Market building technologies does not stand still and periodically surprises consumers with its novelties. One of them is invisible in daylight ultraviolet paint, which is widely used by decorators and designers today.
Its name involuntarily evokes fantastic associations, although in fact it is quite a common material for interior decoration.
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The range of such products can be roughly divided into two groups:
- luminescent;
- fluorescent.
Each has its own special properties that determine the specifics of their application, as well as a wide range of colors. These materials are based on insoluble and opaque alkyd or water-based pigments. Afternoon on light surfaces they are practically invisible, at the same time on dark surfaces they look like whitish traces.
Let's dwell a little on pigments, since it would be good to know more information about them when painting any surface. For example, each coloring agent has such a characteristic as hiding power, i.e. how much material is required to paint the conditional amount of a unit of area.
If you take an ultramarine pigment, you will need about 50 g / 1 m 2. By the way, not many people know from which mineral ultramarine paint is obtained: natural from lapis lazuli, but artificially- from a mixture of kaolin, Glauber's salt, soda, sulfur and coal.
Azure can be used as a stand-alone shade or used to enhance color. Now you know what ultramarine paint is made of - from which mineral it was first obtained, and you can always give the correct answer.
Fluorescent
- Invisible paint, glowing in ultraviolet light, brightly acidic shades.
- Colors of paint:
- lemon;
- yellow;
- blue;
- blue;
- red;
- brown;
- purple;
- mustard;
- purple;
as well as other colors.
- Invisible black acrylic paint does not glow in ultraviolet rays, but it makes it possible to create 3D shadows in drawings.
- The material is used for design:
- living quarters;
- clubs;
- restaurants;
- and decoration of textiles and sports equipment;
- signal signs.
Luminescent
This type of invisible paint can accumulate light energy, which then gradually gives off, glowing in the dark.
The duration and intensity of the glow depends on:
- pigments and their quality;
- intensity and time of light irradiation of the material;
- base layer colors;
- degree of illumination.
In normal light, it has a pale greenish tint, but in the dark it begins to glow with a bright corresponding color.
Luminescent paints can be used:
- yellow;
- blue;
- green;
- purple;
- orange;
- red.
Invisible fluorescent paints can only glow with these colors:
- blue-green;
- green-yellow;
- blue.
The material has found its application in interior decoration, it is applied with their own hands on wallpaper, as well as others decorative coatings, they are decorated with decorative elements, including shades, candlesticks and vases.
Places of application
For interior
Paint on acrylic base specially designed for the protection and decoration of indoor wallpaper. Such materials dry very quickly, have chemical and mechanical resistance, and high elasticity. Each comes with instructions for use.
Special additives in the composition prevent mold and mildew from appearing on the painted surface.
Used for ceilings and walls made of dense and porous materials:
- bricks;
- cement-lime plasters;
- concrete;
- wallpaper.
For metal
They form a glossy transparent finish.
Possess:
- weather resistance;
- increased strength;
- resistance to oils;
- detergents;
- some organic solvents.
Have high level drying, are used for and outside the premises. They are used in airbrushing, auto-tuning, for painting car disks, in decor and design of exteriors and interiors.
Advice: when using fire-retardant paints for metal Polistil.
Basics for paint
Currently invisible luminescent and fluorescent paints can be alkyd and water based.
Consider their characteristics below:
- Water-based materials are non-toxic, their price is quite affordable, they do not have a specific smell, therefore they are much more often used to decorate the interiors of residential premises and entertainment establishments. In addition, they can be successfully used for the design of facades and other finishing works outside buildings.
The paints are resistant to external influences and will not be washed off by rain and snow. They should be applied on previously degreased wood, glass, metal, woven and stone surfaces. - The alkyd base is more resistant to various influences, in addition, it is not washed off from surfaces detergents... Due to the toxic fumes during drying, such paints should be used for external design.
For example, use the compositions when decorating the facades of buildings that will acquire the original appearance with appropriate illumination. They are often used when decorating entrances to restaurants, sports clubs, discos, bars and other similar establishments.
Output
If you want to give the interior of a room or house from the outside original view, use special glowing paints for this. They are of two types - fluorescent and luminescent, which differ from each other in special characteristics. The video in this article will help you find Additional information on this topic.
Few people know, but a grandiose light show is constantly happening around us, which we, unfortunately, do not see. The fact is that many arthropods (insects, spiders, etc.) have one interesting feature: they glow in ultraviolet light.
Fireflies and other animals, endowed with bioluminescence, glow due to a chemical reaction that takes place in special organs of the glow. This phenomenon has been seen by many. But scorpions, some spiders and a number of related organisms are capable of producing a blue-green glow using the phenomenon of fluorescence.
