Co-reporter:Wenhuan Yao, Yanzi Gao, Xiao Yuan, Baofeng He, Haifeng Yu, Lanying Zhang, Zhihao Shen, Wanli He, Zhou Yang, Huai Yang and Dengke Yang
Journal of Materials Chemistry A 2016 vol. 4(Issue 7) pp:1425-1440
Publication Date(Web):20 Jan 2016
DOI:10.1039/C5TC04331J
A series of polysiloxane side chain liquid crystal polymers (PSCLCPs) with chiral and achiral substitutions in the side chains, denoted as PMMS-Xchol-n (n = 0, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5 0.6, 0.7. 0.8, 0.9, and 1.0, respectively, the molar content of the chiral cholesteric unit (Xchol) in a specific polymer), were successfully synthesized via thiol–ene click chemistry. The molecular structures of the polymers were confirmed by 1H-NMR, FT-IR, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). Their liquid crystalline (LC) properties and self-assembling behaviors were investigated in detail by a combination of various techniques, such as differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffraction. The results demonstrated that the phase transition behaviour and the self-assembly structure of the polymers were significantly influenced by Xchol and temperatures. With increased Xchol, the clearing points increased significantly, their mesogenic temperature ranges greatly widened, and abundant mesophases developed. Generally, two different types of LC phase structures and three different molecular arrangements were observed, depending on the two LC building blocks. Polymers with Xchol below 0.3 could self-assemble into a smectic E (SmE)-like structure and a single layer smectic A (SmAs) structure upon heating. When Xchol was between 0.4 and 0.7, a single phase structure of a SmAs or a bilayer smectic A (SmAd) could be observed. While for polymers with Xchol over 0.8, a SmAd phase structure was self-organized, further heating led to a SmAs structure. Moreover, when the molar ratio of the chiral group or achiral group was about 0.1, a microphase-separated smectic morphology could be found, indicating that the introduction of a small amount of any components in the copolymers might destroy the well-ordered structures.
Co-reporter:Pengxia Liang;Yongsheng Mi;Jinshuai Duan;Zhou Yang;Dong Wang;Hui Cao;Huai Yang
Chinese Journal of Chemistry 2016 Volume 34( Issue 4) pp:381-386
Publication Date(Web):
DOI:10.1002/cjoc.201500144
Abstract
To investigate photoelectric properties of meso-extended porphyrin derivatives with electron-donating or electron-withdrawing substituents, a series of functionalized porphyrin materials have been designed and synthesized by Suzuki coupling reaction. The meso-extended structures were fully characterized by 1H NMR, IR spectroscopy and mass spectrometry. The photophysical properties of porphyrin derivatives were carefully examined by UV-Visible and fluorescence spectra, and the solvatochromic effect was observed and discussed. In particular, Z-scan technique was employed to characterize the third-order nonlinear optical (NLO) properties of the products such as nonlinear absorption and refraction, the third-order nonlinear refractive indexes ((3)-value) of these porphyrin derivatives achieved 3.9×10−12 esu. In addition, the compounds could be self-assembled into highly organized morphologies through phase-exchange method. All the results indicated that the discotic materials have the potential for optoelectronic applications.
Co-reporter:Xingwu Chen, Ling Wang, Yinjie Chen, Chenyue Li, Guoyan Hou, Xin Liu, Xiaoguang Zhang, Wanli He and Huai Yang
Chemical Communications 2014 vol. 50(Issue 6) pp:691-694
Publication Date(Web):06 Nov 2013
DOI:10.1039/C3CC47438K
A chiral nematic liquid crystal–photopolymerizable monomer–chiral azobenzene compound composite was prepared and then polymerized under UV irradiation. The reflection wavelength of the composite can be extended to cover the 1000–2400 nm range and also be adjusted to the visible light region by controlling the concentration of chiral compounds.
Co-reporter:Wan-Li He, Mei-Ju Wei, Huai Yang, Zhou Yang, Hui Cao and Dong Wang
Physical Chemistry Chemical Physics 2014 vol. 16(Issue 12) pp:5622-5626
Publication Date(Web):2014/01/27
DOI:10.1039/C3CP55150D
Novel cinnamic-acid-derived H-bonded liquid crystals with enantiotropic BP*s were facilely prepared. When simply modifying the donor–acceptor ratio, the proportion of (S)-4-(2-octanyloxy) cinnamic acid to 4-(4-propylcyclohexyl) phenyl isonicotinate, the generated BP temperature ranges were consequentially extended with the widest range of about 10 °C, which is seldom found in enantiotropic BP materials. The optimized results of density-functional-theory calculations show that cinnamic-acid-derived mesogens have a bent shape and thus could be beneficial to stabilize enantiotropic blue phases.
Co-reporter:Xingwu Chen, Ling Wang, Chenyue Li, Jiumei Xiao, Hangjun Ding, Xin Liu, Xiaoguang Zhang, Wanli He and Huai Yang
Chemical Communications 2013 vol. 49(Issue 86) pp:10097-10099
Publication Date(Web):04 Sep 2013
DOI:10.1039/C3CC46117C
A new series of azobenzene-dimers were synthesized and doped into the blue phase liquid crystals to broaden the temperature range of BPs. It is found that not only can the reflection wavelength of BPI be reversibly controlled but BPI can also be transformed into the cholesteric phase owing to isomerization of azobenzene induced by light.
