关键词: 结构色薄膜, 加色法, 全光谱色, 光子晶体, SiO₂纳米颗粒

Abstract:

Objective Structural colors have the advantages of brilliant colors and no pollution to the environment, and are of great interest in textile coloration. However, because one structural color corresponds to one particle size, the workload of using the method of preparing spheres with different particle sizes to achieve the full spectrum of structure colors is heavy, and the amorphous photonic crystals will be affected by non-correlated scattered light, resulting in poor saturation of structure color films, which is not suitable for the industrial development of structural colors. In this work, a simple method for preparing highly saturated, fully visible spectrum structural colors is proposed. The effective construction of highly saturated, full visible spectrum structural colors is achieved by mixing SiO₂ of different particle sizes in different ratios to adjust the crystal plane distance and adding ink to increase the saturation of structure color films. This method improves the preparation efficiency of structural colors and further promotes the rapid preparation of full visible spectrum structural colors.
Method In this paper, SiO₂ nanoparticles with uniform particle sizes of 304, 260 and 200 nm were synthesized by solvent modulation method. The three different particle sizes of SiO₂ suspensions were mixed two by two according to different mass ratios by using the principle of three-primary additive color method, and the ink was added to the mixed ratio of SiO₂ suspensions to absorb part of the incoherent scattered light and background light. Colloidal particles were self-assembled on glass sheets by gravity sedimentation method, and full spectrum amorphous photonic crystal structure color films were successfully prepared.
Results The wavelength of the reflection peak of the structure color film of the photonic crystal decreases uniformly with the increase of the proportion of smaller size SiO₂. The blue shift phenomenon occurs in the structural color, which is due to the increase of the proportion of smaller size SiO₂ making the lattice distance decrease uniformly. The wavelength of the photonic crystal also decreases following the Bragg's diffraction law. With the increase of ink content, the structural color lightness gradually decreases, and the chromaticity first increases and then decreases, and the structural color saturation is the best when the ink content is 0.4%. When the ink is added, the structural color appears reddish and yellowish. By measuring the CIE color space of the ink, it is found that the ink itself is reddish and yellowish, which explains the color redshift phenomenon of the SiO₂/ink amorphous photonic crystal film.
Conclusion In this study, SiO₂ nanoparticles with different particle sizes are prepared, and a full spectrum structural color film is prepared by the principle of additive color method and the saturation of photonic crystal structural color is improved by adding ink. The method is simple, efficient, and reduces cost of preparing full spectrum structural colors. It has great potential in the textile coloration and finishing industry, contributing to solving the problems of high pollution and high energy consumption in textile printing and coloration process, and promoting the industrialization of photonic crystal structural colors.

Key words: structure color film, additive color method, full spectrum color, photonic crystal, SiO₂ nanoparticle