Search results
Results from the WOW.Com Content Network
Crystal powder is obtained by grinding crystals, resulting in powder particles, made up of one or more crystallites. Both polycrystals and crystal powder consist of many crystallites with varying orientation. Crystal phases are defined as regions with the same crystal structure, irrespective of orientation or twinning. Single and twinned ...
Acta Crystallographica was established in conjunction with the foundation of the International Union of Crystallography in 1948. Both were established to maintain an international forum for crystallography after the Second World War had led to a loss of international subscription to, and the eventual nine-year closure of, the main pre-war crystallography journal, Zeitschrift für ...
Photoalignment is a technique for orienting liquid crystals to desired alignment by exposure to polarized light and a photo reactive alignment chemical. [1] It is usually performed by exposing the alignment chemical ('command surface') to polarized light with desired orientation which then aligns the liquid crystal cells or domains to the exposed orientation.
Liquid crystal color transitions are used on many aquarium and pool thermometers as well as on thermometers for infants or baths. [84] Other liquid crystal materials change color when stretched or stressed. Thus, liquid crystal sheets are often used in industry to look for hot spots, map heat flow, measure stress distribution patterns, and so on.
Crystallography ranges from the fundamentals of crystal structure to the mathematics of crystal geometry, including those that are not periodic or quasicrystals. At the atomic scale it can involve the use of X-ray diffraction to produce experimental data that the tools of X-ray crystallography can convert into detailed positions of atoms, and ...
CrystEngComm is a peer-reviewed online-only scientific journal publishing original research and review articles on all aspects of crystal engineering including properties, polymorphism, target materials, and crystalline nanomaterials. It is published biweekly by the Royal Society of Chemistry and the editor-in-chief is Pierangelo Metrangolo.
Plastic crystals were discovered in 1938 by Belgian chemist Jean Timmermans [4] by their anomalously low entropy of fusion.He found that organic substances having an entropy of fusion lower than approximately 17 J·K −1 ·mol −1 (~2R, where R is the molar gas constant) had peculiar properties.
The liquid crystal properties arise because mesogenic compounds are composed of rigid and flexible parts, which help characterize the order and mobility of its structure. [2] The rigid components align mesogen moieties in one direction and have distinctive shapes that are typically found in the form of rod or disk shapes. [ 2 ]