共查询到18条相似文献,搜索用时 125 毫秒
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通过两次光照法制备了一种基于共价键结构的自组装光控取向膜。首先采用重氮树脂与聚(4-丙烯酰氧基肉桂酸(4′-磺酸钠)苯酚酯)在水溶液状态下通过静电离子沉积法制备了layer-by-layer型的自组装多层膜,制备过程的紫外-可见光谱表明薄膜为逐层、均匀沉积。第一次光照将膜层间的重氮磺酸盐离子键转化为共价键结构,然后采用线性偏振紫外光进行第二次光照,获得具有各向异性的光控取向膜。紫外-可见光谱法证实了薄膜辐照过程中的光化学反应方式。这种液晶光控取向膜可以水平均匀取向向列相液晶,而且具有良好的热稳定性,可达到150℃。 相似文献
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向列相液晶在自组装膜上取向的研究 总被引:1,自引:1,他引:0
通过在具有微米级沟槽(一个沟槽周期5μm)的玻璃基底上进行平面镀金,制备了具有相同沟槽周期的Au膜;并在Au膜上制备Cu2 修饰的巯基十一酸自组装敏感膜。向列相液晶5CB在Au膜基底上呈平行于Au膜沟槽的沿面排列;5CB在自组装敏感膜表面上的取向排列方式为垂直排列。通过检测甲基膦酸二甲酯时液晶织构的变化,表明5CB的取向排列方式由垂直排列转变为倾斜排列,并阐明了液晶型化学传感器的作用机理。首次证实以微米级沟槽状Au膜为基底制作的液晶型化学传感器可以用于检测目标化合物。 相似文献
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液晶分子的初始排列在液晶显示器中起着关键的作用。纳米粒子掺杂到液晶体系可扰乱液晶分子的排列,从而改变液晶的自组装特性,进而影响液晶的各项性能。将制备的Au八面体纳米颗粒掺杂到向列相液晶4-氰基-4′-正戊基联苯(5CB)中,灌入液晶盒后,通过使用偏光显微镜对液晶盒的观察发现,掺杂的八面体Au纳米颗粒诱导5CB液晶分子发生了垂直取向,而球形Au纳米颗粒不能诱导液晶分子垂直取向。这归因于八面体Au纳米颗粒的表面能比较小,液晶分子间的作用力比较大,使液晶分子易于垂直取向。随着O-Au NPs的浓度增大,液晶分子的取向效果先变好又逐渐变差。这是因为O-Au NPs的浓度越高,可诱导越多的液晶分子垂直取向排列,但随着纳米粒子浓度的增加,纳米粒子团聚,减少了与液晶分子的作用,使取向效果变差。动态过程实验显示,0.1%的八面体金纳米颗粒可诱导向列相液晶5CB在2 min内快速完成垂直取向,表明O-Au NPs具有优异的诱导5CB取向的动态效果。 相似文献
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虽然传统的平行取向技术已广泛应用于液晶显示器的生产,但其存在窄视角、低对比度和慢响应时间等问题,因此液晶分子的垂直取向技术在国外已经被广泛研究。在实验中,一种含有液晶结构侧链的聚酰亚胺通过均苯四羧酸二酐(PMDA),4,4′-二胺基二苯甲烷(MDA)和4-己氧基联苯酚-3′,5′-二胺基苯甲酸酯(C6BBDA,实验室自制)共聚被制备,并且被用作液晶取向膜,研究其取向性能。试验发现,该种聚酰亚胺作为取向膜可以诱导液晶分子垂直取向,即使在摩擦之后依然可以获得大于89°的预倾角;使用正交偏光显微镜观察所制得液晶盒中的液晶取向效果,发现垂直取向均匀良好;为了测试该垂直取向的热稳定性,将制备的液晶盒在120℃下烘烤12h后,偏光显微镜下观察发现垂直取向仍然良好均匀,表明该取向膜具有良好的热稳定性。 相似文献
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侧链含稠环的新型聚酰亚胺液晶垂直取向剂的制备及表征 总被引:2,自引:2,他引:0
以3,5-二硝基苯甲酰氯、雌二醇及溴代正辛烷为原料合成了含有稠环结构的新型功能性二胺(H8-c)。用1,2,3,4-环丁烷四甲酸二酐(CBDA)、对苯二胺(PDA)及H8-c共聚制备了一种聚酰亚胺(PI)液晶垂直取向剂。该PI膜作为取向层制得的液晶盒,在120℃下烘烤12h仍可垂直取向,拥有良好的垂直取向热稳定性。热重分析(TGA)测试表明其具有良好的热稳定性,在氮气中,这种PI的5%热失重温度(T5)和10%热失重温度(T10)分别高达400℃和480℃。紫外可见光谱(UV-vis)显示此PI膜在400nm以上具有高的透过率,可达95%以上。 相似文献
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Unprecedented Dual Alignment Mode and Freedericksz Transition in Planar Nematic Liquid Crystal Cells Doped with Gold Nanoclusters 总被引:1,自引:0,他引:1
We demonstrate that alkylthiol‐capped gold nanoclusters doped into nematic liquid crystals (N‐LCs) with positive dielectric anisotropy give rise to an unprecedented dual alignment mode and electro‐optical response, which has a potential impact on current liquid crystal (LC) display technologies and N‐LC optical‐biosensor design. By fine‐tuning experimental conditions (temperature, electric field, and alignment), N‐LCs doped with gold nanoclusters can be aligned and electrically reoriented either like N‐LCs with a positive dielectric anisotropy in a planar cell or, alternatively, as N‐LCs with a negative dielectric anisotropy in a homeotropic cell, both at lower threshold voltages than the pure N‐LC. 相似文献
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On p. 212, Torsten Hegmann and co‐workers describe nematic liquid crystals (N‐LCs) confined in planar liquid crystal cells after doping with small quantities of gold nanoclusters. These give rise to a dual alignment mode and electro‐optic response (Freedericksz transition). By fine‐tuning of experimental conditions, N‐LCs doped with gold nanoclusters can be electrically reoriented and aligned either like N‐LCs with a positive dielectric anisotropy (used in twisted nematic displays) in a planar cell or alternatively as N‐LCs with a negative dielectric anisotropy (used in large LCD TVs based on the vertical alignment mode). We demonstrate that alkylthiol‐capped gold nanoclusters doped into nematic liquid crystals (N‐LCs) with positive dielectric anisotropy give rise to an unprecedented dual alignment mode and electro‐optical response, which has a potential impact on current liquid crystal (LC) display technologies and N‐LC optical‐biosensor design. By fine‐tuning experimental conditions (temperature, electric field, and alignment), N‐LCs doped with gold nanoclusters can be aligned and electrically reoriented either like N‐LCs with a positive dielectric anisotropy in a planar cell or, alternatively, as N‐LCs with a negative dielectric anisotropy in a homeotropic cell, both at lower threshold voltages than the pure N‐LC. 相似文献
