Green and blue pigments

Another portion of the substance is boiled with water and filtered, the filtrate being tested with silver nitrate and with barium nitrate to ascertain if soluble chlorides or sulphates are present. 

A little of the substance is treated with hot dilute hydrochloric add any insoluble residue remaining may contain especially barium sulphate or free sulphur, and sometimes cinnabar, arsenic sulphide, etc. If the hydrochloric acid solution is coloured, chrome yellow may be present and is easily identified. The solution gives a yellow precipitate with hydrogen sulphide if the filtrate is rendered turbid by addition of ammonia and ammonium sulphide, zinc is present. 

A further portion of the substance is digested with acetic acid and filtered, the filtrate being tested by the ordinary methods for cadmium (presence of hydroxide, carbonate or other compound of cadmium) and zinc (presence of zinc oxide or carbonate). 

Lastly, a little of the substance is digested with ammonia and filtered, the filtrate being acidified with hydrochloric acid if this gives a white precipitate, zinc oxide is present, or if a yellow coloration, arsenic is present. 

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Paints are a mixture of particles of pigment in a liquid base. Once the liquid evaporates, the pigment particles coat a painted surface. Transition elements and their compounds are often used as paint pigments. Iron oxides are used as red, yellow, and brown pigments. Chromium, copper, and cobalt compounds produce green and blue pigments. Titanium dioxide is often used for white paint. 

Titanates are used as yellow, green, and blue pigments [2] they are stable but their low tinctorial strength and their high cost reduce their application range. 

The hue of the colorant varies gready with the amount and type of pigment found in the fish scales. Carotenoids produce reds and yellows, melanin results in blacks, and combinations of guanine and melanin produce greens and blues. Only when guanine is found alone is the product silvery or peady white. 

The compounds of the t/block elements show a wide range of interesting properties. Some are vital to life. Iron is an essential component of mammalian blood. Compounds of cobalt, molybdenum, and zinc are found in vitamins and essential enzymes. Other compounds simply make life more interesting and colorful. The beautiful color of cobalt blue glass, the brilliant greens and blues of kiln-baked pottery, and many pigments used by artists make use of d-block compounds. 

To identify a certain pigment, monochromatic light is required, but the assessment of food quality by a human inspector or by a device requires normal daylight. The evaluation procedure, however, to be discussed in the next section, also involves decomposition into monochromatic (red, green, and blue) regions. Monochromatic dissection of a continuous spectrum by monochromators can be achieved in three ways ... 

Zeolites are structurally related to colorless sodalite, Na4Cl[Al3Si3012], and to deeply colored ultramarines. These have aluminosilicate frameworks that enclose cations but no water molecules (Fig. 16.25). Their special feature is the additional presence of anions in the hollows, e.g. Cl-, S()4, S2, or S. The two last-mentioned species are colored radical ions (green and blue, respectively) that are responsible for the brilliant colors. The best-known representative is the blue mineral lapis lazuli, Na4S (.[Al3Si3012], which is also produced industrially and serves as color pigment. 

Nathans, J., Thomas, D. and Hogness, D. S. Molecular genetics of human color vision The genes encoding blue, green, and red pigments. Science 232 193-202,1986. 

Of the arsenic-free pigments the best known are Mountain green and blue (basic copper carbonates) and Bremen green and blue (copper hydroxides) use is made, but less commonly, of greens based on the basic acetate, basic sulphate, oxychloride and stannate of copper, already mentioned. All these products may be adulterated with the usual extraneous white substances, such mixtures being given special names. 

This is because red pigment absorbs green waves and blue pigment absorbs red and red-orange waves, leaving violet for us to observe.)... 

There are still challenges BrUUant, inorganic, nontoxic, stable and cheap green or blue pigments are amongst these. Probably, the mixed crystal systems are promising fields for new discoveries. 

Mixed metal oxide pigments cobalt green and blue chromium rutile orange nickel rutile yellow, chromium rutile yellow zinc iron spinel, Mn-Fe brown... 

Pigments such as phthalocyanine greens and blue, and some blacks, may cause high paste viscosities. 

A conventional production method for a color filter is a pigment dispersing method. In this method, a photosensitive resin layer containing dispersed pigments is formed on a substrate and then patterned to obtain a monochromatic pattern. This process is repeated three times to form color filter layers in red, green, and blue. This method, however, needs to repeat the same process three times to form the three colors. 

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