Content of SPECIAL TOPIC—Physical research in liquid crystal in our journal

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    Random lasing from dye-doped negative liquid crystals using ZnO nanoparticles as tunable scatters
    Long-Wu Li(李龙武), Zhen-Zhen Shang(尚真真), Luogen Deng(邓罗根)
    Chin. Phys. B, 2016, 25 (9): 090301.   DOI: 10.1088/1674-1056/25/9/090301
    Abstract640)   HTML    PDF (1620KB)(439)      
    This work demonstrates the realization of a lasing in scattering media, which contains dispersive solution of ZnO nanoparticles (NPs) and laser dye 4-dicyanomethylene-2-methyle-6-(p-dimethylaminostyryl)-4H-pyran(DCM) in negative liquid crystals (LCs) that was injected into a cell. The lasing intensity of the dye-doped negative LC laser can be tuned from low to high if the NPs concentration is increased. The tunability of the laser is attributable to the clusters-sensitive feature in effective refractive index of the negative LCs. Such a tunable negative liquid crystal laser can be used in the fabrication of new optical sources, optical communication, and liquid crystal laser displays.
    Influence of amphotericin B on liquid crystal state of the Cholesterol/Dipalmitoylphosphatidylcholine monolayer in the presence of different metal cations
    Juan Wang(王娟), Rui-Xin Shi(史瑞新), Run-Guang Sun(孙润广), Chang-Chun Hao(郝长春), Jun-Hua Li(李俊花), Xiao-Long Lu(逯晓龙)
    Chin. Phys. B, 2016, 25 (9): 090505.   DOI: 10.1088/1674-1056/25/9/090505
    Abstract519)   HTML    PDF (1145KB)(495)      
    Amphotericin B is a very effective antifungal drug, but it has an adverse reaction to the membrane of mammals' cells. The interaction between AmB and cholesterol (Chol) causes the formation of pores on the membrane to destroy its integrity. In particular, AmB has a significant effect on the permeability of membrane for K+ ions. It has been reported that Na+ ions and Ca2+ ions may have some influence on the interaction between amphotericin B and lipid molecules. In this work, the effects of these metal cations on the physical state and intermolecular interaction of the Cholesterol/ Dipalmitoylphosphatidylcholine (Chol/DPPC) monolayer with and without AmB have been investigated. The addition of AmB induces the change of physical state of the lipid monolayer from liquid-gel phase to liquid phase. Different metal cations could influence the phase transition of the AmB-lipid monolayer. The K+ ions and Ca2+ ions make the obvious phase transition disappear. However, the presence of Na+ ions has little influence on the phase transition of the AmB-lipid monolayer. The addition of AmB and the presence of different metal cations weaken the attractive force on the monolayers. After addition of AmB, the force between the molecules is the strongest in the environment of K+ ions, thus is the weakest in the environment of Ca2+ ions, which may be due to the distribution of these metal cations inside and outside of cells. A large number of K+ ions distribute inside of the cells, thus most of Na+ and Ca2+ ions exist out of the cells. Hence, it may be possible that when AmB molecules are out of the cells, the reaction between the drug and lipid molecules is weaker than that inside the cells. These results may have a great reference value for further studying the toxicity mechanism of AmB and the influence of metal cations on the membrane.
