Color is a substance that has a certain color in itself and can color other objects. According to the solubility in the solvent, the color can be divided into two categories of dyes and pigments, in the relevant literature, the two are often mixed as – talk. Both dyes and pigments can be called colors. Color material is a non-luminous body, and its color mainly depends on its absorption and reflection of external light.
Many practical luminescent materials have been developed. Here, fluorescent dyes and fluorescent pigments are collectively referred to as fluorescent colors. The so-called fluorescent material is a substance that can emit fluorescence after being excited by visible light, ultraviolet light, X-ray and electron rays and other exciting sources, and its luminescence can also maintain a certain time after irradiation. When the fluorescent material is excited by ultraviolet light, part of ultraviolet light will be reflected by the surface of the fluorescent material. The other part is absorbed by the fluorescent material, converted into fluorescent radiation, or in the form of lattice vibration, the absorbed energy is converted into heat consumption. Fluorescent materials, also known as photoluminescent materials, are essentially a process of light energy conversion, in which the energy absorbed by molecules is dissipated in the form of fluorescence. Photoluminescent materials also include phosphorescent materials. Fluorescent materials are particularly important, and their applications are also the most widespread.
There are three main types of fluorescent materials according to their composition. ① Organic fluorescent materials. Organic fluorescent materials are unsaturated molecules with a large common system, usually poor stability, easy oxidation decomposition, but because its fluorescence intensity is not affected by the fineness of processing
At the same time, it has good affinity with many carriers and is easy to process and display color, so it is widely used. The modified organic fluorescent materials have better stability. ② Inorganic fluorescent materials. Inorganic fluorescent compounds have high stability, but their fluorescence intensity is greatly affected by the fineness of processing, so their application in many fields is limited. The inorganic fluorescent material synthesized by high temperature is the luminous material used for the fluorescent screen and daylight lamp tube, which has good radiation resistance and high stability, but it is difficult to disperse in oily media, high synthesis difficulty and poor water resistance. ③ Chemical synthesis of rare earth organic complex fluorescent materials.
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