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Simon studied Chemistry at the University of Münster from 1960-1964. He worked on his doctoral thesis in the group of Harald Schäfer from 1964-1966 and finished his habilitation in 1971. In 1972, he was appointed as an associate professor at the University of Münster. Starting in 1974, he was a member of the Max-Planck Society and one of the directors at the Max Planck Institute for Solid State Research in Stuttgart. Since 1975, he was a honorary professor at the University of Stuttgart. Since 2010, he has been an emeritus. | 1 | Solid-state chemistry |
Oil-based defoamers have an oil carrier. The oil might be mineral oil, vegetable oil or any other oil that is insoluble in the foaming medium, except silicone oil. An oil-based defoamer also contains a wax and/or hydrophobic silica to boost the performance. Typical waxes are ethylene bis stearamide (EBS), paraffin waxes, ester waxes and fatty alcohol waxes. These products might also have surfactants to improve emulsification and spreading in the foaming medium.
These are heavy duty defoamers and are normally best at knocking down surface foam. | 0 | Colloidal Chemistry |
McMillan was born in Edinburgh, Midlothian, and brought up in Loanhead, a small mining and farming village at the base of the Pentland Hills. He attended Lasswade High School, where he graduated with the Marshall Memorial medal. He then studied for a bachelor's degree in chemistry at the University of Edinburgh. After graduating, McMillan moved to Arizona State University, where he researched geochemistry with John Holloway and Alexandra Navrotsky. His doctoral research was in using vibrational spectroscopy to investigate the structures of silicate glasses. | 1 | Solid-state chemistry |
Emissions from memory foam mattresses may directly cause more respiratory irritation than other mattresses. Memory foam, like other polyurethane products, can be combustible. Laws in several jurisdictions have been enacted to require that all bedding, including memory foam items, be resistant to ignition from an open flame such as a candle or cigarette lighter. US bedding laws that went into effect in 2010 change the Cal-117 Bulletin for FR testing.
There is concern that high levels of the fire retardant PBDE commonly used in memory foam could cause health problems for some users. PBDEs are no longer used in most bedding foams, especially in the European Union.
Manufacturers caution about leaving babies and small children unattended on memory foam mattresses, as they may find it difficult to turn over and may suffocate.
The United States Environmental Protection Agency published two documents proposing National Emissions Standards for Hazardous Air Pollutants (HAP) concerning hazardous emissions produced during the making of flexible polyurethane foam products. The HAP emissions associated with polyurethane foam production include methylene chloride, toluene diisocyanate, methyl chloroform, methylene diphenyl diisocyanate, propylene oxide, diethanolamine, methyl ethyl ketone, methanol, and toluene. However, not all chemical emissions associated with the production of these material have been classified. Methylene chloride makes up over 98 percent of the total HAP emissions from this industry. Short-term exposure to high concentrations of methylene chloride also irritates the nose and throat. The effects of chronic (long-term) exposure to methylene chloride in humans involve the central nervous system, and include headaches, dizziness, nausea, and memory loss. Animal studies indicate that inhalation of methylene chloride affects the liver, kidney, and cardiovascular system. Developmental or reproductive effects of methylene chloride have not been reported in humans, but limited animal studies have reported lowered fetal body weights in exposed rats. | 0 | Colloidal Chemistry |
For many applications, the counterion simply provides charge and lipophilicity that allows manipulation of its partner ion. The counterion is expected to be chemically inert. For counteranions, inertness is expressed in terms of low Lewis basicity. The counterions are ideally rugged and unreactive. For quaternary ammonium and phosphonium countercations, inertness is related to their resistance of degradation by strong bases and strong nucleophiles. | 1 | Solid-state chemistry |
In April 1986, Georg Bednorz and Karl Müller, working at IBM in Zurich, discovered that certain semiconducting oxides became superconducting at relatively high temperature, in particular, a lanthanum barium copper oxide becomes superconducting at 35 K. This oxide was an oxygen-deficient perovskite-related material that proved promising and stimulated the search for related compounds with higher superconducting transition temperatures. In 1987, Bednorz and Müller were jointly awarded the Nobel Prize in Physics for this work.
Following Bednorz and Müllers discovery, a team led by Paul Ching Wu Chu at the University of Alabama in Huntsville and University of Houston discovered that YBCO has a superconducting transition critical temperature (T') of 93 K. The first samples were YBaCuO, but this was an average composition for two phases, a black and a green one. Workers at Bell Laboratories identified the black phase as the superconductor, determined its composition YBaCuO and synthesized it in single phase
YBCO was the first material found to become superconducting above 77 K, the boiling point of liquid nitrogen, whereas the majority of other superconductors require more expensive cryogens. Nonetheless, YBCO and its many related materials have yet to displace superconductors requiring liquid helium for cooling. | 1 | Solid-state chemistry |
Her awards and honours include;
* 1978 Royal Society of Chemistry Undergraduate Award
* 2010 Canadian Society for Chemistry Rio Tinto Alcan Award for Electrochemistry
* 2011 International Battery Association Award
* 2011 Royal Society of Canada Fellowship
* 2012 International Union of Pure and Applied Chemistry Distinguished Women in Chemistry
* 2013 Society of German Chemists August-Wilhelm-von-Hofmann Lectureship
* 2014 Web of Science Most Highly Cited Researchers
* 2014 Thomson Reuters World's Most Influential Scientific Minds
* 2015 Officer of the Order of Canada
* 2017 University of Waterloo Outstanding Performance Award
* 2018 Thomson Reuters Most Highly Cited Researchers
* 2019 Chemical Institute of Canada Medal
*2020 Elected Fellow of the Royal Society | 1 | Solid-state chemistry |
Double layer interactions are relevant in a wide number of phenomena. These forces are responsible for swelling of clays. They may also be responsible for the stabilization of colloidal suspension and will prevent particle aggregation of highly charged colloidal particles in aqueous suspensions. At low salt concentrations, the repulsive double layer forces can become rather long-ranged, and may lead to structuring of colloidal suspensions and eventually to formation of colloidal crystals. Such repulsive forces may further induce blocking of surfaces during particle deposition. Double layer interactions are equally relevant for surfactant aggregates, and may be responsible to the stabilization of cubic phases made of spheroidal micelles or lamellar phases consisting of surfactant or lipid bilayers. | 0 | Colloidal Chemistry |
Blinking colloidal nanocrystals is a phenomenon observed during studies of single colloidal nanocrystals that show that they randomly turn their photoluminescence on and off even under continuous light illumination.
This has also been described as luminescence intermittency.
Similar behavior has been observed in crystals made of other materials. For example, porous silicon also exhibits this affect. | 0 | Colloidal Chemistry |
In the Zimmermann reaction the Janovski adduct is oxidized with excess base to a strongly colored enolate with subsequent reduction of the dinitro compound to the aromatic nitro amine. This reaction is the basis of the Zimmermann test used for the detection of ketosteroids. | 1 | Solid-state chemistry |
The JTE is usually associated with degeneracies that are well localised in space, like those occurring in a small molecule or associated to an isolated transition metal complex. However, in many periodic high-symmetry solid-state systems, like perovskites, some crystalline sites allow for electronic degeneracy giving rise under adequate compositions to lattices of JT-active centers. This can produce a cooperative JTE, where global distortions of the crystal occur due to local degeneracies.
In order to determine the final electronic and geometric structure of a cooperative JT system, it is necessary to take into account both the local distortions and the interaction between the different sites, which will take such form necessary to minimise the global energy of the crystal.
While works on the cooperative JTE started in the late fifties, it was in 1960 that Kanamori published the first work on the cooperative JTE where many important elements present in the modern theory for this effect were introduced. This included the use of pseudospin notation to discuss orbital ordering, and discussions of the importance of the JTE to discuss magnetism, the competition of this effect with the spin–orbit coupling and the coupling of the distortions with the strain of the lattice. This point was later stressed in the review by Gehring and Gehring as being the key element to establish long-range order between the distortions in the lattice. An important part of the modern theory of the cooperative JTE, can lead to structural phase transitions.
It is important to note that many cooperative JT systems would be expected to be metals from band theory as, to produce them, a degenerate orbital has to be partially filled and the associated band would be metallic. However, under the perturbation of the symmetry-breaking distortion associated to the cooperative JTE, the degeneracies in the electronic structure are destroyed and the ground state of these systems is often found to be insulating (see e.g.). In many important cases like the parent compound for colossal magnetoresistance perovskites, LaMnO, an increase of temperature leads to disorder in the distortions which lowers the band splitting due to the cooperative JTE, thus triggering a metal–insulator transition. | 1 | Solid-state chemistry |
Nanofluid-based direct solar collectors are solar thermal collectors where nanoparticles in a liquid medium can scatter and absorb solar radiation. They have recently received interest to efficiently distribute solar energy. Nanofluid-based solar collector have the potential to harness solar radiant energy more efficiently compared to conventional solar collectors.
Nanofluids have recently found relevance in applications requiring quick and effective heat transfer such as industrial applications, cooling of microchips, microscopic fluidic applications, etc. Moreover, in contrast to conventional heat transfer (for solar thermal applications) like water, ethylene glycol, and molten salts, nanofluids are not transparent to solar radiant energy; instead, they absorb and scatter significantly the solar irradiance passing through them.
Typical solar collectors use a black-surface absorber to collect the sun's heat energy which is then transferred to a fluid running in tubes embedded within. Various limitations have been discovered with these configuration and alternative concepts have been addressed. Among these, the use of nanoparticles suspended in a liquid is the subject of research. Nanoparticle materials including aluminium, copper, carbon nanotubes and carbon-nanohorns have been added to different base fluids and characterized in terms of their performance for improving heat transfer efficiency. | 0 | Colloidal Chemistry |
Anthony Czarnik attended the University of Wisconsin and received his B.S. in Biochemistry in 1977. He then studied with Nelson J. Leonard at the University of Illinois at Urbana–Champaign and earned an M.S. in biochemistry in 1980 and a Ph.D. in chemistry in 1981 with a thesis, "Chemical studies on nucleic acid analogues." He then studied with Ronald Breslow at Columbia University (1981–1983) as an NIH Postdoctoral Fellow. | 1 | Solid-state chemistry |
Georg Wiegner (April 20, 1883 – April 14, 1936) was a colloid chemist. He was born in Leipzig and died in Zurich.
