ChemTEB Classification Datasets
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Chemical Classification Datasets for Evaluating Text Embedding Models
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* Croix de Guerre 1939–1945
* Bundesverdienstkreuz (1985)
* Legion of Honour (1988)
* Gay-Lussac Humboldt Prize (1982)
* Prix de la Fondation de la Maison de la Chimie (1986) | 1 | Solid-state chemistry |
Some wine production methods also use depletion forces to remove dispersed particles from wine. Unwanted colloidal particles can be found in wine originating from the must or produced during the winemaking process. These particles typically consist of carbohydrates, pigmentation molecules, or proteins which may adversely affect the taste and purity of the wine. Therefore, flocculants are often added to induce floc precipitation for easy filtration. | 0 | Colloidal Chemistry |
InS features tetrahedral In(III) centers linked to four sulfido ligands.
α-InS has a defect cubic structure. The polymorph undergoes a phase transition at 420 °C and converts to the spinel structure of β-InS. Another phase transition at 740 °C produces the layered γ-InS polymorph.
β-InS has a defect spinel structure. The sulfide anions are closely packed in layers, with octahedrally-coordinated In(III) cations present within the layers, and tetrahedrally-coordinated In(III) cations between them. A portion of the tetrahedral interstices are vacant, which leads to the defects in the spinel.
β-InS has two subtypes. In the T-InS subtype, the tetragonally-coordinated vacancies are in an ordered arrangement, whereas the vacancies in C-InS are disordered. The disordered subtype of β-InS shows activity for photocatalytic H production with a noble metal cocatalyst, but the ordered subtype does not.
β-InS is an N-type semiconductor with an optical band gap of 2.1 eV. It has been proposed to replace the hazardous cadmium sulfide, CdS, as a buffer layer in solar cells, and as an additional semiconductor to increase the performance of TiO-based photovoltaics.
The unstable γ-InS polymorph has a layered structure. | 1 | Solid-state chemistry |
West's research has covered the synthesis of new oxide materials, crystal structure determination and structure-property relations with particular focus on ionic, electronic and mixed ionic-electronic conduction. This includes lithium ion conductors, oxygen ion conductor and superconductors.
His research on these new materials has covered a broad range of conducting materials, including - solid solutions with high lithium ion conductivity at room temperature, the oxide ion conductor and much research on barium titanate, such as that on the La-doped high permittivity dielectric. He discovered the first 5-volt cathode material for lithium battery applications, .
One of his specialties has been development of the electrochemical impedance spectroscopy (see dielectric spectroscopy) technique for materials characterisation and electrical property measurements.
He developed the impedance and modulus spectroscopy technique of data analysis with his colleague at Aberdeen, Malcolm Ingram and the Almond-West method for ac conductivity data analysis. | 1 | Solid-state chemistry |
MoS is naturally found as either molybdenite, a crystalline mineral, or jordisite, a rare low temperature form of molybdenite. Molybdenite ore is processed by flotation to give relatively pure . The main contaminant is carbon. also arises by thermal treatment of virtually all molybdenum compounds with hydrogen sulfide or elemental sulfur and can be produced by metathesis reactions from molybdenum pentachloride. | 1 | Solid-state chemistry |
Iron(II) oxide is used as a pigment. It is FDA-approved for use in cosmetics and it is used in some tattoo inks. It can also be used as a phosphate remover from home aquaria. | 1 | Solid-state chemistry |
Dithionitronium hexafluoroarsenate is prepared from thiazyl chloride using silver hexafluoroarsenate. The hexachloroantimonate salt can be prepared by treating thiazyl chloride with sulfur in the presence of antimony pentachloride according to this idealized equation:
The dithionitronium cation reacts with nitriles to give dithiadiazolium salts:
Addition to alkynes gives dithiazolium salts: | 1 | Solid-state chemistry |
Fluorescent nanoparticles are highly sought after. They have broad applications, but their use in macroscopic arrays allows them efficient in applications of plasmonics, photonics, and quantum communications. While there are many methods in assembling nanoparticles array, especially gold nanoparticles, they tend to be weakly bonded to their substrate so they can't be used for wet chemistry processing steps or lithography. Nanodiamonds allow for greater variability in access that can subsequently be used to couple plasmonic waveguides to realize quantum plasmonic circuitry.
Nanodiamonds can be synthesized by employing nanoscale carbonaceous seeds created in a single step by using a mask-free electron beam-induced position technique to add amine groups. This assembles nanodiamonds into an array. The presence of dangling bonds at the nanodiamond surface allows them to be functionalized with a variety of ligands. The surfaces of these nanodiamonds are terminated with carboxylic acid groups, enabling their attachment to amine-terminated surfaces through carbodiimide coupling chemistry. This process affords a high yield that relies on covalent bonding between the amine and carboxyl functional groups on amorphous carbon and nanodiamond surfaces in the presence of EDC. Thus unlike gold nanoparticles, they can withstand processing and treatment, for many device applications. | 0 | Colloidal Chemistry |
Li’s focus of research includes areas of solid-state inorganic and materials chemistry. Her current research focuses on the development of new and functional materials that are fundamentally important and relevant for clean and renewable energy applications. These include (a) metal organic frameworks (MOFs) for gas storage and separation, carbon dioxide capture, waste remediation and chemical sensing, and energy efficient lighting applications; These materials are made of a metal ion or metal cluster such as transition metals and organic ligands such as carboxylate groups and nitrogen containing molecules; (b) inorganic-organic hybrid semiconductors for optoelectronic devices such as photovoltaics and solid-state lighting. These crystalline compounds consist of both inorganic and organic structure motifs. They combine the good features of the two components, resulting in enhanced and improved properties. | 1 | Solid-state chemistry |
Surfactant protein B (SP-B) is a small protein, weighing about 8 kDa. Proteins are composed of building blocks called amino acids, and SP-B is composed of 79 of them (Valine, alanine, phenylalanine, leucine, isoleucine, and tryptophan being found in the highest levels). Nine of these carry with them a positive charge, and two carry a negative charge, leaving a protein with a net (total) charge of +7. In the body, two molecules of SP-B stick together and form what is called a homodimer. These are found embedded into membranes and other lipid structures, SP-B is a highly hydrophobic, avoiding contact with water.
SP-B is the mature form of a large precursor protein called proSP-B. Synthesized in the endoplasmic reticulum of type II pneumocytes, proSP-B weighs approximately 40 kDa and is cut down to the size of mature SP-B in the golgi apparatus through a process called post-translational modification. ProSP-B is also created in another type of lung cell called a Club cell, but these cells are unable to edit proSP-B into SP-B.
SP-B is a saposin-like protein, which is a group of related proteins known particularly for binding to membranes with negative charges and facilitating either the fusion or lysis (breaking) of the membrane. More well known proteins in this family include saposin-C, NK-lysin, and amoebopore. | 0 | Colloidal Chemistry |
Photoresists are light-sensitive materials, composed of a polymer, a sensitizer, and a solvent. Each element has a particular function. The polymer changes its structure when it is exposed to radiation. The solvent allows the photoresist to be spun and to form thin layers over the wafer surface. Finally, the sensitizer, or inhibitor, controls the photochemical reaction in the polymer phase.
Photoresists can be classified as positive or negative. In positive photoresists, the photochemical reaction that occurs during exposure, weakens the polymer, making it more soluble to the developer so the positive pattern is achieved. Therefore, the masks contains an exact copy of the pattern, which is to remain on the wafer, as a stencil for subsequent processing. In the case of negative photoresists, exposure to light causes the polymerization of the photoresist so the negative resist remains on the surface of the substrate where it is exposed, and the developer solution removes only the unexposed areas. Masks used for negative photoresists contain the inverse or photographic “negative” of the pattern to be transferred. Both negative and positive photoresists have their own advantages. The advantages of negative photoresists are good adhesion to silicon, lower cost, and a shorter processing time. The advantages of positive photoresists are better resolution and thermal stability. | 0 | Colloidal Chemistry |
All of the experiments have led to at least one common conclusion: colloidal crystals may indeed mimic their atomic counterparts on appropriate scales of length (spatial) and time (temporal). Defects have been reported to flash by in the blink of an eye in thin films of colloidal crystals under oil using a simple optical microscope. But quantitatively measuring the rate of its propagation provides an entirely different challenge, which has been measured at somewhere near the speed of sound. | 0 | Colloidal Chemistry |
A plate less than one inch thick has enough resistance to turn a .30-06 Springfield standard-issue M2 armour-piercing bullet to dust. The test plate outperformed a solid metal plate of similar thickness, while weighing far less. Other potential applications include nuclear waste (shielding X-rays, gamma rays and neutron radiation) transfer and thermal insulation for space vehicle atmospheric re-entry, with many times the resistance to fire and heat as the plain metals. Another study testing CMF's resistance to .50 caliber rounds found that CMF could stop such rounds at less than half the weight of rolled homogeneous armour. | 0 | Colloidal Chemistry |
Relative permittivity is typically denoted as (sometimes , lowercase kappa) and is defined as
where ε(ω) is the complex frequency-dependent permittivity of the material, and ε is the vacuum permittivity.
Relative permittivity is a dimensionless number that is in general complex-valued; its real and imaginary parts are denoted as:
The relative permittivity of a medium is related to its electric susceptibility, , as .
In anisotropic media (such as non cubic crystals) the relative permittivity is a second rank tensor.
The relative permittivity of a material for a frequency of zero is known as its static relative permittivity. | 0 | Colloidal Chemistry |
Her research is mainly focused on the structure and the stability of both natural and synthetic nanomaterials along with their dependence of temperature and pressure. She is also looking into the application of nanomaterials in geochemical pollutant transport in the air as it relates to the global climate change. | 1 | Solid-state chemistry |
In medicine, nephelometry is used to measure immune function. It is also used in clinical microbiology, for preparation of a standardized inoculum (McFarland suspension) for antimicrobial susceptibility testing. | 0 | Colloidal Chemistry |
Through literature discussing the fabrication of a completely porous nanofoam biopolymer is scarce, recent endeavors have resulted in the formation of nanofoam surfaces on biopolymers. In these instances, biopolymers such as collagen and gelatine, chitosan, and pure curcumin have been used to varying degrees. | 0 | Colloidal Chemistry |
*Thomas Hipke, Günther Lange, René Poss: Taschenbuch für Aluminiumschäume. Aluminium-Verlag, Düsseldorf 2007, .