    Behavior of lysozyme adsorbed onto biological liquid crystal lipid monolayer at the air/water interface
    Xiaolong Lu(逯晓龙), Ruixin Shi(史瑞新), Changchun Hao(郝长春), Huan Chen(陈欢), Lei Zhang(张蕾), Junhua Li(李俊花), Guoqing Xu(徐国庆), Runguang Sun(孙润广)
    Chin. Phys. B, 2016, 25 (9): 090506.   DOI: 10.1088/1674-1056/25/9/090506
    Abstract730)   HTML    PDF (1303KB)(374)      
    The interaction between proteins and lipids is one of the basic problems of modern biochemistry and biophysics. The purpose of this study is to compare the penetration degree of lysozyme into 1,2-diapalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethano-lamine (DPPE) by analyzing the data of surface pressure-area (π-A) isotherms and surface pressure-time (π-T) curves. Lysozyme can penetrate into both DPPC and DPPE monolayers because of the increase of surface pressure at an initial pressure of 15 mN/m. However, the changes of DPPE are larger than DPPC, indicating stronger interaction of lysozyme with DPPE than DPPC. The reason may be due to the different head groups and phase state of DPPC and DPPE monolayers at the surface pressure of 15 mN/m. Atomic force microscopy reveals that lysozyme was absorbed by DPPC and DPPE monolayers, which leads to self-aggregation and self-assembly, forming irregular multimers and conical multimeric. Through analysis, we think that the process of polymer formation is similar to the aggregation mechanism of amyloid fibers.
    Analysis of the induction of the myelin basic protein binding to the plasma membrane phospholipid monolayer
    Lei Zhang(张蕾), Changchun Hao(郝长春), Ying Feng(冯盈), Feng Gao(高峰), Xiaolong Lu(逯晓龙), Junhua Li(李俊花), Runguang Sun(孙润广)
    Chin. Phys. B, 2016, 25 (9): 090507.   DOI: 10.1088/1674-1056/25/9/090507
    Abstract568)   HTML    PDF (1418KB)(429)      
    Myelin basic protein (MBP) is an essential structure involved in the generation of central nervous system (CNS) myelin. Myelin shape has been described as liquid crystal structure of biological membrane. The interactions of MBP with monolayers of different lipid compositions are responsible for the multi-lamellar structure and stability of myelin. In this paper, we have designed MBP-incorporated model lipid monolayers and studied the phase behavior of MBP adsorbed on the plasma membrane at the air/water interface by thermodynamic method and atomic force microscopy (AFM). By analyzing the pressure-area (π-A) and pressure-time (π-T) isotherms, univariate linear regression equation was obtained. In addition, the elastic modulus, surface pressure increase, maximal insertion pressure, and synergy factor of monolayers were detected. These parameters can be used to modulate the monolayers binding of protein, and the results show that MBP has the strongest affinity for 1,2-dipalmitoyl-sn-glycero-3- phosphoserine (DPPS) monolayer, followed by DPPC/DPPS mixed and 1,2-dipalmitoyl-sn-glycero-3-phospho-choline (DPPC) monolayers via electrostatic and hydrophobic interactions. AFM images of DPPS and DPPC/DPPS mixed monolayers in the presence of MBP (5 nM) show a phase separation texture at the surface pressure of 20 mN/m and the incorporation of MBP put into the DPPC monolayers has exerted a significant effect on the domain structure. MBP is not an integral membrane protein but, due to its positive charge, interacts with the lipid head groups and stabilizes the membranes. The interaction between MBP and phospholipid membrane to determine the nervous system of the disease has a good biophysical significance and medical value.
    High signal-to-noise ratio sensing with Shack-Hartmann wavefront sensor based on auto gain control of electron multiplying CCD
    Zhao-Yi Zhu(朱召义), Da-Yu Li(李大禹), Li-Fa Hu(胡立发), Quan-Quan Mu(穆全全), Cheng-Liang Yang(杨程亮), Zhao-Liang Cao(曹召良), Li Xuan(宣丽)
    Chin. Phys. B, 2016, 25 (9): 090702.   DOI: 10.1088/1674-1056/25/9/090702
    Abstract859)   HTML    PDF (1745KB)(278)      
    High signal-to-noise ratio can be achieved with the electron multiplying charge-coupled-device (EMCCD) applied in the Shack-Hartmann wavefront sensor (S-H WFS) in adaptive optics (AO). However, when the brightness of the target changes in a large scale, the fixed electron multiplying (EM) gain will not be suited to the sensing limitation. Therefore an auto-gain-control method based on the brightness of light-spots array in S-H WFS is proposed in this paper. The control value is the average of the maximum signals of every light spot in an array, which has been demonstrated to be kept stable even under the influence of some noise and turbulence, and sensitive enough to the change of target brightness. A goal value is needed in the control process and it is predetermined based on the characters of EMCCD. Simulations and experiments have demonstrated that this auto-gain-control method is valid and robust, the sensing SNR reaches the maximum for the corresponding signal level, and especially is greatly improved for those dim targets from 6 to 4 magnitude in the visual band.
