(1) Printing and dyeing chemical industry
In order to make clothes rich in color, dyeing has become an important link in the textile system. The synthesis of pigments finally became independent and became a branch of chemical industry, thus giving rise to the profession of fine chemicals. Corresponding to it is the daily chemical industry, which specializes in the production of cosmetics, skin protection products, detergents, and cleaners. There is also the pharmaceutical chemical industry, which specializes in the production of western medicine, sterilization, disease treatment, and health care; and the military chemical industry, which produces explosives and explosives. ; Of course there is also the food chemical industry, which produces sweeteners, food additives, etc.
In order to pursue visual beauty, people started coloring fibers almost at the same time as the application of natural fibers such as cotton, linen, and silk. First, dyes are extracted from plants. Many plant stems, leaves, and flowers can be used as dyes, such as the red of madder, the yellow of sophora, and the blue of magnolia. Some are obtained from minerals, such as Chinese painting pigments cinnabar red, lapis lazuli blue, azurite blue, malachite green, androgynous yellow, hematite brown red, etc.
The rise of Western chemical science in the 15th and 16th centuries, and the rise of the industrial revolution in the 17th and 18th centuries, led to the development of artificial dyes, resulting in the birth of Prussian blue and other widely used dyes. In the 20th century, new dyes emerged one after another, and people's clothes entered a world of colorful colors.
(2) The source of metallic luster
This article will mention two dyes: one is metallic dyes, and the other is fluorescent dyes.
In the late 20th century, shiny golden and silver coats that looked like metal appeared on the stage, but they were extremely soft and not metal products at all.
In the 1980s, several staff members of the Ministry of Light Industry went to Shanxi District to ask where sericite schist was found in Shanxi, especially in places with high sericite content. The staff of the General Engineering Office introduced them to me for further understanding. They said: By processing sericite, you can produce dyes that shine with gold and silver. And this dye is actually grinding sericite into a finer paint. The reason why the Ministry of Light Industry does not want muscovite schist and chooses sericite with finer crystallization is because muscovite with large flakes is much more difficult to crush than sericite. Sericite schist itself is an aggregate of fine-crystalline or microcrystalline muscovite, so it is broken It's easier to get up.
Based on this, I learned that the dye paint that looked like metallic luster turned out to be sericite fragments. From this, it is not difficult to imagine that the "bronze figures" in tourist areas, squares or roadside may be clay figures or even real people painted with sericite colorant to give them a bronze color. Many curious people couldn't help but touch their hands and feet. They didn't move or even blink their eyes, making it difficult to tell whether they were real or fake. For example, in many places such as squares and shopping streets in Yuci, Shanxi Province, there are clay sculptures of ancient bronze figures, including vat menders, knife sharpeners, accountants, bodyguards, donkey drivers, etc. The human-sized statues are lifelike, like The real person stands on the pedestrian street and the Old Town Square.
(3) Fluorescence effect
Since the 1980s, fluorescent signs have appeared on both sides of the road, especially along highways. When car headlights are illuminated, the signs emit dazzling fluorescence. As soon as the car passed by, it was immediately dark. Later, traffic police, cleaning workers, etc. also wore fluorescent vests or coats. At the beginning of the 21st century, girls’ dresses had fluorescent ribbons, and children’s sneakers also had fluorescent soles. Fluorescence has gradually entered people's lives.
There are fireflies in nature, which are bioluminescent. Even if they are crushed, they will glow for a few seconds. Before the 1960s, there were luminous watches on hand, which could display the time even in the darkest of nights. In the 1980s, I also bought a luminous wall clock for my home. When I tried it in a shopping mall, the wall clock was indeed fluorescent when I moved it into a dark room. However, when I bought it home, when the light was turned off, the wall clock lost its fluorescence in a minute or two, and it couldn't function. See the role of time at night.
In the 1990s, I went to give lectures at the Bureau of Geology and Mines under the Ministry of Nuclear Industry. The chief engineer of the unit told me a story about a radioactive prospector who found radioactive anomalies almost every day. Later, investigation revealed that he had a "luminous watch" on his hand. Luminous watches have high radioactive intensity. The radioactive anomalies he discovered in the wild turned out to be caused by his watch. This incident left a deep impression on me. It turns out that fluorescent substances contain strong radioactive substances, which are harmful to the body.
After checking the information, I realized that fluorescence emits light when excited by external energy. This external energy can be ultraviolet light, visible light, biological energy, or radioactive substances.
Luminous watches before the 1960s were made by mixing radioactive minerals and phosphor powder. The radioactive rays always acted on the phosphor powder, causing the hands and numbers of the watch to fluoresce. After the 1980s, phosphors no longer added radioactive minerals that are harmful to the human body. They only emit light when stimulated by indoor light, which of course does not cause harm to the human body.
Data show that zinc sulfide and cadmium sulfide will fluoresce as long as they are exposed to visible light, while strontium aluminate can emit light under the action of electricity, and mercury will also emit light under a certain voltage, but this is a photoelectric effect rather than a fluorescence effect.