Bismuth subcarbonate (BiO)2CO3, sometimes written Bi2O2(CO3) is a chemical compound of bismuth containing both oxide and carbonate anions. Bismuth is in the +3 oxidation state. Bismuth subcarbonate occurs naturally as the mineral bismutite. Its structure consists of Bi-O layers and CO3 layers and is related to kettnerite, CaBi(CO3)OF. It is light-sensitive.
bismuth oxycarbonate, bismuthyl carbonate,
3D model (JSmol)
|Molar mass||509.9685 g/mol|
|Appearance||fine white to pale yellow-white powder|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
It is highly radiopaque and for example is used as a filler in radiopaque catheters which can be seen by x-ray. In modern medicine, bismuth subcarbonate has been made into nanotube arrays that exhibit antibacterial properties. It is also used in fireworks to make Dragon's eggs. It is a constituent of milk of bismuth which was a popular digestive tract panacea in the 1930s.
Bismuth subcarbonate may be harmful if swallowed. It may irritate the respiratory and gastrointestinal tract.
Bismuth subcarbonate can be attained from the reaction between bismuth nanoparticles and the atmospheric carbon dioxide (CO2) dissolved in water. Bismuth subcarbonate has the tendency to form nanoplates, but it can be also obtained as small round nanospheres (with controlled size) when it is grown in the presence of halloysite nanotubes. The high pH and high temperature of the aqueous solution helps to reduce the time of synthesis. It is readily formed on the surface of undoped bismuth oxide (β-Bi2O3 and γ-Bi2O3) nanoparticles even when they are not suspended in water.
Bismuth subcarbonate has a structure with a tetragonal unit cell. Layers of (BiO)n positively charged, and carbonate anion (CO32-) are surrounding both sides of the (BiO)n+ layer to compensate the charge. Usually, The (BiO)n layer grows perpendicular to the b axis.
Bernard Fantus (September 1, 1874 - April 14, 1940) was a Hungarian Jewish-American physician. He established the first hospital blood bank in the United States in 1937 at Cook County Hospital, Chicago while he served there as director of the pharmacology and therapeutics department.Bismuth
Bismuth is a chemical element with the symbol Bi and atomic number 83. It is a pentavalent post-transition metal and one of the pnictogens with chemical properties resembling its lighter homologs arsenic and antimony. Elemental bismuth may occur naturally, although its sulfide and oxide form important commercial ores. The free element is 86% as dense as lead. It is a brittle metal with a silvery white color when freshly produced, but surface oxidation can give it a pink tinge. Bismuth is the most naturally diamagnetic element, and has one of the lowest values of thermal conductivity among metals.
Bismuth was long considered the element with the highest atomic mass that is stable, but in 2003 it was discovered to be extremely weakly radioactive: its only primordial isotope, bismuth-209, decays via alpha decay with a half-life more than a billion times the estimated age of the universe. Because of its tremendously long half-life, bismuth may still be considered stable for almost all purposes.Bismuth(III) oxide
Bismuth(III) oxide is perhaps the most industrially important compound of bismuth. It is also a common starting point for bismuth chemistry. It is found naturally as the mineral bismite (monoclinic) and sphaerobismoite (tetragonal, much more rare), but it is usually obtained as a by-product of the smelting of copper and lead ores. Bismuth trioxide is commonly used to produce the "Dragon's eggs" effect in fireworks, as a replacement of red lead.Bismuth silicon oxide
Bismuth silicon oxide is a solid inorganic compound of bismuth, silicon and oxygen. Its most common chemical formula is Bi12SiO20, though other compositions are also known. It occurs naturally as the mineral sillénite and can be produced synthetically, by heating a mixture of bismuth and silicon oxides. Centimeter-sized single crystals of Bi12SiO20 can be grown by the Czochralski process from the molten phase. They exhibit piezoelectric, electro-optic, elasto-optic and photoconductive properties, and therefore have potential applications in spatial light modulators, acoustic delay lines and hologram recording equipment. Bi12SiO20 can be obtained as a whitish powder with band gap of approximately 3.2 eV starting from bismuth subcarbonate and silica in presence of ethyleneglycol. 29Si solid-state NMR is used to proof that the Si(IV) cations are sharing oxygen atoms with the Bi(III) cations. The 29Si chemical shift (δ) in Bi12SiO20 is −78.1 ppm. Unlike the bismuth oxide, the presence of the acidic Si(IV) cations avoid the reactivity with CO2.
