Transitions of bipolar to radial orientation of liquid crystal droplets in amphiphilic system of PDLC film

ABSTRACT

The orientation order of nanoscale droplets of thermotropic liquid crystals (LCs) suspended in polymer dispersed liquid crystal (PDLC) solutions prepared with different medias (e.g., polymers, surfactants, nonpolar materials like dyes) respond sensitively and differently via molecular interactions. Such a valuable knowledge provides basis for understanding the properties of PDLC devices. Previously, many studies have explored the droplets size, electro-optical property variations in PDLC films by varying the materials types and its compositions. However, the variations in droplet orientation order with respect to material type and composition provide a new class of study in this particular field. The current study explored the transition in droplet orientation from bipolar to radial on varying the amphiphilic block copolymer concentrations. Further, the variations in surface energies of LCs in different series of block copolymer medias were investigated by contact angle measurements.

GRAPHICAL ABSTRACT

KEYWORDS:

• Liquid crystal display
• liquid crystal orientations
• optical properties
• phase separation
• Polymer dispersed liquid crystal
• surface energies

Acknowledgment

This paper was written by a part of the Konkuk University’s research support program for its faculty on sabbatical leave in 2014.