一种丙烯酸酯型侧链液晶高分子的合成及液晶性的研究

依据液晶分子结构理论,选择联苯基作为介晶基元,六亚甲基为柔性间隔基,合成了一种丙烯酸酯侧链型液晶高分子。对于合成的中间及目标产物通过FTIR、1HNMR等进行了结构的表征。对于聚合物采用GPC法测量了其分子量,并通过DSC、POM、XRD和计算机模拟等手段研究了其液晶性。研究表明合成的聚合物分子量-Mn=2523、-Mw=2826,具有较宽的温域(45.3～95.2℃),且为典型的近晶A相液晶。     

聚乙烯醇侧链液晶的结构与液晶性研究

研究了聚乙烯醇侧链液晶主链分子量和液晶基元等结构因素对其液晶性的影响，结果表明随着聚合物的分子量增加，导致复合物清亮点温度下降。但是在液晶主链尚未被液晶基元饱和之前，随着液晶基元相对主链摩尔比的增加，样品形成较为完善的氢键结构。     

一种用聚合物网络控制液晶分子取向的方法

从聚合物网络与液晶相互作用的机理出发，对于用聚合物网络控制液晶分子取向的方法进行了较为系统的研究。并根据液晶分子的光透射率计算公式，对实验结果进行了计算与分析。     

热致变色液晶微胶囊化的扫描电镜观察

热致变色液晶微胶囊的合成条件对微胶囊的状态及热敏特性有极大的影响，本文通过扫描电镜以观察，发现和证实这些影响的存在．这对改进合成工艺提供了客观证据。     

液晶分子取向技术研究

综述目前液晶显示器(LCD)工业生产中广泛使用的液晶分子取向技术。主要讨论摩擦技术、非摩擦技术和PI取向膜的性能。对这些技术的发展状况、特点与局限性以及今后的发展趋势进行了较为详尽的论述。     

磁场对双轴分子液晶的影响

在分子场近似下,研究分子双轴性对向列相液晶在各向同性相最低过冷温度的影响,以及对临界磁场的影响。当外加磁场大于临界磁场时,不发生向列相－各向同性相相变。理论结果表明,通过考虑分子双轴性,最低过冷温度Ｔ＾＊与相变温度Ｔｃ的比值向实验值靠近。随着分子双轴性的增加,临界磁场很快下降。     

喷墨打印用超支化聚酯阻焊剂的制备与表征

喷墨打印阻焊剂自研发以来,因树脂油墨剪切变稀和触变性等特点,一直不能有效解决阻焊剂喷墨初始阶段稳定性问题。对此,本研究以BoltornH2O为原料,合戍了一种超支化丙烯酸化合物,在与TMP3EOTA及UV固化剂混合后,可以获得稳定性好的阻焊油墨,在光源照度1w／cm2条件下固化速度低于20S,固化膜的热分解温度超过300℃,阻焊膜的其他性能符合IPC—SM-840C和CPCA4306—2011等相关标准。     

一种新颖的彩色液晶VRAM显示器

1.概述 在工业现代化生产制造和监控测试等领域,对人机对话中显示功能的要求越来越高,除了能显示字符,汉字外,还要对一些数据进行曲线描绘,动态显示,而且显示器的轻便、节能、美观,也是现代各种仪器集成化的迫切需求。 彩色液晶显示器正是顺应这一潮流而出的高新技术产品,它不但体积小,耗电省、寿命长、无射线、抗震、防爆,而且还具有超薄平面,色彩逼真等优点,被公认为是21世纪的主流显示器。     

液晶聚合物薄膜的介电性能

研究了两种液晶聚合物薄膜的介电性能。结果表明,液晶聚合物的介电常数随频率的增加而缓慢变小,高温下的介电常数较大。介电损耗在一定的温度范围内（室温至３５０℃）出现峰值,峰值位置随频率的增加向高温方向移动。     

Two-Photon Laser-Written Photoalignment Layers for Patterning Liquid Crystalline Conjugated Polymer Orientation

Systematic tuning of chemical and physical structure allows fine control over desired electronic and optical properties, including those of conjugated polymer semiconductors. In the case of physical structure, orientation via liquid crystalline alignment allows access to fundamental optical anisotropies and the associated refractive index modification offers great potential for fabrication of photonic structures. In this paper, photoalignment is used to orient the liquid crystalline conjugated polymer poly(9,9-dioctylfluorene-co-benzothiadiazole) (F8BT), specifically involving two-photon infrared laser writing of patterns in an azobenzene sulphonic dye (SD1). These patterns are transferred into the overlying film by thermotropic orientation in the nematic melt, then frozen in place by quenching to a room temperature nematic glass. Optimization of laser power and scan speed allows features with linewidths ≤ 1 µm. Photoluminescence (PL) peak anisotropy values reach PL_II/PL_⊥ = 13 for laser writing, compared with PL_II/PL_⊥ = 9 for polarized ultraviolet light emitting diode exposure of the same SD1 layer. These two approaches also result in different film microstructures; evidenced by characteristic changes in PL spectra. The anisotropic PL spectra provide information on emissive excited states that complements previous studies on non-oriented F8BT and related copolymers, also suggesting two emissive states.     