Georg Wiegner studied natural sciences at the University of Leipzig, and received a doctorate in 1906. He was an assistant to Wilhelm Fleischmann at the University of Göttingen from 1907. He was appointed professor of agricultural chemistry at the ETH Zurich in 1913, where he remained until the year of his death, in 1933. He was responsible for seminal discoveries in coagulation and ion exchange. His group at the ETH strongly influenced ecological pedology in Switzerland. The group who worked with him included Hermann Gessner (1897–1981), Hans Jenny (1899–1992) and Hans Pallmann (1903–1965). His group also influenced the work of Max Düggeli, who had a major influence on soil biology in Switzerland. | 0 | Colloidal Chemistry |
The detergent effect draws on surfactin's ability to insert its fatty acid chain into the phospholipid layer, disorganizing the cell membrane to increase its permeability. Insertion of several surfactin molecules into the membrane can lead to the formation of mixed micelles by self-association and bilayer influenced by fatty chain hydrophobicity ultimately leading to bilayer solubilization. | 0 | Colloidal Chemistry |
Heated iron metal interacts with steam to form iron oxide and hydrogen gas.
Under anaerobic conditions, ferrous hydroxide (Fe(OH)) can be oxidized by water to form magnetite and molecular hydrogen. This process is described by the Schikorr reaction:
This works because crystalline magnetite (FeO) is thermodynamically more stable than amorphous ferrous hydroxide (Fe(OH) ).
The Massart method of preparation of magnetite as a ferrofluid, is convenient in the laboratory: mix iron(II) chloride and iron(III) chloride in the presence of sodium hydroxide.
A more efficient method of preparing magnetite without troublesome residues of sodium, is to use ammonia to promote chemical co-precipitation from the iron chlorides: first mix solutions of 0.1 M FeCl·6HO and FeCl·4HO with vigorous stirring at about 2000 rpm. The molar ratio of the FeCl:FeCl should be about 2:1. Heat the mix to 70 °C, then raise the speed of stirring to about 7500 rpm and quickly add a solution of NHOH (10 volume %). A dark precipitate of nanoparticles of magnetite forms immediately.
In both methods, the precipitation reaction relies on rapid transformation of acidic iron ions into the spinel iron oxide structure at pH 10 or higher.
Controlling the formation of magnetite nanoparticles presents challenges: the reactions and phase transformations necessary for the creation of the magnetite spinel structure are complex. The subject is of practical importance because magnetite particles are of interest in bioscience applications such as magnetic resonance imaging (MRI), in which iron oxide magnetite nanoparticles potentially present a non-toxic alternative to the gadolinium-based contrast agents currently in use. However, difficulties in controlling the formation of the particles, still frustrate the preparation of superparamagnetic magnetite particles, that is to say: magnetite nanoparticles with a coercivity of 0 A/m, meaning that they completely lose their permanent magnetisation in the absence of an external magnetic field. The smallest values currently reported for nanosized magnetite particles is Hc = 8.5 A m, whereas the largest reported magnetization value is 87 Am kg for synthetic magnetite.
Pigment quality FeO, so called synthetic magnetite, can be prepared using processes that use industrial wastes, scrap iron or solutions containing iron salts (e.g. those produced as by-products in industrial processes such as the acid vat treatment (pickling) of steel):
*Oxidation of Fe metal in the Laux process where nitrobenzene is treated with iron metal using FeCl as a catalyst to produce aniline:
:CHNO + 3 Fe + 2 HO → CHNH + FeO
*Oxidation of Fe compounds, e.g. the precipitation of iron(II) salts as hydroxides followed by oxidation by aeration where careful control of the pH determines the oxide produced.
Reduction of FeO with hydrogen:
:3FeO + H → 2FeO +HO
Reduction of FeO with CO:
:3FeO + CO → 2FeO + CO
Production of nano-particles can be performed chemically by taking for example mixtures of Fe and Fe salts and mixing them with alkali to precipitate colloidal FeO. The reaction conditions are critical to the process and determine the particle size.
Iron(II) carbonate can also be thermally decomposed into Iron(II,III): | 1 | Solid-state chemistry |
Pulmonary surfactant protein D (SP-D), has an important role in acting as a lung host defence protein. SP-D has a significant roles in immune and inflammatory regulation of the lung as it regulates of the level of surfactant in the lungs by a process named surfactant homeostasis. | 0 | Colloidal Chemistry |
There are several methods to prepare unilamellar liposomes and the protocols differ based on the type of desired unilamellar vesicles. Different lipids can be bought either dissolved in chloroform or as lyophilized lipids. In the case of lyophilized lipids, they can be solubilized in chloroform. Lipids are then mixed with a desired molar ratio. Then chloroform is evaporated using a gentle stream of nitrogen (to avoid oxygen contact and oxidation of lipids) at room temperature. A rotary evaporator can be used to form a homogeneous layer of liposomes. This step removes the bulk of chloroform. To remove the residues of trapped chloroform, lipids are placed under vacuum from several hours to overnight. Next step is re-hydration where the dried lipids are re-suspended in the desired buffer. Lipids can be vortexed for several minutes to insure that all the lipid residues get re-suspended. SUVs can be obtained in via two methods. Either by sonication (for instance with 1 second pulses in 3 Hz cycles at a power of 150 W) or by extrusion. In extrusion method, the lipid mixture is passed through a membrane for 10 or more times. Depending on the size of the membrane, either SUVs or LUVs can be obtained. Keeping vesicles under argon and away from oxygen and light can extend their lifetime. | 0 | Colloidal Chemistry |
Some of Keszler’s early work shows the importance of his research in material science for application purposes. For example, in 2002, he worked on thin-film electroluminescent devices which display high definition monochromic color outputs, and developing them to display a full range of color. They specifically focused on phosphor ZnGaS:Mn and strontium sulfide codoped with copper and potassium powders which was observed to have identical emission properties as thin films. Essentially by codoping, the band gap length of a material can be tuned so that the color of the light can be adjusted. The light itself is emitted when excited electrons in the conduction band fall back down to the valence band. By manipulating the properties of crystal and defect chemistry, any color can be portrayed for display.
Keszler has also developed a convenient method for solid synthesis. In 2001, he demonstrated a hydrothermal dehydration technique of precipitates which avoids formation of amorphous products that are created through the conventional drying process of heating. Through this method, he showed the formation of ZnSiO and SnSiO. This technique has allowed for development of materials such as powders, thin films, and luminescent materials.
In 2000, Douglas Keszler and his colleagues worked with non-linear optical materials such as CaGdO(BO)(GdCOB). They measured the Raman spectra of CaGdO(BO)(GdCOB) which was grown using the Czochralski method. This experiment was done to ultimately understand the spectroscopic features of Yb and Nd by analyzing vibrations of two different types of (BO) groups. | 1 | Solid-state chemistry |
Soil salinity is the salt content in the soil; the process of increasing the salt content is known as salinization. Salts occur naturally within soils and water. Salination can be caused by natural processes such as mineral weathering or by the gradual withdrawal of an ocean. It can also come about through artificial processes such as irrigation and road salt. | 1 | Solid-state chemistry |
Brines are produced in multiple ways in nature. Modification of seawater via evaporation results in the concentration of salts in the residual fluid, a characteristic geologic deposit called an evaporite is formed as different dissolved ions reach the saturation states of minerals, typically gypsum and halite. Dissolution of such salt deposits into water can produce brines as well. As seawater freezes, dissolved ions tend to remain in solution resulting in a fluid termed a cryogenic brine. At the time of formation, these cryogenic brines are by definition cooler than the freezing temperature of seawater and can produce a feature called a brinicle where cool brines descend, freezing the surrounding seawater.
The brine cropping out at the surface as saltwater springs are known as "licks" or "salines". The contents of dissolved solids in groundwater vary highly from one location to another on Earth, both in terms of specific constituents (e.g. halite, anhydrite, carbonates, gypsum, fluoride-salts, organic halides, and sulfate-salts) and regarding the concentration level. Using one of several classification of groundwater based on total dissolved solids (TDS), brine is water containing more than 100,000 mg/L TDS. Brine is commonly produced during well completion operations, particularly after the hydraulic fracturing of a well. | 1 | Solid-state chemistry |
Organic molecules often come in two mirror-image forms, often referred to as "right-handed" and "left-handed". This handedness is called chirality. For example, the amino acid alanine comes in a right-handed (D-alanine) and a left-handed (L-alanine) form. Living cells are very selective, choosing amino acids only in the left-handed form and sugars in the right-handed form. However, most abiotic processes produce an equal amount of each. Somehow life must have developed this preference (homochirality); but while scientists have proposed several theories, they have no consensus on the mechanism.
Hazen investigated the possibility that organic molecules might acquire a chiral asymmetry when grown on the faces of mineral crystals. Some, like quartz, come in mirror-image forms; others, like calcite, are symmetric about their centers but their faces come in pairs with opposite chirality. With Tim Filley, an expert at organic chemical analysis, and Glenn Goodfriend, a geochemist, Hazen cleaned large calcite crystals and dipped them into aspartic acid. They found that each face of the crystal had a small preference for either left- or right-handed forms of aspartate. They proposed that a similar mechanism might work on other amino acids and sugars. This work attracted a lot of interest from the pharmaceutical industry, which needs to produce some of their drugs with a pure chirality. | 1 | Solid-state chemistry |
In 2009, Czarnik submitted 240 patent applications covering the use of deuterium-substitution in drug discovery.. He has also invented drugs such as (R)-d1-lenalidomide and (R)-d1-pioglitazone, for clinical studies. | 1 | Solid-state chemistry |
A hexagonal phase of lyotropic liquid crystal is formed by some amphiphilic molecules when they are mixed with water or another polar solvent. In this phase, the amphiphile molecules are aggregated into cylindrical structures of indefinite length and these cylindrical aggregates are disposed on a hexagonal lattice, giving the phase long-range orientational order.
