Effect of droplet size on the dielectric properties of PDLC films

✍ Scribed by Sung-Chang Peng; Jiunn-Wen Yu; Sung-Nung Lee

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 206 KB
• Volume: 35
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(19970715)35:9<1373::aid-polb7>3.0.co;2-n

✦ Synopsis

Polymer dispersed liquid crystal (PDLC) films (5CB/PMMA, 60/40) of different droplet size were prepared by a solvent-induced phase separation method under different N 2 flow speeds. The effects of droplet size on the thermal transitions of the LC and various dielectric properties such as dielectric constant, conductance, dielectric loss, and the electric field induced in a droplet were examined. The configuration of the LC in the film with smaller droplets can be identified by comparing the dielectric constant of the film with the one predicted by Boettcher's mixture formula. In addition, the effect of droplet size on the electro-optical response of the PDLC film was investigated. Variations of the conductance and the dielectric constant of the film were analyzed under various AC frequencies, with the purpose of elucidating the polarization mechanism of the LC molecules in the droplet.