    Phase-only stereoscopic hologram calculation based on Gerchberg-Saxton iterative algorithm
    Xinyi Xia(夏心怡), Jun Xia(夏军)
    Chin. Phys. B, 2016, 25 (9): 094204.   DOI: 10.1088/1674-1056/25/9/094204
    Abstract934)   HTML    PDF (1165KB)(472)      
    A phase-only computer-generated holography (CGH) calculation method for stereoscopic holography is proposed in this paper. The two-dimensional (2D) perspective projection views of the three-dimensional (3D) object are generated by the computer graphics rendering techniques. Based on these views, a phase-only hologram is calculated by using the Gerchberg-Saxton (GS) iterative algorithm. Comparing with the non-iterative algorithm in the conventional stereoscopic holography, the proposed method improves the holographic image quality, especially for the phase-only hologram encoded from the complex distribution. Both simulation and optical experiment results demonstrate that our proposed method can give higher quality reconstruction comparing with the traditional method.
    Holographic storage of three-dimensional image and data using photopolymer and polymer dispersed liquid crystal films
    Hong-Yue Gao(高洪跃), Pan Liu(刘攀), Chao Zeng(曾超), Qiu-Xiang Yao(姚秋香), Zhiqiang Zheng(郑志强), Jicheng Liu(刘吉成), Huadong Zheng(郑华东), Ying-Jie Yu(于瀛洁), Zhen-Xiang Zeng(曾震湘), Tao Sun(孙涛)
    Chin. Phys. B, 2016, 25 (9): 094205.   DOI: 10.1088/1674-1056/25/9/094205
    Abstract539)   HTML    PDF (1732KB)(387)      
    We present holographic storage of three-dimensional (3D) images and data in a photopolymer film without any applied electric field. Its absorption and diffraction efficiency are measured, and reflective analog hologram of real object and image of digital information are recorded in the films. The photopolymer is compared with polymer dispersed liquid crystals as holographic materials. Besides holographic diffraction efficiency of the former is little lower than that of the latter, this work demonstrates that the photopolymer is more suitable for analog hologram and big data permanent storage because of its high definition and no need of high voltage electric field. Therefore, our study proposes a potential holographic storage material to apply in large size static 3D holographic displays, including analog hologram displays, digital hologram prints, and holographic disks.
    Random lasing in dye-doped polymer dispersed liquid crystal film
    Rina Wu(乌日娜), Rui-xin Shi(史瑞新), Xiaojiao Wu(邬小娇), Jie Wu(吴杰), Qin Dai(岱钦)
    Chin. Phys. B, 2016, 25 (9): 094209.   DOI: 10.1088/1674-1056/25/9/094209
    Abstract607)   HTML    PDF (1192KB)(823)      
    A dye-doped polymer-dispersed liquid crystal film was designed and fabricated, and random lasing action was studied. A mixture of laser dye, nematic liquid crystal, chiral dopant, and PVA was used to prepare the dye-doped polymer-dispersed liquid crystal film by means of microcapsules. Scanning electron microscopy analysis showed that most liquid crystal droplets in the polymer matrix ranged from 30 μm to 40 μm, the size of the liquid crystal droplets was small. Under frequency doubled 532 nm Nd:YAG laser-pumped optical excitation, a plurality of discrete and sharp random laser radiation peaks could be measured in the range of 575-590 nm. The line-width of the lasing peak was 0.2 nm and the threshold of the random lasing was 9 mJ. Under heating, the emission peaks of random lasing disappeared. By detecting the emission light spot energy distribution, the mechanism of radiation was found to be random lasing. The random lasing radiation mechanism was then analyzed and discussed. Experimental results indicated that the size of the liquid crystal droplets is the decisive factor that influences the lasing mechanism. The surface anchor role can be ignored when the size of the liquid crystal droplets in the polymer matrix is small, which is beneficial to form multiple scattering. The transmission path of photons is similar to that in a ring cavity, providing feedback to obtain random lasing output.