In normal topology hexagonal phases, which are formed by type I amphiphiles, the hydrocarbon chains are contained within the cylindrical aggregates such that the polar-apolar interface has a positive mean curvature. Inverse topology hexagonal phases have water within the cylindrical aggregates and the hydrocarbon chains fill the voids between the hexagonally packed cylinders. Normal topology hexagonal phases are denoted by H while inverse topology hexagonal phases are denoted by H. When viewed by polarization microscopy, thin films of both normal and inverse topology hexagonal phases exhibit birefringence, giving rise to characteristic optical textures. Typically, these textures are smoke-like, fan-like or mosaic in appearance. The phases are highly viscous and small air bubbles trapped within the preparation have highly distorted shapes. Size and shapes of lamellar, micellar and hexagonal phases of lipid bilayer phase behavior and mixed lipid polymorphism in aqueous dispersions can be easily identified and characterized by negative staining transmission electron microscopy too. | 0 | Colloidal Chemistry |
In chemistry, an inert salt is a salt used to adjust the ionic strength of a solution. This is usually done in equilibrium or kinetic studies in order to reduce relative changes in the ionic strength of a solution. The real goal is to reduce changes in the activity coefficients of ionic species which allows the definition of conditional equilibrium or rate constants.
Any salt will affect the ionic strength, inert salts have the additional property that both the cations and the anions of the salt do or should not not interfere in any way with the molecules that are investigated. They are supposed to only influence the ionic strength.
Typical inert salts that are used include: NaClO, NaCl, KNO, NaNO, triflates (e.g. NaOSOCF).
Inert salts are never perfectly inert and their use will always interfere with the process under investigation, although the influence may be negligible. | 1 | Solid-state chemistry |
In colloidal chemistry, the critical micelle concentration (CMC) of a surfactant is one of the parameters in the Gibbs free energy of micellization. The concentration at which the monomeric surfactants self-assemble into thermodynamically stable aggregates is the CMC. The Krafft temperature of a surfactant is the lowest temperature required for micellization to take place. There are many parameters that affect the CMC. The interaction between the hydrophilic heads and the hydrophobic tails play a part, as well as the concentration of salt within the solution and surfactants. | 0 | Colloidal Chemistry |
Nano-thermite or super-thermite is a metastable intermolecular composite (MIC) characterized by a particle size of its main constituents, a metal and a metal oxide, under 100 nanometers. This allows for high and customizable reaction rates. Nano-thermites contain an oxidizer and a reducing agent, which are intimately mixed on the nanometer scale. MICs, including nano-thermitic materials, are a type of reactive materials investigated for military use, as well as for general applications involving propellants, explosives, and pyrotechnics.
What distinguishes MICs from traditional thermites is that the oxidizer and a reducing agent, normally iron oxide and aluminium, are in the form of extremely fine powders (nanoparticles). This dramatically increases the reactivity relative to micrometre-sized powder thermite. As the mass transport mechanisms that slow down the burning rates of traditional thermites are not so important at these scales, the reaction proceeds much more quickly. | 0 | Colloidal Chemistry |
Most of the world reserves of potassium (K) were deposited as sea water in ancient inland oceans. After the water evaporated, the potassium salts crystallized into beds of potash ore. These are the locations where potash is being mined today. The deposits are a naturally occurring mixture of potassium chloride (KCl) and sodium chloride (NaCl), more commonly known as table salt. Over time, as the surface of the earth changed, these deposits were covered by thousands of feet of earth. | 1 | Solid-state chemistry |
*Prince, Leon M., Microemulsions in Theory and Practice Academic Press (1977) .
*Rosano, Henri L and Clausse, Marc, eds., Microemulsion Systems (Surfactant Science Series) Marcel Dekker, Inc. (1987) | 0 | Colloidal Chemistry |
InS nanoparticles luminesce in the visible spectrum. Preparing InS nanoparticles in the presence of other heavy metal ions creates highly efficient blue, green, and red phosphors, which can be used in projectors and instrument displays. | 1 | Solid-state chemistry |
Ion implantation may be used to treat the surfaces of dielectric materials such as sapphire and silica to make composites with near-surface dispersions of metal or oxide nanoparticles. | 0 | Colloidal Chemistry |
In a 2022 study by Chaudhary et al., aquasomes were explored for delivery of the drug dithranol, which is a treatment for psoriasis. A limitation of the practical application of free dithranol in the treatment of psoriasis is its degradation when encountering oxygen, light, alkaline pH, and heavy metallic elements, leading to the exploration of aquasomes as a delivery system for dithranol to overcome these limitations. Aquasomes displayed a 72% drug entrapment efficiency for dithranol, and drug release studies showed 55% release within 12 hours in vitro and good deposition of the drug ex vivo, indicating a strong controlled release profile for dithranol-loaded aquasomes. This study indicates support for aquasomes as a drug delivery system due to their ability to stabilize easily degradable drugs such as dithranol, while also providing controlled drug release profiles.
In a 2019 study by Kutlehria et al., aquasomes were explored for the oral delivery of the drug bromelain, which inhibits platelet aggregation and modulates anti-inflammatory cytokines, and has shown anti-tumor activity. A challenge in the administration of bromelain has been its limited ability to reach the site of therapeutic action before it degrades. The water-absorbent nature of aquasomes allows for the aqueous transfer of bromelain. The Kutlehria et al. study demonstrated desirable drug-carrying properties for bromelain-loaded aquasomes, such as a drug entrapment efficiency of 72% to 79% and sustained release in vitro, showing promise as an oral delivery mechanism to increase the bioavailability of bromelain. Such applications may be useful for the transport and targeting of poorly soluble drugs, enabled by the structure and polysaccharide coating of aquasomes.
Dual drug delivery is another application of aquasomes enabled by their structure. Dual drug delivery systems can deliver two drugs simultaneously, and aim to enhance the therapeutic efficiency and reduce the side effects of the drugs delivered. Such systems can be useful in treating patients suffering from multiple diseases. Challenges in dual drug delivery include independently controlling release rates of each of the drugs loaded in the system. In a 2019 study by Damera et al., aquasomes were used to deliver bovine serum albumin (BSA) in combination with one of three therapeutic drugs (C153, WAR, and IBU), allowing release of a bioactive molecule and a hydrophobic drug simultaneously. Damera et al. suggested that dual drug delivery was enabled by the bioactive molecule layer of the aquasome being BSA. This BSA layer interacted with the hydrophobic therapeutic drugs, and the strength of the binding interactions was shown to affect the release behaviors of the drugs. Dual drug delivery with aquasomes thus shows promise for treatment of patients with coexisting diseases alongside hypoalbuminemia, as the albumin from BSA can treat the hypoalbuminemia while the additional drug treats the disease. | 0 | Colloidal Chemistry |
Soap is known to have been used as a surfactant for washing clothes since the Sumerian time in 2,500 B.C. In ancient Egypt, soda was used as a wash additive. In the 19th century, synthetic surfactants began to be created, for example from olive oil. Sodium silicate (water glass) was used in soap-making in the United States in the 1860s, and in 1876, Henkel sold a sodium silicate-based product that can be used with soap and marketed as a "universal detergent" (Universalwaschmittel) in Germany. Soda was then mixed with sodium silicate to produce Germanys first brand name detergent Bleichsoda. In 1907, Henkel also added a bleaching agent sodium perborate to launch the first self-acting' laundry detergent Persil to eliminate the laborious rubbing of laundry by hand.
During the First World War, there was a shortage of oils and fats needed to make soap. In order find alternatives for soap, synthetic detergents were made in Germany by chemists using raw material derived from coal tar. These early products, however, did not provide sufficient detergency. In 1928, effective detergent was made through the sulfation of fatty alcohol, but large-scale production was not feasible until low-cost fatty alcohols become available in the early 1930s. The synthetic detergent created was more effective and less likely to form scum than soap in hard water, and can also eliminate acid and alkaline reactions and decompose dirt. Commercial detergent products with fatty alcohol sulphates began to be sold, initially in 1932 in Germany by Henkel. In the United States, detergents were sold in 1933 by Procter & Gamble (Dreft) primarily in areas with hard water. However, sales in the US grew slowly until the introduction of built detergents with the addition of effective phosphate builder developed in the early 1940s. The builder improves the performance of the surfactants by softening the water through the chelation of calcium and magnesium ions, helping to maintain an alkaline pH, as well as dispersing and keeping the soiling particles in solution. The development of the petrochemical industry after the Second World War also yielded material for the production of a range of synthetic surfactants, and alkylbenzene sulfonates became the most important detergent surfactants used. By the 1950s, laundry detergents had become widespread, and largely replaced soap for cleaning clothes in developed countries.
Over the years, many types of detergents have been developed for a variety of purposes, for example, low-sudsing detergents for use in front-loading washing machines, heavy-duty detergents effective in removing grease and dirt, all-purpose detergents and specialty detergents. They become incorporated in various products outside of laundry use, for example in dishwasher detergents, shampoo, toothpaste, industrial cleaners, and in lubricants and fuels to reduce or prevent the formation of sludge or deposits. The formulation of detergent products may include bleach, fragrances, dyes and other additives. The use of phosphates in detergent, however, led to concerns over nutrient pollution and demand for changes to the formulation of the detergents. Concerns were also raised over the use of surfactants such as branched alkylbenzene sulfonate (tetrapropylenebenzene sulfonate) that lingers in the environment, which led to their replacement by surfactants that are more biodegradable, such as linear alkylbenzene sulfonate. Developments over the years have included the use of enzymes, substitutes for phosphates such as zeolite A and NTA, TAED as bleach activator, sugar-based surfactants which are biodegradable and milder to skin, and other green friendly products, as well as changes to the form of delivery such as tablets, gels and pods. | 0 | Colloidal Chemistry |
Copper(I) thiocyanate is a hole conductor, a semiconductor with a wide band gap (3.6 eV, therefore transparent to visible and near infrared light). It is used in photovoltaics in some third-generation cells as a hole transfer layer. It acts as a P-type semiconductor and as a solid-state electrolyte. It is often used in dye-sensitized solar cells. Its hole conductivity is however relatively poor (0.01 S·m). This can be improved by various treatments, e.g. exposure to gaseous chlorine or doping with (SCN).
CuSCN with NiO act synergically as a smoke suppressant additive in polyvinyl chloride (PVC).
CuSCN precipitated on carbon support can be used for conversion of aryl halides to aryl thiocyanates.
