Polymer-Stabilized Liquid Crystal Films Containing Dithienyldicyanoethene-Based Chiral Photoswitch: Multi-Modulation for Environment-Adaptative Smart Windows.

A polymer-stabilized liquid crystal (PSLC) based environment-adaptative smart window with multi-modulations is demonstrated. This PSLC system contains a right-handed dithienyldicyanoethene-based chiral photoswitch and a chiral dopant S811 with the opposite handedness, of which the reversible cis-trans photoisomerization of the switch can drive the self-shading of the smart window under UV light stimulus because of the transition from nematic phase to cholesteric one. With the assistance of solar heat, the opacity of the smart window can be deepened due to that heat promotes the isomerization conversion rate of the switch. This switch has no thermal relaxation, so the smart window exhibits dual stabilization: transparent state (cis-isomer) and opaque state (trans-isomer). Meanwhile, the throughput of sunlight can be regulated by an electric field, which meets the need in some specific situations. Such an energy-saving device can be applied to buildings and vehicles to control indoor temperature and adapt to the required ambiance.