High dielectric properties, TiO₂ nanoparticles doped PDLC devices for lower switching voltage

ABSTRACT

Polymer dispersed liquid crystal (PDLC) films were prepared using a nematic liquid crystal, photo-curable polymer and TiO₂ nanoparticles by polymerisation-induced phase separation (PIPS) method. Electro-optical properties of doped and undoped samples including transmittance, driving voltage, contrast ratio and response time of the transmittance-voltage were measured, compared and analysed. The morphology of polymer network has been investigated by means of SEM. The phase separation of LC droplets was found to be dependent on the content of prepolymer, LC and nanoparticles used. The high dielectric properties and high refractive index of TiO₂ nanoparticles make PDLC have low driving voltage and high contrast. In particular, the nanoparticles concentration can be optimised to obtain promising electronic materials with minimum threshold and high contrast for display applications.

Graphical Abstract

KEYWORDS:

• Liquid crystal
• TiO₂ nanoparticles
• phase separation
• low driving voltage
• high contrast

Acknowledgments

This work was supported by Natural Science Basic Research Plan in Shaanxi Province of China (Program No.2021JM-531, No.2021GY-205, No.2021JQ-877), the Fundamental Research Funds for the Central Universities (Grant No. FRF-GF-19-003B), the National Natural Science Foundation of China (Grant No. 52073027, 51973017, 51773017), Scientific Research Program Funded by Shaanxi Provincial Education Department (Program No.20JK0959).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Fundamental Research Funds for the Central Universities [FRF-GF-19-003B]; Scientific Research Program Funded by Shaanxi Provincial Education Department [20JK0959]; Natural Science Basic Research Plan in Shaanxi Province of China [No.2021JM-531, No.2021GY-205, No.2021JQ-877]; the National Natural Science Foundation of China [52073027, 51973017, 51773017].