Co-reporter:Xingwu Chen, Ling Wang, Chenyue Li, Jiumei Xiao, Hangjun Ding, Xin Liu, Xiaoguang Zhang, Wanli He and Huai Yang
Chemical Communications 2013 - vol. 49(Issue 86) pp:NaN10099-10099
Publication Date(Web):2013/09/04
DOI:10.1039/C3CC46117C
A new series of azobenzene-dimers were synthesized and doped into the blue phase liquid crystals to broaden the temperature range of BPs. It is found that not only can the reflection wavelength of BPI be reversibly controlled but BPI can also be transformed into the cholesteric phase owing to isomerization of azobenzene induced by light.
Co-reporter:Wenhuan Yao, Yanzi Gao, Xiao Yuan, Baofeng He, Haifeng Yu, Lanying Zhang, Zhihao Shen, Wanli He, Zhou Yang, Huai Yang and Dengke Yang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 7) pp:NaN1440-1440
Publication Date(Web):2016/01/20
DOI:10.1039/C5TC04331J
A series of polysiloxane side chain liquid crystal polymers (PSCLCPs) with chiral and achiral substitutions in the side chains, denoted as PMMS-Xchol-n (n = 0, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5 0.6, 0.7. 0.8, 0.9, and 1.0, respectively, the molar content of the chiral cholesteric unit (Xchol) in a specific polymer), were successfully synthesized via thiol–ene click chemistry. The molecular structures of the polymers were confirmed by 1H-NMR, FT-IR, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). Their liquid crystalline (LC) properties and self-assembling behaviors were investigated in detail by a combination of various techniques, such as differential scanning calorimetry (DSC), polarized optical microscopy (POM), and X-ray diffraction. The results demonstrated that the phase transition behaviour and the self-assembly structure of the polymers were significantly influenced by Xchol and temperatures. With increased Xchol, the clearing points increased significantly, their mesogenic temperature ranges greatly widened, and abundant mesophases developed. Generally, two different types of LC phase structures and three different molecular arrangements were observed, depending on the two LC building blocks. Polymers with Xchol below 0.3 could self-assemble into a smectic E (SmE)-like structure and a single layer smectic A (SmAs) structure upon heating. When Xchol was between 0.4 and 0.7, a single phase structure of a SmAs or a bilayer smectic A (SmAd) could be observed. While for polymers with Xchol over 0.8, a SmAd phase structure was self-organized, further heating led to a SmAs structure. Moreover, when the molar ratio of the chiral group or achiral group was about 0.1, a microphase-separated smectic morphology could be found, indicating that the introduction of a small amount of any components in the copolymers might destroy the well-ordered structures.
Co-reporter:Wan-Li He, Mei-Ju Wei, Huai Yang, Zhou Yang, Hui Cao and Dong Wang
Physical Chemistry Chemical Physics 2014 - vol. 16(Issue 12) pp:NaN5626-5626
Publication Date(Web):2014/01/27
DOI:10.1039/C3CP55150D
Novel cinnamic-acid-derived H-bonded liquid crystals with enantiotropic BP*s were facilely prepared. When simply modifying the donor–acceptor ratio, the proportion of (S)-4-(2-octanyloxy) cinnamic acid to 4-(4-propylcyclohexyl) phenyl isonicotinate, the generated BP temperature ranges were consequentially extended with the widest range of about 10 °C, which is seldom found in enantiotropic BP materials. The optimized results of density-functional-theory calculations show that cinnamic-acid-derived mesogens have a bent shape and thus could be beneficial to stabilize enantiotropic blue phases.
Co-reporter:Wan-Li He, Wei-Kai Zhang, Huan Xu, Li-Hao Li, Zhou Yang, Hui Cao, Dong Wang, Zhi-Gang Zheng and Huai Yang
Physical Chemistry Chemical Physics 2016 - vol. 18(Issue 42) pp:NaN29032-29032
Publication Date(Web):2016/10/05
DOI:10.1039/C6CP05421H
The magnetic Fe3O4 nanoparticle-doped blue phase liquid crystal (BPLC) was found to have a relatively strong contrast ratio in magnetic-addressed display performance compared to the composites in other phases; this is a new application of the BPLC and a way to prepare a new type of power-free magnetically-driven LC flexible display.
Co-reporter:Xingwu Chen, Ling Wang, Yinjie Chen, Chenyue Li, Guoyan Hou, Xin Liu, Xiaoguang Zhang, Wanli He and Huai Yang
Chemical Communications 2014 - vol. 50(Issue 6) pp:NaN694-694
Publication Date(Web):2013/11/06
DOI:10.1039/C3CC47438K
A chiral nematic liquid crystal–photopolymerizable monomer–chiral azobenzene compound composite was prepared and then polymerized under UV irradiation. The reflection wavelength of the composite can be extended to cover the 1000–2400 nm range and also be adjusted to the visible light region by controlling the concentration of chiral compounds.