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Micelle Scheme-en
A micelle () or micella () (plural micelles or micellae, respectively) is an aggregate (or supramolecular assembly) of surfactant amphipathic lipid molecules dispersed in a liquid, forming a colloidal suspension (also known as associated colloidal system). A typical micelle in water forms an aggregate with the hydrophilic "head" regions in contact with surrounding solvent, sequestering the hydrophobic single-tail regions in the micelle centre. This phase is caused by the packing behavior of single-tail lipids in a bilayer. The difficulty filling all the volume of the interior of a bilayer, while accommodating the area per head group forced on the molecule by the hydration of the lipid head group, leads to the formation of the micelle. This type of micelle is known as a normal-phase micelle (oil-in-water micelle). Inverse micelles have the head groups at the centre with the tails extending out (water-in-oil micelle). Micelles are approximately spherical in shape. Other p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union Of Pure And Applied Chemistry
The International Union of Pure and Applied Chemistry (IUPAC ) is an international federation of National Adhering Organizations working for the advancement of the chemical sciences, especially by developing nomenclature and terminology. It is a member of the International Science Council (ISC). IUPAC is registered in Zürich, Switzerland, and the administrative office, known as the "IUPAC Secretariat", is in Research Triangle Park, North Carolina, United States. This administrative office is headed by IUPAC's executive director, currently Lynn Soby. IUPAC was established in 1919 as the successor of the International Congress of Applied Chemistry for the advancement of chemistry. Its members, the National Adhering Organizations, can be national chemistry societies, national academies of sciences, or other bodies representing chemists. There are fifty-four National Adhering Organizations and three Associate National Adhering Organizations. IUPAC's Inter-divisional Committee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bilayer
A bilayer is a double layer of closely packed atoms or molecules. The properties of bilayers are often studied in condensed matter physics, particularly in the context of semiconductor devices, where two distinct materials are united to form junctions (such as p–n junctions, Schottky junctions, etc.). Layered materials, such as graphene, boron nitride, or transition metal dichalchogenides, have unique electronic properties as a bilayer system and are an active area of current research. In biology a common example is the Lipid bilayer, which describes the structure of multiple organic structures, such as the membrane of a cell. See also * Monolayer * Non-carbon nanotube A non-carbon nanotube is a cylindrical molecule often composed of metal oxides, or group III-Nitrides and morphologically similar to a carbon nanotube. Non-carbon nanotubes have been observed to occur naturally in some mineral deposits. A few year ... * Semiconductor * Thin film References Phases of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clathrate Hydrate
Clathrate hydrates, or gas hydrates, clathrates, hydrates, etc., are crystalline water-based solids physically resembling ice, in which small non-polar molecules (typically gases) or polar molecules with large hydrophobic moieties are trapped inside "cages" of hydrogen bonded, frozen water molecules. In other words, clathrate hydrates are clathrate compounds in which the host molecule is water and the guest molecule is typically a gas or liquid. Without the support of the trapped molecules, the lattice structure of hydrate clathrates would collapse into conventional ice crystal structure or liquid water. Most low molecular weight gases, including , , , , , , , , and , as well as some higher hydrocarbons and freons, will form hydrates at suitable temperatures and pressures. Clathrate hydrates are not officially chemical compounds, as the enclathrated guest molecules are never bonded to the lattice. The formation and decomposition of clathrate hydrates are first order pha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Bonds
In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing a lone pair of electrons—the hydrogen bond acceptor (Ac). Such an interacting system is generally denoted , where the solid line denotes a polar covalent bond, and the dotted or dashed line indicates the hydrogen bond. The most frequent donor and acceptor atoms are the second-row elements nitrogen (N), oxygen (O), and fluorine (F). Hydrogen bonds can be intermolecular (occurring between separate molecules) or intramolecular (occurring among parts of the same molecule). The energy of a hydrogen bond depends on the geometry, the environment, and the nature of the specific donor and acceptor atoms and can vary between 1 and 40 kcal/mol. This makes them somewhat stronger than a van der Waals interaction, and weaker than fully covale ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Self-assembly
In chemistry and materials science, molecular self-assembly is the process by which molecules adopt a defined arrangement without guidance or management from an outside source. There are two types of self-assembly: intramolecular and intermolecular. Commonly, the term ''molecular self-assembly'' refers to the former, while the latter is more commonly called '' folding''. Supramolecular systems Molecular self-assembly is a key concept in supramolecular chemistry. This is because assembly of molecules in such systems is directed through non-covalent interactions (e.g., hydrogen bonding, metal coordination, hydrophobic forces, van der Waals forces, pi-stacking interactions, and/or electrostatic) as well as electromagnetic interactions. Common examples include the formation of colloids, biomolecular condensates, micelles, vesicles, liquid crystal phases, and Langmuir monolayers by surfactant molecules. Further examples of supramolecular assemblies demonstrate that a variety ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monomer