Copper thiocyanate is used in some anti-fouling paints. Advantages compared to cuprous oxide include that the compound is white and a more efficient biocide. | 1 | Solid-state chemistry |
The objective of acoustic foam is to enhance the sonic properties of a room by effectively managing unwanted reverberations. For this reason, acoustic foam is often used in restaurants, performance spaces, and recording studios. Acoustic foam is also often installed in large rooms with large, reverberative surfaces like gymnasiums, churches, synagogues, theaters, and concert halls where excess reverberation is prone to arise. The purpose is to reduce, but not entirely eliminate, resonance within the room. In unmanaged spaces without acoustic foam or similar sound absorbing materials, sound waves reflect off of surfaces and continue to bounce around in the room. When a wave encounters a change in acoustic impedance, such as hitting a solid surface, acoustic reflections transpire. These reflections will occur many times before the wave becomes inaudible. Reflections can cause acoustic problems such as phase summation and phase cancellation. A new complex wave originates when the direct source wave coincides with the reflected waves. This complex wave will change the frequency response of the source material. | 0 | Colloidal Chemistry |
Various means of doping MgB with carbon (e.g. using 10% malic acid) can improve the upper critical field and the maximum current density
(also with polyvinyl acetate).
5% doping with carbon can raise H from 16 to 36 T while lowering T only from 39 K to 34 K. The maximum critical current (J) is reduced, but doping with TiB can reduce the decrease. (Doping MgB with Ti is patented.)
The maximum critical current (J) in magnetic field is enhanced greatly (approx double at 4.2 K) by doping with ZrB.
Even small amounts of doping lead both bands into the type II regime and so no semi-Meissner state may be expected. | 1 | Solid-state chemistry |
Clay-water interaction is an all-inclusive term to describe various progressive interactions between clay minerals and water. In the dry state, clay packets exist in face-to-face stacks like a deck of playing cards, but clay packets begin to change when exposed to water. Five descriptive terms describe the progressive interactions that can occur in a clay-water system, such as a water mud.
(1) Hydration occurs as clay packets absorb water and swell.
(2) Dispersion (or disaggregation) causes clay platelets to break apart and disperse into the water due to loss of attractive forces as water forces the platelets farther apart.
(3) Flocculation begins when mechanical shearing stops and platelets previously dispersed come together due to the attractive force of surface charges on the platelets.
(4) Deflocculation, or peptization, the opposite effect, occurs by addition of chemical deflocculant to flocculated mud; the positive edge charges are covered and attraction forces are greatly reduced.
(5) Aggregation, a result of ionic or thermal conditions, alters the hydrational layer around clay platelets, removes the deflocculant from positive edge charges and allows platelets to assume a face-to-face structure. | 0 | Colloidal Chemistry |
Chan moved to New York City at the age of eight and spent her childhood in North America. Chan studied at Baylor University and graduated in 1993. Initially a music majorspecialising in the violinshe soon became interested in chemistry. At Baylor, Chan worked under the supervision of Carlos Manzanares and Marianna Busch. She earned her doctoral degree under the supervision of Susan M. Kauzlarich at the University of California, Davis in 1998. Chan completed postdoctoral research in the ceramics division at the National Institute of Standards and Technology. She has continued to play violin in her church orchestra. | 1 | Solid-state chemistry |
N-Oleoylsarcosine (Sarkosyl O) is an amphiphilic oleic acid derivative having a sarcosine head group (N-methylglycine) which is used as a water-in-oil emulsifier and corrosion inhibitor. | 0 | Colloidal Chemistry |
Due to the special semiconductor properties of carbon nitrides, they show unexpected catalytic activity for a variety of reactions, such as for the activation of benzene, trimerization reactions, and also the activation of carbon dioxide (artificial photosynthesis). | 1 | Solid-state chemistry |
A nanofluid is a fluid containing nanometer-sized particles, called nanoparticles. These fluids are engineered colloidal suspensions of nanoparticles in a base fluid. The nanoparticles used in nanofluids are typically made of metals, oxides, carbides, or carbon nanotubes. Common base fluids include water, ethylene glycol and oil.
Nanofluids have novel properties that make them potentially useful in many applications in heat transfer, including microelectronics, fuel cells, pharmaceutical processes, and hybrid-powered engines, engine cooling/vehicle thermal management, domestic refrigerator, chiller, heat exchanger, in grinding, machining and in boiler flue gas temperature reduction. They exhibit enhanced thermal conductivity and the convective heat transfer coefficient compared to the base fluid. Knowledge of the rheological behaviour of nanofluids is found to be critical in deciding their suitability for convective heat transfer applications.
Nanofluids also have special acoustical properties and in ultrasonic fields display additional shear-wave reconversion of an incident compressional wave; the effect becomes more pronounced as concentration increases.
In analysis such as computational fluid dynamics (CFD), nanofluids can be assumed to be single phase fluids; however, almost all new academic papers use a two-phase assumption. Classical theory of single phase fluids can be applied, where physical properties of nanofluid is taken as a function of properties of both constituents and their concentrations. An alternative approach simulates nanofluids using a two-component model.
The spreading of a nanofluid droplet is enhanced by the solid-like ordering structure of nanoparticles assembled near the contact line by diffusion, which gives rise to a structural disjoining pressure in the vicinity of the contact line. However, such enhancement is not observed for small droplets with diameter of nanometer scale, because the wetting time scale is much smaller than the diffusion time scale. | 0 | Colloidal Chemistry |
MOBs are composed of two major components: a metal ion or cluster of metal ions and a biological molecule. Examples include CuHARS which contain copper as the metal ion and cystine as the biological molecule. Another example includes the use of silver as the metal ion in combination with cystine. Cystine is the dimer form of the amino acid cysteine. Cobalt has also been used in combination with cystine to form CoMOBs.
When combined with copper to form CuHARS, the cystine may provide a linker function leading to a linear, high-aspect ratio structure that gives CuHARS its name: copper high-aspect ratio structures. In contrast to CuHARS, MOBs formed with silver and cystine, result in silver nanoparticles with spherical, rounded structure. These have been named AgCysNPs. Figure 1 shows comparative electron microscopy of CuHARS and AgCysNPs. | 0 | Colloidal Chemistry |
The properties of a material in nanoparticle form are unusually different from those of the bulk one even when divided into micrometer-size particles. Many of them arise from spatial confinement of sub-atomic particles (i.e. electrons, protons, photons) and electric fields around these particles. The large surface to volume ratio is also significant factor at this scale. | 0 | Colloidal Chemistry |
Electrodiffusiophoresis is a motion of particles dispersed in liquid induced by external homogeneous electric field, which makes it similar to electrophoresis. | 0 | Colloidal Chemistry |
Composite metal foam has shown an ability to shield against x-ray and neutron radiation, absorbs/mitigates shocks, sounds, and vibrations, and can withstand over 1,000,000 high load cycles, outperforming traditional solid metals in each case. | 0 | Colloidal Chemistry |
A preparation of indium sulfide made with the radioactive In can be used as a lung scanning agent for medical imaging. It is taken up well by lung tissues, but does not accumulate there. | 1 | Solid-state chemistry |
Composite metal foam has been tested in a puncture test. Puncture tests were conducted on S-S CMF-CSP with different thicknesses of stainless steel face sheets and CMF core. The bonding of the S-S CMF core and face sheets was done via adhesive bonding and diffusion bonding. Various thicknesses of the CMF core and face sheets created a variety of target areal densities from about 6.7 to about 11.7 kg per each tile of 30 x 30 cm. Targets were impacted using 2.54 and 3.175 cm diameter steel balls fired at velocities ranging from 120 to 470 m per second, resulting in puncture energies from 488 to 14 500 J over a 5.06–7.91 cm2 impact area for the two size sphere balls. None of the panels, even those with the lowest areal densities, showed complete penetration/puncture through their thickness. This was mostly due to the energy absorption capacity of the S-S CMF core in compression, whereas the face sheets strengthen the CMF core to better handle tensile stresses. Sandwich panels with thicker face sheets show less effectiveness, and a thin face sheet seemed to be sufficient to support the S-S CMF core for absorbing such puncture energies. Panels assembled using adhesive bonding showed debonding of the face sheets from the CMF core upon the impact of the projectile while the diffusion bonded panels showed more flexibility at the interface and better accommodated the stresses. Most diffusion bonded panels did not show a debonding of face sheets from the S-S CMF core. This study proved CMF's energy absorption abilities, indicating that CMF can be used to simultaneously increase protections and decrease weight. | 0 | Colloidal Chemistry |
Cleavable detergents, also known as cleavable surfactants, are special surfactants (detergents) that are used in biochemistry and especially in proteomics to enhance protein denaturation and solubility. The detergent is rendered inactive by cleavage, usually under acidic conditions, in order to make the sample compatible with a following procedure or in order to selectively remove the cleavage products.
Applications for cleavable detergents include protease digestion of proteins such as in-gel digestion with trypsin after SDS PAGE and peptide extractions from electrophoresis gels. Cleavable detergents are mainly used in sample preparations for mass spectrometry. | 0 | Colloidal Chemistry |
Mohammad Khaja Nazeeruddin (born 1957 in Thumboor, Andhra Pradesh, India) is an Indian-Swiss chemist and materials scientist who conducts research on Perovskite solar cells, dye-sensitized solar cells, and light-emitting diodes. He is a professor at EPFL (École Polytechnique Fédérale de Lausanne) and the director of the Laboratory for Molecular Engineering of Functional Materials at School of Basic Sciences. | 1 | Solid-state chemistry |
Stephen Lee was born to 1957 Nobel Prize winner in Physics Tsung-Dao Lee and Hui-Chun Jeannette Chin (), who died in 1996. Lee has one brother, James Lee (; born 1952), who is the dean of the School of Humanities and Social Science at the Hong Kong University of Science and Technology and chair professor of the Division of Social Science at the same university. | 1 | Solid-state chemistry |
[https://www.epw.senate.gov/public/index.cfm/superfund-sites-identified-by-epa-to-have-pfas-contamination Five military installations] in Washington State have been identified by the U.S. Senate Committee on Environment and Public Works as having PFAS contamination. Toward environmental and consumer protections, the Washington State Department of Ecology published a [https://apps.ecology.wa.gov/publications/summarypages/2104048.html Chemical Action Plan] in November 2021, and in June 2022 the governor tasked the Washington State Department of Ecology with [https://app.leg.wa.gov/RCW/default.aspx?cite=70A.350.090 phasing out manufacture and import of products containing PFASs]. Initial steps taken by the Washington State Department of Health to protect the public from exposure through drinking water have included setting [https://doh.wa.gov/sites/default/files/2022-02/PFAS%20Rule%20Adoption%20Notice%20and%20Adopted%20Rule%20Language.pdf?uid=62c866e64514c State Action Levels] for five PFASs (PFOA, PFOS, PFNA, PFHxS, and PFBS), which were implemented in November 2021. | 0 | Colloidal Chemistry |
A comprehensive list can be found in the cv on the institutes website.'
