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Recipes of luminous paints

Recipes of luminous paints

The phenomenon of phosphorescence can be observed well on alkaline earth metal sulphides. It consists in the fact that some substances, being preliminarily subjected to illumination, continue to glow in the dark for a while. The essence of the phenomenon consists in excitation of electrons of a phosphorescent substance under the influence of extraneous illumination and their subsequent return to the lowest energy levels, accompanied by light emission. Phosphorescent substances are, therefore, as a battery of light energy.

Practically luminous compositions (otherwise, "phosphors", or "luminophores") are prepared by fusing a mixture of individual constituents, possibly chemically pure. In addition to the substances necessary for the formation of phosphors, substances usually used to lower the melting point (melting) are usually introduced into the initial mixture.

Good phosphors glow quite brightly, and the duration of their glow is measured in hours. This is the basis of making of them luminous paints to cover various nocturnal signals, and also an insignificant part is used in art (paintings, masks, etc.).

For the preparation of high-quality phosphors, substances of a class not lower than "HC" (chemically pure), as well as the thoroughness of the grinding of substances and their mixing are required. Melting of mixtures is carried out in a clean porcelain crucible, which is closed with a porcelain lid (not too tightly). For heating, a muffle furnace with a temperature regulator is used.

PRECAUTIONARY MEASURES

The composition for the preparation of phosphors can include poisonous substances (here they will be marked with *). Store them in a container with a special label and in a lockable locker.

When sulphides come into contact with acids, a poisonous gas of hydrogen sulphide is released with a hideous smell of rotten eggs. Its danger is increased by the fact that it paralyzes the olfactory center.

Sulphides of alkali and alkaline earth metals destroy nails and hair when they come into contact with them, so they should not be allowed to fall on any part of the body, and after working with them, wash hands thoroughly.

When sintering mixtures in the furnace, harmful gases are released (the mixture foams), so heating should be carried out outdoors or in a well-ventilated room, and the crucible must be filled with no more than 1/3 before staging in the furnace.

Purple

Calcium oxide CaO - 20   g , sulfur S - 6th   g , lithium sulfate Li 2 SO 4 - 1.5   g, 1   ml of a 0.5% alcohol solution of Bi ( NO 3 ) 3 bismuth nitrate . Pour at 700 ° C for 40   minutes.

Blue colour

Calcium oxide CaO - 20   g , barium hydroxide ** B a ( O H ) 2 - 20   g , sulfur S - 8   g , sulfate of cadmium K 2 SO 4 - 1   g , sodium sulfate Na 2 SO 4 - 1   g , lithium sulfate Li 2 SO 4 - 2   g , 2   ml of a 0.5% alcohol solution of Bi ( NO 3 ) 3 bismuth nitrate . Pour 40   minutes at a temperature of 800 ° C.

Blue-blue color

Calcium carbonate CaCO 3 - 100   g , magnesium oxide Mg O - 25   g , sulfur S - 50   g , sucrose C 12 H 22 O 11 - 10   g , sodium fluoride * NaF - 3   g , potassium sulfide K 2 S - 2,5   g, sodium sulfide Na 2 S - 2.5   g, (0.5%) alcohol solutions: thorium nitrate Th ( NO 3 ) 4 - 1.6   ml, thallium nitrate *** TlNO 3 - 1.6   ml, bismuth nitrate Bi ( NO 3 ) 3-3.6   ml, rubidium nitrate RbNO 3 - 8   ml. Boil at a temperature of 1100 ° C for 150   minutes.

Aquamarine

Calcium oxide CaO - 10   g , strontium oxide SrO - 20   g , calcium tungstate CaWO 4 - 1   g , sulfur S - 8   g , sulfates of potassium and sodium K 2 SO 4 , Na 2 SO 4 - by 1   g , lithium sulfate Li 2 SO 4 - 2   g , 2   ml of a 0.5% solution of Bi ( NO 3 ) 3 bismuth nitrate in alcohol. Pour 40   minutes at a temperature of 800 ° C.

Purple color

Potassium oxide CaO - 100   g , sulfur S - thirty   g , 10   ml of a 0.5% alcohol solution of Bi ( NO 3 ) 3 bismuth nitrate. Killing 30   minutes at 1200 ° C.

Light green color

Strontium carbonate SrCO 3 - 40   g , sulfur S - 6th   g , arsenic sulfate ( III ) *** As 2 S 3 - 1   g , lithium carbonate Li 2 CO 3 -1   g, 2   ml 0.5% alcohol solution of thallium nitrate *** T1 N O 3 . Mourning 45   minutes at 1200 ° C.

Yellow

Strontium hydroxide Sr ( OH ) 2 - 15   g , barium carbonate ** BaCO 3 - 25   g , calcium tungstate CaWO 4 - 1   g , cepa S - 10   g , lithium sulfate Li 2 SO 4 - 1   g , 3   ml 0.4% alcohol solution of copper sulfate * CuSO 4 , 3   ml of a 0.5% alcohol solution of thorium nitrate Th ( NO 3 ) 4 . Pour at 800 ° C for 40   minutes.

Red Tones

To obtain pure red tones, the initial substances of the class " Os.Ch " (especially clean), clean dishes and the absence of dust in the air are required.

Red color

Barium oxide ВаО - 40   g , sulfur S - 9   g , lithium phosphate Li 3 PO 4 - 0.7   g, 3   ml 0.4% alcohol solution of copper sulfate * CuSO 4 . Heat 40 minutes at 800 ° C.

