ZnO is a relatively soft material with approximate hardness of 4.5 on the Mohs scale. Its elastic constants are smaller than those of relevant III-V semiconductors, such as GaN. The high heat capacity and heat conductivity, low thermal expansion and high melting temperature of ZnO are beneficial for ceramics. The E2 optical phonon in ZnO exhibits an unusually long lifetime of 133 ps at 10 K. Among the tetrahedrally bonded semiconductors, it has been stated that ZnO has the highest piezoelectric tensor, or at least one comparable to that of GaN and AlN. This property makes it a technologically important material for many piezoelectrical applications, which require a large electromechanical coupling.
Mechanical properties
Zinc oxide
Zinc oxide | Mechanical properties
It is a relatively soft material with approximate hardness of 4.5 on the Mohs scale. Also its elastic constants are smaller than those of relevant III-V semiconductors. ZnO is a relatively soft material with approximate hardness of 4.5 on the Mohs scale. It is beneficial for ceramics, piezoelectrical applications It is a relatively soft material, its elastic constants are smaller than those of relevant III-V semiconductors, such as GaN, the high heat capacity and heat conductivity, low thermal expansion and high melting temperature of ZnO are beneficial for ceramics
describe in general terms the structure of ionic solids such as nacl
user
Ions typically pack into extremely regular crystalline structures, in an arrangement that minimizes the lattice energy.
assistant
what can you tell me about their boiling point?
user
Boiling points exhibit similar trends to melting points in terms of the size of ions and strength of other interactions. When vapourized, the ions are still not freed of one another.
assistant
can you name any compounds?
user
Ammonium acetate, zinc oxide, aluminum hydroxide,  aluminium oxide and lead(II) oxide.
assistant
what are the uses of the aforesaid initial one?
user
It is also used as a diuretic.
assistant
what can you tell me about its production?
user
Ammonium acetate is produced by the neutralization of acetic acid with ammonium carbonate or by saturating glacial acetic acid with ammonia.
assistant
what are the applications of the second one?
user
It is used for making plastics, ceramics, glass, cement, rubber, lubricants, paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc.
assistant
how is it used in the ceramic industry?
user
It is used in ceramic glaze and frit compositions.
assistant
can you name the medicines in which they are used?
user
Calamine lotion, zinc oxide eugenol and others.
assistant
what are its mechanical properties?
user
Zinc oxide as a mixture with about 0.5% iron(III) oxide (FeO) is called calamine and is used in calamine lotion. Two minerals, zincite and hemimorphite, have been historically called calamine. When mixed with eugenol, a ligand, zinc oxide eugenol is formed, which has applications as a restorative and prosthodontic in dentistry. Reflecting the basic properties of ZnO, fine particles of the oxide have deodorizing and antibacterial properties and for that reason are added into materials including cotton fabric, rubber, oral care products, and food packaging. Enhanced antibacterial action of fine particles compared to bulk material is not exclusive to ZnO and is observed for other materials, such as silver.
Zinc oxide | Medicine
This property results from the increased surface area of the fine particles. Zinc oxide is widely used to treat a variety of skin conditions, including dermatitis, itching due to eczema, diaper rash and acne.
Zinc oxide | Medicine
Therefore ZnO has been in forms of thin film one of the most studied resonator material for thin-film bulk acoustic resonators.
Zinc oxide | Mechanical properties
Zinc is a soft metal (MH 2.5) with poor mechanical properties. It has a crystalline structure (BCN 6+6) that is slightly distorted from the ideal. Many zinc compounds are markedly covalent in character. The oxide and hydroxide of zinc in its preferred oxidation state of +2, namely ZnO and Zn(OH), are amphoteric; it forms anionic zincates in strongly basic solutions. Zinc forms Zintl phases such as LiZn, NaZn and BaZn. Highly purified zinc, at room temperature, is ductile. It reacts with moist air to form a thin layer of carbonate that prevents further corrosion. Cadmium is a soft, ductile metal (MH 2.0) that undergoes substantial deformation, under load, at room temperature.
Post-transition metal | Group 12
A bar of zinc generates a characteristic sound when bent, similar to tin cry.
