Five applications of photochromic materials

In recent years, organic photochromic materials have gradually stepped out of the traditional application of optical information storage and other high-tech fields, and began to emerge in the civil field, especially in clothing, plastics and coatings. Fashion camouflage clothing, color-changing shirts, color-changing shoes on the market, showing the magic effect of organic photochromic materials. In addition, the application of organic photochromic materials in self-developing photographic film and holographic materials, anti-counterfeiting identification technology, military camouflage materials and other fields is also increasing, and the market prospect is promising.

Organic photochromic materials are a new type of light functional materials, in daylight or other light source irradiation can quickly change from colorless or light color into red, green, blue, purple and other colors, and with another light source irradiation or avoid light can return to the original state, and can repeatedly reversible change.

Nankai University student graduation certificate security seal, is also the earliest application of this technology in anti-counterfeiting identification technology. Subsequently, the technology has been applied in clothing, decoration, ink, paint, plastic and other fields, producing color-changing clothing, color-changing sandals, color-changing glasses, etc. Military camouflage materials have also been successfully developed, and chameleon camouflage suits and other color-changing materials are becoming more and more mature. In 2010, Tianjin Fuxin Technology Co., Ltd. upgraded the industrialization of the technology, so that the organic photochromic material technology from the laboratory into the industrialization stage, the production of more than ten kinds of new photochromic materials with national invention patent technology protection, successfully entered the market application, at the same time has developed a variety of civilian photochromic products.

The five main directions of application of photochromic materials are:
1. Application field of people's livelihood
Mainly photochromic coatings, photochromic polymer materials. Photochromic clothing, textiles, clothing, children's clothing, T-shirts and other products have entered mature applications. Photochromic paints, inks, coatings, decorative materials and other varieties have been developed successfully. Photochromic glasses, handicrafts, ornaments, children's toys, intellectual Rubik's cube, light pen dust-free blackboard, photochromic resin plastic film, photochromic plastic products have been marketed.
2. Optical information storage materials
Photochromic material is bistable material, before and after the light is stable, with a light can store the information in, with another light can take out the information, storage information, stable performance, can be used to make R-CD, photochromic computer, it than electronic computer storage information, It is a very hot high-tech project with higher integration, faster computing speed (which can be improved by 2 ~ 3 orders of magnitude), simpler structure and no heat.
3. Self-developing photosensitive film and holographic material can prepare non-silver special photosensitive film by using photochromic material's sensitivity to light radiation. This kind of photosensitive film can be developed by light irradiation of specific wavelength, and all recorded information can be erased by light irradiation of another wavelength, which not only solves the problem of silver salt toxicity, but also can be used repeatedly. Omit the film repeated processing process. The photochromic material is used to make holographic film, which saves the complicated processing process of film processing, and has the advantages of high image solving force and higher signal-to-noise ratio.
4, anti-counterfeiting identification technology
Photochromic materials can be used for anti-counterfeiting identification of valuable commodities. Unique photochromic materials for valuable commodities anti-counterfeiting identification technology, can be intuitive dual anti-counterfeiting identification, anti-counterfeiting mark under the light discoloration, not only can the public anti-counterfeiting identification, but also instrument testing identification, with the visible ultraviolet spectrometer to measure its unique absorption wavelength, can distinguish the true and false.
5. Military concealed camouflage materials
Photochromic materials can not only be used in fixed buildings, national defense and military targets camouflage materials, these targets use the color change of photochromic materials, make them blend into nature camouflage, satellite and other reconnaissance means is not easy to find its true face; The material can also be applied to active military targets, people, weapons and equipment, transportation and other concealed camouflage, the use of photochromic material color changes to these targets, so that they and nature are integrated, so that satellites and other reconnaissance means are not easy to distinguish the true and false, to achieve the purpose of defense.

Japan began to study organic photochromic materials in the early 1980s. However, due to the narrow application field at that time, it did not develop further. At present, the research and development level of the last century is still stuck, and there is no large-scale production in industry. In recent years, Europe and the United States also began to set foot in the field of organic photochromic material application, but its main technology originated from Japan.

Organic photochromic materials began in the 1980s. Nankai University is the first institution engaged in the basic research and application development of organic photochromic materials at home and abroad. The Technical Institute of Physics and Chemistry of the Chinese Academy of Sciences has made good progress in the research of organic photochromic materials in the field of optical information storage.