Coloured water (top) and perfluoroheptane (bottom). Perfluoroheptane is hydrophobic and is denser than water, so it sinks to the bottom and the animals pictured cannot penetrate it. | |
Names | |
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Preferred IUPAC name Hexadecafluoroheptane | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.005.812 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C7F16 | |
Molar mass | 388.051 g·mol−1 |
Appearance | clear liquid [1] |
Density | 1.706 g/cm3 |
Boiling point | 80~82°C [1] |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Perfluoroheptane, C7F16, (usually referring to the straight chain molecule called n-perfluoroheptane) is a perfluorocarbon. [2] It is hydrophobic (water-insoluble) and oleophobic (oil-insoluble). It is used in deacidification of paper as a medium carrying powdered magnesium oxide. [3]
A dye is a colored substance that chemically bonds to the substrate to which it is being applied. This distinguishes dyes from pigments which do not chemically bind to the material they color. Dye is generally applied in an aqueous solution and may require a mordant to improve the fastness of the dye on the fiber.
Mass deacidification is a term used in library and information science as one possible measure against the degradation of paper in old books, the so-called "slow fires". The goal of the process is to increase the pH of acidic paper. Although acid-free paper has become more common, a large body of acidic paper still exists in books made after the 1850s; this is because of its cheaper and simpler production methods. Acidic paper, especially when exposed to light, air pollution, or high relative humidity, yellows and becomes brittle over time. During mass deacidification an alkaline agent is deposited in the paper to neutralize existing acid and prevent further decay. Mass deacidification is intended for objects on acidic paper that will be lost if no action is performed.
Polysaccharides, or polycarbohydrates, are the most abundant carbohydrates found in food. They are long-chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with water (hydrolysis) using amylase enzymes as catalyst, which produces constituent sugars. They range in structure from linear to highly branched. Examples include storage polysaccharides such as starch, glycogen and galactogen and structural polysaccharides such as hemicellulose and chitin.
Dietary fiber or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition and can be grouped generally by their solubility, viscosity and fermentability which affect how fibers are processed in the body. Dietary fiber has two main subtypes: soluble fiber and insoluble fiber which are components of plant-based foods such as legumes, whole grains, cereals, vegetables, fruits, and nuts or seeds. A diet high in regular fiber consumption is generally associated with supporting health and lowering the risk of several diseases. Dietary fiber consists of non-starch polysaccharides and other plant components such as cellulose, resistant starch, resistant dextrins, inulin, lignins, chitins, pectins, beta-glucans, and oligosaccharides.
Prussian blue is a dark blue pigment produced by oxidation of ferrous ferrocyanide salts. It has the chemical formula FeIII
4[FeII
(CN)
6]
3. Turnbull's blue is chemically identical, but is made from different reagents, and its slightly different color stems from different impurities and particle sizes.
Fenobucarb is a carbamate insecticide, also widely known as BPMC. A pale yellow or pale red liquid, insoluble in water; used as an agricultural insecticide, especially for control of Hemipteran pests, on rice and cotton and moderately toxic for humans.
Acid-free paper is paper that, if infused in water, yields a neutral or basic pH. It can be made from any cellulose fiber as long as the active acid pulp is eliminated during processing. It is also lignin- and sulfur-free. Acid-free paper addresses the problem of preserving documents and preserving artwork for long periods.
Cyanuric acid or 1,3,5-triazine-2,4,6-triol is a chemical compound with the formula (CNOH)3. Like many industrially useful chemicals, this triazine has many synonyms. This white, odorless solid finds use as a precursor or a component of bleaches, disinfectants, and herbicides. In 1997, worldwide production was 160 000 tonnes.
Cadmium telluride (CdTe) is a stable crystalline compound formed from cadmium and tellurium. It is mainly used as the semiconducting material in cadmium telluride photovoltaics and an infrared optical window. It is usually sandwiched with cadmium sulfide to form a p–n junction solar PV cell.
Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C-N=N-C linkage. Azo dyes are synthetic dyes and do not occur naturally. Most azo dyes contain only one azo group but there are some that contain two or three azo groups, called "diazo dyes" and "triazo dyes" respectively. Azo dyes comprise 60-70% of all dyes used in food and textile industries. Azo dyes are widely used to treat textiles, leather articles, and some foods. Chemically related derivatives of azo dyes include azo pigments, which are insoluble in water and other solvents.
Mercury selenide is a chemical compound of mercury and selenium. It is a grey-black crystalline solid semi-metal with a sphalerite structure. The lattice constant is 0.608 nm.
Indium(III) oxide (In2O3) is a chemical compound, an amphoteric oxide of indium.
Diethylzinc (C2H5)2Zn, or DEZ, is a highly pyrophoric and reactive organozinc compound consisting of a zinc center bound to two ethyl groups. This colourless liquid is an important reagent in organic chemistry. It is available commercially as a solution in hexanes, heptane, or toluene, or as a pure liquid.
The hydrophilic–lipophilic balance (HLB) of a surfactant is a measure of its degree of hydrophilicity or lipophilicity, determined by calculating percentages of molecular weights for the hydrophilic and lipophilic portions of the surfactant molecule, as described by Griffin in 1949 and 1954. Other methods have been suggested, notably in 1957 by Davies.
2-Methylhexane (C7H16, also known as isoheptane, ethylisobutylmethane) is an isomer of heptane. It is structurally a hexane molecule with a methyl group attached to its second carbon atom. It exists in most commercially available heptane merchandises as an impurity but is usually not considered as impurity in terms of reactions since it has very similar physical and chemical properties when compared to n-heptane (straight-chained heptane).
The Brittle Books Program is an initiative carried out by the National Endowment for the Humanities at the request of the United States Congress. The initiative began officially between 1988 and 1989 with the intention to involve the eventual microfilming of over 3 million endangered volumes.
Malate dehydrogenase (decarboxylating) (EC 1.1.1.39) or NAD-malic enzyme (NAD-ME) is an enzyme that catalyzes the chemical reaction
O-2694 is a drug that is a cannabinoid derivative. It has analgesic effects and is used in scientific research. Unlike most cannabinoids discovered to date, it is highly water-soluble, which gives it considerable advantages over many related drugs. It has high affinity for both CB1 and CB2 receptors, with Ki values of 3.7 nM at CB1 and 2.8 nM at CB2. However, it has complex pharmacokinetics as most of the administered dose is metabolised by hydrolysis of the ester link to the water-insoluble compound O-2372, thus producing a biphasic effects profile that is less suitable for research purposes than the related compound O-2545.
n-Butylsodium CH3CH2CH2CH2Na is an organometallic compound with the idealized formula NaC4H9. Like other simple organosodium compounds, it is polymeric and highly basic. In contrast to n-butyllithium, n-butylsodium is only of specialized academic interest.
Platinum(II) sulfide is the inorganic compound with the formula PtS. It is a green solid, insoluble in all solvents. The compound adopts an unusual structure, being composed of square planar Pt and tetrahedral sulfide centers. A related compound is platinum disulfide, PtS2.