* 2015 – Honorary doctorate from the University of Silesia in Katowice
* 2014 – Tsungming-Tu Prize, awarded by the National Science Council in Taiwan (the country’s highest academic distinction which can be bestowed on non-Taiwanese citizens)
* 2014 – Gottfried Wilhelm Leibniz Prize
* 2007 – Masao Ikeda Award, Ikeda Memorial Foundation, Kyoto, Japan
* 2001 – Outstanding Achievements Award, International Symposium on Integrated Ferroelectrics (ISIF)
* 2000 – Ferroelectrics Recognition Award, IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society | 1 | Solid-state chemistry |
Unlike conventional composites, which typically fail catastrophically, RCCM fail incrementally because of the non-linear deformation phase and the multiplicity of joints and links. These results matched finite-element simulations with finely-meshed rigid body models. In addition to convergence to the observed coordinated buckling mode, these simulations accurately predict the relative strength scaling observed in load test experiments. These results are consistent with the observation that open-cell lattice materials fail through micro-structural strut bending failures with σmax ∝. The simulations also suggest that the coordinated buckling phenomenon as well as the modulus measurements are not dominated by edge effects, with minimal influence on overall results beyond characteristic lengths exceeding several units.
Varying the locations of more and less rigid elements can trigger pure axial compression, simple uni-directional Euler buckling and complex buckling. | 0 | Colloidal Chemistry |
In 1965, Frank Ham proposed that the dynamic JTE could reduce the expected values of observables associated with the orbital wavefunctions due to the superposition of several electronic states in the total vibronic wavefunction. This effect leads, for example, to a partial quenching of the spin–orbit interaction and allowed the results of previous Electron Paramagnetic Resonance (EPR) experiments to be explained.
In general, the result of an orbital operator acting on vibronic states can be replaced by an effective orbital operator acting on purely electronic states. In first order, the effective orbital operator equals the actual orbital operator multiplied by a constant, whose value is less than one, known as a first-order (Ham) reduction factor. For example, within a triplet T electronic state, the spin–orbit coupling operator can be replaced by , where is a function of the strength of the JT coupling which varies from 1 in zero coupling to 0 in very strong coupling. Furthermore, when second-order perturbation corrections are included, additional terms are introduced involving additional numerical factors, known as second-order (Ham) reduction factors. These factors are zero when there is no JT coupling but can dominate over first-order terms in strong coupling, when the first-order effects have been significantly reduced.
Reduction factors are particularly useful for describing experimental results, such as EPR and optical spectra, of paramagnetic impurities in semiconducting, dielectric, diamagnetic and ferrimagnetic hosts. | 1 | Solid-state chemistry |
The presence of dangling bonds can lead to ferromagnetism in materials that are normally magnetically inactive, such as polymers and hydrogenated graphitic materials. A dangling bond contains/consists of an electron and can thus contribute its own net (para)magnetic moment. This only happens when the dangling bond electron does not pair its spin to that of another electron.
Ferromagnetic properties in various carbon nanostructures can be described using dangling bonds and may be used to create metal-free organic spintronics and polymeric ferromagnetic materials (see Applications). Creating dangling bonds with unpaired electrons can, for example, be achieved by cutting or putting large mechanical strain on a polymer. In this process, covalent bonds between carbon atoms are broken. One electron can end up on each of the carbon atoms that originally contributed to the bond, leading to two unpaired dangling bonds. | 1 | Solid-state chemistry |
Nanoaluminum, or ultra fine grain (UFG) aluminum, powders are a key component of most nano-thermitic materials. A method for producing this material is the dynamic gas-phase condensation method, pioneered by Wayne Danen and Steve Son at Los Alamos National Laboratory. A variant of the method is being used at the Indian Head Division of the Naval Surface Warfare Center. Another method for production is electrothermal synthesis, developed by NovaCentrix, which uses a pulsed plasma arc to vaporize the aluminum. The powders made by the dynamic gas-phase condensation and the electrothermal synthesis processes are indistinguishable. A critical aspect of the production is the ability to produce particles of sizes in the tens of nano-meter range, as well as with a limited distribution of particle sizes. In 2002, the production of nano-sized aluminum particles required considerable effort, and commercial sources for the material were limited.
An application of the sol-gel method, developed by Randall Simpson, Alexander Gash and others at the Lawrence Livermore National Laboratory, can be used to make the actual mixtures of nano-structured composite energetic materials. Depending on the process, MICs of different density can be produced. Highly porous and uniform products can be achieved by super-critical extraction. | 0 | Colloidal Chemistry |
Magnéli studied at Stockholm University and graduated with a Licentiate in 1941. He moved to Uppsala University to conduct his graduate research under Gunnar Hägg, obtaining his PhD in 1950 for the study on tungsten bronzes. He took up a teaching position at Stockholm University in 1953, and later became the Chair of Inorganic Chemistry at the university until his retirement in 1980.
From his research into the structures of transition metal oxides, Magnéli developed the concept of recurrent dislocations, which nowadays is known as crystallographic shear. The Magnéli phases of transition metal oxides, such as nonstoichiometric tungsten oxide, molybdenum oxide, titanium oxide, and vanadium oxide are named after him. | 1 | Solid-state chemistry |
NaH is colorless, although samples generally appear grey. NaH is around 40% denser than Na (0.968 g/cm).
NaH, like LiH, KH, RbH, and CsH, adopts the NaCl crystal structure. In this motif, each Na ion is surrounded by six H centers in an octahedral geometry. The ionic radii of H (146 pm in NaH) and F (133 pm) are comparable, as judged by the Na−H and Na−F distances. | 1 | Solid-state chemistry |
Jing Li has received numerous awards and honors for her academic achievements, including:
* Henry Rutgers Research Fellow, Rutgers University, 1991–1993
* Henry Dreyfus Teacher-Scholar, The Camille & Henry Dreyfus Foundation, 1994–1998
* Presidential Faculty Fellow, The National Science Foundation, 1995–2000
* NSF CAREER Award, The National Science Foundation, 1995
* The Board of Trustees Fellowship for Scholarly Excellence, Rutgers University, 1996
* Outstanding Achievement Award, Chinese Association of Science and Technology, US, 2002
* The U.S. Clean Energy Education and Empowerment (C3E) Award, The Department of Energy, 2012
* Elected Fellow of the American Association for the Advancement of Science (AAAS), 2012
* The Humboldt Research Award (Humboldt Prize), Alexander von Humboldt Foundation, 2013
* Board of Trustees Award for Excellence in Research, Rutgers University, 2013
* Fellow of the Royal Society of Chemistry, The Royal Society of Chemistry, 2015 | 1 | Solid-state chemistry |
Tantalum(III) chloride is formed by reducing tantalum(V) chloride with tantalum metal. this is done by heating tantalum(III) chloride to 305 °C, passing the vapour over tantalum foil at 600°, and condensing the trichloride at 365 °C. If the condensing region is kept at too high a temperature, then TaCl deposits instead.
The trichloride can also be prepared by thermal decomposition of TaCl, with removal of volatile TaCl. TaCl can be vapourised leaving behind TaCl.
"Salt-free reduction" of a toluene solution of TaCl with 1,4-disilyl-cyclohexadiene in the presence of ethylene produces a complex of TaCl: | 1 | Solid-state chemistry |
*Fellow of the Indian Academy of Sciences (FASc, 1965)
*Fellow of the Indian National Science Academy (FNA, 1974)
*Fellow of the Royal Society (FRS, 1982)
*Founding Fellow of The World Academy of Sciences (FTWAS, 1983)
*Honorary Fellow of the Royal Society of Chemistry (Hon. FRSC, 1989)
*Foreign Member of the Academia Europaea (MAE, 1997)
*Honorary Fellow of the Institute of Physics (Hon.FInstP, 2007)
*Member of many of the world's scientific associations, including the National Academy of Sciences, American Academy of Arts and Sciences, Royal Society of Canada, French Academy, Japanese Academy, Serbian Academy of Sciences and Arts and Polish Academy of Sciences, Czechoslovak Academy of Sciences, Serbian Academy of Sciences, Slovenian Academy of Sciences, Brazilian Academy of Sciences, Spanish Royal Academy of Sciences, National Academy of Sciences of Korea, African Academy of Sciences, and the American Philosophical Society. He is also a member of the Pontifical Academy. | 1 | Solid-state chemistry |
EWM is an effective mechanism by which to get a short duration high intensity light source. The peak intensity for copper wire, for example, is 9.6·10 candle power/cm. J.A. Anderson wrote in his initial spectrography studies that the light was comparable to a black body at 20,000 K. The advantage of a flash produced in this way is that it is easily reproducible with little variation in intensity. The linear nature of the wire allows for specifically shaped and angled light flashes and different types of wires can be used to produce different colors of light. The light source can be used in interferometry, flash photolysis, quantitative spectroscopy, and high-speed photography. | 0 | Colloidal Chemistry |
Reduction of magnetite ore by CO in a blast furnace is used to produce iron as part of steel production process:
Controlled oxidation of FeO is used to produce brown pigment quality γ-FeO (maghemite):
More vigorous calcining (roasting in air) gives red pigment quality α-FeO (hematite): | 1 | Solid-state chemistry |
It has recently been shown that the lamellar phase of the APFN/2HO system form multilamellar vesicles under shear rate. | 0 | Colloidal Chemistry |
Magnetic nanoparticle clusters or magnetic nanobeads with the size 80–150 nanometers form ordered structures along the direction of the external magnetic field with a regular interparticle spacing on the order of hundreds of nanometers resulting in strong diffraction of visible light in suspension. | 0 | Colloidal Chemistry |
HFB machines measure the strength of particle interactions using liquid flow to separate the particles. This method is used to find depletion force strength by adhering to a static plate one particle in a dispersion particle doublet and applying shear force through fluid flow. The drag created by the dispersion particles resists the depletion force between them, pulling the free particle away from the adhered particle. A force balance of the particles at separation can be used to determine the depletion force between the particles. | 0 | Colloidal Chemistry |
As illustrated by the mineral djurleite, a cuprous sulfide is also known. With the approximate formula CuS, this material is non-stoichiometric (range CuS-CuS) and has a monoclinic structure with 248 copper and 128 sulfur atoms in the unit cell. CuS and CuS are similar in appearance and hard to distinguish one from another. | 1 | Solid-state chemistry |
In chemistry, a counterion (sometimes written as "counter ion", pronounced as such) is the ion that accompanies an ionic species in order to maintain electric neutrality. In table salt (NaCl, also known as sodium chloride) the sodium ion (positively charged) is the counterion for the chloride ion (negatively charged) and vice versa.
