A quasiperiodic crystal, or quasicrystal, is a structure that is ordered but not periodic. A quasicrystalline pattern can continuously fill all available space, but it lacks translational symmetry. While crystals, according to the classical crystallographic restriction theorem, can possess only two-, three-, four-, and six-fold rotational symmetries, the Bragg diffraction pattern of quasicrystals shows sharp peaks with other symmetry orders—for instance, five-fold.
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically.
A coupling reaction in organic chemistry refers to a variety of reactions where two fragments are joined together. Often such reactions require the aid of a metal catalyst. In one important reaction type, a main group organometallic compound of the type R-M reacts with an organic halide of the type R'-X with formation of a new carbon-carbon bond in the product R-R'. The most common type of coupling reaction is the cross coupling reaction.
The Kværner process or the Kværner carbon black and hydrogen process (CB&H) is a method of producing carbon black and hydrogen gas from hydrocarbons such as methane, natural gas and biogas with no greenhouse gas pollution. The process was developed in the 1980s by the Norwegian engineering firm Kværner, and was first commercially exploited in 1999. Further refinement enabled the methane pyrolysis process for implementation at high-volume and low-cost.
National Institute for Materials Science is an Independent Administrative Institution and one of the largest scientific research centers in Japan.
Organic materials are expected to have relatively strong nonlinear optical properties due to delocalized electrons at * orbitals. This expectation explains extensive search for better NLO materials among organic crystals.
Covalent superconductors are superconducting materials where the atoms are linked by covalent bonds. The first such material was boron-doped synthetic diamond grown by the high-pressure high-temperature (HPHT) method. The discovery had no practical importance, but surprised most scientists as superconductivity had not been observed in covalent semiconductors, including diamond and silicon.
Chlormayenite (after Mayen, Germany), Ca12Al14O32[☐4Cl2], is a rare calcium aluminium oxide mineral of cubic symmetry.
Hideo Hosono, ForMemRS, is a Japanese material scientist most known for the discovery of iron-based superconductors.
Phenacenes are a class of organic compounds consisting of fused aromatic rings. They are polycyclic aromatic hydrocarbons, related to acenes and helicenes from which they differ by the arrangement of the fused rings.
MCM-41 is a mesoporous material with a hierarchical structure from a family of silicate and alumosilicate solids that were first developed by researchers at Mobil Oil Corporation and that can be used as catalysts or catalyst supports.
Nanobottles are hollow bottle-shaped particle with the maximal dimension smaller or comparable with 1 micrometer. They can be used for storing and distributing various chemical compounds, for example, inside the human body.
National Metal and Materials Technology Center (MTEC) is one of Thailand's National Research Centers. It is directed by the National Science and Technology Development Agency (NSTDA), which belongs to Ministry of Higher Education, Science, Research and Innovation. A publicly funded governmental organization, MTEC enjoys more freedom in its operation than government-only bodies. MTEC aims to promote, support and coordinate research and development in polymers, metals, ceramics, and related materials, and to encourage collaborations among research, education and technology organizations.
Titanium butoxide is an metal-organic chemical compound with the formula Ti(OBu)4 (Bu = CH2CH2CH2CH3). It is a colorless odorless liquid, although aged samples are yellowish with a weak alcohol-like odor. It is soluble in many organic solvents. It hydrolyzes to give titanium dioxide, which allows deposition of TiO2 coatings of various shapes and sizes down to the nanoscale.
Fullerene whiskers are thin rods composed of fullerene molecules, such as C60, C70, or their mixtures. Hollow fullerene whiskers are called fullerene tubes. Such structures typically have a diameter of a few micrometers. When the diameter becomes smaller than 1 micron, the corresponding structures are called fullerene nanowhiskers or fullerene nanotubes.
Katsuhiko Ariga is a Japanese chemist specializing in nanotechnology and self-assembly. He was educated at the Tokyo Institute of Technology, where he defended his PhD in 1990 and later worked as assistant professor. Since 2004 he carries out research at the National Institute for Materials Science, and teaches at the University of Tokyo, where he is a full professor. Ariga is a Fellow of the Royal Society of Chemistry (2013) and an editor of the journal Science and Technology of Advanced Materials.
Oxyarsenides or arsenide oxides are chemical compounds formally containing the group AsO, with one arsenic and one oxygen atom. The arsenic and oxygen are not bound together as in arsenates or arsenites, instead they make a separate presence bound to the cations (metals), and could be considered as a mixed arsenide-oxide compound. So a compound with OmAsn requires cations to balance a negative charge of 2m+3n. The cations will have charges of +2 or +3. The trications are often rare earth elements or actinides. They are in the category of oxypnictide compounds.
Oxybismuthides or bismuthide oxides are chemical compounds formally containing the group BiO, with one bismuth and one oxygen atom. The bismuth and oxygen are not bound together as in bismuthates, instead they make a separate presence bound to the cations (metals), and could be considered as a mixed bismuthide-oxide compound. So a compound with OmBin requires cations to balance a negative charge of 2m+3n. The cations will have charges of +2 or +3. The trications are often rare earth elements or actinides. They are in the category of oxypnictide compounds.
Gallium palladide is an intermetallic combination of gallium and palladium. In the Iron monosilicide crystal structure. The compound has been suggested as an improved catalyst for hydrogenation reactions. In principle, gallium palladide can be a more selective catalyst since unlike substituted compounds, the palladium atoms are spaced out in a regular crystal structure rather than randomly.
