Quasi-Ordered Nanosphere-Based Photonic Crystals with High- Fastness Structural Colors via Screen Printing: Implications for Textile Printing and Dyeing

Patterned photonic crystals (PCs) have great development potential in the textile field because of their unique high-saturation iridescent pattern displays. Herein, PC-produced patterns were printed on the fabric surface via screen printing technology. The nanosphere dispersion has reached the required level of viscosity for printing (2435 mPa s) and possessed obvious shear thinning after adding 2.5 wt% of synthetic thickener with strong thickening ability. The interference of the thickener to the self-assembly of nanospheres was weakened as the synthetic thickener accounted for a small proportion in the printing precursor, so the regularity of the microstructure evolution of the assembled PCs was in quasi-ordered arrangement that is short-range order/long-range quasi-order. Therefore, the structurally colored PC pattern exhibited a visual "flicker" effect with certain angular dependence. In addition, the polymer-bearing layer pretreated on the fabric surface enabled to improve the structural stability of the PC pattern. Thus, the patterned PCs obtained via screen printing have promising applications in textile coloration industry.