Crab spider fluorescence Exoskeleton molecules ( outer shell) these animals are swallowed up invisible to our eye ultraviolet light(320-400 nm), after which ultraviolet light is re-emitted into the bluish light that is visible to us.
It turns out that many arthropods glow under ultraviolet light. Photographer Niki Bey (his photographs along with mine are used in the article about) made a series of wonderful pictures of bioluminescence of arthropods, which I used to illustrate this text.
Why do arthropods glow in ultraviolet light?
In short: for many of the fluorescent animals, we don't know why. There is a lot of literature about the glow of various arthropods, the main idea of which can be reduced to: “Wow! It shines !!! ".
Kivsaki also fluoresces in UV light. True, for scorpions, the mechanism of this glow has been studied in more detail.
In scorpions, the so-called cuticular fluorescence is observed. It involves two compounds found in the epicuticle of a scorpion: beta-carboline and 4-methyl, 7-hydroxycoumarin. Coumarin, by the way, is used in perfume or as a cinnamon-flavored flavoring agent.
Scorpion fluorescence is a very beautiful phenomenon There are a couple of hypotheses regarding the purpose of scorpion fluorescence. Most insects can see ultraviolet light, so their world looks very different from ours.
Spider Heteropoda sp. human and insect eyes According to some experiments, scorpions can use the ability to absorb ultraviolet light to seek shelter. During the experiment, the scorpions were put on tiny glasses that prevented the animals from seeing with their eyes. But as soon as the UV light was turned on, the animals quickly found suitable hiding places. Apparently, orientation was due to signals received from surfaces that absorbed ultraviolet light (published in the journal Animal Behavior).
Perhaps ultraviolet light helps scorpions navigate According to another version, the glow of scorpions in ultraviolet light is a relic of the early Devonian period, when the earth was inhabited by giant scorpions and centipedes. Substances accumulated in the integument, capable of absorbing ultraviolet light and emitting blue light, could protect ancient arthropods from sunburn... At least in young plant seedlings, it is coumarin that acts as a sunscreen.
There are many minerals that, when illuminated ultraviolet light, begin to glow with unusual bright colors... In this case, the visible, electric light should be turned off, and if you want to see the glow in ultraviolet during the day, you should go to dark room and there shine an ultraviolet lamp on the stone. You will see wonderful pictures brightest colors and fancy patterns ...
So, we have a stone ball with a diameter of 6 cm.It consists of several minerals, a blue mineral - sodalite. It is difficult to accurately determine the mineral composition - for this you need to saw a ball, make from it thin section tenths of a millimeter thick and look under a microscope (well, I'm not an expert in alkaline rocks, so that by the eye like this ...))
But it's a pity to cut the ball. Therefore, we will restrict ourselves general definition, let's go into the dark, and ... Turn on the ultraviolet lamp. Everyone has seen such lamps - they are used in clubs, bars, sometimes at home, as decorative lighting. In the light of these lamps, viscose, cotton, feather, paper shine with a bright blue light. Lamps give long-wave ultraviolet radiation.
In ultraviolet light, our stone is transformed beyond recognition - light minerals begin to glow with a bright yellow light, the ball looks lacy and translucent. V selected locations there is a glow of pink and turquoise spots. This picture is somewhat similar to images of the Earth at night from space - bright lights cities merge into solid spots, all of Europe is a luminous sea of electric lights ... 
Some collectors of minerals collect stones, which are ordinary-looking in ordinary light. For them, you can make a special showcase or cabinet, and arrange the lamps so that the blue light of the lamp does not hit the eyes, but shines only on the samples.
Actually, ultraviolet itself, neither short-wave, nor medium-wave, nor long-wave, is not visible to the eye. And the lamps shine blue (violet), since they, along with ultraviolet light, preserve the visible part of the spectrum.
You can see how the Greenlandic sodalite glows in ultraviolet light.
Why do minerals glow in ultraviolet light? Research by chemists has shown that the glow creates chemical elements having incomplete electronic shells of atoms (luminogenic elements).
Let's look at periodic table and see that it is metals(iron groups): iron proper (trivalent), manganese, chromium, tungsten, molybdenum and uranium. And also rare earth elements - lanthanum, scandium, yttrium, cerium and others. Ultraviolet light excites electrons, and their vibrations lead to radiation electromagnetic waves of different lengths - the light that we see.
If the glow stops immediately after the lamp is turned off , then it bears the name fluorescence or luminescence... But in some minerals, the glow stops only after a few seconds, or minutes after turning off, this phenomenon is called phosphorescence.
