| Autor: |
Zenaida B. Domingo, Claire M. Macale, Cheryll Lei E. Mahinay, Leonorina G. Cada, Fairland F. Amos |
| Rok vydání: |
2001 |
| Předmět: |
|
| Zdroj: |
Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals. 365:305-311 |
| ISSN: |
1058-725X |
| DOI: |
10.1080/10587250108025308 |
| Popis: |
Transmittance behavior of nematic E48: polyvinylpyrrolidone (PVP) polymer dispersed liquid crystals (PDLC) is investigated in relation to the liquid crystals to polymer ratio. Five E48:PVP concentration mixtures are prepared: 75:25, 77.5:22.5, 80:20, 82.5:17.5, and 85:15. Solvent Induced Phase Separation and Thermally Induced Phase Separation techniques are used. Droplet sizes are measured using a polarizing microscope, and the 80:20 mixture prepared by slow cooling is determined to have the largest droplets. The liquid crystal cells prepared by fast cooling needed a higher switching voltage (ranging from 7V-35V) while the switching voltage of slow-cooled samples varied from 6V-47V, with most of the samples having switching voltages close to 10V. The transmittance behavior and contrast ratio of PDLC's are then investigated with a 660–680 nm light source. It is observed that fast-cooled samples had higher contrast ratios compared to slow cooled samples. Photographs of each sample are acquired to d... |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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