    A high precision phase reconstruction algorithm for multi-laser guide stars adaptive optics
    Bin He(何斌), Li-Fa Hu(胡立发), Da-Yu Li(李大禹), Huan-Yu Xu(徐焕宇), Xing-Yun Zhang(张杏云), Shao-Xin Wang(王少鑫), Yu-Kun Wang(王玉坤), Cheng-Liang Yang(杨程亮), Zhao-Liang Cao(曹召良), Quan-Quan Mu(穆全全), Xing-Hai Lu(鲁兴海), Li Xuan(宣丽)
    Chin. Phys. B, 2016, 25 (9): 094214.   DOI: 10.1088/1674-1056/25/9/094214
    Abstract759)   HTML    PDF (529KB)(410)      
    Adaptive optics (AO) systems are widespread and considered as an essential part of any large aperture telescope for obtaining a high resolution imaging at present. To enlarge the imaging field of view (FOV), multi-laser guide stars (LGSs) are currently being investigated and used for the large aperture optical telescopes. LGS measurement is necessary and pivotal to obtain the cumulative phase distortion along a target in the multi-LGSs AO system. We propose a high precision phase reconstruction algorithm to estimate the phase for a target with an uncertain turbulence profile based on the interpolation. By comparing with the conventional average method, the proposed method reduces the root mean square (RMS) error from 130 nm to 85 nm with a 30% reduction for narrow FOV. We confirm that such phase reconstruction algorithm is validated for both narrow field AO and wide field AO.
    Liquid crystal Fresnel lens display
    Xiao-Qian Wang(王骁乾), Srivastava Abhishek Kumar, Ming-Wai Alwin Tam(谈明威), Zhi-Gang Zheng(郑致刚), Dong Shen(沈冬), Chigrinov G Vladimir, Hoi-Sing Kwok(郭海成)
    Chin. Phys. B, 2016, 25 (9): 094215.   DOI: 10.1088/1674-1056/25/9/094215
    Abstract632)   HTML    PDF (891KB)(406)      

    A novel see-through display with a liquid crystal lens array was proposed. A liquid crystal Fresnel lens display (LCFLD) with a holographic screen was demonstrated. The proposed display system has high efficiency, simple fabrication, and low manufacturing cost due to the absence of a polarizer and color filter.

    Configuration optimization of laser guide stars and wavefront correctors for multi-conjugation adaptive optics
    Li Xuan(宣丽), Bin He(何斌), Li-Fa Hu(胡立发), Da-Yu Li(李大禹), Huan-Yu Xu(徐焕宇), Xing-Yun Zhang(张杏云), Shao-Xin Wang(王少鑫), Yu-Kun Wang(王玉坤), Cheng-Liang Yang(杨程亮), Zhao-Liang Cao(曹召良), Quan-Quan Mu(穆全全), Xing-Hai Lu(鲁兴海)
    Chin. Phys. B, 2016, 25 (9): 094216.   DOI: 10.1088/1674-1056/25/9/094216
    Abstract603)   HTML    PDF (947KB)(275)      
    Multi-conjugation adaptive optics (MCAOs) have been investigated and used in the large aperture optical telescopes for high-resolution imaging with large field of view (FOV). The atmospheric tomographic phase reconstruction and projection of three-dimensional turbulence volume onto wavefront correctors, such as deformable mirrors (DMs) or liquid crystal wavefront correctors (LCWCs), is a very important step in the data processing of an MCAO's controller. In this paper, a method according to the wavefront reconstruction performance of MCAO is presented to evaluate the optimized configuration of multi laser guide stars (LGSs) and the reasonable conjugation heights of LCWCs. Analytical formulations are derived for the different configurations and are used to generate optimized parameters for MCAO. Several examples are given to demonstrate our LGSs configuration optimization method. Compared with traditional methods, our method has minimum wavefront tomographic error, which will be helpful to get higher imaging resolution at large FOV in MCAO.