Another bismuth silicate has formula Bi2O9Si3.Bismutite
Bismutite or bismuthite is a bismuth carbonate mineral with formula Bi2(CO3)O2 (bismuth subcarbonate). Bismutite occurs as an oxidation product of other bismuth minerals such as bismuthinite and native bismuth in hydrothermal veins and pegmatites. It crystallizes in the orthorhombic system and typically occurs as earthy to fibrous masses.It was first described in 1841 for an occurrence in Saxony.The term bismuthite has been used in the past for bismuthinite.Decoppering
Decoppering is the act of removing copper and it is most commonly used in the context of the removal of copper residues from the rifling of gun barrels.
Decoppering agents are frequently added to smokeless powder propellants. Decoppering is most important for large guns (especially naval guns), but the additives are used even in medium and small caliber guns.
The most common decoppering additives are:
Tin metal and compounds, e.g. tin dioxide
Bismuth metal and compounds, e.g. bismuth trioxide, bismuth subcarbonate, bismuth nitrate, bismuth antimonide; the bismuth compounds are favored as copper dissolves in molten bismuth, forming brittle and easily removable alloy
Lead foil and lead compounds, now phased out due to lead toxicityDragon's egg
A dragon's egg is a fireworks pyrotechnic star which first burns for a period for a visual effect then explodes with a loud report. Manufacture of this effect became controversial because of the toxic compounds once used, particularly lead tetroxide (Pb3O4). Nowadays, however, bismuth trioxide or bismuth subcarbonate are commonly used as more environmentally friendly substitutes for lead compounds to achieve the effect, and its occurrence in fireworks displays has since become much more common.
Because of how heavy an individual bismuth atom is, a shell or cake containing mainly dragon's eggs (and therefore enriched in bismuth) is often noticeably heavier than a similar device containing other effects.Halloysite
Halloysite is an aluminosilicate clay mineral with the empirical formula Al2Si2O5(OH)4. Its main constituents are aluminium (20.90%), silicon (21.76%) and hydrogen (1.56%). Halloysite typically forms by hydrothermal alteration of alumino-silicate minerals. It can occur intermixed with dickite, kaolinite, montmorillonite and other clay minerals. X-ray diffraction studies are required for positive identification. It was first described in 1826 and named after the Belgian geologist Omalius d'Halloy.Smokeless powder
Smokeless powder is the name given to a number of propellants used in firearms and artillery that produce negligible smoke when fired, unlike the gunpowder or black powder they replaced. The term is unique to the United States and is generally not used in other English-speaking countries, which initially used proprietary names such as "Ballistite" and "Cordite" but gradually shifted to "propellant" as the generic term.
The basis of the term smokeless is that the combustion products are mainly gaseous, compared to around 55% solid products (mostly potassium carbonate, potassium sulfate, and potassium sulfide) for black powder. Despite its name, smokeless powder is not completely free of smoke; while there may be little noticeable smoke from small-arms ammunition, smoke from artillery fire can be substantial. This article focuses on nitrocellulose formulations, but the term smokeless powder was also used to describe various picrate mixtures with nitrate, chlorate, or dichromate oxidizers during the late 19th century, before the advantages of nitrocellulose became evident.Since the 14th century gunpowder was not actually a physical "powder", and smokeless powder can be produced only as a pelletized or extruded granular material. Smokeless powder allowed the development of modern semi- and fully automatic firearms and lighter breeches and barrels for artillery. Burnt gunpowder leaves a thick, heavy fouling that is hygroscopic and causes rusting of the barrel. The fouling left by smokeless powder exhibits none of these properties (though some primer compounds can leave hygroscopic salts that have a similar effect; non-corrosive primer compounds were introduced in the 1920s). This makes an autoloading firearm with many moving parts feasible (which would otherwise jam or seize under heavy black powder fouling).
Smokeless powders are classified as, typically, division 1.3 explosives under the UN Recommendations on the transportation of Dangerous goods – Model Regulations, regional regulations (such as ADR) and national regulations (such as the United States' ATF). However, they are used as solid propellants; in normal use, they undergo deflagration rather than detonation.