| Part I. A ridge fringe field multi-domain homeotropic (RFFMH) liquid crystal display (LCD) was made and its properties were demonstrated with a wider viewing angle. In this LCD, ridges are built on top of the ITO layer of the color filter to control the pretilt direction of liquid crystal molecules, substituting the rubbing treatment. Photolithography is used as the method to build ridges. Ridges are made from a negative photoresist, which can be manipulated by controlling exposure, bake temperature and time (including softbake and post-expose-bake), and development.;The combination effect of ridge structure and pixel fringe field controls the tilting direction of the liquid crystal molecules when a voltage is applied to a pixel, yielding a wide viewing angle.;Compared with the conventional TN LCD, this particular type of LCD has some advantages, such as the absence of rubbing treatment, a wider viewing angle, faster response time, better dark state, and higher contrast ratio (larger than 300). Ultimately, these advantages will possibly enable RFFMH LCD to replace the conventional TN LCD in the computer industry and other industries.;Part II. Solutions of polyaniline (PANI) doped with camphor sulfonic acid (CSA) in m-cresol were studied with UV-VIS, NIR, DSC, TGA, conductivity measurement and X-ray diffraction. Solutions with different PANI/CSA molar ratios were prepared. All the measurements suggest that (i) m-cresol is a better solvent for PANI compared with chloroform and NMP. The reason is that m-cresol can have hydrogen-bonding and phenyl-phenyl interaction with polymer chains, which leads to deaggregation of the polymer chains. It solvates and slightly dopes PANI. (ii) at the molar ratio of 1:0.7 (PANI:CSA), the highest doping level was achieved, at which point the strongest PANI-CSA-m-cresol interaction was observed. In addition, at this particular ratio, the highest conductivity ( ∼ 340S/cm) and degree of crystallinity were obtained. |
