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Expandable Graphite
Expandable graphite is produced from the naturally occurring mineral graphite. The layered structure of graphite allows some molecules to be intercalated in between the graphite layers. Through incorporation of acids, usually sulfuric acid graphite can be converted into expandable graphite.Vijay J. Bhagat: Behaviour of expandable graphite as a flameretardant in flexible polyurethane foam Presented at: Polyurethane Foam Association (PFA)Arlington, Virginia, USA, May 10, 2001 Characteristics If expandable graphite is heated, the graphite flakes will expand to a multiple of their starting volume. The main products in the market have a starting temperature in the range of 200 °C. The expanded flakes have a “worm-like” appearance and are generally several millimeters long.Vijay J. Bhagat: Behaviour of expandable graphite as a flameretardant in flexible polyurethane foam Presented at: Polyurethane Foam Association (PFA)Arlington, Virginia, USA, May 10, 2001 Production To ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Graphite
Graphite () is a Crystallinity, crystalline allotrope (form) of the element carbon. It consists of many stacked Layered materials, layers of graphene, typically in excess of hundreds of layers. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on a large scale (1.3million metric tons per year in 2022) for uses in many critical industries including refractories (50%), lithium-ion batteries (18%), foundries (10%), and lubricants (5%), among others (17%). Graphite converts to diamond under extremely high pressure and temperature. Graphite's low cost, thermal and chemical inertness and characteristic conductivity of heat and electricity finds numerous applications in high energy and high temperature processes. Types and varieties Graphite can occur naturally or be produced synthetically. Natural graphite is obtained from naturally occurring geologic deposits and synthetic graphite is produced t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Intercalation (chemistry)
Intercalation is the reversible inclusion or insertion of a molecule (or ion) into layered materials with layered structures. Examples are found in graphite and transition metal dichalcogenides. : Examples Graphite One famous intercalation host is graphite, which intercalates potassium as a guest. Intercalation expands the van der Waals gap between sheets, which requires energy. Usually this energy is supplied by charge transfer between the guest and the host solid, i.e., redox. Two potassium graphite compounds are KC8 and KC24. Carbon fluorides (e.g., (CF)x and (C4F)) are prepared by reaction of fluorine with graphitic carbon. The color is greyish, white, or yellow. The bond between the carbon and fluorine atoms is covalent, thus fluorine is not intercalated. Such materials have been considered as a cathode in various lithium batteries. Treating graphite with strong acids in the presence of oxidizing agents causes the graphite to oxidise. Graphite bisulfate, 24sup>+ SO4sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Sulfuric Acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula . It is a colorless, odorless, and Viscosity, viscous liquid that is Miscibility, miscible with water. Pure sulfuric acid does not occur naturally due to its Dehydration reaction, strong affinity to water vapor; it is Hygroscopy, hygroscopic and readily absorbs water vapor from the Atmosphere of Earth, air. Concentrated sulfuric acid is a strong oxidant with powerful dehydrating properties, making it highly corrosive towards other materials, from rocks to metals. Phosphorus pentoxide is a notable exception in that it is not dehydrated by sulfuric acid but, to the contrary, dehydrates sulfuric acid to sulfur trioxide. Upon addition of sulfuric acid to water, a considerable amount of heat is releas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Acid
An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid. The first category of acids are the proton donors, or Brønsted–Lowry acid–base theory, Brønsted–Lowry acids. In the special case of aqueous solutions, proton donors form the hydronium ion H3O+ and are known as Acid–base reaction#Arrhenius theory, Arrhenius acids. Johannes Nicolaus Brønsted, Brønsted and Martin Lowry, Lowry generalized the Arrhenius theory to include non-aqueous solvents. A Brønsted–Lowry or Arrhenius acid usually contains a hydrogen atom bonded to a chemical structure that is still energetically favorable after loss of H+. Aqueous Arrhenius acids have characteristic properties that provide a practical description of an acid. Acids form aqueous solutions with a sour taste, can turn blue litmus red, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Oxidizing Agent
An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ''electron donor''). In other words, an oxidizer is any substance that oxidizes another substance. The oxidation state, which describes the degree of loss of electrons, of the oxidizer decreases while that of the reductant increases; this is expressed by saying that oxidizers "undergo reduction" and "are reduced" while reducers "undergo oxidation" and "are oxidized". Common oxidizing agents are oxygen, hydrogen peroxide, and the halogens. In one sense, an oxidizing agent is a chemical species that undergoes a chemical reaction in which it gains one or more electrons. In that sense, it is one component in an oxidation–reduction (redox) reaction. In the second sense, an oxidizing agent is a chemical species that transfers electronegative atoms, usually oxygen, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Fire Protection
Fire protection is the study and practice of mitigating the unwanted effects of potentially Conflagration, destructive fires. It involves the study of the behaviour, Compartmentalization (fire protection), compartmentalisation, suppression and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of mitigating systems. In structures, be they land-based, offshore or even ships, owners and operators may be responsible for maintaining their facilities in accordance with a design-basis rooted in law, including local building code, building and fire code, fire codes. Buildings must be maintained in accordance with the current fire code, enforced by fire prevention officers of a local fire department. In the event of fire emergencies, Firefighters, fire investigators, and other fire prevention personnel are called to mitigate, investigate and learn from the Fire damage, damage of a fire. Classifying fires When dec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
