Preparation of dye-doped polymer-dispersed liquid crystals using acrylic monomers, and enhancement of contrast by using THF solvent as a cleaning agent

• Main Authors: Ming-yu Chen, 陳名俞
• Other Authors: Jiunn-yih Lee
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/91701516091710046806

碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 101 === Polymer-dispersed liquid crystal (PDLC), with characteristics of high contrast and low driving voltage, has found many product applications and is an important material for new generations. In this experiment, we used 2-Phenoxy ethyl acrylate (2-PEA) and Tripropxlene Glycol Diacrylate (TPGDA), two acrylic monomers, to prepare PDLC, and we compared various preparation conditions in order to investigate the impact of structural properties on the optical behavior of PDLC. While maintaining the low driving voltage and high contrast of a PDLC, a dichroic dye was added to turn the device into a dye-doped PDLC. Using polarized light microscopye, it was observed that direct injection of the dye resulted in overflow of the dichroic dye into the outside of the thin film, reducing the contrast of the PDLC. Therefore, we utilized tetrahydrofuran (THF) solvent to wash away the liquid crystal (LC) from the PDLC, followed by re-addition of the dye-containing LC. This successfully solved the dye overflow problem and was found to enhance the PDLC contrast effectively.