Electro-optical properties of PDLC films using diethylenetriamine (DETA) hardener

ABSTRACT

The author's results obtained today and in previous works are summarized. The present work has been performed to investigate the effects of the structure and electro-optical (E-O) properties of epoxy resin based polymer dispersed liquid crystal (PDLC) films smart glass using Diethylenetriamine (DETA) as hardener with 4-cyano-4′-penthylbiphenyl (5CB) liquid crystal. In this study we have been prepared PDLC films by the thermal polymerization-induced phase separation (PIPS) method, with a thickness of 10.0 ± 1.0 μm controlled by a polyethylene terephathalate (PET) spacer and optimal preparation condition were 25% and 30% 5CB LC, respectively, with a curing time 7 hours at 70°c temperature. In addition, PDLC films were prepared with different amounts of DETA to investigate the best ratio of the hardener. Results showed that when the weight ratio of LC 5CB was 30% in PDLC and mol 3% of DETA hardener, then dispersed state of LC were well proportioned, and the variation of transmittance reached the highest value. The optical characterization of the PDLC film indicates an improvement of the angular transmission of visible light. Meanwhile, it is examined that by adjusting the mol% of hardener and LC 5CB content possesses good E-O properties with a low energy efficient method for preparing PDLC smart glass display technology.

KEYWORDS:

• Diethylenetriamine
• electro-optical properties (E-O)
• epoxy resins
• polymer dispersed liquid crystal
• smart glass

Acknowledgments

This work was supported by the HEC fund for distinguished Young Scholars and the research fund of the State Key Laboratory for Advanced Metals and Materials. The authors wish to express appreciation to the QUA University and University of Karachi for laboratory experiment support and technical assistance.