*Hannelore Dittmar-Ilgen: Metalle lernen schwimmen. In: Dies.: Wie der Kork-Krümel ans Weinglas kommt. Hirzel, Stuttgart 2006, , S. 74. | 0 | Colloidal Chemistry |
Stacy has been recognized for her contributions to chemistry education through numerous awards at the national and local level:
*Garvan-Olin Medal, American Chemical Society 1995
*Distinguished Teaching Scholar, National Science Foundation (2005)
*James Flack Norris Award for Outstanding Achievement in Teaching Chemistry, American Chemical Society (1998)
*President's Chair for Teaching, University of California (1993-1996)
*Award for Professional Excellence, Iota Sigma Pi Society (1996)
*Noyce Prize for Excellence in Undergraduate Teaching (Chemistry), University of California, Berkeley (1996)
*Catalyst Award, Chemical Manufacturers Association (1995)
*Francis P. Garvan-John M. Olin Medal, American Chemical Society (1994)
*Technology Transfer Certificate of Merit, Lawrence Berkeley National Laboratory (1991)
*Faculty Award for Women Scientists and Engineers, National Science Foundation (1991)
*Berkeley Distinguished Teaching Award, University of California, Berkeley (1991)
*Sloan Foundation Fellowship (1988-1990)
*Teacher-Scholar Award, Camille and Henry Dreyfus Foundation (1988)
*ExxonMobil Award Faculty Fellowship for Solid State Chemistry, American Chemical Society (1987)
*Prytanean Society Faculty Enrichment Award, University of California, Berkeley (1986)
*Presidential Young Investigator, National Science Foundation (1984-1989) | 1 | Solid-state chemistry |
A salt lake or saline lake is a landlocked body of water that has a concentration of salts (typically sodium chloride) and other dissolved minerals significantly higher than most lakes (often defined as at least three grams of salt per litre). In some cases, salt lakes have a higher concentration of salt than sea water; such lakes can also be termed hypersaline lakes, and may also be pink lakes on account of their colour. An alkalic salt lake that has a high content of carbonate is sometimes termed a soda lake.
One saline lake classification differentiates between:
*subsaline: 0.5–3‰ (0.05-0.3%)
*hyposaline: 3–20‰ (0.3-2%)
*mesosaline: 20–50‰ (2-5%)
*hypersaline: greater than 50‰ (5%)
Large saline lakes make up 44% of the volume and 23% of the area of lakes worldwide. | 1 | Solid-state chemistry |
Bengt Aurivillius (4 December, 1918 in Linköping – 2 May, 1994 in St. Peter's Parish, Malmöhus County) was a Swedish chemist known for his research in metal and mixed oxides. | 1 | Solid-state chemistry |
Jerome Vinograd (February 9, 1913 – July 7, 1976) was an American biochemist who developed density gradient ultracentrifugation and analytical band centrifugation, and contributed to the understanding of DNA supercoiling. | 0 | Colloidal Chemistry |
Arne Magnéli (6 December 1914 – 22 July 1996) was a Swedish chemist and crystallographer known for his work on the structure determination of transition metal oxides and alloys, including the study into their homologous series and nonstoichiometric phenomenon. | 1 | Solid-state chemistry |
The solid-gas flow systems are present in many industrial applications, as dry, catalytic reactors, settling tanks, pneumatic conveying of solids, among others. Obviously, in industrial operations the drag rule is not simple as a single sphere settling in a stationary fluid. However, this knowledge indicates how drag behaves in more complex systems, which are designed and studied by engineers applying empirical and more sophisticated tools.
For example, settling tanks are used for separating solids and/or oil from another liquid. In food processing, the vegetable is crushed and placed inside of a settling tank with water. The oil floats to the top of the water then is collected. In drinking water and waste water treatment a flocculant or coagulant is often added prior to settling to form larger particles that settle out quickly in a settling tank or (lamella) clarifier, leaving the water with a lower turbidity.
In winemaking, the French term for this process is débourbage. This step usually occurs in white wine production before the start of fermentation. | 0 | Colloidal Chemistry |
Expanded polyethylene copolymers (EPC) are also known - such as 50:50 (weight) materials with polystyrene. Though other properties are intermediate between the two bases, toughness for the copolymer exceeds either, with good tensile and puncture resistance. It is particularly applicable for re-usable products. | 0 | Colloidal Chemistry |
Since they are salts of fatty acids, soaps have the general formula (RCO)M, where R is an alkyl, M is a metal and n is the charge of the cation. The major classification of soaps is determined by the identity of M. When M is Na (sodium) or K (potassium), the soaps are called toilet soaps, used for handwashing. Many metal dications (Mg, Ca, and others) give metallic soap. When M is Li, the result is lithium soap (e.g., lithium stearate), which is used in high-performance greases. A cation from an organic base such as ammonium can be used instead of a metal; ammonium nonanoate is an ammonium-based soap that is used as an herbicide.
When used in hard water, soap does not lather well and a scum of stearate, a common ingredient in soap, forms as an insoluble precipitate. | 1 | Solid-state chemistry |
Wagner officially retired in 1966 but from 1967 to 1977 was a Scientific Member of the Max Planck Institute in Göttingen, continuing to contribute to publications. Many modern inventions based on solid-state technology and semiconductor fabrication, used in devices such as solar energy conversion have been developed with the aid of Wagner's theories. Some examples of solid state electrochemical devices are typically, fuel cells, batteries, sensors and membranes.
Wagner died on 10 December 1977 in Göttingen. | 1 | Solid-state chemistry |
Examples of the PJTE being used to explain chemical, physical, biological, and materials science phenomena are innumerable; as stated above, the PJTE is the only source of instability and distortions in high-symmetry configurations of molecular systems and solids with nondegenerate states, hence any phenomenon stemming from such instability can be explained in terms of the PJTE. Below are some illustrative examples. | 1 | Solid-state chemistry |
As materials for the investigation (samples) are in principle all materials that can be solid and liquid. Depending on the question and the purpose of the investigation, certain framework conditions arise. For the observation of clear perturbation frequencies it is necessary, due to the statistical method, that a certain proportion of the probe atoms are in a similar environment and e.g. experiences the same electric field gradient. Furthermore, during the time window between the start and stop, or approximately 5 half-lives of the intermediate state, the direction of the electric field gradient must not change. In liquids, therefore, no interference frequency can be measured as a result of the frequent collisions, unless the probe is complexed in large molecules, such as in proteins. The samples with proteins or peptides are usually frozen to improve the measurement.
The most studied materials with PAC are solids such as semiconductors, metals, insulators, and various types of functional materials. For the investigations, these are usually crystalline. Amorphous materials do not have highly ordered structures. However, they have close proximity, which can be seen in PAC spectroscopy as a broad distribution of frequencies. Nano-materials have a crystalline core and a shell that has a rather amorphous structure. This is called core-shell model. The smaller the nanoparticle becomes, the larger the volume fraction of this amorphous portion becomes. In PAC measurements, this is shown by the decrease of the crystalline frequency component in a reduction of the amplitude (attenuation). | 1 | Solid-state chemistry |
At the height of the past glaciation (about 20,000 years ago), the land was pushed down by the weight of the ice (isostatic depression). All of the ground-up rock was deposited in the surrounding ocean, which had penetrated significantly inland. The loose deposition of the silt and clay particles in the marine environment, allowed an unusual flocculation to take place. Essentially, this formed a strongly bonded soil skeleton, which was glued by highly mobile sea-salt ions.
At this point, there was only the formation of very strong marine clay, which is found all over the world and highly stable, but with its own unique geotechnical problems. When the glaciers retreated, the land mass rose (post-glacial rebound), the clay was exposed, and formed the soil mass for new vegetation. The rainwater in these northern countries was quite aggressive to these clays, perhaps because it was softer (containing less calcium), or the higher silt content allowed more rainwater and snowmelt to penetrate. The final result was that the ionic glue of the clay was weakened, to give a weak, loose soil skeleton, enclosing significant amounts of water (high sensitivity with high moisture content).
Quick clay deposits are rarely located directly at the ground surface, but are typically covered by a normal layer of topsoil. While this topsoil can absorb most normal stresses, such as normal rainfall or a modest earth tremor, a shock that exceeds the capacity of the topsoil layer — such as a larger earthquake, a large mass added near a slope, or an abnormal rainfall which leaves the topsoil fully saturated so that additional water has nowhere to permeate except into the clay — can disturb the clay and initiate the process of liquefaction. | 0 | Colloidal Chemistry |
Inorganic nanoparticles have emerged as highly valuable functional building blocks for drug delivery systems due to their well-defined and highly tunable properties such as size, shape, and surface functionalization. Inorganic nanoparticles have been largely adopted to biological and medical applications ranging from imaging and diagnoses to drug delivery. Inorganic nanoparticles are usually composed of inert metals such as gold and titanium that form nanospheres, however, iron oxide nanoparticles have also become an option.
Quantum dots (QDs), or inorganic semiconductor nanocrystals, have also emerged as valuable tools in the field of bionanotechnology because of their unique size-dependent optical properties and versatile surface chemistry. Their diameters (2 - 10 nm) are on the order of the exciton Bohr radius, resulting in quantum confinement effects analogous to the "particle-in-a-box" model. As a result, optical and electronic properties of quantum dots vary with their size: nanocrystals of larger sizes will emit lower energy light upon fluorescence excitation.
