The thesis can be divided into two chapters: synthesis and application. The first chapter presents the basis of synthesis. Generally, electronic-deficient aromatic molecules require activation before reacting with metal reagents and then can go coupling reaction. Our lab has developed a new bipyridine coupling method without pre-functionalization of pyridines to the corresponding activated halide or metal forms or using of transition metal catalysts. This new method is quite efficient and advantageous for environmental protection. In second chapter, we synthesized 3,3¡¦-dihydroxy-2,2¡¦-bipyridine -based molecules and the functional groups were modified to investigate its liquid crystal properties. According to analyzing data of differential scanning calorimetry (DSC), polarized optical microscope (POM) and powder x-ray diffraction (XRD), we found that a-3 may possess cubic mesophaes with Im3m symmetry, and a series of d-1~d-3 compounds exhibit mesophase and may be further identified as smectic phase.

In this study, we study polymer-dispersed blue-phase liquid-crystal (PDBPLC)films. The PDBPLC film is fabricated by using BPLC instead of nematic LC in a PDLC film. The experimental results show that the PDBPLC films and can be switchable as the conventional PDLC. The polymer morphology of the PDBPLC is affected by the concentration of monomer in the BPLC/monomer mixture. The PDBPLC exhibits a good contrast ratio with monomer concentration of 39.17 wt%. The rise time of PDBPLC films decreases as the polymer concentration increases. Moreover, the results also show that a complete phase separation occurs with the exposure time of 20 minutes. For the future work, we will improve the high driving voltage and low ratio of the PDBPLC film.

Blue phases have been known to exist in chiral liquid crystals between the cholesteric and isotropic phases. A blue phase as a self-assembled three-dimensional cubic structure with lattice periods of several hundred nanometers exhibits not only selective Bragg reflections of light in the visible wavelength but optically isotropy owning to its highly symmetric molecular structure. Locally, blue phases still exhibit local anisotropic physical properties because of anisotropic structure of the nematic liquid crystal molecules, which make it possible to be easily controlled by an external field. This dissertation studies the effects in blue phases under various external fields, including electrical field, optical field, and temperature. Firstly, we investigated the bistable effect under the influence of an electric field and transition mechanism between various lattice orientations in the negative liquid crystal blue phase. The blue phase exists over a wide temperature range ~16oC, and three lattices (110), (112) and (200) of BPI are confirmed with Kossel diagrams. The red platelet (110) lattice and blue platelet (200) lattice can be stabilized and switched to each other by particular pulse voltages. We also studied the behavior that an electric field induced planar state and electro-hydrodynamatic effect in the blue phase. Additionally, the reflected color of the (200) lattice can be adjusted from 455nm to 545 nm by temperature induced lattice distortions and provided with reversibility. Secondly, we presented an optically switchable band gap of a 3D photonic crystal that is based on an azobenzene-doped liquid crystal blue phase. Two kinds of azobenzene, M12C and 4MAB, were utilized to switch photonic band gap of blue phases and to change the phase transition temperature of blue phase, respectively. For M12C- doped liquid crystal blue phase, the trans-cis photoisomerization of M12C induced by irradiation using 473nm light caused the deformation of the cubic unit cell of the blue phase and a shift in the photonic band gap. The fast back-isomerization of azobenzene was induced by irradiation with 532nm light. The crystalline structure was verified using a Kossel diffraction diagram. Moreover, we also demonstrated an optically addressable blue phase display, based on Bragg reflection from the photonic band gap. For 4MAB- doped liquid crystal blue phase, the trans-cis photoisomerization of 4MAB destabilizes cubic unit cell of the blue phase and reduces the phase transition temperature. We observed the phase sequences of the 4MAB-doped blue phase as a function of the time of UV irradiation. Various distinct phases can be switched to another specific phase by controlling irradiated time and temperature of the sample. Therefore, the corresponding bandgap can be switched on and off between blue phase and isotropic phase, or varied from 3D to 1D between blue phase and cholesteric phase. Finally, we investigated the thermal hysteresis in the phase transition between the cholesteric liquid crystal and the blue phase of liquid crystal. The thermal hysteresis of such a chiral doped nematic liquid crystal occurs over 6oC. Both the CLC phase and the blue phase can stably exist at room temperature and be switched to each other using temperature-controlled processes. Further, we demonstrated two sets of bistable conditions using various surface treatments. In a homogeneous aligned sample, two stable states, CLC with a planar alignment and blue phase with a uniform lattice distribution, reflect light of wavelengths 480-510nm and 630nm, respectively, as determined by the corresponding Bragg¡¦s reflection conditions. In the untreated sample, the CLC phase with a focal conic texture can scatter light and the blue phase with a non-uniform lattice distribution provides high isotropic optical transparency.

The common discotic mesogen molecules are known to have a flat structure, comprising a rigid core, e.g., polynuclear aromatic structure, and a ring of four to nine flexible aliphatic side chains. We take the electron deficient heterocyclic hexaazatriphenylene (HAT) as our central core and readily synthesized by the condensation of hexaketocyclohexane with the respective 1,2-bis-alkoxy-4,5-diaminobenzene. The new molecules with electron deficient discotic liquid crystal properties are successfully.