Photo-Triggered Shape Reconfiguration in Stretchable Reduced Graphene Oxide-Patterned Azobenzene-Functionalized Liquid Crystalline Polymer Networks

In recent years, the “Kirigami” have been exploited to engineer stretchable electronics that exhibit enhanced deformability without sacrificing their mechanical and electrical properties. However, kirigami-inspired engineering is often limited to passive mechanical stretching for 3D shape morphing. To counter this problem, in this study, azobenzene-functionalized liquid crystalline polymer networks (azo-LCNs) are monolithically integrated with patterned reduced graphene oxide (rGO), called azo-LCN/rGO, to achieve on-demand shape reconfiguration in response to external stimuli (UV, NIR, solar rays, and portable light); in addition, the azo-LCN/rGO exhibit highly enhanced mechanical and electrical properties. The cross-sectional area and thickness of rGO patterns are controlled using a masking technique and evaporative self-assembly. By the spatial patterning of rGO, insulating azo-LCNs are converted into electrically conducting structures (381.9 S cm⁻¹). The elastic modulus of <2 µm thick azo-LCN can be tailored in the range of 1.3–6.4 GPa by integration with rGO layers of thickness less than 2 µm. Upon UV irradiation, azo-LCN/rGO exhibit both for/backward in-plane bending as well as out-of-plane chiral twisting, thus overcoming the typical trade-off relationship between elastic modulus and deformability. Finally, an on-demand contactless shape reconfiguration in azo-LCN/rGO by UV irradiation in conjunction with passive mechanical strain is demonstrated.     

高分子液晶态向列相中向错的电镜观察

向错是液晶态结构的一种缺陷,本工作选用热致性芳香共聚酯液晶,用透射电子显微镜研究了高分子液晶态向列相中强度S=±l/2和S=±1的全部向错形式,其中S=±1的四种向错是首次获得TEM的观察结果。本文分析了向错的电镜图象,并讨论了电镜观察结果与纹影织构图的关系。     

含氰基三联苯聚噻吩液晶共轭聚合物单体合成

通过Sszuki偶联和Mitsunobu酯化等反应,设计合成了一种新型含氰基三联苯聚噻吩类液晶共轭聚合物单体,利用核磁共振(1H NMR)、红外光谱(IR)等方法表征了单体的结构.利用示差扫描量热仪(DSC)、带热台的偏光显微镜(POM)、紫外光谱(UV)和荧光光谱(PL)研究了单体液晶性和光电性能.结果表明,该单体具有近晶A型液晶态扇形织构,同时,由于三联苯的存在赋予了单体很好的紫外吸收和光致发光性能,在320 nm紫外光激发下,可发射400 nm的蓝光.     

Light-Responsive Programmable Shape-Memory Soft Actuator Based on Liquid Crystalline Polymer/Polyurethane Network

Liquid crystalline polymers (LCPs), especially liquid crystalline elastomers (LCEs) can generate ultrahigh shape change amplitude but has lower mechanical strength. Although some attempts have been tried to improve the mechanical performance of LCE, there are still limitations including complicated fabrication and high actuation temperature. Here, a versatile method is reported to fabricate light-driven actuator by covalently cross-linking polyurethane (PU) into LCP networks (PULCN). This new scheme is distinct from the previous interpenetrating network strategy, the hydrogen bonds and covalent bonds are used in this study to improve the miscibility of non-liquid-crystalline PU and LCP materials and enhance the stability of the composite system. This material not only possesses the shape memory properties of PU but shows shape-changing behavior of LCPs. With a shrinkage ratio of 20% at the phase transition temperature, the prepared materials reached a maximum mechanical strength of 20 MPa, higher than conventional LCP. Meanwhile, the resulting film shows diverse and programmable initial shapes by constructing crosslinking density gradient across the thickness of the film. By integration of PULCN with near-infrared light-responsive polydopamine, local and sequential light control is achieved. This study may provide a new route for the fabrication of programmable and mechanically robust light-driven soft actuator.     

一种聚合物/液晶体系的结构与模型分析

为提高液晶器件的响应速度,介绍了一种基于聚合物/液晶(预应力液晶)的结构与制作工艺,其响应速度可达毫秒级.对制作过程中预应力液晶结构(液晶微滴的尺寸和形状)与制作工艺条件(聚合物含量、紫外曝光光强、聚合温度)的关系进行了分析,并建立了预应力液晶的简易模型,给出了其响应时间与液晶微滴的尺寸和剪切比之间的关系.结果证明这种模型与实验结果基本相符.     

Stable Light-Emitting Electrochemical Cells Using Hyperbranched Polymer Electrolyte

The choice of an adequate electrolyte is a fundamental aspect in polymer light-emitting electrochemical cells (PLECs) as it provides the in situ electrochemical doping and influences the performance of these devices. In this study, a hyperbranched polymer (Hybrane DEO750 8500) blended with a Li salt is used as a novel electrolyte in state-of-the-art Super Yellow (a polyphenylenevinylene) based LECs. Due to the desirable properties of the hyperbranched polymer and the homogeneous and smooth films that it forms with the emitting polymer, PLEC with excellent electroluminescent properties are obtained using a pulsed current bias scheme. The devices are very stable, with lifetimes in excess of 2000 h with initial luminance values above 450 cd m⁻², a peak efficiency of 12.6 lm W⁻¹, and sub-minute turn-on times. The stability of the devices is also studied by measuring the photoluminescence (PL) of the semiconductor during electroluminescent operation. The findings suggest that it is possible to observe the quenching of the PL in vertically stacked devices due to the advancement of the doped fronts in the film and an immediate PL recovery when the bias is removed.