Our selenium compounds polymeric

Selenium- physical and chemical properties, uses - WriteWork


These arrangements of selenium do not have definite melting points. However, they progressively become softer when they are heated converting to grey selenium at 180 à °C. This grey selenium has a 'hexagonal crystal lattice consisting of helical polymeric chains and is the most stable and dense form of selenium' (Calinpop 2012)

Tellurium - Wikipedia


Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid.Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens.It is occasionally found in native form as elemental crystals.

Selenium Compound - an overview | ScienceDirect Topics


Selenium compounds are poisoneous and it is strongly recommended to work always in a well ventilated hood, and one should especially avoid swallowing the powder dust of selenium compounds. ... Polymeric network structures of zinc and selenium with N,N ...

Boron–Sulfur and Boron–Selenium Compounds—From Unique ...


9 Olaf Conrad, Christoph Jansen, Bernt Krebs, ChemInform Abstract: Boron-Sulfur and Boron-Selenium Compounds - From Unique Molecular Structural Principles to Novel Polymeric Materials, ChemInform, 2010, 30, 17, noWiley Online Library

Selenium Compounds | Profiles RNS


"Selenium Compounds" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings).Descriptors are arranged in a hierarchical structure, which enables searching at various levels of specificity.

Selenium - Simple English Wikipedia, the free encyclopedia


Properties Physical properties. Selenium (selenium atoms only) has several different forms. They are called allotropes.The most stable of these is a dense gray semimetal (an element that is partially a metal and a nonmetal).The way the atoms are put together is a named a trigonal polymer chain.It lets electricity pass through it better in the light than in the dark.

Selenium-Containing Polymers: Promising Biomaterials for ...


Selenium is an essential element in human body with potential antioxidant properties. Because of selenium's electronegativity and atomic radius, selenium-containing compounds exhibit unique bond energy (C–Se bond 244 kJ mol –1; Se–Se bond 172 kJ mol –1). These values give the C–Se or Se–Se covalent bonds dynamic character and make ...

How selenium compounds might become catalysts -- ScienceDaily


Jul 13, 2017· A new approach for activating chemical reactions based on the element selenium has been tested by scientists. They demonstrated that selenium …

Materials | Special Issue : Current Problems of the ...


Sulfur- and/or selenium-containing organic compounds, including polymers and materials displaying special properties, are of great importance in both academic, basic research and for large scale industrial applications. Sulfur belongs to a narrow group of elements that appear both in bound and non ...

Influence of the nature of the stabilizing polymeric ...


Influence of the nature of the stabilizing polymeric matrix on the self-organization of selenium nanoclusters. Authors; Authors and affiliations ... The influence of the nature of the polymeric matrix and of the selenium: polymer weight ratio on the rate constant and hydrodynamic radius was determined. ... Institute of Macromolecular Compounds ...

SAFETY DATA SHEET - Fisher Scientific


The information provided in this Safety Data Sheet is correct to the best of our knowledge, information and belief at the date of its publication. The information given is designed only as a guidance for safe handling, use, processing, storage, transportation, disposal and release and is not to be considered a warranty or quality specification.

Antimicrobial selenium nanoparticle coatings on polymeric ...


Antimicrobial selenium nanoparticle coatings on polymeric medical devices Article in Nanotechnology 24(15):155101 · March 2013 with 112 Reads How we measure 'reads'

Selenium Compounds - Alfa Chemistry


Selenium compounds can trap free radicals, thereby converting them into stable compounds. For human beings, selenium is an essential element, that plays a major role in many physiological and biochemical processes. Selenium compounds are readily absorbed through the digestive tract and respiratory system, and selenyl chloride enters through the ...

Electronic structures of polymeric CSe2, CSe, and C2Se


However, the calculations show that it reacts with other compounds of which some could be of interest from a ``synthetic metal'' point of view. Finally, our results are compared with results of similar calculations on polymeric selenium, carbon chains, polyacetylene, and CSe 2 molecules.

Selenium‐ and Tellurium‐Containing Organic π‐Conjugated ...


Most of these oligomers and polymers are selenophene based materials with only a few examples of tellurophene based oligomers and polymers known. Examples of selenium‐ and tellurium‐containing organic polymeric and oligomeric materials that have selenium or tellurium atoms in the backbone but not as a part of the heterocyclic ring are quite ...

