Uniaxially Oriented and Polymerized Chromonic Nanocolumns for Redox-Responsive Smart Glass

Abstract

Bandwidth-tunable anisotropic spatial light modulators are fabricated with redox-responsive dichroic mesogens. By introducing an ionic group and a polymerizable group into the chromophore, the programmed reactive mesogen (PDI-MA) exhibits a lyotropic chromonic liquid crystal (LCLC) phase. The PDI-MA molecule forms a stable aromatic dianion state so that the absorption wavelengths of the dichroic mesogen can be reversibly tuned by redox reactions. Through a continuous process of coating, molecular self-assembly, and polymerization, redox-responsive and uniaxially oriented LCLC polymer films are fabricated. Because of the high dichroic ratio of PDI-MA, the uniaxially oriented LCLC network is capable of anisotropic light modulation in the visible-light spectrum. Uniaxially oriented LCLC films are applied to flexible multichromic smart windows and optical security filters for anticounterfeiting.