Xiangshen Meng,Jian Li,Yueqiang Lin,Xiaodong Liu,Jianwei Zhao,Decai Li,Zhenghong He
The electro-optical features of the PDLC films applied with a low-frequency square wave voltage were investigated. The transmittance curves indicated the double frequency of the applied voltage at 0–50 Hz, which resulted from the relaxation of an internal electric field polarized by ions in LC droplets. When the local electric field was reversed, the internal polarization electric field could be maintained and superimposed on the local electric field. The relaxation of the internal polarized electric field resulted in the relaxation of the transmittance. Furthermore, the transmittance curves changed with the frequency of the applied voltage.Keywords:PDLC;ion;square-wave voltage;effective electric field
In this work, the methods of doping different fluorine-containing monomers and fluorine-containing nanoparticles into the mixture were adopted to boost the electro-optical performance of PDLC films. The electro-optical measurements indicate the improved electro-optical performance of PDLCs through the introduction of MX-3 monomer, and the corresponded SEM results demonstrate the successful adjustment of surface morphology. Further doping F-Si@SiO2 nanoparticles into MX-3 monomer-modified PDLC system, the Vth and Vsat values are greatly reduced and reach lowest when F-Si@SiO2 content is 5 wt.%. The enhanced electro-optical property is due to the combined control of fluorine-containing MX-3 monomer and F-Si@SiO2 nanoparticles, the fluorine functional group can promote the uniform dispersion of nanoparticles; the existence of F-Si@SiO2 nanoparticles can regulate the anchoring effect on liquid crystal molecules in the polymer matrix, thus electric-optic characteristics of the PDLC materials are greatly enhanced.
Yong Wu,Hui Cao,Manyu Duan,Erli Li,Huihui Wang,Zhou Yang,Dong Wang,Wanli He
Polymer dispersed liquid crystal (PDLC) films are fabricated by well-known polymerization-induced phase separation method. In this paper, the dispersion of multi-walled carbon nanotubes (MWCNT) in liquid crystals has been enhanced by chemical modification and we have investigated their effects on the morphology, electro-optical properties and conductivity of the PDLC films. Results indicated that the threshold voltage and the saturation voltage of PDLC films decreased with the increase of the doping concentration of MWCNT or chemically modified MWCNT, because carbon nanotubes can enhance the electric field by reducing the resistivity of the medium and increasing the capacitance of the cells. It can be viewed obviously that the contrast ratio of the PDLC films doped with the chemically modified MWCNT is higher than that of the MWCNT.
In this paper, polymer-dispersed liquid crystal (PDLC) films were prepared from a blend of prepolymer, liquid crystal and BaTiO 3 (BTO) nanoparticle-laden nanofibres films by a polymerisation-induced phase separation (PIPS) method. By contrasting the microstructure and electro-optical curves of various proportions of monomer types, it was demonstrated that the hole size of the polymer network had a significant influence on the electro-optical nature of the PDLC films. nanofibres films loaded with different BTO nanoparticle contents were introduced into the liquid crystal mixture specimens, and the alterations in the polymer network, electro-optical nature of these specimens were analysed using SEM images, EDS and electro-optical curves. The electro-optical nature of the nanofibres films doped with PDLCs were found to be improved and the ageing resistance was greatly enhanced. Therefore, the development of PDLC films with faster response times and better electro-optical nature of reticular nanofibres films doped with PDLCs will significantly improve the promising technological applications of PDLC-based equipment for optical windows, displays, energy storage and flexible devices.
危险品化学品经营许可证（带存储）