The mineral barite can glow after exposure to ultraviolet radiation for several hours (this was discovered and described by Kashiarolla, an alchemist from Italy in 1602). He did not have an electric ultraviolet lamp, but barite glows faintly in the dark even after long stay in the sun.
Greenish fluorite glows in ultraviolet light with a bright blue light (left), and dark green apatite with a faint reddish light (right)
The glow can be different and bright - all colors of the rainbow. Rather, the glow resembles bright neon lights. big city: yellow, blue, red, purple, green ...
exhibition of minerals glowing in the ultraviolet
collection of glowing minerals
The same minerals can glow in different ways - both in intensity and in color. It depends on the quantity elements - luminogens.
Sometimes the glow of stones in ultraviolet light is used in the search and enrichment of minerals. For example, a conveyor belt with rock, in which there are diamonds, illuminate with ultraviolet light and choose diamonds with hands that glow with bright blue, light green or yellow or other light. The tungsten-containing mineral scheelite glows blue. Uranium micas glow green, yellow-green, etc.
I use a stationary lamp, normal Wall Light bought in electrical goods. But there are handy portable ultraviolet lamps battery operated. This is a rare thing in Russia. But, I think, on the Internet you can find a store that sells such devices, if not here, then abroad. And those who are interested in this amazing property stones, like fluorescence, will soon find a lot of interesting stones in the world around us.
The glow of minerals in ultraviolet light (video).
Most people when asked "What is luminescence?" remember fluorescent discharge lamps. Indeed, this is one of the most famous applications of a bright (literally) physical phenomenon, namely photoluminescence (excitation by light). Glass tubes contain mercury vapors, excited by an electric discharge and emitting in the ultraviolet region. The coating applied to the tube walls - a phosphor - converts ultraviolet light into radiation visible to the human eye. Depending on the type of phosphor, the glow color can be different - this makes it possible to produce lamps not only "cold" and "warm" light, but also different colors- red, blue, etc. that appeared in recent times energy-saving lamps, which surpass incandescent lamps in the visible light range, are the same fluorescent lamps, only greatly reduced due to the miniaturization of electronics. Another type of luminescence is cathodoluminescence. It is she who underlies cathode-ray tubes: the phosphor covering the screen glows under the action of an electron beam. X-ray luminescence, for example, is used in fluorography - a screen covered with a phosphor glows when exposed to X-rays.
According to the definition given in Physical encyclopedia, luminescence radiation, which is an excess over the thermal radiation of the body and continues for a time significantly exceeding the period of light oscillations. The first part of the definition separates luminescence from thermal equilibrium radiation and shows that this concept is applicable only to a set of atoms (molecules) in a state close to equilibrium. With a strong deviation from the equilibrium state, it makes no sense to talk about thermal radiation or luminescence. In the visible region of the spectrum, thermal radiation becomes noticeable only at a body temperature of thousands of degrees, while it can luminesce in this region at any temperature; therefore, luminescence is often called cold glow. The second part of the definition (a sign of duration) was introduced by S.I. Vavilov to separate the luminescence from different types scattering, reflection, parametric transformation of light, bremsstrahlung and Cherenkov-Vavilov radiation. In contrast to light scattering, during luminescence, intermediate processes occur between absorption and emission, the duration of which is longer than the period of the light wave. As a result, during luminescence, the correlation between the oscillation phases of the absorbed and emitted light is lost.
Fast and slow
After termination of the excitation, the luminescence decays. If this happens quickly, then the process is referred to as fluorescence (from the name of the mineral fluorite, in which this phenomenon was discovered), and if the glow continues long time- then to phosphorescence. Fluorescence under the influence of light (visible and UV) can often be observed in everyday life - dyes of markers, road sign coatings and workwear fabrics glow. It is fluorescence that is responsible for the fact that freshly washed White shirt seems bright sunlight"Whiter than white". And this effect is not psychological. Just washing powders contain special substances, optical brighteners, which, under the influence of ultraviolet radiation, emit visible light (usually in the blue-violet region). This also explains the fact that white clothing glows under the influence of UV lamps in discos. Slowly decaying luminescence (phosphorescence) is also very common in everyday life - remember the dials of watches and the hands of other devices (as well as the screens of old oscilloscopes).
Other
In addition to the aforementioned varieties, there is radioluminescence - under the action of penetrating radiation (used in scintillation counters), chemiluminescence under the action of chemical reactions(including bioluminescence), candoluminescence (under mechanical action), luminescence (when crystals dissolve), electroluminescence (under the action of electric field), etc. Some of them are quite familiar to readers. For example, the glow of white phosphorus is the result of chemiluminescence: being oxidized under the influence of atmospheric oxygen, phosphorus vapors glow. Oxidation also explains the glow of plastic "flashlights" - chemical light sources, only they do not use phosphorus and oxygen, but an organic dye and hydrogen peroxide.