Zinc | Physical properties
Controllable n-type doping is easily achieved by substituting Zn with group-III elements such as Al, Ga, In or by substituting oxygen with group-VII elements chlorine or iodine. Reliable p-type doping of ZnO remains difficult. This problem originates from low solubility of p-type dopants and their compensation by abundant n-type impurities. This problem is observed with GaN and ZnSe. Measurement of p-type in "intrinsically" n-type material is complicated by the inhomogeneity of samples.
Zinc oxide | Electrical properties
The piezoelectricity in textile fibers coated in ZnO have been shown capable of fabricating "self-powered nanosystems" with everyday mechanical stress from wind or body movements. In 2008 the "Center for Nanostructure Characterization" at the Georgia Institute of Technology reported producing an electricity generating device (called flexible charge pump generator) delivering alternating current by stretching and releasing zinc oxide nanowires. This mini-generator creates an oscillating voltage up to 45 millivolts, converting close to seven percent of the applied mechanical energy into electricity. Researchers used wires with lengths of 0.2–0.3 mm and diameters of three to five micrometers, but the device could be scaled down to smaller size.
Zinc oxide | Piezoelectricity
Calamine lotion, used to treat mild itchiness, is chiefly composed of a combination of zinc oxide, acting as astringent, and about 0.5% iron(III) oxide, the product's active ingredient, acting as antipruritic. The red color of iron(III) oxide is also mainly responsible for the lotion's widely familiar pink color.
Iron(III) oxide | Medicine
Pure ZnO is a white powder, but in nature it occurs as the rare mineral zincite, which usually contains manganese and other impurities that confer a yellow to red color. Crystalline zinc oxide is thermochromic, changing from white to yellow when heated in air and reverting to white on cooling. This color change is caused by a small loss of oxygen to the environment at high temperatures to form the non-stoichiometric ZnO, where at 800 °C, x = 0.00007. Zinc oxide is an amphoteric oxide. It is nearly insoluble in water, but it will dissolve in most acids, such as hydrochloric acid: Solid zinc oxide will also dissolve in alkalis to give soluble zincates:
Zinc oxide | Chemical properties
Zinc oxide crystallizes in two main forms, hexagonal wurtzite and cubic zincblende. The wurtzite structure is most stable at ambient conditions and thus most common. The zincblende form can be stabilized by growing ZnO on substrates with cubic lattice structure. In both cases, the zinc and oxide centers are tetrahedral, the most characteristic geometry for Zn(II). ZnO converts to the rocksalt motif at relatively high pressures about 10 GPa. The many remarkable medical properties of creams containing ZnO can be explained by its elastic softness, which is characteristic of tetrahedral coordinated binary compounds close to the transition to octahedral structures.
Zinc oxide | Structure
A small amount of industrial production involves wet chemical processes, which start with aqueous solutions of zinc salts, from which zinc carbonate or zinc hydroxide is precipitated. The solid precipitate is then calcined at temperatures around 800 °C.
Zinc oxide | Wet chemical process
In the indirect or French process, metallic zinc is melted in a graphite crucible and vaporized at temperatures above 907 °C (typically around 1000 °C). Zinc vapor reacts with the oxygen in the air to give ZnO, accompanied by a drop in its temperature and bright luminescence. Zinc oxide particles are transported into a cooling duct and collected in a bag house. This indirect method was popularized by LeClaire (France) in 1844 and therefore is commonly known as the French process. Its product normally consists of agglomerated zinc oxide particles with an average size of 0.1 to a few micrometers.
Zinc oxide | Indirect process
Zinc oxide is used as a weak antiseptic (and sunscreen), and in paints as a white pigment and mold-growth inhibitor. Zinc chloride is a common ingredient in mouthwashes and deodorants, and zinc pyrithione is an ingredient in antidandruff shampoos. Galvanized (zinc-coated) fittings on roofs impede the growth of algae. Copper- and zinc-treated shingles are available. Zinc iodide and zinc sulfate are used as topical antiseptics.
