishna Bisoyi; Jian-Qiu Jin; Cong-Long Yuan; Zhen Liu; Dong Shen; Yan-Qing Lu; Zhi-Gang Zheng; Weian Zhang; Quan Li

doi:10.1002/adma.201800237

Light-Driven Reversible Transformation between Self-Organized Simple Cubic Lattice and Helical Superstructure Enabled by a Molecular Switch Functionalized Nanocage

Adv Mater. 2018 Jun;30(26):e1800237. doi: 10.1002/adma.201800237. Epub 2018 Apr 23.

Authors

Affiliations

¹ Department of Physics, East China University of Science and Technology, Shanghai, 200237, China.
² Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA.
³ Shanghai Key Laboratory of Functional Materials Chemistry, East China University of Science and Technology, Shanghai, 200237, China.
⁴ National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures and Colleague of Engineering and Applied Sciences, Nanjing University, Nanjing, 210093, China.

PMID: 29682817
DOI: 10.1002/adma.201800237

Abstract

Self-organized stimuli-responsive smart materials with adjustable attributes are highly desirable for a plethora of device applications. Simple cubic lattice is quite uncommon in soft condensed matter due to its lower packing factor. Achieving a stable simple cubic soft lattice and endowing such a lattice with dynamic reconstruction capability solely by a facile light irradiation are of paramount significance for both fundamental studies and engineering explorations. Herein, an elegant stable self-organized simple cubic soft lattice, i.e., blue phase II, in a chiral liquid crystal (LC) system is disclosed, which is stable down to room temperature and exhibits both reversible lattice deformation and transformation to a helical superstructure, i.e., cholesteric LC, by light stimulation. Such an amazing trait is attained by doping a judiciously designed achiral photoresponsive molecular switch functionalized polyhedral oligomeric silsesquioxane nanocage into a chiral LC host. An unprecedented reversible collapse and reconstruction of such a high symmetric simple cubic blue phase II driven by light has been achieved. Furthermore, a well-defined conglomerate micropattern composed of simple cubic soft lattice and helical superstructure, which is challenging to fabricate in organic and inorganic crystalline materials, is produced using photomasking technology. Moreover, the promising photonic application based on such a micropattern is demonstrated.

Keywords: 1D helical superstructure; 3D simple cubic lattice; light-driven molecular switch; photoinduced phase transition; stimuli-responsive material.