Surface engineering of QDs is crucial for creating nanoparticle–biomolecule hybrids capable of participating in biological processes. Manipulation of nanocrystal core composition, size, and structure changes QD photo-physical properties Designing coating materials which encapsulate the QD core in an organic shell make nanocrystals biocompatible, and QDs can be further decorated with biomolecules to enable more specific interaction with biological targets. The design of inorganic nanocrystal core coupled with biologically compatible organic shell and surface ligands can combine useful properties of both materials, i.e. optical properties of the QDs and biological functions of ligands attached. | 0 | Colloidal Chemistry |
Aluminium soaps are used as thickening agents, in the production of cosmetics. Other examples include mixed calcium/zinc soaps which are used as heat stabilizer for polyvinyl chloride. Soaps of iron, cobalt and manganese are used as drying agents in paints and varnishes and work by promoting the oxidation and crosslinking of unsaturated oils. | 1 | Solid-state chemistry |
Prior to World War II, he worked as a physicist in Berlin and as a colloid chemist in Cambridge. During World War II he joined the Chemical Defence Experimental Station at Porton Down, Wiltshire, but in 1940 was transferred to the Air Ministry's Assistant Directorate of Intelligence (Science) and spent the rest of the war with the Air Ministry. Due to his work he was made Officer of the Most Excellent Order of the British Empire in 1946.
After the war he moved to the University of Bristol Physics Department to do research in solid state physics, but switched to research on crystal dislocation. His work with William Keith Burton and Nicolás Cabrera was to demonstrate the role dislocations played in the growth of crystals.
Apart from crystal defects, his wide-ranging research interests at Bristol included the mechanical properties of polymers, the theory of liquid crystals, the mechanics of the interior of the Earth, and the origin of biological homochirality.
He was appointed Reader in 1951, Melville Wills Professor in 1954 and Henry Overton Wills Professor and Director of the H.H. Wills Physics Laboratory in 1969. He retired in 1976 but remained active in attending conferences, writing papers and corresponding with colleagues well into the 1990s. He edited the Farm Hall Transcripts from Operation Epsilon well into his eighties. | 0 | Colloidal Chemistry |
During implantation, a radioactive ion beam is generated, which is directed onto the sample material. Due to the kinetic energy of the ions (1-500 keV) these fly into the crystal lattice and are slowed down by impacts. They either come to a stop at interstitial sites or push a lattice-atom out of its place and replace it. This leads to a disruption of the crystal structure. These disorders can be investigated with PAC. By tempering these disturbances can be healed. If, on the other hand, radiation defects in the crystal and their healing are to be examined, unperseived samples are measured, which are then annealed step by step.
The implantation is usually the method of choice, because it can be used to produce very well-defined samples. | 1 | Solid-state chemistry |
Another word used to describe nanoparticle based suspensions is Nanolubricants. They are mainly prepared using oils used for engine and machine lubrication. So far several materials including metals, oxides and allotropes of carbon have been used to formulate nanolubricants. The addition of nanomaterials mainly enhances the thermal conductivity and anti-wear property of base oils. Although MoS2, graphene, Cu based fluids have been studied extensively, the fundamental understanding of underlying mechanisms is still needed.
Molybdenum disulfide (MoS2) and graphene work as third body lubricants, essentially becoming tiny microscopic ball bearings, which reduce the friction between two contacting surfaces. This mechanism is beneficial if a sufficient supply of these particles are present at the contact interface. The beneficial effects are diminished as the rubbing mechanism pushes out the third body lubricants. Changing the lubricant, like-wise, will null the effects of the nanolubricants drained with the oil.
Other nanolubricant approaches, such as Magnesium Silicate Hydroxides (MSH) rely on nanoparticle coatings by synthesizing nanomaterials with adhesive and lubricating functionalities. Research into nanolubricant coatings has been conducted in both the academic and industrial spaces. Nanoborate additives as well as mechanical model descriptions of diamond-like carbon (DLC) coating formations have been developed by Ali Erdemir at Argonne National Labs. Companies such as TriboTEX provide consumer formulations of synthesized MSH nanomaterial coatings for vehicle engines and industrial applications. | 0 | Colloidal Chemistry |
Tensile testings were performed on nanocomposite hydrogels to measure the stress and strain it experiences when elongated under room temperature. The results show that this material can be stretched up to 1000% of its original length. | 0 | Colloidal Chemistry |
Gallium(III) selenide (GaSe) is a chemical compound. It has a defect sphalerite (cubic form of ZnS) structure. It is a p-type semiconductor
It can be formed by union of the elements. It hydrolyses slowly in water and quickly in mineral acids to form toxic hydrogen selenide gas. The reducing capabilities of the selenide ion make it vulnerable to oxidizing agents. It is advised therefore that it not come into contact with bases. | 1 | Solid-state chemistry |
There are several examples of molecules that present amphiphilic properties:
Hydrocarbon-based surfactants are an example group of amphiphilic compounds. Their polar region can be either ionic, or non-ionic. Some typical members of this group are: sodium dodecyl sulfate (anionic), benzalkonium chloride (cationic), cocamidopropyl betaine (zwitterionic), and 1-octanol (long-chain alcohol, non-ionic).
Many biological compounds are amphiphilic: phospholipids, cholesterol, glycolipids, fatty acids, bile acids, saponins, local anaesthetics, etc.
Soap is a common household amphiphilic surfactant compound. Soap mixed with water (polar, hydrophilic) is useful for cleaning oils and fats (non-polar, lipiphillic) from kitchenware, dishes, skin, clothing, etc. | 0 | Colloidal Chemistry |
Choy Jin-ho (; born September 1, 1948) is a South Korean scientist. He was a professor in the department of chemistry at Seoul National University from 1981 to 2004, and thereafter a distinguished professor and director of the Center for Intelligent Nano-Bio Materials (CINBM) at Ewha Womans University. | 1 | Solid-state chemistry |
Many metals such as the alkali metals react directly with the electronegative halogens gases to salts.
Salts form upon evaporation of their solutions. Once the solution is supersaturated and the solid compound nucleates. This process occurs widely in nature and is the means of formation of the evaporite minerals.
Insoluble ionic compounds can be precipitated by mixing two solutions, one with the cation and one with the anion in it. Because all solutions are electrically neutral, the two solutions mixed must also contain counterions of the opposite charges. To ensure that these do not contaminate the precipitated ionic compound, it is important to ensure they do not also precipitate. If the two solutions have hydrogen ions and hydroxide ions as the counterions, they will react with one another in what is called an acid–base reaction or a neutralization reaction to form water. Alternately the counterions can be chosen to ensure that even when combined into a single solution they will remain soluble as spectator ions.
If the solvent is water in either the evaporation or precipitation method of formation, in many cases the ionic crystal formed also includes water of crystallization, so the product is known as a hydrate, and can have very different chemical properties compared to the anhydrous material.
Molten salts will solidify on cooling to below their freezing point. This is sometimes used for the solid-state synthesis of complex ionic compounds from solid reactants, which are first melted together. In other cases, the solid reactants do not need to be melted, but instead can react through a solid-state reaction route. In this method, the reactants are repeatedly finely ground into a paste and then heated to a temperature where the ions in neighboring reactants can diffuse together during the time the reactant mixture remains in the oven. Other synthetic routes use a solid precursor with the correct stoichiometric ratio of non-volatile ions, which is heated to drive off other species.
In some reactions between highly reactive metals (usually from Group 1 or Group 2) and highly electronegative halogen gases, or water, the atoms can be ionized by electron transfer, a process thermodynamically understood using the Born–Haber cycle.
Salts are formed by salt-forming reactions
*A base and an acid, e.g., NH + HCl → NHCl
*A metal and an acid, e.g., Mg + HSO → MgSO + H
*A metal and a non-metal, e.g., Ca + Cl → CaCl
*A base and an acid anhydride, e.g., 2 NaOH + ClO → 2 NaClO + HO
*An acid and a base anhydride, e.g., 2 HNO + NaO → 2 NaNO + HO
*In the salt metathesis reaction where two different salts are mixed in water, their ions recombine, and the new salt is insoluble and precipitates. For example:
*: Pb(NO) + NaSO → PbSO↓ + 2 NaNO | 1 | Solid-state chemistry |
Reutzel-Edens joined Eli Lilly and Company, where she recognized that it would be challenging to identify and design increasingly complicated drug targets, and instead proposed the use of computation approaches. Through collaborations with the Cambridge Crystallographic Database, Reutzel-Edens founded the Lilly solid form design program. Her research has considered crystal polymorphism and the crystal nucleation. She used computational approaches to identify commercially viable small molecule drug products. To this end, Reutzel-Edens proposed the use of crystal structure prediction to identify pharmaceutical molecules to complement experimental investigations. She has described Olanzapine as “an incredible molecule, a gift to crystal chemistry that keeps on giving,”.
In 2018, Reutzel-Edens was appointed Fellow of the Royal Society of Chemistry. She serves on the editorial boards of CrystEngComm and Crystal Growth and Design. In 2021 Reutzel-Edens joined the Cambridge Crystallographic Database as Head of Science. | 1 | Solid-state chemistry |
During the 1970s and 80s, when the first thorough fundamental studies with nanoparticles were underway in the United States by Granqvist and Buhrman and Japan within an ERATO Project, researchers used the term ultrafine particles. However, during the 1990s, before the National Nanotechnology Initiative was launched in the United States, the term nanoparticle had become more common, for example, see the same senior author's paper 20 years later addressing the same issue, lognormal distribution of sizes. | 0 | Colloidal Chemistry |
* Low-expansion foams, such as aqueous film forming foams (AFFFs), have an expansion ratio of less than 20, are low-viscosity, mobile, and can quickly cover large areas.
* Medium-expansion foams have an expansion ratio of 20–200.
* High-expansion foams have an expansion ratio over 200–1000 and are suitable for enclosed spaces such as hangars, where quick filling is needed.
* Alcohol-resistant foams contain a polymer that forms a protective layer between the burning surface and the foam, preventing foam breakdown by alcohols in the burning fuel. Alcohol-resistant foams are used in fighting fires of fuels containing oxygenates, e.g. methyl tert-butyl ether (MTBE), or fires of liquids based on or containing polar solvents. | 0 | Colloidal Chemistry |
Quantum mechanics effects become noticeable for nanoscale objects. They include quantum confinement in semiconductor particles, localized surface plasmons in some metal particles, and superparamagnetism in magnetic materials. Quantum dots are nanoparticles of semiconducting material that are small enough (typically sub 10 nm or less) to have quantized electronic energy levels.