Phosphorus selenide - Wikipedia


There have been some studies of the phosphorus - selenium phase diagram and the glassy amorphous phases are reported. The compounds that have been reported are shown below. While some are similar to their phosphorus analogues, the phosphorus sulfides, there are some new forms, molecular P 2 Se 5 and the polymeric catena-[P 4 Se 4] x.

Removal of selenium from water by complexation with ...


Apr 23, 1996· Selenium compounds are reported to comprise 0.9 ppm of the earth's crust. While important as a trace mineral in living organisms, selenium is known to be toxic to life in small quantities. Selenium compounds are found naturally in ground waters, and in agricultural runoffs from the use of selenium containing insecticides and herbicides.

Selenium Compounds - Organic Building Blocks | Sigma-Aldrich


Sigma-Aldrich Online Catalog Product List: Selenium Compounds

Redox-Active Selenium Compounds—From Toxicity and Cell ...


May 13, 2015· Selenium is generally known as an antioxidant due to its presence in selenoproteins as selenocysteine, but it is also toxic. The toxic effects of selenium are, however, strictly concentration and chemical species dependent. One class of selenium compounds is a potent inhibitor of cell growth with remarkable tumor specificity.

Selenium Facts for Kids - Kiddle


Some selenium compounds are very toxic and harmful to things that live in water. Consuming around 5 mg of selenium per day can kill a human being after a certain amount of time. Related pages. Selenium compounds; Images for kids. Structure of hexagonal (gray) selenium. Structure of the polymer SeO2: The (pyramidal) Se atoms are yellow.

Selenium dioxide - Wikipedia


Selenium dioxide is the active ingredient in some cold-bluing solutions. It was also used as a toner in photographic developing. Safety. Selenium is an essential element, but ingestion of more than 5 mg/day leads to nonspecific symptoms.

Selenium - Wikipedia


Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic.It rarely occurs in its elemental state or as pure ore compounds in the Earth's crust.

A Medley of Potpourri: Selenium


Selenium is most commonly found as an impurity, replacing a small part of the sulfur in sulfide ores of many metals. In living systems, selenium is found in the amino acids selenomethionine, selenocysteine, and methylselenocysteine. In these compounds, selenium plays a role analogous to that of sulfur.

Selenium Bromide, Polymer-Bound | AMERICAN ELEMENTS


Most metal bromide compounds are water soluble for uses in water treatment, chemical analysis and in ultra high purity for certain crystal growth applications. The bromide ion in an aqueous solution can be detected by adding carbon disulfide (CS 2) and chlorine. Selenium Bromide (polymer bound) is generally immediately available in most volumes.

Dynamic Chemistry of Selenium: Se–N and Se–Se Dynamic ...


Dynamic Chemistry of Selenium: Se–N and Se–Se Dynamic Covalent Bonds in Polymeric Systems Article in ACS Macro Letters 5(1):78-82 · December 2015 with 138 Reads How we measure 'reads'

Selenium/tellurium containing polymer materials in ...


Selenium/tellurium containing polymers have been attracting growing interest due to their unique properties and potential applications as bio-nanomaterials. The introduction of selenium or tellurium chemistry into block copolymers endows self-assembled nanomaterials with novel stimuli responsiveness and enhanced sensitivity.

Sulfur- and selenium-based linkers in polymer-supported ...


Sulfur- and selenium-based linkers in polymer-supported organic synthesis 511 SCHEME 1 and guanidine-containing molecules through their side-chains. Incorporation of Fmoc-Arg-OAllyl was carried out in CHCl 3 in the presence of DIEA for 8h at 25 C to afford resin 8 (scheme 3). Compounds were released from the solid support by treatment with TFA ...

Selenium nanoparticles inhibit Staphylococcus aureus growth


Jul 29, 2011· Some researchers have reported the synthesis of selenium nanoparticles and their biological effects toward mammalian cells in vitro.15,16 Others reported inhibitory effects of selenium compounds (in the form of coatings) on the growth of some types of bacteria.17 However, the influence of selenium nanoparticles on bacteria growth remains ...

Aromatic selenium compound polymer - GTE Laboratories ...


Jul 05, 1988· Aromatic selenium compound polymer . United States Patent 4755589 . Abstract: This invention constitutes a method for preparing molecular and polymeric aromatic selenide compounds such as bis-phenyl selenide and poly(p-phenylene selenide). The method comprises reacting an aryl halide with an alkali metal selenide reagent formed in an aprotic ...

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