A counterion will be more commonly referred to as an anion or a cation, depending on whether it is negatively or positively charged. Thus, the counterion to an anion will be a cation, and vice versa.
In biochemistry, counterions are generally vaguely defined. Depending on their charge, proteins are associated with a variety of smaller anions and cations. In plant cells, the anion malate is often accumulated in the vacuole to decrease water potential and drive cell expansion. To maintain neutrality, ions are often accumulated as the counterion. Ion permeation through hydrophobic cell walls is mediated by ion transport channels. Nucleic acids are anionic, the corresponding cations are often protonated polyamines. | 1 | Solid-state chemistry |
Rigid polyurethane foam has many desirable properties which has enabled increased use in various applications, some of which are quite demanding. These properties include low thermal conduction making it useful as an insulator. It also has low density compared to metals and other materials and also good dimensional stability. A metal will expand on heating whereas rigid PU foam does not. They have excellent strength to weight ratios. Like many applications, there has been a trend to make rigid PU foam from renewable raw materials in place of the usual polyols.
They are used in vehicles, planes and buildings in structural applications. They have also been used in fire-retardant applications. | 0 | Colloidal Chemistry |
Surfactants which are less effective at foam production, may have additional co-surfactants added to increase foaming. In which case, the co-surfactant is referred to as the foaming agent. These are surfactants used in lower concentration in a detergent system than the primary surfactant, often the cocamide family of surfactants. Cocamide foaming agents include the nonionic cocamide DEA and cocamidopropylamine oxide, and the zwitterionic cocamidopropyl betaine and cocamidopropyl hydroxysultaine. | 0 | Colloidal Chemistry |
Kanatzidis developed synthesis methodologies to synthesizing new chalcogenide materials and intermetallics. One of his notable contributions is the panoramic synthesis method, which enables the design and discovery of novel materials. He is also credited with developing flux synthesis techniques that allow for reactions to occur at lower temperatures than conventional methods, leading to the formation of unique structures and compositions.
In addition to these contributions, Kanatzidis's research has resulted in the discovery of metal sulfide ion-exchangers, which have practical applications in the remediation of heavy metals in industrial waste water. These findings demonstrate his ability to not only generate new materials but also to identify and apply them in real-world settings.
Kanatzidis is also credited with defining the concept of nanostructuring in the thermoelectric field. By developing new approaches to controlling the structure and composition of thermoelectric materials at the nanoscale, he has contributed to the advancement of this field and the creation of high-performance materials with unique properties. These methods for achieving "nanostructuring" and all-scale architecturing of thermoelectric semiconductors, resulted in the creation of high-performance materials with unprecedented ZT figures of merit (ZT~2.5). These materials feature coherently embedded nanodots, such as those found in PbTe (a phenomenon known as endotaxy), which significantly reduce thermal conductivity by over 70%, while maintaining high electrical conductivity. This unique combination of properties allows for the attainment of very high ZT values exceeding 2.5 in nanostructured thermoelectric materials.
----Kanatzidis, along with fellow researcher Professor Robert P.H. Chang at Northwestern, developed a Novel solar cell technology that utilizes tin instead of lead perovskite. In their groundbreaking study, they published the first solid-state solar cell device incorporating a film of CsSnI3 perovskitein a solid-state dye-sensitized Gratzel cell, which achieved an efficiency of approximately 10%. Kanatzidis was also the first to demonstrate the functionality of CH3NH3SnI3-based solar cells, and he discovered the anomalous bandgap dependence between lead and tin-based solid solutions APb1-xSnxI3 (A=Cs, CH3NH3, formamidinium). This discovery revealed that bandgaps as low as 1.1 eV are achievable, which is useful in the development of tandem solar cells.
In 2016, Kanatzidis and Mohite demonstrated that 2D iodide perovskites form films with vertical slab orientation, and showed >12% efficiency in a solar cell with far better stability than corresponding 3D MAPbI3-based solar cells. . Since then, 2D iodide perovskites have become widely used in mixtures of 2D/3D perovskites for solar cells, exhibiting both high stability and efficiency.
In 2013 he reported the x-ray detecting properties of the perovskite CsPbBr semiconductor with potential applications in gamma-ray spectroscopy having better than 1.4% energy resolution.
Kanatzidis has proposed ideas and concepts for predictive synthesis to new materials including "infinitely adaptive" homologous superseries and the panoramic synthesis strategy where with a single experiment all phases in the course of a given reaction can be detected. This offers a panoramic view of all the phases present, and could help unravel the mechanisms of how new materials form.
Kanatzidis is credited with inventing a new category of materials known as chalcogels. These unique inorganic compounds exhibit aerogel properties. Chalcogels have a sponge-like structure that enables them to effectively absorb heavy-metal atoms from polluted water. Due to their high surface area-to-volume ratio, even small pieces of chalcogels can purify thousands of liters of water. Chalcogels have demonstrated the ability to reduce mercury, lead, and cadmium concentrations to parts per trillion (ppt) levels as well as radionuclides. Biomimetic chalcogels containing bioinorganic FeS have been reported to photochemically convert N to NH. The International Mineralogical Association named a new mineral, Kanatzidisite, belonging to the sulfosalt class with a composition of [BiSbS3][Te2]. | 1 | Solid-state chemistry |
Soapmakers in Naples were members of a guild in the late sixth century (then under the control of the Eastern Roman Empire), and in the eighth century, soap-making was well known in Italy and Spain. The Carolingian capitulary De Villis, dating to around 800, representing the royal will of Charlemagne, mentions soap as being one of the products the stewards of royal estates are to tally. The lands of Medieval Spain were a leading soapmaker by 800, and soapmaking began in the Kingdom of England about 1200. Soapmaking is mentioned both as "women's work" and as the produce of "good workmen" alongside other necessities, such as the produce of carpenters, blacksmiths, and bakers.
In Europe, soap in the 9th century was produced from animal fats and had an unpleasant smell. This changed when olive oil began to be used in soap formulas instead, after which much of Europe's soap production moved to the Mediterranean olive-growing regions. Hard toilet soap was introduced to Europe by Arabs and gradually spread as a luxury item. It was often perfumed. By the 15th century, the manufacture of soap in the Christendom had become virtually industrialized, with sources in Antwerp, Castile, Marseille, Naples and Venice. | 1 | Solid-state chemistry |
Arndt Simon (born 14 January 1940) is a German inorganic chemist. He was a director at the Max Planck Institute for Solid State Research in Stuttgart. | 1 | Solid-state chemistry |
Roth studied geology at Coe College and University of Illinois Urbana-Champaign, where he obtained his PhD in 1951. He worked at the United States Geological Survey as a field assistant, and after his PhD, he joined the National Bureau of Standards (later NIST), where he remained for most of his career. Since 1981, he was a senior editor of the book series Phase Diagrams for Ceramists, a major set of reference books in the field of ceramic materials.
While visiting CSIRO in Melbourne, Australia in the 1960s, Roth collaborated with the Australian materials scientist Arthur D. Wadsley to understand the structures of transition metal oxides, which led to a series of publications. The ordered phases of transition metal oxides exhibiting shear structures are now referred to as the Wadsley-Roth phases. | 1 | Solid-state chemistry |
Bismuth selenide is a semiconductor and a thermoelectric material. While stoichiometric bismuth selenide should be a semiconductor with a gap of 0.3 eV, naturally occurring selenium vacancies act as electron donors, so BiSe is intrinsically n-type.
Bismuth selenide has a topologically insulating ground-state. Topologically protected Dirac cone surface states have been observed in Bismuth selenide and its insulating derivatives leading to intrinsic topological insulators, which later became the subject of world-wide scientific research.
Bismuth selenide is a van der Waals material consisting of covalently bound five-atom layers (quintuple layers) which are held together by van der Waals interactions and spin-orbit coupling effects. Although the (0001) surface is chemically inert (mostly due to the inert-pair effect of Bi), there are metallic surface states, protected by the non-trivial topology of the bulk. For this reason, the BiSe surface is an interesting candidate for van der Waals epitaxy and subject of scientific research. For instance, different phases of antimony layers can be grown on BiSe, by means of which topological pn-junctions can be realised. More intriguingly, Sb layers undergo topological phase transitions when attached to the BiSe surface and thus inherit the non-trivial topological properties of the BiSe substrate. | 1 | Solid-state chemistry |
Molybdenite is extremely soft with a metallic luster, and is superficially almost identical to graphite, to the point where it is not possible to positively distinguish between the two minerals without scientific equipment. It marks paper in much the same way as graphite. Its distinguishing feature from graphite is its higher specific gravity, as well as its tendency to occur in a matrix. | 1 | Solid-state chemistry |
In relation to packaging, starches and biopolyesters make up these biofoams as they are adequate replacements to expanded polystyrene. Polylactic acids (PLAs) are a common form of the basis of these biofoams since they offer a substitute for polyolefin-based foams that are commonly used in automotive parts, pharmaceutical products, and short life-time disposable packaging industries due to their bio-based and biodegradable properties. PLA comes from the formation of lactide produced from lactic acid due to bacterial fermentation through ring-opening polymerization, in which the process is shown through Figure 4.
PLA does not have the most desirable traits for biodegradability in the packaging industry as it contains a low heat distortion temperature and has unfavorable water barrier characteristics. On the other hand, PLA has been shown to have desirable packaging properties including high ultraviolet light barrier properties, and low melting and glass transition temperatures. As of recently, PGA has been introduced in the packaging industry as it is a good solvent and comparable to PLA. Table 1 shows the characteristics of both biofoams and how they compare. As shown, PGA contains a strong stereochemistry structure which in turn causes it to have high barrier and mechanical properties making it desirable for the packaging industry. The study of mixing both PGA and PLA has been explored by using copolymerization in order for PGA to help enhance the barrier properties of PLA when used in packaging.