Quantum effects are responsible for the deep-red to black color of gold or silicon nanopowders and nanoparticle suspensions. Absorption of solar radiation is much higher in materials composed of nanoparticles than in thin films of continuous sheets of material. In both solar PV and solar thermal applications, by controlling the size, shape, and material of the particles, it is possible to control solar absorption.
Core-shell nanoparticles can support simultaneously both electric and magnetic resonances, demonstrating entirely new properties when compared with bare metallic nanoparticles if the resonances are properly engineered. The formation of the core-shell structure from two different metals enables an energy exchange between the core and the shell, typically found in upconverting nanoparticles and downconverting nanoparticles, and causes a shift in the emission wavelength spectrum.
By introducing a dielectric layer, plasmonic core (metal)-shell (dielectric) nanoparticles enhance light absorption by increasing scattering. Recently, the metal core-dielectric shell nanoparticle has demonstrated a zero backward scattering with enhanced forward scattering on a silicon substrate when surface plasmon is located in front of a solar cell. | 0 | Colloidal Chemistry |
Adjacent to the channel walls, the charge-neutrality of the liquid is violated due to the presence of the electrical double layer: a thin layer of counterions attracted by the charged surface.
The transport of counterions along with the pressure-driven fluid flow gives rise to a net charge transport: the streaming current. The reverse effect, generating a fluid flow by applying a potential difference, is called electroosmotic flow. | 0 | Colloidal Chemistry |
Corbett was born to parents Alexander and Elizabeth Corbett in Yakima, Washington, on March 23, 1926, and had two brothers. He was married to F. Irene Lienkaemper from 1948 until her death in 1996. The couple raised three children. Corbett died on September 2, 2013, at the age of 87, following a stroke. The John D. Corbett Professorship was established in 2007, within Iowa State University's Department of Chemistry. | 1 | Solid-state chemistry |
In chemistry, a plumbate often refers to compounds that can be viewed as derivatives of the hypothetical anion. | 1 | Solid-state chemistry |
The use of photoconductive materials (for example, in lab-on-chip devices) allows for localized inducement of dielectrophoretic forces through the application of light. In addition, one can project an image to induce forces in a patterned illumination area, allowing for some complex manipulations. When manipulating living cells, optical dielectrophoresis provides a non-damaging alternative to optical tweezers, as the intensity of light is about 1000 times less. | 0 | Colloidal Chemistry |
When heated to over 600 °C niobium trichloride disproportionates to niobium metal and niobium pentachloride. | 1 | Solid-state chemistry |
Historically, pyrotechnic or explosive applications for traditional thermites have been limited due to their relatively slow energy release rates. Because nanothermites are created from reactant particles with proximities approaching the atomic scale, energy release rates are far greater.
MICs or super-thermites are generally developed for military use, propellants, explosives, incendiary devices, and pyrotechnics. Research into military applications of nano-sized materials began in the early 1990s. Because of their highly increased reaction rate, nano-thermitic materials are being studied by the U.S. military with the aim of developing new types of bombs several times more powerful than conventional explosives. Nanoenergetic materials can store more energy than conventional energetic materials and can be used in innovative ways to tailor the release of this energy. Thermobaric weapons are one potential application of nanoenergetic materials. | 0 | Colloidal Chemistry |
Iron minerals on the Earths surface are typically richly oxidized, forming hematite, with Fe state, or in somewhat less oxidizing environments, magnetite, with a mixture of Fe and Fe. Wüstite, in geochemistry, defines a redox buffer' of oxidation within rocks at which point the rock is so reduced that Fe, and thus hematite, is absent.
As the redox state of a rock is further reduced, magnetite is converted to wüstite. This occurs by conversion of the Fe ions in magnetite to Fe ions. An example reaction is presented below:
The formula for magnetite is more accurately written as FeO·FeO than as FeO. Magnetite is one part FeO and one part FeO, rather than a solid solution of wüstite and hematite. Magnetite is termed a redox buffer because, until all Fe present in the system is converted to Fe, the oxide mineral assemblage of iron remains wüstite-magnetite. Furthermore, the redox state of the rock remains at the same level of oxygen fugacity. Considering buffering the redox potential (E) in the Fe–O redox system, this can be compared to buffering the pH in the H/OH acid–base system of water.
Once the Fe is consumed, then oxygen must be stripped from the system to further reduce it and wüstite is converted to native iron. The oxide mineral equilibrium assemblage of the rock becomes wüstite–magnetite–iron.
In nature, the only natural systems which are chemically reduced enough to even attain a wüstite–magnetite composition are rare, including carbonate-rich skarns, meteorites, fulgurites and lightning-affected rock, and perhaps the mantle where reduced carbon is present, exemplified by the presence of diamond or graphite. | 1 | Solid-state chemistry |
Magnesium can be removed either thermally or by reactive measures through the dissolution in acid.
Esen & Bor found a critical content of magnesium as a space holder to be 55-60%, above which compacts shrink excessively during sintering. Foams ranging in porosity from 45 to 70% with a bimodal pore distribution and compressive strength of 15 MPa (for 70% porosity) were demonstrated. Kim et al. fabricated foams with anisotropic pores through the intentional deformation of Mg particles during compaction in an effort to enhance mechanical properties. A final porosity of 70% equated to a yield strength of 38 MPa for normal orientation of pores and 59 MPa when pores were aligned with the direction of compression. | 0 | Colloidal Chemistry |
The most common approach to understand the formation of these particles, first used by Ino in 1969, is to look at the energy as a function of size comparing icosahedral twins, decahedral nanoparticles and single crystals. The total energy for each type of particle can be written as the sum of three terms:
for a volume , where is the surface energy, is the disclination strain energy to close the gap (or overlap for marcasite and others), and is a coupling term for the effect of the strain on the surface energy via the surface stress, which can be a significant contribution. The sum of these three terms is compared to the total surface energy of a single crystal (which has no strain), and to similar terms for an icosahedral particle. Because the decahedral particles have a lower total surface energy than single crystals due (approximately, in fcc) to more low energy {111} surfaces, they are lower in total energy for an intermediate size regime, with the icosahedral particles more stable at very small sizes. (The icosahedral particle have even more {111} surfaces, but also more strain.) At large sizes the strain energy can become very large, so it is energetically favorable to have dislocations and/or a grain boundary instead of a distributed strain. The very large mineral samples are almost certainly trapped in metastable higher energy configurations.
There is no general consensus on the exact sizes when there is a transition in which type of particle is lowest in energy, as these vary with material and also the environment such as gas and temperature; the coupling surface stress term and also the surface energies of the facets are very sensitive to these. In addition, as first described by Michael Hoare and P Pal and R. Stephen Berry and analyzed for these particles by Pulickel Ajayan and Marks as well as discussed by others such as Amanda Barnard, David J. Wales, Kristen Fichthorn and Baletto and Ferrando, at very small sizes there will be a statistical population of different structures so many different ones will coexist. In many cases nanoparticles are believed to grow from a very small seed without changing shape, and reflect the distribution of coexisting structures. For systems where icosahedral and decahedral morphologies are both relatively low in energy, the competition between these structures has implications for structure prediction and for the global thermodynamic and kinetic properties. These result from a double funnel energy landscape where the two families of structures are separated by a relatively high energy barrier at the temperature where they are in thermodynamic equilibrium. This situation arises for a cluster of 75 atoms with the Lennard-Jones potential, where the global potential energy minimum is decahedral, and structures based upon incomplete Mackay icosahedra are also low in potential energy, but higher in entropy. The free energy barrier between these families is large compared to the available thermal energy at the temperature where they are in equilibrium. An example is shown in the figure, with probability in the lower part and energy above with axes of an order parameter and temperature . At low temperature the decahedral cluster (Dh) is the global free energy minimum, but as the temperature increases the higher entropy of the competing structures based on incomplete icosahedra (Ic) causes the finite system analogue of a first-order phase transition; at even higher temperatures a liquid-like state is favored.
There has been experiment support based upon work where single nanoparticles are imaged using electron microscopes either as they grow or as a function of time. One of the earliest works was that of Yagi et al who directly observed changes in the internal structure with time during growth. More recent work has observed variations in the internal structure in liquid cells, or changes between different forms due to either (or both) heating or the electron beam in an electron microscope including substrate effects. | 1 | Solid-state chemistry |
Paul Hagenmuller (August 3, 1921 – January 7, 2017) was a French chemist. Hagenmuller founded the Laboratoire de Chimie du Solide (Solid-State Chemistry Laboratory) of the French National Centre for Scientific Research (CNRS) and he served as its Director until 1985. He is considered "one of the founders of solid-state chemistry." | 1 | Solid-state chemistry |
* Honest Sex (2003 [1969], with coauthor Della Roy), Signet Press, .
* Experimenting With Truth: The Fusion of Religion With Technology Needed for Humanitys Survival' [1979 Hibbert Lectures] (1980), Pergamon Press, .
* Radioactive Waste (1982), Pergamon Press, .
* Lost at the Frontier: U.S. Science and Technology Policy Adrift (1985), ISI Press, . | 1 | Solid-state chemistry |
has a variety of specialized applications and generally, applications distinguish between "chemical grade", which is relatively pure material for specialty applications, and "metallurgical grade", which is mainly used for the production of alloys. It is used in the ceramic industry to make frits, ferrites, and porcelain glazes. The sintered oxide is used to produce nickel steel alloys. Charles Édouard Guillaume won the 1920 Nobel Prize in Physics for his work on nickel steel alloys which he called invar and elinvar.
is a commonly used hole transport material in thin film solar cells. It was also a component in the nickel-iron battery, also known as the Edison Battery, and is a component in fuel cells. It is the precursor to many nickel salts, for use as specialty chemicals and catalysts. More recently, was used to make the NiCd rechargeable batteries found in many electronic devices until the development of the environmentally superior NiMH battery. an anodic electrochromic material, have been widely studied as counter electrodes with tungsten oxide, cathodic electrochromic material, in complementary electrochromic devices.
About 4000 tons of chemical grade are produced annually. Black is the precursor to nickel salts, which arise by treatment with mineral acids. is a versatile hydrogenation catalyst.