Abstract Advocate ' the knowledge economy ' in era in the whole world now, the enterprises possess knowledge which also calling the value of Intangible Assets, has already surmounted the general tangible assets gradually, and can produce the greatest value for enterprises. In view of the knowledge economy era arrival, how is the enterprise via ' Knowledge Management (KM), make the latent knowledge and technology inside personnel transform outside show knowledge, and it is the key subject that enterprises face to reach the knowledge application and innovation through storing, sharing and spreading. LCD display industry is following semiconductor, Taiwan does one's utmost to promote one of the industries of development. The industry of the display is an industry with keen competition, the life cycle of the products is short, and the technical development of the products is fast. So it need under limited resources, avoid making the repeated mistake and paying, save the time of solving problems in order to be absorbed in the products for reform and innovation. So, this main key of research lies in inspecting how LCD display industry uses the effective knowledge management style to promote one's own competitiveness. The extensive academic theory and knowledge management style of current industry at first of this text carries on the research discussion, the purpose lies in that it influences organizing to promote the information management factor to find out. And the high-order executive and advisor representative to enterprises, carry on depth interview, make deep quality and analyze the data. The result of study finds, the enterprise culture is influenced organization to carry out the important factor of knowledge management. In addition, external knowledge becomes and offers the important source that enterprises maintain the competition advantage.

We fabricated the liquid crystal cell which had the property of the diffraction optical element. The concentric electrode had been fabricated on an indium-tin-oxide (ITO) substrate by etching technology. With the application of a proper voltage, it produces an inhomogeneous grating-like electric field in space to form phase Fresnel liquid crystal lens. Because of liquid crystals (LCs) are excellent electro-optic materials with electrical and optical anisotropies. Their optical properties can easily be modulated by the external electric field. Hence based on the electro-optic properties, the function of the as-constructed phase Fresnel liquid crystal lens has been studied in this paper. In this study, we discuss the diffraction efficiency of Fresnel LC lenses and collocated plano-convex to form dual focal length optical element.

In this study, a high power Q-switch pulse laser has been used as the writing beams. The laser-induced holographic gratings in the DR1-doped liquid crystal samples and the DR1-PMMA polymer thin films were investigated by changing the temperature of samples and the angles of two writing beams. The He-Ne cw laser has been used as a real-time probe beam to detect the first order diffraction signals. Without external field, the gratings are the results of concentrations and diffusions of azo dye isomers. The diffusion model has been utilized to analyze the first order diffraction signals in order to understand the mechanics of gratings and the effect of temperature and angle.

Abstract The present investigation is performed by repeated experiments to simulate the impingement cooling heat transfer in leading-edge region of gas turbine with thermochromic liquid crystals. The experiments was studied on a rotating square duct without crossflow effect from three different rotational speeds of 0, 30 and 60 rpm. The study covered jet Reynolds number 7000 to 9000 and the rotational speeds from 0 to 60 rpm. Results are presented and focused on the effect of three different rotational speeds. Nusselt number values increased (up to 14%) with Reynolds number. However, Rotation induced coriolis and centrifuged forces and decreased the Nusselt number values about 9% which is quite coincided with those of previous studies.

This year (2002), Taiwan participates in WTO under the worldwide economic depression. Besides facing the worldly market competition, Taiwan competes with the cheap labor force pressure from mainland China. In the meanwhile, Taiwan is at the transitional point of economic organization. K company is an over thirty-year overseas branch of an international Japanese Industry. How should it work out new management strategies for liquid crystal industry to promote its competition at this moment? Liquid crystal industry has developed for ten years. It has had one Crystal Cycle every three year. Under the economic depression, the demands of the worldwide PC market and information products have been decreasing. The price of panels has been going down. Factories have suffered heavy loss. Thus, how to work out management strategies for products to avoid virulent competition and to promote profitable competence is the most important issue for the managers of economic industry. This report research on K company¡¦s creative management strategies for liquid crystal. They include (1) Core Strategy (2) Strategic Resources (3) Customer Interface (4) Value Network (5) Customerization Goods Strategy. By industrial analysis and by management strategic analysis of Taiwan crystal industry, the report applies the organization analysis and research on business model, and then synthesizes K company¡¦s whole creative management strategies for liquid crystal industry. Key Words: liquid crystal, market competition, management strategy, customization goods

Configuration-bias Monte Carlo simulation is used to investigate the structural property of liquid crystal. Our results show that the surface molecules of the smaller nanoclusters are formed the helical structure, In addition, the morphologies of nanoclusters show a tube-like structure when the surface molecules formed the helical structure; however, as the surface molecules do not form the helical structure, the morphologies of nanoclusters become a ball-like structure. For the tube-like structure, because of the configurations of nanoclusters are simpler, the nanoclusters will show an order structure. In the case of the ball-like structure, the molecules will attract with others, so the nanocluster reveals an ordered structure at local area. According to the result of the averaged order parameters, as the averaged order parameter larger than 0.5, the configuration of nanocluster will be a tube-like structure, while as the averaged order parameters smaller than 0.5, the configuration of nanocluster will form a ball-like structure.