Self-cleaning and anti-counterfeiting structural color coating based on fluorescent SiO2@PPy@CQDs microspheres

Photonic crystals (PCs) structural color coatings have been widely studied due to their advantages of environmental friendliness, resistance to fading and high color saturation. However, they still have problems such as single function and being easily affected by the external environment. In this research, fluorescent SiO 2 @polypyrrole@carbon quantum dots (SiO 2 @PPy@CQDs) microspheres were synthesized by incorporating CQDs into SiO 2 @PPy microspheres, which were self-assembled on the white cotton fabrics to form an amorphous photonic structure (APS). These APS exhibited angle-independent structural colors under natural light and blue fluorescence under UV light. The structural colored cotton fabrics obtained superhydrophobicity with a water contact angle (WCA) greater than 150° and self-cleaning function after treatment with polydimethylsiloxane (PDMS). The anti-counterfeiting structural colored fabrics with single response to UV light and dual responses to water/UV light based on SiO 2 @PPy@CQDs, SiO 2 @PPy and SiO 2 microspheres were prepared by using multi-layer alternating atomization deposition and PDMS hydrophobic treatment processes. This study provides a novel approach for developing multifunctional structural color coatings with self-cleaning and anti-counterfeiting based on fluorescent organic/inorganic hybrid microspheres.