Heating nickel oxide with either hydrogen, carbon, or carbon monoxide reduces it to metallic nickel. It combines with the oxides of sodium and potassium at high temperatures (>700 °C) to form the corresponding nickelate. | 1 | Solid-state chemistry |
* Korean Chemical Society (1997),
* National science award in chemistry from the South Korean government (2000),
* Distinguished Service Knight Medal from the French Government (Palmes Academiques Chevalier dans l’Ordre des Palmes Academiques: 2003)
* 1st Class National Science Medal (2006)
* Korean Best Scientist Award from the President of South Korea (2007)
* Role Model in Science from the South Korean government
* Award of Fellow from the Royal Society of Chemistry, UK (2008)
* Culture award in science from Seoul City (2010)
* Academic award from Ewha Womans University (2012).
* Permanent member of Korean Academy of Science and Technology (2002). | 1 | Solid-state chemistry |
Jean-Marie Tarascon FRSC (born September 21, 1953) is Professor of Chemistry at the Collège de France in Paris and Director of the French Research Network on Electrochemical Energy Storage (RS2E). | 1 | Solid-state chemistry |
Wein filter. In Wien filter mass separation is done with crossed homogeneous electric and magnetic fields perpendicular to ionized cluster beam. The net force on a charged cluster with mass M, charge Q, and velocity v vanishes if E = Bv/c. The cluster ions are accelerated by a voltage V to an energy QV. Passing through the filter, clusters with M/Q = 2V/(Ec/B) are un-deflected. The un-deflected cluster ions are selected with appropriately positioned collimators.
Quadrupole mass filter. The quadrupole mass filter operates on the principle that ion trajectories in a two-dimensional quadrupole field are stable if the field has an AC component superimposed on a DC component with appropriate amplitudes and frequencies. It is responsible for filtering sample ions based on their mass-to-charge ratio.
Time of flight mass spectroscopy. Time-of-flight spectroscopy consists of an ion gun, a field-free drift space and an ion cluster source. The neutral clusters are ionized, typically using pulsed laser or an electron beam. The ion gun accelerates the ions that pass through the field-free drift space (flight tube) and ultimately impinge on an ion detector. Usually an oscilloscope records the arrival time of the ions. The mass is calculated from the measured time of flight.
Molecular beam chromatography. In this method, cluster ions produced in a laser vaporized cluster source are mass selected and introduced in a long inert-gas-filled drift tube with an entrance and exit aperture. Since cluster mobility depends upon the collision rate with the inert gas, they are sensitive to the cluster shape and size. | 0 | Colloidal Chemistry |
The migration of atoms within a solid is strongly influenced by the defects associated with non-stoichiometry. These defect sites provide pathways for atoms and ions to migrate through the otherwise dense ensemble of atoms that form the crystals. Oxygen sensors and solid state batteries are two applications that rely on oxide vacancies. One example is the CeO-based sensor in automotive exhaust systems. At low partial pressures of O, the sensor allows the introduction of increased air to effect more thorough combustion. | 1 | Solid-state chemistry |
Organic molecular wires usually consist aromatic rings connected by ethylene group or acetylene groups. Transition metal-mediated cross-coupling reactions are used to connect simple building blocks together in a convergent fashion to build organic molecular wires. For example, a simple oligo (phenylene ethylnylene) type molecular wire (B) was synthesized starting from readily available 1-bromo-4-iodobenzene (A). The final product was obtained through several steps of Sonogashira coupling reactions.
Other organic molecular wires include carbon nanotubes and DNA. Carbon nanotubes can be synthesized via various nano-technological approaches. DNA can be prepared by either step-wise DNA synthesis on solid-phase or by DNA-polymerase-catalyzed replication inside cells.
It was recently shown that pyridine and pyridine-derived polymers can form electronically conductive polyazaacetylene chains under simple ultraviolet irradiation, and that the common observation of "browning" of aged pyridine samples is due in part to the formation of molecular wires. The gels exhibited a transition between ionic conductivity and electronic conductivity on irradiation. | 1 | Solid-state chemistry |
At room temperature, taurates are usually pasty masses, which dissolve well in water and react then neutral to slightly alkaline (pH 7–8). Their toxicity is low (the LD, rat, oral is 7800 mg·kg for cocoyl tauride). They are easily biodegradable, they are not prone to bioaccumulation, but they are harmful to aquatic organisms (like all surfactants). Due to their amide bond, taurates are stable in a much wider pH range (about 2–10) than the corresponding esters, as for example isethionates. They are very mild surfactants with good foaming ability and high foam stability, even in the presence of fats and oils. Taurates retain their good washing properties even in hard water or seawater. Taurates are suitable in concentrations of about 2% as co-surfactants because of their good compatibility with all nonionic and anionic surfactants. | 0 | Colloidal Chemistry |
In order to aid his experiments, he developed a system of chemical notation in which the elements composing any particular chemical compound were given simple written labels—such as O for oxygen, or Fe for iron—with their proportions in the chemical compound denoted by numbers. Berzelius thus invented the system of chemical notation still used today, the main difference being that instead of the subscript numbers used today (e.g., HO or FeO), Berzelius used superscripts (HO or FeO). | 1 | Solid-state chemistry |
According to the nomenclature recommended by IUPAC, ionic compounds are named according to their composition, not their structure. In the most simple case of a binary ionic compound with no possible ambiguity about the charges and thus the stoichiometry, the common name is written using two words. The name of the cation (the unmodified element name for monatomic cations) comes first, followed by the name of the anion. For example, MgCl is named magnesium chloride, and NaSO is named sodium sulfate (, sulfate, is an example of a polyatomic ion). To obtain the empirical formula from these names, the stoichiometry can be deduced from the charges on the ions, and the requirement of overall charge neutrality.
If there are multiple different cations and/or anions, multiplicative prefixes (di-, tri-, tetra-, ...) are often required to indicate the relative compositions, and cations then anions are listed in alphabetical order. For example, KMgCl is named magnesium potassium trichloride to distinguish it from KMgCl, magnesium dipotassium tetrachloride (note that in both the empirical formula and the written name, the cations appear in alphabetical order, but the order varies between them because the symbol for potassium is K). When one of the ions already has a multiplicative prefix within its name, the alternate multiplicative prefixes (bis-, tris-, tetrakis-, ...) are used. For example, Ba(BrF) is named barium bis(tetrafluoridobromate).
Compounds containing one or more elements which can exist in a variety of charge/oxidation states will have a stoichiometry that depends on which oxidation states are present, to ensure overall neutrality. This can be indicated in the name by specifying either the oxidation state of the elements present, or the charge on the ions. Because of the risk of ambiguity in allocating oxidation states, IUPAC prefers direct indication of the ionic charge numbers. These are written as an arabic integer followed by the sign (... , 2−, 1−, 1+, 2+, ...) in parentheses directly after the name of the cation (without a space separating them). For example, FeSO is named iron(2+) sulfate (with the 2+ charge on the Fe ions balancing the 2− charge on the sulfate ion), whereas Fe(SO) is named iron(3+) sulfate (because the two iron ions in each formula unit each have a charge of 3+, to balance the 2− on each of the three sulfate ions). Stock nomenclature, still in common use, writes the oxidation number in Roman numerals (... , −II, −I, 0, I, II, ...). So the examples given above would be named iron(II) sulfate and iron(III) sulfate respectively. For simple ions the ionic charge and the oxidation number are identical, but for polyatomic ions they often differ. For example, the uranyl(2+) ion, , has uranium in an oxidation state of +6, so would be called a dioxouranium(VI) ion in Stock nomenclature. An even older naming system for metal cations, also still widely used, appended the suffixes -ous and -ic to the Latin root of the name, to give special names for the low and high oxidation states. For example, this scheme uses "ferrous" and "ferric", for iron(II) and iron(III) respectively, so the examples given above were classically named ferrous sulfate and ferric sulfate.
Common salt-forming cations include:
* Ammonium
* Calcium
* Iron and
* Magnesium
* Potassium
* Pyridinium
* Quaternary ammonium , R being an alkyl group or an aryl group
* Sodium
* Copper
Common salt-forming anions (parent acids in parentheses where available) include:
* Acetate (acetic acid)
* Carbonate (carbonic acid)
* Chloride (hydrochloric acid)
* Citrate (citric acid)
* Cyanide (hydrocyanic acid)
* Fluoride (hydrofluoric acid)
* Nitrate (nitric acid)
* Nitrite (nitrous acid)
* Oxide (water)
* Phosphate (phosphoric acid)
* Sulfate (sulfuric acid)
Salts with varying number of hydrogen atoms replaced by cations as compared to their parent acid can be referred to as monobasic, dibasic, or tribasic, identifying that one, two, or three hydrogen atoms have been replaced; polybasic salts refer to those with more than one hydrogen atom replaced. Examples include:
* Sodium phosphate monobasic (NaHPO)
* Sodium phosphate dibasic (NaHPO)
* Sodium phosphate tribasic (NaPO) | 1 | Solid-state chemistry |
LASiS has some limitations in the size control of NMNp, which can be overcome by laser treatments of NMNp. Other cons of LASiS include: the slow rate of NPs production, high consumption of energy, laser equipment cost, and decreased ablation efficiency with longer usage of the laser within a session. Other pros of LASiS include: minimal waste production, minimal manual operation, and refined size control of nanoparticles. | 0 | Colloidal Chemistry |
Copper(I) iodide, like most binary (containing only two elements) metal halides, is an inorganic polymer. It has a rich phase diagram, meaning that it exists in several crystalline forms. It adopts a zinc blende structure below 390 °C (γ-CuI), a wurtzite structure between 390 and 440 °C (β-CuI), and a rock salt structure above 440 °C (α-CuI). The ions are tetrahedrally coordinated when in the zinc blende or the wurtzite structure, with a Cu-I distance of 2.338 Å. Copper(I) bromide and copper(I) chloride also transform from the zinc blende structure to the wurtzite structure at 405 and 435 °C, respectively. Therefore, the longer the copper–halide bond length, the lower the temperature needs to be to change the structure from the zinc blende structure to the wurtzite structure. The interatomic distances in copper(I) bromide and copper(I) chloride are 2.173 and 2.051 Å, respectively. Consistent with its covalency, CuI is a p-type semiconductor. | 1 | Solid-state chemistry |
In 1998, Dr. Czarnik’s group at Parke-Davis reported the first successful drug discovery effort in which RNA was the target. His group also conducted the first successful effort to discover small molecule drugs that work by binding to RNA. This has led to the creation of a new field of drug discovery, notably the focus of startup companies and scientific conferences. | 1 | Solid-state chemistry |
NTA and related technologies were developed by Bob Carr. Along with John Knowles, Carr founded NanoSight Ltd in 2003. This United Kingdom-based company, of which Knowles is the chairman and Carr is the chief technology officer, manufactures instruments that use NTA to detect and analyze small particles in industrial and academic laboratories. In 2004 Particle Metrix GmbH was founded in Germany by Hanno Wachernig. Particle Metrix makes the ZetaView which operates on the same NTA principle but uses different optics and fluidics in an attempt to improve sampling, zeta potential, and fluorescence detection. | 0 | Colloidal Chemistry |
The functional principle is basically the same as with normal spray dryers. There are just different technologies that are used to do similar things.
