In previous studies, I learned the curing of the electro-optical effects in polymer stabilize blue phase liquid crystal under different temperature, such as the hysteresis effect, residual transmittance, drive voltage. So find out before curing blue phase temperature range is very important.
Since previous studies have used methods is polarizing microscope and measuring reflectance spectra. In order to the blue phase be used in the display. If we use of Bragg reflectors in the visible blue phase liquid crystal. Resulting in the dark state is not good, the contrast reduction, so we must use the blue phase liquid crystal reflectance spectra in the non-visible light. But this liquid crystal cannot use the previously described methods to define the blue phase liquid crystal temperature range.
In our experiment, we use different ways to recognized liquid crystal. We have used polarizing microscope, DSC, Kossel diagram and measuring reflectance spectra. We cannot see blue phase by polarizing microscope and Kossel diagram because the blue phase liquid crystal reflectance spectra in the non-visible light. The liquid crystal material absorbs the UV light. Our DSC resolution is not enough to found the blue phase temperature range. When we recognized liquid crystal, we found the light run through the liquid crystal box. In different phase have different lateral scattering intensity. When we cooling temperature can found the lateral scattering intensity is weak in isotropic. When we phase enter the blue phase II, the lateral scattering intensity rise slowly. When the blue phase II into the blue phase I, we can see first decreased and then increased curve. Last when into the cholesterol phase, the lateral scattering intensity rises quickly. We observe this property can discriminate the blue phase temperature range.
When we found the blue phase temperature range, we analyze the hysteresis and drive voltage in different curing temperature. We found this material property. When we curing in high temperature. The drive voltage has decrease, but the hysteresis has increase. When curing in low temperature. The drive voltage has increase, but the hysteresis has decrease. Last we use SEM analyze the polymer structure. But we lost the slight polymer structure when we wash the liquid crystal. So we cannot analyze the slight polymer structure.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0726112-021734 |
| Date | 26 July 2012 |
| Creators | Liao, Po-Hsuan |
| Contributors | Andy Ying-Guey Fun, Shie-Chang Jeng, Wen-Jun Zheng, Wei Lee, Tsung-Hsien Lin |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0726112-021734 |
| Rights | user_define, Copyright information available at source archive |
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