There are no secret inscriptions
Luminescence under the influence of ultraviolet radiation is actively used to verify the authenticity of various documents, forms and banknotes. Now almost any cashier has a machine with a UV lamp at hand for checking banknotes. This method has been used since the beginning of the 20th century; Robert Wood, the famous American physicist, experimented with it at the end of the First World War. This is how Wood himself describes it in the book by his biographer William Seabrook “Robert Wood. The modern magician of the physical laboratory ":
... They [the Bureau of the Chief Censor of the British Navy] proudly told me that they had invented paper on which it was impossible to make an "invisible" secret record. It was sold in all post offices, and the letters written on it could not be subjected to any tests. This paper became very popular as the letters were not delayed by the censorship. It was regular note paper printed with frequent parallel lines, pink, green, and blue. Red paint was diluted in water, green in alcohol, and blue in gasoline. The paper looked gray to the eye. Since almost any liquid in which invisible ink is dissolved belongs to one of these three classes, one of the colored lines will dissolve in the colorless liquid flowing from the pen, and traces of the inscription will appear. I remembered that Chinese whitewash turns out to be black as coal in photographs taken in ultraviolet rays, and I said: “Suppose I would write on it with a thin stick with Chinese whitewash - then none of the lines will dissolve, and yet the inscription can be will read it if you take a photo of the paper. "
Marks applied invisible ink, glowing in ultraviolet light, are very often used to determine the authenticity of various documents. And the paper itself, as a rule, contains fibers that glow in ultraviolet light.
“Oh no,” they replied, “you can write on it even with a toothpick or glass stick without any paint. The colored lines are made slightly soft or tacky so that they smudge into dark gray letters. Here's a glass rod - try it yourself! " (...)
I said, “Okay. I'll try, though. Bring me a rubber stamp and some Vaseline. " They brought me a large, sleek clean stamp of military censorship. I rubbed it with Vaseline, then wiped it off with a handkerchief until it stopped leaving marks on the paper. Then I pressed it tightly against the "spy-resistant" paper, preventing it from sliding to the side.
"Can you find an inscription here?" I asked.
They tested the paper in reflected and polarized light and said, "There is nothing here."
“Then let's light it up ultraviolet rays". We took her to the booth and put her in front of my black window. On the paper, in bright blue letters, as if a stamp had been applied to it, smeared with ink, the words shone: "There are no secret inscriptions."
Searching for traces of blood on different surfaces, as well as the instruments of crime - this is one of the main tasks faced by employees of forensic centers and departments. At the same time, traces of blood can not always be identified visually. They can be washed out or have microscopic dimensions, which requires the use of specific methods for their search, in particular, ultraviolet light.
The second area of application of ultraviolet lights is hunting for wounded animals on the trail of blood by hunters. Because on vegetation or soil at night it is very difficult to replace it.
How blood glows in ultraviolet light
Answering the question of whether blood glows in ultraviolet light, it should immediately be noted that this biological fluid does not fluoresce under the influence of UV rays. Blood completely absorbs the entire spectrum of ultraviolet radiation, acquiring an absolutely black color. It is for this reason that in various specialized forums you can find negative reviews about lanterns (people expect it to start glowing) designed to search for blood. BUT the black color of blood is also a result. Because all other surfaces (grass, vegetation, earth, leaves) reflect ultraviolet light. Those. BLACK traces of blood will be clearly visible on the gray-blue-white forest surface. Therefore, you can answer YES, a UV flashlight can help you find the wounded animal. But not in the way that many expect after watching movies. By the way, we will explain this below.
But how and why, in this case, ultraviolet is used to identify blood in criminology around the world?
In fact, the identification of blood is carried out using a special method, the essence of which is the processing of the alleged places of the presence of its traces with a special composition - luminol. This organic compound is capable of reacting with hemoglobin, which results in a blue fluorescence. That is why blood treated with such a composition glows in ultraviolet light. It should be noted that this method provides the ability to detect even the smallest in size and washed out with cleaning agents traces of blood, since it is almost impossible to completely erase them.
Another feature of the search for blood with ultraviolet light is the short-term irradiation of its traces. The fact is that UV irradiation destroys the DNA in the blood, which makes it impossible to further study it. That is why, when a positive reaction is received, the effect of UV light on the blood is suspended, and its samples are taken for further laboratory studies. 
The catalog of our online store contains a wide selection of professional forensic and hunting UV lights for detecting traces of blood. Each offered model is developed on the basis of original high quality components and meets all modern standards. Wholesale supplies of flashlights to forensic centers and specialized laboratories are possible.