Article
Materials Science, Multidisciplinary
Ping Yu, Xianliang Chen, Jianjing Gao, Ruijuan Yao, Cheng Ma, Cuihong Zhang, Haiquan Zhang, Zongcheng Miao
Summary: In this paper, polymer-stabilized cholesteric liquid crystal (PSCLC) films with broadband reflection were fabricated using photomask polymerization. The formation of a gradient of UV light intensity in the upper part of the liquid crystal cell perpendicular to the glass substrate induced the formation of a pitch gradient due to the small hole diffraction effect of light. By studying the concentration of polymerizable monomers, temperature, time, and UV light intensity, the optimal experimental conditions for the reflection bandwidth were obtained. The results showed that the reflectance bandwidth was broadened from 293 nm to 508 nm. The method offers a simple preparation process, effective broadening of reflection bandwidth, and reusability, providing new practical guidance for the preparation of PSCLC films with broadband reflectance.
Article
Chemistry, Applied
Huimin Zhang, Jie Liu, Xiangrong Zhao, Jianjing Gao, Cheng Ma, Yang Zhao, Ruijuan Yao, Zongcheng Miao, Wenbo Shen
Summary: This work presents a novel method for preparing polymer-stabilized cholesteric liquid crystal films with broadband reflection capability and achieving electrically induced coloration. The results show that these films can change from a colorless state to a colored state under low voltage.
Article
Energy & Fuels
Amid Ranjkesh, Yeongyu Choi, Jae-Won Huh, Seung-Won Oh, Tae-Hoon Yoon
Summary: A flexible cholesteric liquid crystal (CLC) polymer reflector is proposed in this study to selectively control the reflection of infrared (IR) light, effectively lowering indoor temperature. The fabricated IR reflector demonstrates thinness, high mechanical stability, flexibility, durability, resistance to solvents and acids, high transparency, and low haze in visible light. This innovative approach shows promise for applications in anti-IR devices, energy-saving windows for cars, and modern building facades.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2021)
Article
Materials Science, Multidisciplinary
Yuzhen Zhao, Huimin Zhang, Zhun Guo, Yang Zhao, Zemin He, Jianjing Gao, Cheng Ma, Yuduo Wang, Zongcheng Miao
Summary: By controlling the polymerization and diffusion processes, broadband reflective PSCLC films were fabricated. The dissolved photoinitiator caused regional differences in polymerization rate, resulting in non-uniform pitch distribution.
Article
Chemistry, Multidisciplinary
Weiting Shi, Xuetao Zhang, Rui Han, Hui Li, Hui Cao, Yinjie Chen, Dong Wang, Zhou Yang, Wanli He
Summary: The study presents the preparation of a polymer network using a broadband reflective cholesteric liquid crystal (CLC) film through a washing out method. It demonstrates the selective reflection property and broadband reflection memory effect of the polymer network, while also showing that different LC fillers can affect the initial reflection bandwidth of CLCs. Refilling the polymer network with different LCs results in reflective bands with different central wavelengths and bandwidths.
Article
Polymer Science
Xiaoyu Jin, Yuning Hao, Zhuo Su, Ming Li, Guofu Zhou, Xiaowen Hu
Summary: In this study, an electrically switchable window based on polymer stabilized cholesteric liquid crystals (PSCLCs) is presented. The window allows dynamic transmission of both visible light and infrared (IR) light by adjusting the transmittance through vertical alternating current electric field. The transmittance of visible light decreases from 90% to less than 15% when the cholesteric liquid crystals (CLC) switches to a scattering focal conic state, while the infrared reflection bandwidth can be tuned by applying an in-plane interdigital direct current (DC) electric field.
Article
Chemistry, Multidisciplinary
Yuzhen Zhao, Tingting Lang, Yaqin Chu, Chaonian Li, Yang Zhao, Huimin Zhang, Zhun Guo, Zongcheng Miao, Dong Wang
Summary: A new method for constructing polymer-stabilized cholesteric liquid crystal films with broadband reflection in the NIR region has been proposed. This method utilizes chiral dopant-loaded mesoporous polystyrene-divinylbenzene microspheres. The diffusion of the chiral dopant and the polymerization process were controlled to achieve an optimized reflection bandwidth of 860 nm, which has potential applications in smart windows and military infrared shielding devices.