Table 1: The properties of PLA in comparison to PGA. | 0 | Colloidal Chemistry |
The salt and ice challenge is an Internet challenge where participants pour salt on their bodies, usually on the arm, and ice is then placed on the salt. This causes a "burning" sensation similar to frost bite, and participants vie to withstand the pain for the longest time. The challenge can be recorded and posted on YouTube or other forms of social media.
The mixture of ice and salt create
eutectic frigorific mixture which can get as cold as .
The salt and ice challenge can quickly cause second- and third-degree injuries similar to frostbite or being burnt with the metal end of a lighter, as well as causing painful open sores to form on the skin. Due to the numbing sensation of the cold and possible nerve damage during the stunt, participants are often unaware of the extent of any injuries sustained during the challenge, only feeling pain once the salt on their skin enters lesions created during the challenge. Skin discoloration from the challenge may remain after the challenge has been attempted. | 1 | Solid-state chemistry |
Compared to the general public exposed to contaminated drinking water, professional ski wax technicians are more strongly exposed to PFASs (PFOA, PFNA, PFDA, PFHpA, PFDoDA) from the glide wax used to coat the bottom of skis to reduce the friction between the skis and snow. During the coating process, the wax is heated, which releases fumes and airborne particles. Compared to all other reported occupational and residential exposures, ski waxing had the highest total PFAS air concentrations. | 0 | Colloidal Chemistry |
Settling is the process by which particulates move towards the bottom of a liquid and form a sediment. Particles that experience a force, either due to gravity or due to centrifugal motion will tend to move in a uniform manner in the direction exerted by that force. For gravity settling, this means that the particles will tend to fall to the bottom of the vessel, forming sludge or slurry at the vessel base.
Settling is an important operation in many applications, such as mining, wastewater and drinking water treatment, biological science, space propellant reignition,
and scooping. | 0 | Colloidal Chemistry |
Powder defoamers are in principle oil-based defoamers on a particulate carrier like silica. These are added to powdered products like cement, plaster and detergents. | 0 | Colloidal Chemistry |
Simon was awarded a number of awards and honorary doctorates:
* 1972 Chemistry Award of the Göttingen Academy of Sciences and Humanities
* 1985 Wilhelm Klemm Award of the Society of German Chemists
* 1987 Otto Bayer Award
* 1990 Gottfried Wilhelm Leibniz Prize
* 1998 Dr. rer.nat. h.c. of Technical University Dresden
* 1998 Dr. rer.nat. h.c. of University (TH) Karlsruhe
* 1998 Centenary Prize, Royal Society of Chemistry
* 2001 Dr. phil. h.c. of Stockholm University
* 2002 Dr. h.c. of Université de Rennes I
* 2004 Sir Nevill Mott Lecture, University of Loughborough
* 2004 Liebig-Denkmünze of the Society of German Chemists
* 2011 Terrae Rarae Award
He is also a member of several academies of sciences:
* 1989 Member of the Academy of Sciences and Literature Mainz (Corresponding Member since 1994)
* 1990 Member of the Heidelberg Academy of Sciences and Humanities
* 1990 Member of the Academia Europaea
* 1992 Member of the Russian Academy of Sciences
* 1998 Member of the Academy of Sciences Leopoldina
* 1998 Foreign Member of the French Academy of Sciences
* 2003 Honorary Fellow of the Chemical Research Society of India | 1 | Solid-state chemistry |
Potash was one of the most important industrial chemicals. It was refined from the ashes of broadleaved trees and produced primarily in the forested areas of Europe, Russia, and North America. Although methods for producing artificial alkalis were invented in the late 18th century, these did not become economical until the late 19th century and so the dependence on organic sources of potash remained.
Potash became an important international trade commodity in Europe from at least the early 14th century. It is estimated that European imports of potash required 6 or more million cubic metres each year from the early 17th century. Between 1420 and 1620, the primary exporting cities for wood-derived potash were Gdańsk, Königsberg and Riga. In the late 15th century, London was the lead importer due to its position as the centre of soft soap making while the Dutch dominated as suppliers and consumers in the 16th century. From the 1640s, geopolitical disruptions (i.e. Russo-Polish War (1654–1667)) meant that the centres of export moved from the Baltic to Archangel, Russia. In 1700, Russian ash was dominant though Gdańsk remained notable for the quality of its potash. | 1 | Solid-state chemistry |
Hydrocarbon chains are long chains which consist of a carbon backbone hydrogen substituents, making them very hydrophobic. Hydrocarbon chains alone form waxes and oils and retain these characteristics when they are incorporated into surfactant. A good example of surfactants containing a hydrocarbon chain are lipids, which form cell membranes.
Alkyl ether chains are similar to hydrocarbon chains, except with oxygens incorporated within the backbone as well as carbons. There are two alkyl chains commonly used in surfactants: polyethylene oxide and polypropylene oxide. Polyethylene oxide chains have an oxygen and two carbon (-O-CH-CH-) repeating unit and has an increased hydrophilic character compared to hydrocarbons. Polypropylene oxide has the same backbone structure as polyethylene oxide but with a methyl group substituent of one of the carbons, and this structure has hydrophobicity between hydrocarbons and polyethylene oxides.
Fluorocarbon chain tails consist of a carbon backbone that has fluorine substituents instead of hydrogens. Fluorocarbons help to lower the surface tension of water and other solvents because of their lipophobic nature even in harsh conditions such as low pH. When fluorocarbons are incorporated into surfactants they are used as stain repellents and incorporated into coatings in order to decrease surface defects.
Siloxane chains consist of a backbone which contains alternating oxygen and silicon atoms. Surfactants with siloxane tails have been found to resist hydrolysis and prevent breakdown polymer chains which can cause cracking in the paint and are thus used in products such as cosmetics, deodorants, defoamer, and soap. | 0 | Colloidal Chemistry |
Pyrite usually forms cuboid crystals, sometimes forming in close association to form raspberry-shaped masses called framboids. However, under certain circumstances, it can form anastomosing filaments or T-shaped crystals.
Pyrite can also form shapes almost the same as a regular dodecahedron, known as pyritohedra, and this suggests an explanation for the artificial geometrical models found in Europe as early as the 5th century BC. | 1 | Solid-state chemistry |
Rundle died from a stroke in Iowa Methodist Hospital on October 9, 1963. He was survived by his wife and three sons. | 1 | Solid-state chemistry |
Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ‰).
Salinity is an important factor in determining many aspects of the chemistry of natural waters and of biological processes within it, and is a thermodynamic state variable that, along with temperature and pressure, governs physical characteristics like the density and heat capacity of the water.
A contour line of constant salinity is called an isohaline, or sometimes isohale. | 1 | Solid-state chemistry |
Dronskowski studied chemistry and physics at the University of Münster from 1981 to 1986. He completed his chemistry diploma with Bernt Krebs and Arndt Simon in 1987. He finished his physics diploma with Ole Krogh Andersen and Johannes Pollmann in 1989. He received his doctorate under supervision of Arndt Simon at the University of Stuttgart. From 1991 to 1992, he was a visiting scientist in the group of Roald Hoffmann at Cornell University. In 1995, he finished his habilitation at the University of Dortmund. Since 1997, he is a full professor at the RWTH Aachen University. | 1 | Solid-state chemistry |
Numerous experimental techniques have been developed to study particle
aggregation. Most frequently used are time-resolved optical techniques that are based on transmittance or scattering of light.
Light transmission. The variation of transmitted light through an aggregating suspension can be studied with a regular spectrophotometer in the visible region. As aggregation proceeds, the medium becomes more turbid, and its absorbance increases. The increase of the absorbance can be related to the aggregation rate constant k and the stability ratio can be estimated from such measurements. The advantage of this
technique is its simplicity.
Light scattering. These techniques are based on probing the scattered light from an aggregating suspension in a time-resolved fashion. Static light scattering yields the change in the scattering intensity, while dynamic light scattering the variation in the apparent hydrodynamic radius. At early-stages of aggregation, the variation of each of these quantities is directly proportional to the aggregation rate constant
k.
At later stages, one can obtain information on the clusters formed (e.g., fractal dimension). Light scattering works well for a wide range of particle sizes. Multiple scattering effects may have to be considered, since scattering becomes increasingly important for larger particles or larger aggregates. Such effects can be neglected in weakly turbid suspensions. Aggregation processes in strongly scattering systems have been studied with transmittance, backscattering techniques or diffusing-wave spectroscopy.
Single particle counting. This technique offers excellent resolution, whereby clusters made out of tenths of particles can be resolved individually. The aggregating suspension is forced through a narrow capillary particle counter and the size of each aggregate is being analyzed by light scattering. From the scattering intensity, one can deduce the size of each aggregate, and construct a detailed aggregate size distribution. If the suspensions contain high amounts of salt, one could equally use a Coulter counter. As time proceeds, the size distribution shifts towards larger aggregates, and from this variation aggregation and breakup rates involving different clusters can be deduced. The disadvantage of the technique is that the aggregates are forced through a narrow capillary under high shear, and the aggregates may disrupt under these conditions.
Indirect techniques. As many properties of colloidal suspensions depend on the state of aggregation of the suspended particles, various indirect techniques have been used to monitor particle aggregation too. While it can be difficult to obtain quantitative information on aggregation rates or cluster properties from such experiments, they can be most valuable for practical applications. Among these techniques settling tests are most relevant. When one inspects a series of test tubes with suspensions prepared at different concentration of the flocculant, stable suspensions often remain dispersed, while the unstable ones settle. Automated instruments based on light scattering/transmittance to monitor suspension settling have been developed, and they can be used to probe particle aggregation. One must realize, however, that these techniques may not always reflect the actual aggregation state of a suspension correctly. For example, larger primary particles may settle even in the absence of aggregation, or aggregates that have formed a colloidal gel will remain in suspension. Other indirect techniques capable to monitor the state of aggregation include, for example, filtration, rheology, absorption of ultrasonic waves, or dielectric properties. | 0 | Colloidal Chemistry |
Banhart describes two dominating perspectives in which cellular metals are characterized, referring to them as atomistic and macroscopic. The atomistic (or molecular) perspective holds that a cellular material is a construction of struts, membranes, and other elements which possess mechanical properties of their bulk metal counterpart. Indeed, the physical, mechanical, and thermal properties of titanium foams are commonly measured using the same methods as that of their solid counterparts. However, special precautions must be taken due to the cellular structure of metal foams. From a macroscopic perspective, the cellular structure is perceived as a homogeneous structure and characterized by considering the effective (or averaged) material parameters. | 0 | Colloidal Chemistry |
Governments have set standards on the allowable turbidity in drinking water. In the United States, public water systems that use conventional or direct filtration methods must not have a turbidity higher than 1.0 NTU at the plant outlet and all samples for turbidity must be less than or equal to 0.3 NTU for at least 95 percent of the samples in any month. Systems that use filtration other than the conventional or direct filtration must follow state limits, which must include turbidity at no time exceeding 5 NTU. Many drinking water utilities strive to achieve levels as low as 0.1 NTU. The European turbidity standard is 4 NTU. | 0 | Colloidal Chemistry |
The plasmon resonance displayed by nanoparticles, gold particles are most often used as an example, can be altered using the interfacial layer. When either anionic or cationic ligands bound to a nanoparticle made of gold for example are increased in length, the wavelength of the plasmon resonance will shift to red.