Bright red color

Barium carbonate B aCO 3 - 100   g , sulfur S - 15   g , borax Na 2 B 4 O 7 2.5 g, lithium phosphate Li 3 PO 4 2.5   g, 2   ml of a 0.5% alcohol solution of rubidium nitrate RbNO 3 . 4 ml of 0.5% alcohol solution of copper nitrate * Cu ( NO 3 ) 2 . Heat for 45 minutes at 1200 ° C.

Brief information on luminous substances

·   Glow can occur due to slow oxidation of the substance in air (for example, white phosphorus, luciferin in some insects, microbes, fungi, fish). Such substances without the access of an oxidizing agent (for example, oxygen of air) do not shine. With increasing temperature, the glow of such substances increases (white phosphorus is highly toxic and self-igniting at a temperature of 18-25 ° C).

·   Some substances can shine from friction or shaking (for example, crystalline chelidonin, some sulphides activated by manganese, etc.). This luminescence is called triboluminescence.

·   Substances luminous in the presence of radiation or invisible to the eye of X-ray beams are used for the production of compositions with a constant luminescence. As a radioactive substance, for example, paraffin is used, in molecules of which part of the atoms of ordinary hydrogen (protium) is replaced by atoms of superheavy radioactive hydrogen (tritium). Due to the presence of radioactive elements in the composition of such sources of visible light are hazardous to health.

·   The fourth class of luminous substances are those that shine thanks to stored energy. Their glow can continue very intensely even a few hours after the preliminary illumination. Recipes of just such formulations are given above. Compared to other light components, they have a number of advantages: they do not oxidize, they do not contain radioactive impurities, they can glow irrespective of air access, they do not require any friction or shaking, unlike triboluminescents. Their only drawback is that they need from time to time "recharging" for the accumulation of energy.

After removing from the furnace, the crucible without opening, set aside to cool. Then open, remove the crust and grind the alloy into powder. To prepare the paint, the powder must be mixed with nitro-lacquer or other film-forming substance, which does not contain water and acids.

Covering various items, souvenirs, paintings with luminous paints

Items covered with luminous paints are landmarks in a dark room, which saves energy. In the wall clock, figures, arrows covered with luminous paints, give information of time in the dark. Souvenirs, paintings, covered with such colors, create a spectacular effect.

Below are the recipes and the way to prepare luminous paints.

The main constituent of the luminous paints are sulfur salts: zinc sulphide, barium sulfide, etc. All substances entering into the composition of luminous paints must be chemically pure . When preparing, you must adhere to the following sequence: first, the salts are mixed with starch, then with solutions, after which the resulting mixture is dried. Further, the dry mixture is combined with sulfur and oxides with careful mixing in a porcelain crucible. This crucible is placed in an oven having a chimney and calcined in it at 1200 ° C for 25-30 minutes. The incandescent mixture will initially have a bright red color and at the end straw-yellow. The cooled mixture is triturated in a mortar and sieved through the finest sieve. The result is a powder of luminous paint.

To cover the objects, the paint powders are diluted with diluents. It must be remembered that the diluted paint must be applied immediately to prevent it from drying out. Apply paint not on clean metal or object, but on the places, pretreated with varnish or oil paint, using a soft brush, sharp stick or goose feather.

The density of the paint should be such that it slowly drains from a brush or a stick. Glowing colors are afraid of dampness and moisture. Their glow is limited depending on the recipe, so the items on which the luminous mass is applied need to be restored (charged), i.e. irradiate with daylight or an electric lamp, causing the paint to again intensively glow.

Note : When composing recipes per unit of measure, 1 cm 3 is taken, since a beaker (graduated cylinder) is used.

Recipe violet-blue (long-lasting glow) (cm 3 )

Calcium oxide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .    40

Sulfur crystalline (powder). . . . . . . . . . . . . . . . . . . . . . . . . . . . 6th

Carbon Lithium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Starch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Potassium sulphate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Sulfuric acid sodium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Aqueous-alcoholic solution

nitric acid bismuth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2     Semi-percentage

Aqueous-alcoholic solution                                                                                            solution -

tantalum nitrate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2      activator

The recipe is orange-red (medium intensity) (cm 3 )

Carbonate barium. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Sulfur crystalline (powder). . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Sugar. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

Bura. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .03

Sernized sodium salt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .03

Phosphorolithium salt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3

Nitric acid copper. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.5     0.5% solution-

Nitric acid lead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.5     activator

The simplest recipe is yellow (cm 3 )

Strontium carbonate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100

Sulfur crystalline (powder). . . . . . . . . . . . . . . . . . . . . . . . . . . . .thirty

Sodium carbonate anhydrous (soda). . . . . . . . . . . . . . . . . . . . . . . . . . 2

As diluents for all the above luminous paints can be used liquid glass (silicate glue), turpentine. It is possible to build luminous paints with damrass lacquer, which includes: dammar resin 52%, xylene 43% and castor oil 5%. The resin is poured with xylene and mixed thoroughly, after the dissolution of the resin, castor oil is added. The resulting mixture is filtered through suede. The varnish has a straw-yellow color, it evaporates easily, therefore it needs to be stored in a glass container with ground glass stopper. If, in the course of time, there is a precipitate in the dishes, then the varnish must be filtered out again. 2.5 parts of the luminous ink is dissolved in 1 part of the dammarovy lacquer, and the mixture is thoroughly mixed.