Article
Biochemistry & Molecular Biology
Yutong Liu, Rui Han, Xiaohui Zhao, Yue Cao, Hui Cao, Yinjie Chen, Zhou Yang, Dong Wang, Wanli He
Summary: This paper focuses on the preparation of broadband reflective liquid crystal films using monofunctional and bifunctional monomers through diffusion in a photoinduced trilayer system. By combining different liquid crystal surface treatment technologies, a liquid crystal composite system is formed, and the gradient distribution of liquid crystal pitch is achieved through the difference in polymerization rates between monofunctional and bifunctional monomers, resulting in an extended reflective range.
Article
Chemistry, Multidisciplinary
Hongbo Lu, Qi Wang, Mengmeng Zhu, Peng Huang, Miao Xu, Longzhen Qiu, Jun Zhu
Summary: An electrically controllable reflection bandwidth polymer-stabilised cholesteric liquid crystals (PSCLCs) with low operating voltage is developed and studied in this research. The influence of crosslink density of the polymer network on the bandwidth expansion and the ability of the polymer network to trap ionic impurities under direct-current (DC) electric fields are investigated. The compatibility between the polymer and liquid crystals and the motion of soft segments under DC electric field are found to be correlated with nonideal optical properties in some samples.
Article
Chemistry, Physical
Wan-Li He, Ya-Qian Zhang, Wen-Tuo Hu, Hui-Min Zhou, Zhou Yang, Hui Cao, Dong Wang
Summary: In this study, a liquid crystal composite material was developed for tuning the reflective bands. By doping specific compounds, the reflective bands can be adjusted by tuning the electric field parameters. The effects of electric field frequency, voltage, retention time, and molecular structure on the reflection bandwidth were investigated in detail.
Article
Chemistry, Multidisciplinary
Ping Gan, Xuetao Zhang, Limin Zhao, Weiting Shi, Hui Cao, Huihui Wang, Zhou Yang, Dong Wang, Wanli He
Summary: Broadband reflective films were prepared by thermal diffusion of zinc oxide nanoparticles in chiral nematic liquid crystals, with UV light inducing pitch gradients. The study showed that the content of ZnO NPs and UV intensity affect the reflective bandwidth. Observations with SEM and theoretical analysis were used to explore the experimental conditions' impact on the broadband reflection performance of the films.
Article
Chemistry, Multidisciplinary
Ya-Ru Ma, Xue-Song Zhang, Xuan Xie, Yue-Jiao Huang, Xiao-Zhi He, Yue-Hua Cong, Bao-Yan Zhang, Ying-Gang Jia
Summary: A series of side-chain cholesteric liquid-crystal polymers were synthesized in this study, showing excellent thermal stability and a wide range of mesophases. As the content of a specific monomer increased, colorful Grandjean textures and good selective reflection were observed.
Article
Nanoscience & Nanotechnology
Runwei Yu, Yu Cao, Kai Chen, Yi Li, Wei Liu, Baozong Li, Hongkun Li, Yonggang Yang
Summary: In this study, photochromic CLC mixtures were prepared by adding a photoisomerizable chiral additive and a photoinitiator in the liquid crystal, and the effect of oxygen inhibition on photopolymerization was investigated. The results lay the foundations for preparing colorful-patterned polymer-stabilized cholesteric liquid crystal films.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Zhaozhong Li, Ruochen Lan, Jinying Bao, Wei Hu, Meng Wang, Lanying Zhang, Huai Yang
Summary: In this study, electric-field-driven systems with tunable circularly polarized luminescence (CPL) signals were fabricated using polymer-stabilized cholesteric liquid crystal (PSChLC) doping by fluorescent molecules. The possible mechanism of this phenomenon and the variation of CPL signals and g(lum) values induced by the applied electric field were discussed. The research demonstrates the potential of the novel materials in the design and preparation of CPL-emitting devices with electrically tunable CPL intensity and g(lum).
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Runwei Yu, Yu Cao, Kai Chen, Yi Li, Wei Liu, Baozong Li, Hongkun Li, Yonggang Yang
Summary: This study successfully prepared photochromic cholesteric liquid crystal mixtures by adding a photoisomerizable chiral additive and a photoinitiator in the nematic liquid crystal. The effects of oxygen inhibition and UV irradiation on the reaction were investigated, and the foundations for preparing colorful-patterned polymer-stabilized cholesteric liquid crystal films were laid.
ACS APPLIED MATERIALS & INTERFACES
(2022)
