A comparison of smart window approaches with polymer-modified and gel-glass dispersed liquid crystals

Various approaches to smart windows, including polymer-stabilised, polymer-dispersed, and gel-glass dispersed liquid crystals (GDLC), are discussed with respect to their electro-optic performance based on diffuse reflectivity. The diffuse backward scattering of different devices under an electric field is analysed in detail. The study focuses on the novelty of GDLCs, which utilised a sol–gel derived matrix embedded with a nematic liquid crystal. The unique porous architecture and surface anchoring of GDLCs enhances the electro-optic properties. A comparison between three polymer-modified liquid crystal systems and the GDLC system demonstrates that GDLC provide new opportunities for optical devices, exhibiting lower switch-on voltage, smaller voltages required to achieve stable states and small voltage hysteresis.