An example of another effect, that has recently been observed by Amendola et al. on small gold nanoparticles, of 10 nm or less, is that dense monolayers that consist of certain specific short chain ligands tend to dampen the surface plasmon resonance effects.
Plasmon resonance can be used to analyze the surfactants of the nanoparticle. This principle is based on the so-called Fröhlich condition which states that the refractive index of the surrounding medium of a nanoparticle can be used to tune or alter the frequency of the surface plasmon resonance. The equation that relates both properties is as follows:
In which is the wavelength at which the plasmon resonance frequency peaks, is the refractive index of the environment, which relates to the dielectric constant of the medium as follows: . Furthermore is the frequency of the plasmon resonance and is the speed of light in vacuum.
The relation between the wavelength and the refractive index of the environment is not strictly linear but for small values of the theoretical predictions align with experimental results.
This relation can thus be used to analyse the environment of the nanoparticle, i.e. the interfacial layer, by measuring the wavelength of the plasmon resonance. | 0 | Colloidal Chemistry |
When one or more salt layers are present during extensional tectonics, a characteristic set of structures is formed. Extensional faults propagate up from the middle part of the crust until they encounter the salt layer. The weakness of the salt prevents the fault from propagating through. However, continuing displacement on the fault offsets the base of the salt and causes bending of the overburden layer. Eventually the stresses caused by this bending will be sufficient to fault the overburden. The types of structures developed depend on the initial salt thickness. In the case of a very thick salt layer there is no direct spatial relationship between the faulting beneath the salt and that in the overburden, such a system is said to be unlinked. For intermediate salt thicknesses, the overburden faults are spatially related to the deeper faults, but offset from them, normally into the footwall; these are known as soft-linked systems. When the salt layer becomes thin enough, the fault that develops in the overburden is closely aligned with that beneath the salt, and forms a continuous fault surface after only a relatively small displacement, forming a hard-linked fault.
In areas of thrust tectonics salt layers act as preferred detachment planes. In the Zagros fold and thrust belt, variations in the thickness and therefore effectiveness of the late Neoproterozoic to Early Cambrian Hormuz salt are thought to have had a fundamental control on the overall topography. | 1 | Solid-state chemistry |
Caliche beds can cause problems for agriculture. First, an impermeable caliche layer prevents water from draining properly, which can keep roots from getting enough oxygen. Salts can also build up in the soil due to the lack of drainage. Both of these situations are detrimental to plant growth. Second, the impermeable nature of caliche beds prevents plant roots from penetrating the bed, which limits the supply of nutrients, water, and space so they cannot develop normally. Third, caliche beds can also cause the surrounding soil to be basic. The basic soil, along with calcium carbonate from the caliche, can prevent plants from getting enough nutrients, especially iron. An iron deficiency makes the youngest leaves turn yellow. Soil saturation above the caliche bed can make the condition worse. Its hardness can also make digging for projects such as canals more difficult. | 1 | Solid-state chemistry |
Turbidity in open water may be caused by growth of phytoplankton. Human activities that disturb land, such as construction, mining and agriculture, can lead to high sediment levels entering water bodies during rain storms due to storm water runoff. Areas prone to high bank erosion rates as well as urbanized areas also contribute large amounts of turbidity to nearby waters, through stormwater pollution from paved surfaces such as roads, bridges, parking lots and airports. Some industries such as quarrying, mining and coal recovery can generate very high levels of turbidity from colloidal rock particles.
In drinking water, the higher the turbidity level, the higher the risk that people may develop gastrointestinal diseases. This is especially problematic for immunocompromised people, because contaminants like viruses or bacteria can become attached to the suspended solids. The suspended solids interfere with water disinfection with chlorine because the particles act as shields for viruses and bacteria. Similarly, suspended solids can protect bacteria from ultraviolet (UV) sterilization of water.
In water bodies such as lakes, rivers and reservoirs, high turbidity levels can reduce the amount of light reaching lower depths, which can inhibit growth of submerged aquatic plants and consequently affect species which are dependent on them, such as fish and shellfish. High turbidity levels can also affect the ability of fish gills to absorb dissolved oxygen. This phenomenon has been regularly observed throughout the Chesapeake Bay in the eastern United States.
For many mangrove areas, high turbidity is needed in order to support certain species, such as to protect juvenile fish from predators. For most mangroves along the eastern coast of Australia, in particular Moreton Bay, turbidity levels as high as 600 Nephelometric Turbidity Units (NTU) are needed for proper ecosystem health. | 0 | Colloidal Chemistry |
Another commonly employed space-holder for titanium foams is urea, which yielded porosities from 20 to 75%. Wen et al. produced foams exhibiting a bimodal pore distribution with porosities ranging from 55 to 75%, Young's moduli between 3–6.4 GPa, and a plateau stress of 10–35 MPa. An inverse relationship between plateau stress and porosity was observed with increased porosity resulting in decreased plateau stress. Tuncer et al. utilized urea in combination with irregularly shaped titanium powders in an effort to increase green strength through increased packing efficiency (of particles). This also eliminated the need for the incorporation of a binder. | 0 | Colloidal Chemistry |
Joseph McLain was born in Weirton, West Virginia on July 11, 1916, the son of Howard and Elizabeth McLain. He spent his childhood in Baltimore, Maryland. Like his older brother, McLain was educated at Washington College. While in college, McLain was a member of Theta Chi, president of the class of 1937, and played basketball, football, lacrosse, and track. He did his doctoral work at Johns Hopkins University in chemistry. During World War II, McLain paused his education to serve as a major in the US Army Chemical Corps doing research on smoke screens and pyrotechnics.
Joseph McLain received his doctorate in 1946 and joined the faculty of Washington College the same year. While he was a professor, McLain was a partner in the Kent Manufacturing Company, which made fireworks, until there was an explosion at the plant in 1954. During the explosion, McLain rescued two women from the plant. After the disaster, McLain and his partners dissolved the company and McLain and worked on safety standards for fireworks with fellow Washington College alumnus and professor John Conkling. The pair wrote recommendations for the safe storage for fireworks that became part of the first US standards. In addition to his pyrotechnic research, McLain was active in environmental work, serving as a trustee of the Chesapeake Bay Foundation and sitting on Maryland Water Pollution Control Commission. In 1973, McLain became the president of Washington College. He is the only alumnus of the school to ever serve as president. McLain took a leave of absence from the college in 1981 and died in Baltimore at Johns Hopkins Hospital the same year. | 1 | Solid-state chemistry |
Metal matrix nanocomposites can also be defined as reinforced metal matrix composites. This type of composites can be classified as continuous and non-continuous reinforced materials. One of the more important nanocomposites is Carbon nanotube metal matrix composites, which is an emerging new material that is being developed to take advantage of the high tensile strength and electrical conductivity of carbon nanotube materials. Critical to the realization of CNT-MMC possessing optimal properties in these areas are the development of synthetic techniques that are (a) economically producible, (b) provide for a homogeneous dispersion of nanotubes in the metallic matrix, and (c) lead to strong interfacial adhesion between the metallic matrix and the carbon nanotubes. In addition to carbon nanotube metal matrix composites, boron nitride reinforced metal matrix composites and carbon nitride metal matrix composites are the new research areas on metal matrix nanocomposites.
A recent study, comparing the mechanical properties (Young's modulus, compressive yield strength, flexural modulus and flexural yield strength) of single- and multi-walled reinforced polymeric (polypropylene fumarate—PPF) nanocomposites to tungsten disulfide nanotubes reinforced PPF nanocomposites suggest that tungsten disulfide nanotubes reinforced PPF nanocomposites possess significantly higher mechanical properties and tungsten disulfide nanotubes are better reinforcing agents than carbon nanotubes. Increases in the mechanical properties can be attributed to a uniform dispersion of inorganic nanotubes in the polymer matrix (compared to carbon nanotubes that exist as micron sized aggregates) and increased crosslinking density of the polymer in the presence of tungsten disulfide nanotubes (increase in crosslinking density leads to an increase in the mechanical properties). These results suggest that inorganic nanomaterials, in general, may be better reinforcing agents compared to carbon nanotubes.
Another kind of nanocomposite is the energetic nanocomposite, generally as a hybrid sol–gel with a silica base, which, when combined with metal oxides and nano-scale aluminum powder, can form superthermite materials. | 1 | Solid-state chemistry |
Rarely encountered, thioxanthates arise by the reaction of CS with thiolate salts. For example, sodium ethylthioxanthate has the formula CHSCSNa. Dithiocarbamates are also related compounds. They arise from the reaction of a secondary amine with CS. For example, sodium diethyldithiocarbamate has the formula (CH)NCSNa. | 1 | Solid-state chemistry |
Chan began her career as an assistant professor of chemistry at Louisiana State University in 2000. In 2002 she was awarded an National Science Foundation CAREER Award and selected as one of the American Chemical Society women making an impact in chemistry. In 2004 Chan was awarded an ExxonMobil Faculty Fellowship Award. She was part of the 2010 American Chemical Society Women Chemists of Colour Summit. She joined the chemistry department at University of Texas at Dallas as a full professor in 2013. In 2022 Chan moved to Baylor University.
At the Baylor University, Chan investigates the physical properties of magnetic materials synthesized in her laboratory, with a focus on quantum materials that contain lanthanide cations. She has developed new techniques to grow single crystals of intermetallic phases. She was the Guest Editor of the American Chemical Society Inorganic Chemistry theme issue on Solid-State Inorganic Chemistry. In 2019 Chan was inducted into the American Association for the Advancement of Science. | 1 | Solid-state chemistry |