Oligodynamic effect | Zinc
Zinc is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish. It is somewhat less dense than iron and has a hexagonal crystal structure, with a distorted form of hexagonal close packing, in which each atom has six nearest neighbors (at 265.9 pm) in its own plane and six others at a greater distance of 290.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. Above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a fair conductor of electricity.
Zinc | Physical properties
This property accounts for the preferential formation of wurtzite rather than zinc blende structure, as well as the strong piezoelectricity of ZnO. Because of the polar Zn-O bonds, zinc and oxygen planes are electrically charged. To maintain electrical neutrality, those planes reconstruct at atomic level in most relative materials, but not in ZnO – its surfaces are atomically flat, stable and exhibit no reconstruction. However, studies using wurtzoid structures explained the origin of surface flatness and the absence of reconstruction at ZnO wurtzite surfaces in addition to the origin of charges on ZnO planes.
Zinc oxide | Structure
ZnO is a relatively soft material with approximate hardness of 4.5 on the Mohs scale. Its elastic constants are smaller than those of relevant III-V semiconductors, such as GaN. The high heat capacity and heat conductivity, low thermal expansion and high melting temperature of ZnO are beneficial for ceramics. The E2 optical phonon in ZnO exhibits an unusually long lifetime of 133 ps at 10 K. Among the tetrahedrally bonded semiconductors, it has been stated that ZnO has the highest piezoelectric tensor, or at least one comparable to that of GaN and AlN. This property makes it a technologically important material for many piezoelectrical applications, which require a large electromechanical coupling.
Zinc oxide | Mechanical properties
Zinc compounds were probably used by early humans, in processed and unprocessed forms, as a paint or medicinal ointment, but their composition is uncertain. The use of "pushpanjan", probably zinc oxide, as a salve for eyes and open wounds, is mentioned in the Indian medical text the Charaka Samhita, thought to date from 500 BC or before. Zinc oxide ointment is also mentioned by the Greek physician Dioscorides (1st century AD). Galen suggested treating ulcerating cancers with zinc oxide, as did Avicenna in his "The Canon of Medicine". Zinc oxide is no longer used for treating skin cancer, though it is still used as an ingredient in products such as baby powder and creams against diaper rashes, calamine cream, anti-dandruff shampoos, and antiseptic ointments.
Zinc oxide | History
Selection of luting agent to be used for a given restoration should be based on a basic knowledge of the materials available, the type of restoration to be placed, the requirements of the patient and the expertise and experience of the clinician.
Luting agent | Zinc oxide eugenol
ZnO has a relatively large direct band gap of ~3.3 eV at room temperature. Advantages associated with a large band gap include higher breakdown voltages, ability to sustain large electric fields, lower electronic noise, and high-temperature and high-power operation. The band gap of ZnO can further be tuned to ~3–4 eV by its alloying with magnesium oxide or cadmium oxide. Most ZnO has "n"-type character, even in the absence of intentional doping. Nonstoichiometry is typically the origin of n-type character, but the subject remains controversial. An alternative explanation has been proposed, based on theoretical calculations, that unintentional substitutional hydrogen impurities are responsible.
Zinc oxide | Electrical properties
Eugenol (4-allyl-2-methoxy phenol) is the principal constituent of clove oil, and when mixed with zinc oxide leads to a chelating reaction. All eugenol reacts to zinc oxide eugenol, meaning none is available to diffuse once setting is complete. Supposedly its therapeutic effects are supported by dentinal tubule fluid promoting the release of eugenol and its penetration towards the pulp. Zinc oxide-eugenol is often found as a two-paste material when used for temporary cementation. The paste containing zinc oxide often includes mineral or vegetable oils, and the eugenol has fillers incorporated into it to form the other paste. A well-known product utilised in the two-paste form is Temp-Bond™.
Luting agent | Zinc oxide-eugenol
Zinc oxide is an inorganic compound with the formula . ZnO is a white powder that is insoluble in water. It is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically. ZnO is a wide-band gap semiconductor of the II-VI semiconductor group. The native doping of the semiconductor due to oxygen vacancies or zinc interstitials is n-type. Other favorable properties include good transparency, high electron mobility, wide band gap, and strong room-temperature luminescence.
