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Tunable Nanoporous Carbon
Carbide-derived carbon (CDC), also known as tunable nanoporous carbon, is the common term for carbon materials derived from carbide precursors, such as binary (e.g. SiC, TiC), or ternary carbides, also known as MAX phases (e.g., Ti2AlC, Ti3SiC2). CDCs have also been derived from polymer-derived ceramics such as Si-O-C or Ti-C, and carbonitrides, such as Si-N-C. CDCs can occur in various structures, ranging from amorphous to crystalline carbon, from sp2- to sp3-bonded, and from highly porous to fully dense. Among others, the following carbon structures have been derived from carbide precursors: micro- and mesoporous carbon, amorphous carbon, carbon nanotubes, onion-like carbon, nanocrystalline diamond, graphene, and graphite. Among carbon materials, microporous CDCs exhibit some of the highest reported specific surface areas (up to more than 3000 m2/g). By varying the type of the precursor and the CDC synthesis conditions, microporous and mesoporous structures with controllable ave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbide
In chemistry, a carbide usually describes a compound composed of carbon and a metal. In metallurgy, carbiding or carburizing is the process for producing carbide coatings on a metal piece. Interstitial / Metallic carbides The carbides of the group 4, 5 and 6 transition metals (with the exception of chromium) are often described as interstitial compounds. These carbides have metallic properties and are refractory. Some exhibit a range of stoichiometries, being a non-stoichiometric mixture of various carbides arising due to crystal defects. Some of them, including titanium carbide and tungsten carbide, are important industrially and are used to coat metals in cutting tools. The long-held view is that the carbon atoms fit into octahedral interstices in a close-packed metal lattice when the metal atom radius is greater than approximately 135 pm: *When the metal atoms are cubic close-packed, (ccp), then filling all of the octahedral interstices with carbon achieves 1:1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gleb Yushin
Gleb (; ) or Hlib (, ) is a Slavic male given name derived from the Old Norse name ''Guðleifr'', which means "heir of god." According to another version, the name Gleb comes from the name Olaf. It is popular in Russia due to an early martyr, Saint Gleb, who is venerated by Eastern Orthodox churches. Behind the Name It is also commonly used in Ukraine and Belarus. Notable people with the name include: People * (died 1171), Rus’ prince * Gleb Axelrod (1923–2003), Russian pianist * Gleb Baklanov (1910–1976), Russian general *[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elżbieta Frąckowiak
Elżbieta Frąckowiak (born 17 November 1950) is a Polish electrochemical engineer whose research concentrates on carbon-based supercapacitors and energy storage. She is a professor in the Faculty of Chemical Technology at the Poznań University of Technology, and a former vice-president of the Polish Academy of Sciences. Education and career Frąckowiak studied chemistry at Adam Mickiewicz University in Poznań, earning a master's degree in 1972. After working as a research assistant at the Academy of Mining and Metallurgy in Kraków since 1973, she earned a Ph.D. in applied electrochemistry from the Poznań University of Technology in 1988, and at that time joined the university's Faculty of Chemical Technology as an assistant professor. She completed her habilitation in 2000 and was named a full professor in 2003. She was vice-president of the Polish Academy of Sciences for 2015–2018. Recognition Frąckowiak was elected as a corresponding member of the Polish Academy of S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allotropes Of Carbon
Carbon is capable of forming many allotropy, allotropes (structurally different forms of the same element) due to its Valence (chemistry), valency (Tetravalence, tetravalent). Well-known forms of carbon include diamond and graphite. In recent decades, many more allotropes have been discovered and researched, including ball shapes such as buckminsterfullerene and sheets such as graphene. Larger-scale structures of carbon include carbon nano tube, nanotubes, Carbon nanobud, nanobuds and Graphene nanoribbon, nanoribbons. Other unusual forms of carbon exist at very high temperatures or extreme pressures. Around 500 hypothetical 3‑periodic allotropes of carbon are known at the present time, according to the Samara Carbon Allotrope Database (SACADA). Atomic and diatomic carbon Under certain conditions, carbon can be found in its atomic form. It can be formed by vaporizing graphite, by passing large electric currents to form a carbon arc under very low pressure. It is extrem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanoengineering
Nanoengineering is the practice of engineering on the nanoscale. It derives its name from the nanometre, a unit of measurement equalling one billionth of a meter. Nanoengineering is largely a synonym for nanotechnology, but emphasizes the engineering rather than the pure science aspects of the field. History * 4th Century Rome: The Lycurgus Cup was crafted using dichroic glass which is a product of nanoengineering * 6th-15th Centuries: Stained glass windows were created in European cathedrals which contained nanoparticles of gold chloride or other metal oxides or chlorides. These nanoparticles give the glass its vibrant colors. * 9th-17th Centuries: A sparkling layer on the outside of ceramics was used containing silver, copper, or other metallic nanoparticles. * 13th-18th Centuries: "Damascus" saber blades were crafted using techniques that resulted in nanotubes and cementite nanowires. * 1950: Victor La Mer and Robert Dinegar created a process that was used to create speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanomaterials
