The effect of doping sulphhydryl-functionalised silica with different diameters on the electro-optical properties of PDLC

ABSTRACT

In this study, we synthesised two kinds of spherical SiO₂-SH particles with uniform and non-uniform morphologies, and investigated their effects on the electro-optical properties of PDLC. Compared with uniform SiO₂-SH nanoparticles, we found that the samples doped with non-uniform SiO₂-SH regulate the electro-optical properties of PDLC better. The electro-optical properties test results demonstrated that doping a small amount of SiO₂-SH with different sizes significantly reduced the driving voltage of PDLC and maintained a high contrast ratio. SEM results indicated that the size of the polymer meshes was broadened with increasing SiO₂-SH doping. This phenomenon can be attributed to the larger specific surface area and higher concentration of sulphhydryl groups in SiO₂-SH particles of different sizes. These characteristics enable SiO₂-SH to better react with acrylate monomers, thereby improving modulation effects on the electro-optical properties of PDLC. However, when the doping amount exceeded a certain value, the driving voltage of PDLC began to rise, and its electro-optical properties deteriorated because of the agglomeration of nanoparticles at higher doping levels. This study demonstrated that doping SiO₂-SH particles of different sizes can optimise the properties of PDLC, which provided new ideas and directions for doping PDLC with nanomaterials.

GRAPHICAL ABSTRACT

KEYWORDS:

• Polymer dispersed liquid crystal
• SiO₂-SH
• driving voltage
• electro-optical properties

Disclosure statement

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

Additional information

Funding

Financial support from the National Natural Science Foundation [Grant No. 52263033], China Postdoctoral Science Foundation Funded Project [Grant No. 2021M690954], Natural Science Foundation of Gansu Province [Grant No. 20JR10RA105], the Natural Science Basic Research Plan in Shaanxi Province of China [No.2024JC-YBMS-445], the Natural Science Foundation of Hunan Province [Grant No. 2022JJ30152], and the graduate research funding project of Northwest Normal University [Grant No. 2023KYZZ-S157] are gratefully acknowledged.