Latex-Stabilized Cholesteric Liquid Crystal Coatings for Thermochromic Textiles*

Cholesteric liquid crystals (CLCs) dispersed in commercial water-based latex varnish (CLC-Latex) are coated on yarns and fabrics. The CLC-latex coatings displayed bright and stable colors that change with temperature. The optical and stability properties of CLC-latex coated polyester fibers are better than found before using conventional polymer dispersed liquid crystals  and comparable to that planar CLCs clads overcoated with polymer layer [1]. We also sprayed the CLC-Latex on fabrics and found them comparable with fabric coated by commercially available thermochromic liquid crystal inks. We find that the excellent brightness is due to the flattening of the phase separated CLC droplets during the water evaporation from the latex varnishes. These CLC-latex coatings are also durable, environmentally friendly, inexpensive, and easy to coat on fibers and fabrics. The resulting smart textiles could be used for numerous biosensing, medical and decorative applications.