    Bichromatic coherent random lasing from dye-doped polymer stabilized blue phase liquid crystals controlled by pump light polarization
    Lei Wang(王雷), Meng Wang(王萌), Mingchao Yang(杨明朝), Li-Jie Shi(石丽洁), Luogen Deng(邓罗根 ), Huai Yang(杨槐)
    Chin. Phys. B, 2016, 25 (9): 094217.   DOI: 10.1088/1674-1056/25/9/094217
    Abstract499)   HTML    PDF (1804KB)(392)      
    In this paper, we investigate the bichromatic coherent random lasing actions from the dye-doped polymer stabilized blue phase liquid crystals. Two groups of lasing peaks, of which the full widith at half maximum is about 0.3 nm, are clearly observed. The shorter- and longer-wavelength modes are associated with the excitation of the single laser dye (DCM) monomers and dimers respectively. The experimental results show that the competition between the two groups of the lasing peaks can be controlled by varying the polarization of the pump light. When the polarization of the pump light is rotated from 0° to 90°, the intensity of the shorter-wavelength lasing peak group reduces while the intensity of the longer-wavelength lasing peak group increases. In addition, a red shift of the longer-wavelength modes is also observed and the physical mechanisms behind the red-shift phenomenon are discussed.
    Asymmetric dynamic phase holographic grating in nematic liquid crystal
    Chang-Yu Ren(任常愚), Hong-Xin Shi(石宏新), Yan-Bao Ai(艾延宝), Xiang-Bao Yin(尹向宝), Feng Wang(王丰), Hong-Wei Ding(丁红伟)
    Chin. Phys. B, 2016, 25 (9): 094218.   DOI: 10.1088/1674-1056/25/9/094218
    Abstract597)   HTML    PDF (535KB)(293)      
    A new scheme for recording a dynamic phase grating with an asymmetric profile in C60-doped homeotropically aligned nematic liquid crystal (NLC) was presented. An oblique incidence beam was used to record the thin asymmetric dynamic phase holographic grating. The diffraction efficiency we achieved is more than 40%, exceeding the theoretical limit for symmetric profile gratings. Both facts can be explained by assuming that a grating with an asymmetric saw-tooth profile is formed in the NLC. Finally, physical mechanism and mathematical model for characterizing the asymmetric phase holographic grating were presented, based on the photo-refractive-like (PR-like) effect.
    Determining the imaging plane of a retinal capillary layer in adaptive optical imaging
    Le-Bao Yang(杨乐宝), Li-Fa Hu(胡立发), Da-Yu Li(李大禹), Zhao-Liang Cao(曹召良), Quan-Quan Mu(穆全全), Ji Ma(马骥), Li Xuan(宣丽)
    Chin. Phys. B, 2016, 25 (9): 094219.   DOI: 10.1088/1674-1056/25/9/094219
    Abstract652)   HTML    PDF (2252KB)(430)      
    Even in the early stage, endocrine metabolism disease may lead to micro aneurysms in retinal capillaries whose diameters are less than 10 μ. However, the fundus cameras used in clinic diagnosis can only obtain images of vessels larger than 20 μ in diameter. The human retina is a thin and multiple layer tissue, and the layer of capillaries less than 10 μ in diameter only exists in the inner nuclear layer. The layer thickness of capillaries less than 10 μ in diameter is about 40 μ and the distance range to rod&cone cell surface is tens of micrometers, which varies from person to person. Therefore, determining reasonable capillary layer (CL) position in different human eyes is very difficult. In this paper, we propose a method to determine the position of retinal CL based on the rod&cone cell layer. The public positions of CL are recognized with 15 subjects from 40 to 59 years old, and the imaging planes of CL are calculated by the effective focal length of the human eye. High resolution retinal capillary imaging results obtained from 17 subjects with a liquid crystal adaptive optics system (LCAOS) validate our method. All of the subjects' CLs have public positions from 127 μm to 147 μm from the rod&cone cell layer, which is influenced by the depth of focus.
