Preparation of a Thermally Light-Transmittance-Controllable Film from a Coexistent System of Polymer-Dispersed and Polymer-Stabilized Liquid Crystals

Abstract

Polymer-dispersed liquid crystal (PDLC) and polymer-stabilized liquid crystal (PSLC) systems are the two primary distinct systems in the field of liquid crystal (LC) technology, and they are differentiated by their unique microstructures. Here, we present a novel coexistent system of polymer-dispersed and polymer-stabilized liquid crystals (PD&SLCs), which forms a homeotropically aligned polymer network (HAPN) within the LC droplets after a microphase separation between the LC and polymer matrix and combines the advantages of both the PDLC and PSLC systems. Then, we prepare a novel thermally light-transmittance-controllable (TLTC) film from the PD&SLC system, where the transmittance can be reversibly changed through thermal control from a transparent to a light-scattering state. The film also combines the advantageous features of flexibility and a potential for large-scale manufacturing, and it shows significant promise in future applications from smart windows to temperature sensors.

Electro-Optical Properties of a Polymer Dispersed and Stabilized Cholesteric Liquid Crystals System Constructed by a Stepwise UV-Initiated Radical/Cationic Polymerization

“…As the LVM content increases from 0 wt% to 1.5 wt%, the threshold voltage (Vth) and the saturation voltage (Vsat) of the films, which are defined as the voltage required when the film transmittance reaches 10% and 90% of maximum transmittance, respectively, are greatly reduced. Specifically, the Vth and Vsat of the films decreases from 43.3 V/88.7 V to 32.2 V/58.8 Moreover, compared to the previously promoted PD&SChLC system, which had 3.0 wt% liquid-crystalline acrylate monomer content [21][22][23][24][25], having 1.5% LVM content in the new PD&SChLC system is the result of the two completely separated polymerizations steps. This is what we envisioned by introducing two means of aggregation, these being free radical and cationic.…”

“…Recently, a coexistent system combining the advantages of both polymer-dispersed and polymer-stabilized liquid crystals (PD&SLCs) has been developed by our group. This hybrid system is garnering substantial popularity in both academia and the industry due to its unique microstructure [21]. The produced electrically switchable PD&SChLC film not only shows a more than 50% decrease in driving voltage compared with conventional PDLC films but also possess high mechanical strength.…”

Polymorphic crystalline structure and diversified crystalline morphology of poly(butylene adipate) blended with low‐molecular‐mass liquid crystals

“…Polymer‐dispersed (or stabilized) liquid crystalline materials have been widely used in the fields such as the smart responsive and holographic films, light shutters, and electrically switchable windows . When the liquid crystals (LCs) are dispersed in or blended with semicrystalline polymers, the interplay between the phase transition of LCs and the crystallization of polymer would result in much more complicated crystalline structure and morphology of the materials; this can significantly influence the physical properties and functions of resulted materials .…”

One-step formation of infrared reflection microsheetsvialocal photo-inducedin situpolymerization

“…18,19 For the latter one, either a reliable polymer-stabilized LC (PSLC) or a sensitive polymer-dispersed LC (PDLC) smart window is generally dependent on the LC phase transition under the stimulus of applied physical signals to change the overall optical properties. [20][21][22][23] Their fundamental defect is that their transmittances are strictly limited by the circular polarization and viewing angle. More specically, PSLC is greatly affected by the inner cross-linked network in the response rate, and PDLC is only used for converting visible transparency.…”