Zinc oxide | Introduction
Typical for an inorganic polymer, Zn(CN) is insoluble in most solvents. The solid dissolves in, or more precisely, is degraded by, aqueous solutions of basic ligands such as hydroxide, ammonia, and additional cyanide to give anionic complexes.
Zinc cyanide | Chemical properties
Zinc oxide-eugenol may present as a powder (zinc oxide) that requires mixing with a liquid (eugenol). The zinc oxide powder may contain up to 8% of other zinc salts (acetate, propionate, or succinate) as accelerators. The liquid containing eugenol has up to 2% of acetic acid added as an accelerator. A well-known product utilised in this powder-liquid form is Kalzinol™.
Luting agent | Zinc oxide-eugenol
One major use is as an absorbent in surgical dressings. It is also used to find zinc salts by mixing sodium hydroxide with the suspect salt.
Zinc hydroxide | Applications
The chemical composition of ZOE is typically: ZOE impression pastes are dispensed as two separate pastes. One tube contains zinc oxide and vegetable or mineral oil; the other contains eugenol and rosin. The vegetable or mineral oil acts as a plasticizer and aids in offsetting the action of the eugenol as an irritant. Oil of cloves, which contains 70% to 85% eugenol, is sometimes used in preference to eugenol because it produces less burning sensation for patients when it contacts the soft tissues. The addition of rosin to the paste in the second tube facilitates the speed of the reaction and yields a smoother, more homogenous product.
Zinc oxide eugenol | Composition
This property also leads to its use in the manufacture of magnesia cements for dental fillings and certain mouthwashes as an active ingredient.
Zinc chloride | As a metallurgical flux
This parallel results from the fact that Zn and Mg have almost identical ionic radii as well as filled electron shells. That two elements so different in atomic number have the same radius is a consequence of the d-block contraction. Whilst calcium is somewhat larger than magnesium, there is a steady decrease in size as atomic number increases from calcium to zinc. Zn(II) complexes are kinetically labile, i.e. the Zn-ligand bonds exchange with other ligands rapidly. For this reason, zinc ions are at the catalytic centers in many enzymes.
Compounds of zinc | General characteristics
By weight, most of the world's zinc oxide is manufactured via French process.
Zinc oxide | Indirect process
A well-known product used in this instance is Temp-Bond NE™.
Luting agent | Zinc oxide non-eugenol
Micronized and nano-scale zinc oxide and titanium dioxide provide strong protection against UVA and UVB ultraviolet radiation, and are used in suntan lotion, and also in UV-blocking sunglasses for use in space and for protection when welding, following research by scientists at Jet Propulsion Laboratory (JPL).
Zinc oxide | UV absorber
Binary compounds of zinc are known for most of the metalloids and all the nonmetals except the noble gases. The oxide ZnO is a white powder that is nearly insoluble in neutral aqueous solutions, but is amphoteric, dissolving in both strong basic and acidic solutions. The other chalcogenides (ZnS, ZnSe, and ZnTe) have varied applications in electronics and optics. Pnictogenides (, , and ), the peroxide (), the hydride (), and the carbide () are also known. Of the four halides, has the most ionic character, while the others (, , and ) have relatively low melting points and are considered to have more covalent character.
Zinc | Zinc(II) compounds
Zinc oxide eugenol (ZOE) is a material created by the combination of zinc oxide and eugenol contained in oil of cloves. An acid-base reaction takes place with the formation of zinc eugenolate chelate. The reaction is catalysed by water and is accelerated by the presence of metal salts. ZOE can be used as a dental filling material or dental cement in dentistry. It is often used in dentistry when the decay is very deep or very close to the nerve or pulp chamber. Because the tissue inside the tooth, i.e. the pulp, reacts badly to the drilling stimulus (heat and vibration), it frequently becomes severely inflamed and precipitates a condition called acute or chronic pulpitis.
Zinc oxide eugenol | Introduction
The applications of zinc oxide powder are numerous, and the principal ones are summarized below. Most applications exploit the reactivity of the oxide as a precursor to other zinc compounds. For material science applications, zinc oxide has high refractive index, high thermal conductivity, binding, antibacterial and UV-protection properties. Consequently, it is added into materials and products including plastics, ceramics, glass, cement, rubber, lubricants, paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc.
