High-Performance Thermoresponsive Dual-Output Dye System for Smart Textile Application

Smart textiles exhibiting optical response to external temperature stimuli are promising functional materials for a wide range of applications. It is critical yet challenging to endow these materials with high-contrast, vivid, and real-time optical signals, such as changes in color or fluorescent emission, for the indication of heating and/or cooling. A thermoresponsive dye system featuring simultaneous thermochromism and thermofluorescence is developed and applied to dyeing of polyester fabrics. The dye system is constructed by encapsulating a solution of indenoquinacridone (IQA) in aliphatic alcohol into SiO2 nanoparticles. The dual-output response relies on the mechanism of solvent-modulated dissociation/aggregation of the IQA molecules. Upon heating, the dye system and the dyed fabric exhibit clear color change and high-contrast, turned-on fluorescence, in a real time and highly reversible manner. The thermoresponsive temperature can be tailored by varying the aliphatic alcohol solvent with different melting point. The integration of high-contrast dual optical outputs into this programmable, robust, and reversible dye system lays the foundation for its employment in a wide range of challenging applications in smart textiles.