A model organic pigment (diketopyrrolopyrrole) is encapsulated by a silica coating in order to improve its photochemical stability. Unlike in previous works where single-layer silica coatings were used for similar purposes, we here propose creation of a multi-layer silica shell synthesized via in-situ sol-gel method, which should significantly improve the homogeneity and thus the protection ability of the coating. This is done by repeating the basic two-step process (pigment surface modification and silica encapsulation) several times, creating the final protective shell in a layer-by-layer fashion. The compositional and structural properties of the prepared coatings is studied using Fourier-transform infrared spectroscopy, differential thermal and thermogravimetric analysis, nitrogen adsorption measurements and transmission electron microscopy. Photochemical stability of non-encapsulated and encapsulated pigment particles is evaluated via the so-called fast-irradiation method. Various correlations between the essential coating properties, such as thickness, porosity, SiO₂ content, and the corresponding photochemical stability of the samples are established and discussed in detail. As a whole, our results confirm the basic hypothesis, that multiple-layered silica shells show improved pigment protection ability in comparison to the single-layer coatings.

为了改善其光化学稳定性，模型有机颜料（二酮吡咯并吡咯）被二氧化硅涂层包裹。与以前的将单层二氧化硅涂层用于类似目的的工作不同，我们在此建议通过现场合成合成多层二氧化硅壳溶胶-凝胶法，应显着提高涂层的均匀性，从而提高涂层的保护能力。这是通过重复几次基本的两步过程（颜料表面改性和二氧化硅封装）来完成的，以逐层的方式创建最终的保护壳。使用傅立叶变换红外光谱，差示热和热重分析，氮吸附测量和透射电子显微镜研究了所制备涂层的组成和结构性能。通过所谓的快速照射法评价未包封和包封的颜料颗粒的光化学稳定性。基本涂层性能之间的各种相关性，例如厚度，孔隙率，SiO ₂建立并详细讨论了样品的含量和相应的光化学稳定性。总体而言，我们的结果证实了基本假设，即与单层涂料相比，多层二氧化硅壳显示出更高的颜料保护能力。