    Optical simulation of in-plane-switching blue phase liquid crystal display using the finite-difference time-domain method
    Hu Dou(窦虎), Hongmei Ma(马红梅), Yu-Bao Sun(孙玉宝)
    Chin. Phys. B, 2016, 25 (9): 094221.   DOI: 10.1088/1674-1056/25/9/094221
    Abstract623)   HTML    PDF (1479KB)(423)      
    The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display. Compared with the matrix optic methods and the refractive method, the finite-difference time-domain method, which is used to directly solve Maxwell's equations, can consider the lateral variation of the refractive index and obtain an accurate convergence effect. The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage. The finite-difference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change.
    Bridging the terahertz near-field and far-field observations of liquid crystal based metamaterial absorbers
    Lei Wang(王磊), Shijun Ge(葛士军), Zhaoxian Chen(陈召宪), Wei Hu(胡伟), Yanqing Lu(陆延青)
    Chin. Phys. B, 2016, 25 (9): 094222.   DOI: 10.1088/1674-1056/25/9/094222
    Abstract614)   HTML    PDF (1591KB)(396)      
    Metamaterial-based absorbers play a significant role in applications ranging from energy harvesting and thermal emitters to sensors and imaging devices. The middle dielectric layer of conventional metamaterial absorbers has always been solid. Researchers could not detect the near field distribution in this layer or utilize it effectively. Here, we use anisotropic liquid crystal as the dielectric layer to realize electrically fast tunable terahertz metamaterial absorbers. We demonstrate strong, position-dependent terahertz near-field enhancement with sub-wavelength resolution inside the metamaterial absorber. We measure the terahertz far-field absorption as the driving voltage increases. By combining experimental results with liquid crystal simulations, we verify the near-field distribution in the middle layer indirectly and bridge the near-field and far-field observations. Our work opens new opportunities for creating high-performance, fast, tunable, terahertz metamaterial devices that can be applied in biological imaging and sensing.
    Low voltage transflective blue-phase liquid crystal display with a non-uniform etching substrate
    Jian Wang(王健), Jiang-Lin Mao(毛江林), Hao-Xiang Fan(范昊翔), Qiong-Hua Wang(王琼华)
    Chin. Phys. B, 2016, 25 (9): 094223.   DOI: 10.1088/1674-1056/25/9/094223
    Abstract728)   HTML    PDF (1025KB)(372)      
    A transflective polymer-stabilized blue-phase liquid crystal display (BP-LCD) with a non-uniform etching substrate is proposed. In-plane switching (IPS) electrodes on the bottom substrate are put on the different gaps, and the bottom substrate between the electrodes is etched into different depths in transmissive (T) and reflective (R) regions. This structure can balance the optical phase retardation in the two regions and is helpful to achieve well-matched voltag-dependent transmittance and reflectance curves. This transflective display has high optical efficiency, a wide viewing angle, and low operating voltage (approximately 6 V).