The drying gas enters the system via the heater. A new kind of heater system allows for laminar air flow. The spray head sprays the fine droplets with a narrow size distribution into the drying chamber. The droplets dry and become solid particles. The solid particles are separated in the electrostatic particle collector. The [exhaust gas] is filtered and sent to a fume hood or the environment. The inlet temperature is controlled by a temperature sensor. and can be very dangerous also due to particulate matter | 0 | Colloidal Chemistry |
Iron-pyrite FeS represents the prototype compound of the crystallographic pyrite structure. The structure is cubic and was among the first crystal structures solved by X-ray diffraction. It belongs to the crystallographic space group Pa and is denoted by the Strukturbericht notation C2. Under thermodynamic standard conditions the lattice constant of stoichiometric iron pyrite FeS amounts to . The unit cell is composed of a Fe face-centered cubic sublattice into which the ions are embedded. (Note though that the iron atoms in the faces are not equivalent by translation alone to the iron atoms at the corners.) The pyrite structure is also seen in other MX compounds of transition metals M and chalcogens X = O, S, Se and Te. Certain dipnictides with X standing for P, As and Sb etc. are also known to adopt the pyrite structure.
The Fe atoms are bonded to six S atoms, giving a distorted octahedron. The material is a semiconductor. The Fe ions is usually considered to be low spin divalent state (as shown by Mössbauer spectroscopy as well as XPS). The material as a whole behaves as a Van Vleck paramagnet, despite its low-spin divalency.
The sulfur centers occur in pairs, described as S.. This material features ferric ions and isolated sulfide (S) centers.
The S atoms are tetrahedral, being bonded to three Fe centers and one other S atom. The site symmetry at Fe and S positions is accounted for by point symmetry groups C and C, respectively. The missing center of inversion at S lattice sites has important consequences for the crystallographic and physical properties of iron pyrite. These consequences derive from the crystal electric field active at the sulfur lattice site, which causes a polarization of S ions in the pyrite lattice. The polarisation can be calculated on the basis of higher-order Madelung constants and has to be included in the calculation of the lattice energy by using a generalised Born–Haber cycle. This reflects the fact that the covalent bond in the sulfur pair is inadequately accounted for by a strictly ionic treatment.
Arsenopyrite has a related structure with heteroatomic As–S pairs rather than S-S pairs. Marcasite also possesses homoatomic anion pairs, but the arrangement of the metal and diatomic anions differ from that of pyrite. Despite its name, chalcopyrite () does not contain dianion pairs, but single S sulfide anions. | 1 | Solid-state chemistry |
The mineral form of is tellurobismuthite which is moderately rare. There are many natural bismuth tellurides of different stoichiometry, as well as compounds of the Bi-Te-S-(Se) system, like (tetradymite). These bismuth tellurides are part of the tetradymite group of minerals.
Bismuth telluride may be prepared simply by sealing mixed powders of bismuth and tellurium metal in a quartz tube under vacuum (critical, as an unsealed or leaking sample may explode in a furnace) and heating it to 800 °C in a muffle furnace. | 1 | Solid-state chemistry |
SnO coatings can be applied using chemical vapor deposition, vapour deposition techniques that employ SnCl or organotin trihalides e.g. butyltin trichloride as the volatile agent. This technique is used to coat glass bottles with a thin (, which helps to adhere a subsequent, protective polymer coating such as polyethylene to the glass.
Thicker layers doped with Sb or F ions are electrically conducting and used in electroluminescent devices and photovoltaics. | 1 | Solid-state chemistry |
Phosphorene is a promising candidate for flexible nano systems due to its ultra-thin nature with ideal electrostatic control and superior mechanical flexibility. Researchers have demonstrated the flexible transistors, circuits and [https://www.youtube.com/watch?v=Sd6JGbKmvUY AM demodulator] based on few-layer phosphorus, showing enhanced am bipolar transport with high room temperature carrier mobility as high as ~310 cm/Vs and strong current saturation. Fundamental circuit units including digital inverter, voltage amplifier and frequency doubler have been realized. Radio frequency (RF) transistors with highest intrinsic cutoff frequency of 20 GHz has been realized for potential applications in high frequency flexible smart nano systems. | 1 | Solid-state chemistry |
Around 1990, theoretical and experimental evidence has emerged that forces between charged particles suspended in dilute solutions of monovalent electrolytes might be attractive at larger distances. This evidence is in contradiction with the PB theory discussed above, which always predicts repulsive interactions in these situations. The theoretical treatment leading to these conclusions was strongly criticized. The experimental findings were mostly based on video-microscopy, but the underlying data analysis was questioned concerning the role of impurities, appropriateness of image processing techniques, and the role of hydrodynamic interactions. Despite the initial criticism, accumulative evidence suggest that the DLVO fails to account for essential physics necessary to describe the experimental observations.
While the community remains skeptical regarding the existence of effective attractions between like-charged species, recent computer molecular dynamics simulations with an explicit description of the solvent have demonstrated that the solvent plays an important role in the structure of charged species in solution, while PB and the primitive model do not account for most of these effects. Specifically, the solvent plays a key role in the charge localization of the diffuse ions in ion-rich
domains that bring charged species closer together. Based on this idea, simulations have explained experimental trends such as the disappearance of a scattering peak in salt-free polyelectrolyte solutions and the structural inhomogeneities of charged colloidal particles/nanoparticles observed experimentally that PB and primitive model approaches fail to explain. | 0 | Colloidal Chemistry |
Tian et al. listed several criteria to assess a foam in a heat exchanger. The comparison of thermal-performance metal foams with materials conventionally used in the intensification of exchange (fins, coupled surfaces, bead bed) first shows that the pressure losses caused by foams are much more important than with conventional fins, yet are significantly lower than those of beads. The exchange coefficients are close to beds and ball and well above the blades.
Foams offer other thermophysical and mechanical features:
* Very low mass (density 5–25% of the bulk solid depending on the manufacturing method)
* Large exchange surface (250–10000 m/m)
* Relatively high permeability
* Relatively high effective thermal conductivities (5–30 W/(mK))
* Good resistance to thermal shocks, high pressures, high temperatures, moisture, wear and thermal cycling
* Good absorption of mechanical shock and sound
* Pore size and porosity can be controlled by the manufacturer
Commercialization of foam-based compact heat exchangers, heat sinks and shock absorbers is limited due to the high cost of foam replications. Their long-term resistance to fouling, corrosion and erosion are insufficiently characterized. From a manufacturing standpoint, the transition to foam technology requires new production and assembly techniques and heat exchanger design.
Kisitu et al. pioneered the experimental investigation of using compressed copper foam for advanced two-phase cooling for high heat flux electronics. The metallic foam samples are designed and manufactured by a US-based company, ERG Aerospace Corporation. Heat fluxes as high as 174 W/cm2 were tested/handled. Data reveal that compressing the foam by four times in the streamwise direction (4X) enhanced thermal performance by more than 3 times, compared to the uncompressed metal foam. This was attributed to the fact that compressing foam proportionally reduces the effective hydraulic diameter and increases both the surface area per unit volume and foam bulk thermal conductivity, which all improve two-phase cooling performance. In addition, results show that compressed foam has a potential to increase the critical heat flux (CHF), which is pivotal in the safe operation of two-phase cooling at high heat densities. Preliminarly results show that compressed metallic foams can solve several issues faced with microchannels, including clogging, flow instabilities, low CHF, and others. As such, compressed foams are being proposed as new powerful alternatives to microchannels in pumped two-phase cooling for high heat flux electronics cooling/thermal management, including high performance computers, aerospace, military and defence, and power electronics. | 0 | Colloidal Chemistry |
The effective volume of a cluster is considered much larger than the volume of the particles due to the lower packing fraction of the cluster. Since, heat can be transferred rapidly within the such clusters, the volume fraction of the highly conductive phase is larger than the volume of solid, thus increasing its thermal conductivity | 0 | Colloidal Chemistry |
The mechanical properties of titanium foams are sensitive to the presence of interstitial solutes, which present limitations to processing routes and utilization. Titanium has a high affinity for atmospheric gases. In foams, this is evidenced by the metal's tendency to trap oxides within cell edges.
Micro-hardness of cell walls, elastic modulus, and yield strength increase as a result of interstitial solutes; ductility, which is a function of the quantity of interstitial impurities, is consequently reduced. Of the atmospheric gases, nitrogen has the most significant impact, followed by oxygen and carbon.
These impurities are often present in the precursor mixture and also introduced during processing. | 0 | Colloidal Chemistry |
As typical for xanthates, potassium amyl xanthate is prepared by reacting n-amyl alcohol with carbon disulfide and potassium hydroxide.
