A Comprehensive Review on Polymer-Dispersed Liquid\nCrystals: Mechanisms, Materials, and Applications

Polymer-dispersed\nliquid crystals (PDLCs) stand at the intersection\nof polymer science and liquid crystal technology, offering a unique\nblend of optical versatility and mechanical durability. These composite\nmaterials are composed of droplets of liquid crystals interspersed\nin a matrix of polymeric materials, harnessing the optical properties\nof liquid crystals while benefiting from the structural integrity\nof polymers. The responsiveness of LCs combined with the mechanical\nrigidity of polymers make polymer/LC compositeswhere the polymer\nnetwork or matrix is used to stabilize and modify the LC phaseextremely\nimportant for scientists developing novel adaptive optical devices.\nPDLCs have garnered significant attention due to their ability to\nmodulate light transmission properties, making them ideal candidates\nfor applications ranging from smart windows and displays to light\nshutters and privacy filters. The incorporation of different ferroelectric,\nthermoelectric, magnetic, and ferromagnetic nanoparticles, quantum\ndots, nanorods, and a variety of dyes in the PDLC matrix has gained\nmomentum over a span of few decades, as it lowers the otherwise-required\nhigh operating voltage and reduces the electro-optical response time\nof these devices. Due to better contrast in the transmittance of these\nmaterials in the field-off and on states, they find extensively wide\napplication in a variety of photonic applications, viz., optical shutters\nand smart windows, photorefractives, modern displays, microlens arrays\nencompassing polymer-gravel lenses, and many other. Since the functional\nparameters of these devices embrace the thermophysical attributes\nof PDLC networks, it therefore becomes necessary to perform a detailed\nanalysis of the properties of PDLCs and their ameliorations upon the\naddition of different dopants. This Review aims to review the recent\nadvances in PDLCs and their enrichment in terms of their performance\nparameters upon the addition of a variety of dopants, as well as the\nimprovement of different photonic applications owing to superior parametric\nimplementation of these networks.