全光谱SiO2结构色薄膜的加色法制备及其光学性能

为解决在制备不同粒径的小球来实现全光谱结构色过程中工作量大的问题，采用溶剂调控法合成粒径均匀的304、260、200 nm的SiO₂纳米颗粒，利用三原色加色法原理将3种不同粒径的纳米SiO₂悬浮液按照不同质量比两两混合，然后放在烘箱中进行重力沉降自组装，制备出全光谱非晶光子晶体结构色薄膜，探究混合比例对SiO₂光子晶体结构色的影响。同时为提高结构色的饱和度，将墨水添加到不同混合比例的SiO₂悬浮液中，研究墨水质量分数对光子晶体结构色的影响。结果表明：随着小粒径SiO₂比例的增加，结构色会出现蓝移现象；墨水质量分数越高，结构色亮度越低，色度呈先增加后减小趋势，当墨水质量分数为0.4%时，结构色饱和度最好。

Preparation and optical properties of full spectrum SiO2 structure color films by additive color method

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.