: CH(CH)OH + CS + KOH → CH(CH)OCSK + HO
Potassium amyl xanthate is a pale yellow powder. Its solutions are relatively stable between pH 8 and 13 with a maximum of stability at pH 10. | 1 | Solid-state chemistry |
Aquasomes with calcium phosphate ceramic cores may be useful for the pharmaceutical administration of substrates such as insulin where drug action is conformationally specific. In a 2000 study by Cherian et al., disaccharides such as trehalose were used to coat the core before insulin was loaded onto the coated cores via adsorption. Albino rats were used as test subjects to test these aquasome insulin formulations, and the efficiency of different carbohydrate coat molecules on the aquasome was explored. Pyridoxal-5-phosphate-coated particles were shown to lower blood glucose levels more efficiently when compared to trehalose- or cellobiose-coated particles, which may be due to their differences in structural stability. The use of these nanoparticles for the delivery of insulin in vivo in rabbits demonstrated that insulin-bearing aquasomes showed slower release and prolonged activity compared to standard insulin solution. Similar to their role in carrying hemoglobin, the carbohydrate layer of aquasomes may be responsible for the ability to protect insulin from degradation when injected subcutaneously as in the albino rats tested. Aquasomes were also shown to release insulin in controlled manners, mimicking the typical release of insulin from the pancreas. This application shows the promise of aquasomes in aiding and improving the efficacy of insulin therapy, which may be used for diabetes treatment upon further investigation of aquasomes’ in vivo behavior. | 0 | Colloidal Chemistry |
A nanoparticle interfacial layer is a well structured layer of typically organic molecules around a nanoparticle. These molecules are known as stabilizers, capping and surface ligands or passivating agents. The interfacial layer has a significant effect on the properties of the nanoparticle and is therefore often considered as an integral part of a nanoparticle.
The interfacial layer has an typical thickness between 0.1 and 4 nm, which is dependent on the type of the molecules the layer is made of.
The organic molecules that make up the interfacial layer are often amphiphilic molecules, meaning that they have a polar head group combined with a non-polar tail. | 0 | Colloidal Chemistry |
The nontoxicity of lecithin leads to its use with food, as a food additive or in food preparation. It is used commercially in foods requiring a natural emulsifier or lubricant.
In confectionery, it reduces viscosity, replaces more expensive ingredients, controls sugar crystallization and the flow properties of chocolate, helps in the homogeneous mixing of ingredients, improves shelf life for some products, and can be used as a coating. In emulsions and fat spreads, such as margarines with a high fat content of more than 75%, it stabilizes emulsions, reduces spattering (splashing and scattering of oil droplets) during frying, improves texture of spreads and flavor release. In doughs and baking, it reduces fat and egg requirements, helps even out distribution of ingredients in dough, stabilizes fermentation, increases volume, protects yeast cells in dough when frozen, and acts as a releasing agent to prevent sticking and simplify cleaning. It improves wetting properties of hydrophilic powders (such as low-fat proteins) and lipophilic powders (such as cocoa powder), controls dust, and helps complete dispersion in water. Lecithin keeps cocoa and cocoa butter in a candy bar from separating. It can be used as a component of cooking sprays to prevent sticking and as a releasing agent.
In the EU Lecithin is designated at food additive E322. | 0 | Colloidal Chemistry |
Nephelometers are also used in global warming studies, specifically measuring the global radiation balance. Three wavelength nephelometers fitted with a backscatter shutter can determine the amount of solar radiation that is reflected back into space by dust and particulate matter. This reflected light influences the amount of radiation reaching the earth's lower atmosphere and warming the planet. | 0 | Colloidal Chemistry |
Fluorosurfactants such as PFOS, PFOA, and PFNA have caught the attention of regulatory agencies because of their persistence, toxicity, and widespread occurrence in the blood of general populations and wildlife. In 2009, PFOS, its salts, and perfluorooctanesulfonyl fluoride were listed as persistent organic pollutants under the Stockholm Convention due to their ubiquitous, persistent, bioaccumulative, and toxic nature. PFAS chemicals were dubbed "forever chemicals" in a 2018 op-ed in the Washington Post. The nickname was derived by combining the two dominant attributes of this class of chemicals: PFAS chemicals are characterized by a carbon-fluorine backbone (the "F-C" in "forever chemicals"), and the carbon-fluorine bond is one of the strongest bonds in organic chemistry, which gives these chemicals an extremely long environmental half-life. The term forever chemicals is commonly used in media outlets in addition to the more technical name of per- and polyfluorinated alkyl substances. Their production has been regulated or phased out by manufacturers, such as 3M, DuPont, Daikin, and Miteni in the U.S., Japan, and Europe. In 2006 3M replaced PFOS and PFOA with short-chain PFASs, such as perfluorohexanoic acid (PFHxA) and perfluorobutanesulfonic acid (PFBS). Shorter fluorosurfactants may be less prone to accumulating in mammals; there is still some concern that they may be harmful to both humans and the environment, though the EPA states, "...research is still ongoing to determine how different levels of exposure to different PFAS can lead to a variety of health effects." Many PFASs are either not covered by European legislation or are excluded from registration obligations under the EU REACH chemical regulation. Several PFASs have been detected in drinking water, municipal wastewater, and landfill leachates worldwide.
It had been thought that PFAAs would eventually end up in the oceans, where they would be diluted over decades, but a field study published in 2021 by researchers at Stockholm University found that they are significantly transferred from water to air when waves break on land, and are a significant source of air pollution, and eventually get into the rain. The researchers concluded that pollution "may impact large areas of inland Europe and other continents, in addition to coastal areas". | 0 | Colloidal Chemistry |
* Coatings for gas evolution reaction electrodes for efficient bubble detachment
* Breast implants
* Contact lenses (silicone hydrogels, polyacrylamides, polymacon)
* Water sustainability: Hydrogels have emerged as promising materials platforms for solar-powered water purification, water disinfection, and Atmospheric water generator.
* Disposable diapers where they absorb urine, or in sanitary napkins
* Dressings for healing of burn or other hard-to-heal wounds. Wound gels are excellent for helping to create or maintain a moist environment.
* EEG and ECG medical electrodes using hydrogels composed of cross-linked polymers (polyethylene oxide, polyAMPS and polyvinylpyrrolidone)
* Encapsulation of quantum dots
* Environmentally sensitive hydrogels (also known as smart gels or intelligent gels). These hydrogels have the ability to sense changes of pH, temperature, or the concentration of metabolite and release their load as result of such a change.
*Fibers
* Glue
* Granules for holding soil moisture in arid areas
* Air bubble-repellent (superaerophobicity). Can improve the performance and stability of electrodes for water electrolysis.
* Culturing cells: Hydrogel-coated wells have been used for cell culture.
* Biosensors: Hydrogels that are responsive to specific molecules, such as glucose or antigens, can be used as biosensors, as well as in DDS.
*Cell carrier: Injectable hydrogels can be used to carry drugs or cells for applications in tissue regeneration or 3D bioprinting. Hydrogels with reversible chemistry are required to allow for fluidization during injection/printing followed by self-healing of the original hydrogel structure.
*Investigate cell biomechanical functions combined with holotomography microscopy
* Provide absorption, desloughing and debriding of necrotic and fibrotic tissue
* Tissue engineering scaffolds. When used as scaffolds, hydrogels may contain human cells to repair tissue. They mimic 3D microenvironment of cells. Materials include agarose, methylcellulose, hyaluronan, elastin-like polypeptides, and other naturally derived polymers.
* Sustained-release drug delivery systems. Ionic strength, pH and temperature can be used as a triggering factor to control the release of the drug.
* The swelling behavior exhibited by charged hydrogels can be used as a valuable tool for investigating interactions between charged polymers and various species, including multivalent ions, peptides, and proteins. This response arises due to fluctuating osmotic swelling forces resulting from the exchange of counterions within the gel matrix. Particularly significant is its application in assessing the binding of peptide drugs to biopolymers within the body, as the swelling response of the gel can provide insights into these interactions.
* Window coating/replacement: Hydrogels are under consideration for reducing infrared light absorption by 75%. Another approach reduced interior temperature using a temperature-responsive hydrogel.
* Thermodynamic electricity generation: When combined with ions allows for heat dissipation for electronic devices and batteries and converting the heat exchange to an electrical charge.
* Water gel explosives
* Controlled release of agrochemicals (pesticides and fertilizer)
* Talin Shock Absorbing Materials - protein-based hydrogels that can absorb supersonic impacts | 0 | Colloidal Chemistry |
*Sodium carbonate
*Sodium acetate
*Potassium cyanide
*Sodium sulfide
*Sodium bicarbonate
*Sodium hydroxide | 1 | Solid-state chemistry |
Silver nanofoams are specific metal nanofoams consisting of mainly silver that are uniquely regarded for their antibacterial and electrical properties. Many of these silver nanofoams are alloys of silver and another metal such as aluminum. They are unique for their hierarchical porous structure are a current point of modern research and development. They have many applications in the fields of mechanical, chemical, and biomedical engineering, including filtration, air management, and use in electrical systems. | 0 | Colloidal Chemistry |
It is produced on a large scale by pyrometallurgy, as one stage in extracting copper from its ores. The ores are treated with an aqueous mixture of ammonium carbonate, ammonia, and oxygen to give copper(I) and copper(II) ammine complexes, which are extracted from the solids. These complexes are decomposed with steam to give CuO.
It can be formed by heating copper in air at around 300–800 °C:
: 2 Cu + O → 2 CuO
For laboratory uses, pure copper(II) oxide is better prepared by heating copper(II) nitrate, copper(II) hydroxide, or basic copper(II) carbonate:
: 2 Cu(NO) → 2 CuO + 4 NO + O (180°C)
: Cu(OH)CO → 2 CuO + CO + HO
: Cu(OH) → CuO + HO | 1 | Solid-state chemistry |
Two methods to extract the Gibbs free energy based on the value of CMC and exist; Phillips method based on the law of mass action and the pseudo-phase separation model. The law of mass action postulates that the micelle formation can be modeled as a chemical equilibrium process between the micelles and its constituents, the surfactant monomers, :
where is the average number of surfactant monomers in solution that associate into a micelle, commonly denoted the aggregation number.