    Azobenzene mesogens mediated preparation of SnS nanocrystals encapsulated with in-situ N-doped carbon and their enhanced electrochemical performance for lithium ion batteries application
    Meng Wang(王勐), Yang Zhou(周旸), Junfei Duan(段军飞), Dongzhong Chen(谌东中)
    Chin. Phys. B, 2016, 25 (9): 096102.   DOI: 10.1088/1674-1056/25/9/096102
    Abstract675)   HTML    PDF (1592KB)(370)      
    In this work, azobenzene mesogen-containing tin thiolates have been synthesized, which possess ordered lamellar structures persistent to higher temperature and serve as liquid crystalline precursors. Based on the preorganized tin thiolate precursors, SnS nanocrystals encapsulated with in-situ N-doped carbon layer have been achieved through a simple solventless pyrolysis process with the azobenzene mesogenic thiolate precursor served as Sn, S, N, and C sources simultaneously. Thus prepared nanocomposite materials as anode of lithium ion batteries present a large specific capacity of 604.6 mAh·g-1 at a current density of 100 mA·g-1, keeping a high capacity retention up to 96% after 80 cycles, and display high rate capability due to the synergistic effect of well-dispersed SnS nanocrystals and N-doped carbon layer. Such encouraging results shed a light on the controlled preparation of advanced nanocomposites based on liquid crystalline metallomesogen precursors and may boost their novel intriguing applications.
    Effect of fluorine groups and different terminal chains on the electro-isomerization of azobenzene liquid crystals
    Jing-Jing Xiong(熊晶晶), Dong Shen(沈冬), Zhi-Gang Zheng(郑致刚), Xiao-Qian Wang(王骁乾)
    Chin. Phys. B, 2016, 25 (9): 096401.   DOI: 10.1088/1674-1056/25/9/096401
    Abstract689)   HTML    PDF (620KB)(251)      
    A series of azobenzene liquid crystals with one or two terminal acrylate groups were synthesized and their polymers were fabricated. The azobenzene liquid crystals and their polymers achieved the photoisomerization from the liquid crystalline trans-isomer to the isotropic cis-isomer with UV irradiation. Then, the cis to trans isomerization induced by an electric field was studied, the time required for electro-isomerization was measured, the texture change and absorption variation from cis to trans form induced by the electric field were observed clearly, and the time required for electro-isomerization was much shorter than that for thermal relaxation. The influence of the polar group (fluorine), terminal acrylate group, and flexible alkyl chain on the time of electro-isomerization was studied. The results show that the compounds with polar fluorine group require shorter time for electro-isomerization and the polymerization of terminal acrylate group delays the electro-isomerization.
    Phase behaviors of binary mixtures composed of electron-richand electron-poor triphenylene discotic liquid crystals
    Lingling An(安玲玲), Min Jing(景敏), Bo Xiao(肖波), Xiao-Yan Bai(白小燕), Qing-Dao Zeng(曾庆祷), Ke-Qing Zhao(赵可清)
    Chin. Phys. B, 2016, 25 (9): 096402.   DOI: 10.1088/1674-1056/25/9/096402
    Abstract610)   HTML    PDF (2850KB)(424)      
    Disk-like liquid crystals (DLCs) can self-assemble to ordered columnar mesophases and are intriguing one-dimensional organic semiconductors with high charge carrier mobility. To improve their applicable property of mesomorphic temperature ranges, we exploit the binary mixtures of electronic donor-acceptor DLC materials. The electron-rich 2,3,6,7,10,11-hexakis(alkoxy)triphenylenes (C4, C6, C8, C10, C12) and an electron-deficient tetrapentyl triphenylene-2,3,6,10-tetracarboxylate have been prepared and their binary mixtures have been investigated. The mesomorphism of the 1:1 (molar ratio) mixtures has been characterized by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), and small angel x-ray scattering (SAXS). The self-assembled monolayer structure of a discogen on a solid-liquid interface has been imaged by the high resolution scanning tunneling microscopy (STM). The match of peripheral chain length has important influence on the mesomorphism of the binary mixtures.
ISSN 1674-1056   CN 11-5639/O4

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