Control of liquid crystal droplet configuration in polymer dispersed liquid crystal with macro-iniferter polystyrene

Abstract

A polystyrene macro-iniferter was applied to control the alignment of liquid crystal molecules at the droplet wall of polymer dispersed liquid crystal (PDLC) films. The aspects of the alignment were monitored by observing the droplet in the PDLC film. With increasing the macro-iniferter polystyrene in the composition, the configuration of LC droplets changes from bipolar to radial. This is because the high concentration of the macro-iniferter polystyrene results in a small surface interaction between the LC and the polymer matrix, which favours the formation of radial configuration. The radial configuration was stable under our conditions. However, increasing the LC and the initiator concentrations resulted in the change from radial to bipolar.

Keywords:

• polymer dispersed liquid crystal
• macroinitiator
• iniferter polymerisation
• polymerisation induced phase separation
• radial configuration

Acknowledgements

We thank Professor Makoto Takeishi for helpful discussions and comments. This work was supported by the National Natural Science Foundation of China (No. 50773045) and the project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, and Science and Technology Innovation Foundation of Sichuan University (No. 2005CF09).