In chemistry, a monomer ( ; ''mono-'', "one" + '' -mer'', "part") is a molecule that can react together with other monomer molecules to form a larger polymer chain or three-dimensional network in a process called polymerization. Classification Monomers can be classified in many ways. They can be subdivided into two broad classes, depending on the kind of the polymer that they form. Monomers that participate in condensation polymerization have a different stoichiometry than monomers that participate in addition polymerization: : Other classifications include: *natural vs synthetic monomers, e.g. glycine vs caprolactam, respectively *polar vs nonpolar monomers, e.g. vinyl acetate vs ethylene, respectively *cyclic vs linear, e.g. ethylene oxide vs ethylene glycol, respectively The polymerization of one kind of monomer gives a homopolymer. Many polymers are copolymers, meaning that they are derived from two different monomers. In the case of condensation polymerizations, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diminutive
A diminutive is a root word that has been modified to convey a slighter degree of its root meaning, either to convey the smallness of the object or quality named, or to convey a sense of intimacy or endearment. A ( abbreviated ) is a word-formation device used to express such meanings. In many languages, such forms can be translated as "little" and diminutives can also be formed as multi-word constructions such as " Tiny Tim". Diminutives are often employed as nicknames and pet names when speaking to small children and when expressing extreme tenderness and intimacy to an adult. The opposite of the diminutive form is the augmentative. Beyond the ''diminutive form'' of a single word, a ''diminutive'' can be a multi-word name, such as "Tiny Tim" or "Little Dorrit". In many languages, formation of diminutives by adding suffixes is a productive part of the language. For example, in Spanish can be a nickname for someone who is overweight, and by adding an suffix, it becomes wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Palmitate
Palmitic acid (hexadecanoic acid in IUPAC nomenclature) is a fatty acid with a 16-carbon chain. It is the most common saturated fatty acid found in animals, plants and microorganisms.Gunstone, F. D., John L. Harwood, and Albert J. Dijkstra. The Lipid Handbook, 3rd ed. Boca Raton: CRC Press, 2007. , Its chemical formula is CH3(CH2)14COOH, and its C:D (the total number of carbon atoms to the number of carbon-carbon double-bonds) is 16:0. It is a major component of the oil from the fruit of oil palms (palm oil), making up to 44% of total fats. Meats, cheeses, butter, and other dairy products also contain palmitic acid, amounting to 50–60% of total fats. Palmitates are the salts and esters of palmitic acid. The palmitate anion is the observed form of palmitic acid at physiologic pH (7.4). Occurrence and production Palmitic acid was discovered by Edmond Frémy in 1840, in saponified palm oil. This remains the primary industrial route for its production, with the triglyceri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Bristol
The University of Bristol is a Red brick university, red brick Russell Group research university in Bristol, England. It received its royal charter in 1909, although it can trace its roots to a Society of Merchant Venturers, Merchant Venturers' school founded in 1595 and University College, Bristol, which had been in existence since 1876. Bristol is organised into #Academic structure, six academic faculties composed of multiple schools and departments running over 200 undergraduate courses, largely in the Tyndalls Park area of the city. The university had a total income of £752.0 million in 2020–21, of which £169.8 million was from research grants and contracts. It is the largest independent employer in Bristol. Current academics include 21 fellows of the Academy of Medical Sciences, 13 fellows of the British Academy, 13 fellows of the Royal Academy of Engineering and 44 fellows of the Royal Society. Among alumni and faculty, the university counts 9 Nobel laureates. Bristol is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James William McBain
James William McBain FRS (March 22, 1882 – March 12, 1953) was a Canadian chemist. He gained a Master of Arts at Toronto University and a Doctor of Science at Heidelberg University. He carried out pioneering work in the area of micelles at the University of Bristol. As early as 1913 he postulated the existence of "colloidal ions", now known as micelles, to explain the good electrolytic conductivity of sodium palmitate solutions. He was elected a Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the judges of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural knowledge, including mathematic ... in May 1923 He won their Davy Medal in 1939. References Fellows of the Royal Society 1882 births 1953 deaths Canadian physical chemists {{Canada-scientist-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detergent
A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more soluble in hard water, because the polar sulfonate (of detergents) is less likely than the polar carboxylate (of soap) to bind to calcium and other ions found in hard water. Definitions The word ''detergent'' is derived from the Latin adjective ''detergens'', from the verb ''detergere'', meaning to wipe or polish off. Detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. However, conventionally, detergent is used to mean synthetic cleaning compounds as opposed to ''soap'' (a salt of the natural fatty acid), even though soap is also a detergent in the true sense. In domestic contexts, the term ''detergent'' refers to household cleaning products such as '' laundry detergent'' o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymorphism (biophysics)
Polymorphism in biophysics is the ability of lipids to aggregate in a variety of ways, giving rise to structures of different shapes, known as "phases". This can be in the form of sphere of lipid molecules (micelles), pairs of layers that face one another (lamellar phase, observed in biological systems as a lipid bilayer), a tubular arrangement (hexagonal), or various cubic phases (Fdm, Imm, Iam, Pnm, and Pmm being those discovered so far). More complicated aggregations have also been observed, such as rhombohedral, tetragonal and orthorhombic phases. It forms an important part of current academic research in the fields of membrane biophysics (polymorphism), biochemistry (biological impact) and organic chemistry (synthesis). Determination of the topology of a lipid system is possible by a number of methods, the most reliable of which is x-ray diffraction. This uses a beam of x-rays that are scattered by the sample, giving a diffraction pattern as a set of rings. The ratio of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