Nanomaterials describe, in principle, chemical substances or materials of which a single unit is sized (in at least one dimension) between 1 and 100 nm (the usual definition of nanoscale). Nanomaterials research takes a materials science-based approach to nanotechnology, leveraging advances in materials metrology and synthesis which have been developed in support of microfabrication research. Materials with structure at the nanoscale often have unique optical, electronic, thermo-physical or mechanical properties. Nanomaterials are slowly becoming commercialized and beginning to emerge as commodities. Definition In ISO/TS 80004, ''nanomaterial'' is defined as the "material with any external dimension in the nanoscale or having internal structure or surface structure in the nanoscale", with ''nanoscale'' defined as the "length range approximately from 1 nm to 100 nm". This includes both ''nano-objects'', which are discrete pieces of material, and ''nanostructu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanotechnology
Nanotechnology is the manipulation of matter with at least one dimension sized from 1 to 100 nanometers (nm). At this scale, commonly known as the nanoscale, surface area and quantum mechanical effects become important in describing properties of matter. This definition of nanotechnology includes all types of research and technologies that deal with these special properties. It is common to see the plural form "nanotechnologies" as well as "nanoscale technologies" to refer to research and applications whose common trait is scale. An earlier understanding of nanotechnology referred to the particular technological goal of precisely manipulating atoms and molecules for fabricating macroscale products, now referred to as molecular nanotechnology. Nanotechnology defined by scale includes fields of science such as surface science, organic chemistry, molecular biology, semiconductor physics, energy storage, engineering, microfabrication, and molecular engineering. The associated rese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Economy
The hydrogen economy is an umbrella term for the roles hydrogen can play alongside low-carbon electricity to reduce emissions of greenhouse gases. The aim is to reduce emissions where cheaper and more energy-efficient clean solutions are not available. In this context, ''hydrogen economy'' encompasses the production of hydrogen and the use of hydrogen in ways that contribute to phasing-out fossil fuels and limiting climate change. Hydrogen can be produced by several means. Most hydrogen produced today is ''gray hydrogen'', made from natural gas through steam methane reforming (SMR). This process accounted for 1.8% of global greenhouse gas emissions in 2021.Greenhouse gas emissions totalled 49.3 Gigatonnes CO2e in 2021. ''Low-carbon hydrogen'', which is made using SMR with carbon capture and storage ('' blue hydrogen''), or through electrolysis of water using renewable power ('' green hydrogen''), accounted for less than 1% of production. Virtually all of the 100 million tonnes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Storage
Several methods exist for storing hydrogen. These include mechanical approaches such as using high pressures and low temperatures, or employing chemical compounds that release H2 upon demand. While large amounts of hydrogen are produced by various industries, it is mostly consumed at the site of production, notably for the synthesis of ammonia. For many years hydrogen has been stored as compressed gas or cryogenic liquid, and transported as such in cylinders, tubes, and cryogenic tanks for use in industry or as propellant in space programs. The overarching challenge is the very low boiling point of H2: it boils around 20.268 K (−252.882 °C or −423.188 °F). Achieving such low temperatures requires expending significant energy. Although molecular hydrogen has very high energy density on a mass basis, partly because of its low molecular weight, as a gas at ambient conditions it has very low energy density by volume. If it is to be used as fuel stored on board a vehic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dangling Bond
In chemistry, a dangling bond is an unsatisfied Valence (chemistry), valence on an immobilized atom. An atom with a dangling bond is also referred to as an immobilized free radical or an immobilized radical, a reference to its structural and chemical similarity to a free radical. When speaking of a dangling bond, one is generally referring to the state described above, containing one electron and thus leading to a neutrally charged atom. There are also dangling bond defects containing two or no electrons. These are negatively and positively charged respectively. Dangling bonds with two electrons have an energy close to the Valence and conduction bands, valence band of the material and those with none have an energy that is closer to the Valence and conduction bands, conduction band. Properties In order to gain enough electrons to fill their valence shells (see also octet rule), many atoms will form covalent bonds with other atoms. In the simplest case, that of a single bond, tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