The equilibrium is characterized by an equilibrium constant defined by , where and are the concentrations of micelles and free surfactant monomers, respectively. In combination with the law of conservation of mass, the system is fully specified by: , where is the total surfactant concentration. Phillips defined the CMC as the point corresponding to the maximum change in gradient in an ideal property-concentration ( against ) relationship =0. By implicit differentiation of three times with respect to and equating to zero it can be shown that the micellization constant is given by for . According to Phillips method the Gibbs free energy change of micellization is therefore given by:
The pseudo-phase separation model was originally derived on its own basis, but it has later been shown that it can be interpreted as an approximation to the mass-action model for large . That is, for micelles behaving in accordance with the law of mass-action, the pseudo-phase phase separation model is only an approximation and will only become asymptotically equal to the mass-action model as the micelle becomes a true macroscopic phase i.e. for →∞. However, the approximation that the aggregation number is large is in most cases sufficient: | 0 | Colloidal Chemistry |
The polyatomic ion , sometimes called allylide, is found in and . The ion is linear and is isoelectronic with . The C–C distance in MgC is 133.2 pm. yields methylacetylene, CHCCH, and propadiene, CHCCH, on hydrolysis, which was the first indication that it contains . | 1 | Solid-state chemistry |
Liquid foams can be used in fire retardant foam, such as those that are used in extinguishing fires, especially oil fires.
In some ways, leavened bread is a foam, as the yeast causes the bread to rise by producing tiny bubbles of gas in the dough. The dough has traditionally been understood as a closed-cell foam, in which the pores do not connect with each other. Cutting the dough releases the gas in the bubbles that are cut, but the gas in the rest of the dough cannot escape. When dough is allowed to rise too far, it becomes an open-cell foam, in which the gas pockets are connected. Cutting the dough or the surface otherwise breaking at that point would cause a large volume of gas to escape, and the dough would collapse. The open structure of an over-risen dough is easy to observe: instead of consisting of discrete gas bubbles, the dough consists of a gas space filled with threads of the flour-water paste. Recent research has indicated that the pore structure in bread is 99% interconnected into one large vacuole, thus the closed-cell foam of the moist dough is transformed into an open cell solid foam in the bread.
The unique property of gas-liquid foams having very high specific surface area is exploited in the chemical processes of froth flotation and foam fractionation.
Foam depopulation or foaming is a means of mass killing farm animals by spraying foam over a large area to obstruct breathing and ultimately cause suffocation. It is usually used to attempt to stop disease spread. | 0 | Colloidal Chemistry |
Kê T'ing-sui or Ge Tingsui (; May 3, 1913 – April 29, 2000), also known as T.S. Kê, was a Chinese physicist and writer renowned for his contributions in internal friction, anelasticity, solid state physics and metallurgy. He was the member of the Chinese Academy of Sciences, known for the Kê-type pendulum and Kê grain-boundary internal friction peak named after him. In March 1982, he founded the Institute of Solid State Physics in Hefei, Anhui, China. | 1 | Solid-state chemistry |
According to Vagn Fabritius Buchwald, wüstite was an important component during the Iron Age to facilitate the process of forge welding. In ancient times, when blacksmithing was performed using a charcoal forge, the deep charcoal pit in which the steel or iron was placed provided a highly reducing, virtually oxygen-free environment, producing a thin wüstite layer on the metal. At the welding temperature, the iron becomes highly reactive with oxygen, and will spark and form thick layers of slag when exposed to the air, which makes welding the iron or steel nearly impossible. To solve this problem, ancient blacksmiths would toss small amounts of sand onto the white-hot metal. The silica in the sand reacts with the wüstite to form fayalite, which melts just below the welding temperature. This produced an effective flux that shielded the metal from oxygen and helped extract oxides and impurities, leaving a pure surface that can weld readily. Although the ancients had no knowledge of how this worked, the ability to weld iron contributed to the movement out of the Bronze Age and into the modern. | 1 | Solid-state chemistry |
Implanted or injected hydrogels have the potential to support tissue regeneration by mechanical tissue support, localized drug or cell delivery, local cell recruitement or immunomodulation, or encapsulation of nanoparticles for local photothermal or brachytherapy. Polymeric drug delivery systems have overcome challenge due to their biodegradability, biocompatibility, and anti-toxicity. Materials such as collagen, chitosan, cellulose, and poly (lactic-co-glycolic acid) have been implemented extensively for drug delivery to organs such as eye, nose, kidneys, lungs, intestines, skin and brain. Future work is focused on reducing toxicity, improving biocompatibility, expanding assembly techniques
Hydrogels have been considered as vehicles for drug delivery. They can also be made to mimic animal mucosal tissues to be used for testing mucoadhesive properties. They have been examined for use as reservoirs in topical drug delivery; particularly ionic drugs, delivered by iontophoresis. | 0 | Colloidal Chemistry |
Molybdenum disilicide (MoSi, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically conductive. At high temperatures it forms a passivation layer of silicon dioxide, protecting it from further oxidation. The thermal stability of MoSi alongside its high emissivity make this material, alongside WSi attractive for applications as a high emissivity coatings in heat shields for atmospheric entry.
MoSi is a gray metallic-looking material with tetragonal crystal structure (alpha-modification); its beta-modification is hexagonal and unstable. It is insoluble in most acids but soluble in nitric acid and hydrofluoric acid.
While MoSi has excellent resistance to oxidation and high Young's modulus at temperatures above 1000 °C, it is brittle in lower temperatures. Also, at above 1200 °C it loses creep resistance. These properties limits its use as a structural material, but may be offset by using it together with another material as a composite material.
Molybdenum disilicide and MoSi-based materials are usually made by sintering. Plasma spraying can be used for producing its dense monolithic and composite forms; material produced this way may contain a proportion of β-MoSi due to its rapid cooling.
Molybdenum disilicide heating elements can be used for temperatures up to 1800 °C, in electric furnaces used in laboratory and production environment in production of glass, steel, electronics, ceramics, and in heat treatment of materials. While the elements are brittle, they can operate at high power without aging, and their electrical resistivity does not increase with operation time. Their maximum operating temperature has to be lowered in atmospheres with low oxygen content due to breakdown of the passivation layer.
Other ceramic materials used for heating elements include silicon carbide, barium titanate, and lead titanate composite materials.
Molybdenum disilicide is used in microelectronics as a contact material. It is often used as a shunt over polysilicon lines to increase their conductivity and increase signal speed. | 1 | Solid-state chemistry |
Antifoaming agents are also sold commercially to relieve bloating. A familiar example is the drug simethicone, which is the active ingredient in drugs such as Gas-X. | 0 | Colloidal Chemistry |
The shape of a surfactant molecule can be described by its surfactant packing parameter, (Israelachvili, 1976). The packing parameter takes into account the volume of the hydrophobic chain (), the equilibrium area per molecule at
the aggregate interface (), and the length of the hydrophobic chain ():
The packing parameter for a specific surfactant is not a constant. It is dependent on various conditions which affect each the volume of the hydrophobic chain, the cross sectional area of the hydrophilic head group, and the length of the hydrophobic chain. Things that can affect these include, but are not limited to, the properties of the solvent, the solvent temperature, and the ionic strength of the solvent. | 0 | Colloidal Chemistry |
Dithionitronium hexafloroarsenate is the inorganic compound with the formula . It is the hexafluoroarsenate () salt of S=N=S. The cation is of interest as the sulfur analogue of nitronium (). Hexafloroarsenate is a weakly coordinating anion. According to X-ray crystallography, S=N=S is linear with S-N distances of 146 picometers. | 1 | Solid-state chemistry |
* National Academy of Sciences, 2023
* ACS Fellow, 2019
* ACS Cope Scholar Award, 2015
* Appointment to the Chemical Sciences Roundtable of the NAS Board on Chemical Sciences and Technology, 2012–2018
* Associate Editor of the Journal of the ACS, 2009–2016
* NSF Creativity Award, 2009–2011
* American Competitiveness and Innovation Fellow, 2008
* Fellow of the AAAS, 2007
* Herbert Newby McCoy Award, UCLA, 1999
* Dean's Marshal Award for the Division of Physical Sciences, UCLA, 1997
* NSF Career Award 1996–99 | 1 | Solid-state chemistry |
The small size of nanoparticles affects their magnetic and electric properties. The ferromagnetic materials in the micrometer range is a good example: widely used in magnetic recording media, for the stability of their magnetization state, those particles smaller than 10 nm are unstable and can change their state (flip) as the result of thermal energy at ordinary temperatures, thus making them unsuitable for that application. | 0 | Colloidal Chemistry |
Pliny the Elder, whose writings chronicle life in the first century AD, describes soap as "an invention of the Gauls".
The word , Latin for soap, likely was borrowed from an early Germanic language and is cognate with Latin , "tallow". It first appears in Pliny the Elders account, Historia Naturalis, which discusses the manufacture of soap from tallow and ashes. There he mentions its use in the treatment of scrofulous sores, as well as among the Gauls as a dye to redden hair which the men in Germania were more likely to use than women. The Romans avoided washing with harsh soaps before encountering the milder soaps used by the Gauls around 58 BC. Aretaeus of Cappadocia, writing in the 2nd century AD, observes among "Celts, which are men called Gauls, those alkaline substances that are made into balls [...] called soap". The Romans preferred method of cleaning the body was to massage oil into the skin and then scrape away both the oil and any dirt with a strigil. The standard design is a curved blade with a handle, all of which is made of metal.
The 2nd-century AD physician Galen describes soap-making using lye and prescribes washing to carry away impurities from the body and clothes. The use of soap for personal cleanliness became increasingly common in this period. According to Galen, the best soaps were Germanic, and soaps from Gaul were second best. Zosimos of Panopolis, circa 300 AD, describes soap and soapmaking. | 1 | Solid-state chemistry |
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Wikipedia Solid-state vs Colloidal Chemistry Binary Classification
This binary classification dataset is curated from English Wikipedia articles and focuses on the subfields of chemistry. It is labeled into two distinct classes based on the subject matter of the articles:
- Class 1: Solid-state Chemistry, also known as materials chemistry, involves the study of the synthesis, structure, and properties of solid phase materials, particularly, but not necessarily exclusively, of non-molecular solids.
- Class 2: Colloidal Chemistry deals with the study of substances microscopically dispersed throughout another substance. The focus is on the behavior and properties of colloids, which are mixtures where one substance is dispersed evenly throughout another.
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