Zinc oxide | Applications
Zinc oxide, ZnO, is the most important manufactured compound of zinc, with a wide variety of uses. It crystallizes with the Wurtzite structure. It is amphoteric, dissolving in acids to give the aqueous Zn ion and in alkali to give the zincate (a.k.a. tetrahydroxozincate) ion, [Zn(OH)]. Zinc hydroxide, Zn(OH) is also amphoteric. Zinc sulfide, ZnS, crystallizes in two closely related structures, the zincblende crystal structure and the Wurtzite crystal structure, which are common structures of compounds with the formula MA. Both Zn and S are tetrahedrally coordinated by the other ion. A useful property of ZnS is its phosphorescence. The other chalcogenides, ZnSe and ZnTe, have applications in electronics and optics.
Compounds of zinc | Binary compounds
This condition usually leads to severe chronic tooth sensitivity or actual toothache and can then only be treated with the removal of the nerve (pulp) called root canal therapy. For persons with a dry socket as a complication of tooth extraction, packing the dry socket with a eugenol-zinc oxide paste on iodoform gauze is effective for reducing acute pain. The placement of a ZOE "temporary" for a few to several days prior to the placement of the final filling can help to sedate the pulp. It is classified as an intermediate restorative material and has anaesthetic and antibacterial properties. It is sometimes used in the management of dental caries as a "temporary filling".
Zinc oxide eugenol | Introduction
Zinc has an electron configuration of [Ar]3d4s and is a member of the group 12 of the periodic table. It is a moderately reactive metal and strong reducing agent. The surface of the pure metal tarnishes quickly, eventually forming a protective passivating layer of the basic zinc carbonate, , by reaction with atmospheric carbon dioxide. Zinc burns in air with a bright bluish-green flame, giving off fumes of zinc oxide. Zinc reacts readily with acids, alkalis and other non-metals. Extremely pure zinc reacts only slowly at room temperature with acids. Strong acids, such as hydrochloric or sulfuric acid, can remove the passivating layer and subsequent reaction with water releases hydrogen gas.
Zinc | Reactivity
Table 1: Summary of mechanical properties of cortical bone and biomaterial
Mechanical properties of biomaterials | Fatigue
Exceptions occur when the anion can form a complex, such as in the case of zinc sulfate, where the complex [Zn(HO)(SO] may be formed, (log K = ca. 2.5).
Compounds of zinc | Salts
A D Wilson and J W Nicholson, Acid-Base Cements, 1993, , Chapter 9
Zinc oxide eugenol | References
It also contains a tRNA-binding cavity that has been shown by X-ray crystallography. A zinc knuckle motif is able to bind one Zn cation. It is related to some elongation factors like EF-Tu.
EIF2 | Structure
ZOE cements were introduced in the 1890s. Zinc oxide eugenol is also used as an impression material during construction of complete dentures and is used in the mucostatic technique of taking impressions, usually in a special tray, (acrylic) produced after primary alginate impressions. However, ZOE is not usually used if the patient has large undercuts or tuberosities, whereby silicone impression materials would be better suited. Zinc oxide eugenol is also used as an antimicrobial additive in paint.
Zinc oxide eugenol | Introduction
Zinc oxide (ZnO) reacts with both acids and with bases: This reactivity can be used to separate different cations, such as zinc(II), which dissolves in base, from manganese(II), which does not dissolve in base. Lead oxide (PbO): Aluminium oxide (AlO)
Amphoterism | Amphoteric oxides
The hydrogel, which contains keratan sulfate in 97% water, has a conductivity of about 1.8 mS/cm, the highest known amongst biological materials.
Ampullae of Lorenzini | Material properties
The special feature of • zM from Aleees a high capacitance and low impedance obtained by the stable control of the ferrites and crystal growth. This improved control is realized by applying strong mechanical stirring forces to the precursors in high oversaturation states, which induces crystallization of the metal oxides and LFP. In patent lawsuits in the US in 2005 and 2006, the University of Texas at Austin|University of Texas-Austin and Hydro-Québec claimed that as the cathode infringed their patents, and . The patent claims involved a unique crystal structure and a chemical formula of the battery cathode material.