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H. M. Song J. C. Kim J. H. Hong Y. B. Lee J. Choi J. I. Lee W. S. Kim J.‐H. Kim N. H. Hur 《Advanced functional materials》2007,17(13):2070-2076
The fabrication of transparent, flexible, and optically homogeneous magnetic composites containing ferrite (Fe3O4) nanoparticles, liquid crystals (LCs), and siloxane backbones is reported. The transparent magnets are achieved by covalently bonding LCs to the siloxane backbones and then linking them to dopamine‐functionalized ferrite nanocrystals. They exhibit simultaneous high transparency and strong magnetic properties. A remarkable feature of these films is that the surface morphology of the LC‐attached ferrite films can be tuned by an external magnetic field, demonstrating a striped surface in the direction of the field. We show that the LC‐attached film can act as an alignment layer to orient LCs, enabling the development of LC alignment surfaces on the basis of these nanomagnet–LC polymer composites. 相似文献
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《Microelectronic Engineering》2007,84(5-8):1003-1006
Nickel template is very suitable for thermal imprinting process since it has high mechanical durability and can easily be duplicated using electroforming technique. However nickel has a poor anti-sticking property; in addition, proper and stable releasing layer on nickel surface is not yet available.In this study, thin layer of SiO2 film was deposited on nickel surface and silane based hydrophobic self-assembled monolayer (SAM) was formed on SiO2 film, coated on nickel. Since the silane based SAM layer can be stably formed on SiO2 layer coated nickel template, it can be used anti-sticking layer for thermal imprint process using thermoplastic polymer resin or thermally curable prepolymer resin. 相似文献
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Hyeok Kim Zheng Meihui Nicolas Battaglini Philippe Lang Gilles Horowitz 《Organic Electronics》2013,14(9):2108-2113
Planar diodes with gold electrodes and a pentacene semiconductor layer were made and electrically characterized. The gold electrodes were modified with self-assembled monolayers of biphenylthiol and biphenylthiol substituted with a terminal fluorine atom (fluorobiphenylthiol). Atomic force microscopy of the pentacene layer reveals large morphological similarities when the film is grown on gold modified with either of the two kinds of self-assembled monolayer. This is at variance with the significant increase of the current observed when the gold electrodes are treated with fluorobiphelylthiol, with a bulk mobility rising up to 1 cm2/V s, while the treatment with biphelylthiol leads to a substantial decrease of the current. These results are interpreted in terms of adjustment of the injection barrier height as a result of the interface dipole induced by the self-assembled monolayer. 相似文献
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《Microelectronic Engineering》2007,84(9-10):2173-2176
We report here that an ultra-thin oxide layer formed in the gate metal by plasma oxidation can serve the same role as self-assembled monolayer (SAM) dielectric, yielding the device performance similar to that for SAM-based organic thin film transistors. In addition, this simple plasma oxidation, unlike the case of SAM dielectrics, allows a smooth coating of the oxide dielectric with a thin (∼ 20 nm) polymer dielectric of poly (vinyl phenol) (PVPh). This organic transistor with the bilayer dielectric is robust. It has a subthreshold swing of 110 mV per decade, which is the best subthreshold voltage reported for an organic transistor. 相似文献