Lithium iron phosphate | Intellectual property
There are numerous methods to characterize the material properties of a gel. These are briefly summarized below.
Organogels | Mechanical properties characterization
The oldest known pills were made of the zinc carbonates hydrozincite and smithsonite. The pills were used for sore eyes and were found aboard the Roman ship Relitto del Pozzino, wrecked in 140 BC.
Zinc | Ancient use
According to ANSI/ADA Specification no:30 (ISO 3107) and depending on intended use and individual formulation designed for each specific purpose:
Zinc oxide eugenol | Types
Those properties are valuable in emerging applications for: transparent electrodes in liquid crystal displays, energy-saving or heat-protecting windows, and electronics as thin-film transistors and light-emitting diodes.
Zinc oxide | Introduction
Black oxide for zinc is also known by the trade name "Ebonol Z". Another product is Ultra-Blak 460, which blackens zinc-plated and galvanized surfaces without using any chrome and zinc die-casts.
Black oxide | Zinc
The monoaquo complex Zn(acac)HO (m.p. 138–140 °C) is pentacoordinate, adopting a square pyramidal structure. The complex is of some use in organic synthesis. Dehydration of this species gives the hygroscopic anhydrous derivative (m.p. 127 °C). This more volatile derivative has been used as a precursor to films of ZnO.
Metal acetylacetonates | Zinc triad
For a metal, zinc has relatively low melting (419.5 °C) and boiling points (907 °C). The melting point is the lowest of all the d-block metals aside from mercury and cadmium; for this, among other reasons, zinc, cadmium, and mercury are often not considered to be transition metals like the rest of the d-block metals. Many alloys contain zinc, including brass. Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium. Although neither zinc nor zirconium is ferromagnetic, their alloy exhibits ferromagnetism below 35 K.
Zinc | Physical properties
In its compounds, Zn ions have an electronic configuration [Ar] 3d. As such, its complexes tend to be symmetrical, ZnO and zinc sulfide, ZnS, (zincblende) in which the oxide and sulfide ions are tetrahedrally bound to four zinc ions. Many complexes, such as ZnCl, are tetrahedral. Tetrahedrally coordinated zinc is found in metallo-enzymes such as carbonic anhydrase. Six-coordinate octahedral complexes are also common, such as the ion [Zn(HO)], which is present when a zinc salts are dissolved in water. Five- and seven-coordination numbers can be imposed by special organic ligands. Many zinc(II) salts are isomorphous (have the same type of crystal structure) with the corresponding salts of magnesium(II).
Compounds of zinc | General characteristics
Mechanical properties of GaNNTs are influenced by the rolling of the nanotubes, though it is unclear if the size of the nanotubes plays a part as well. The Young's modulus was computed to be 793 GPa for a (5,5) armchair nanotube, while that for a (9,0) zig-zag nanotube was calculated to be 721 GPa. For the (5,5) armchair and (9,0) nanotubes, other calculated values include the maximum tensile strength was 4.25 and 3.43 eV/Angstrom, the critical strain was 14.6% and 13.3%, and the Poisson ratio was 0.263 and 0.221 respectively. It is assumed that the properties for any (n, m) nanotube in between would have a property somewhere in those ranges.
Gallium nitride nanotube | Mechanical
Zinc aspartate is a white crystalline powder. It is soluble in dilute hydrochloric acid and insoluble in water.
Zinc L-aspartate | Chemical properties
:Zane Grey • :Zinc oxide eugenol •
Index of oral health and dental articles | Z
In fact the low-molecular weight compounds will ignite spontaneously on contact with air and are immediately destroyed by reaction with water molecules. The use of zinc alkyls has been largely superseded by the use of the more easily handled Grignard reagents. This demonstrates yet another connection between the chemistries of zinc and magnesium. Zinc cyanide, , is used as a catalyst in some organic reactions. Organometallic compounds of zinc(I) contain M—M bonds. Decamethyldizincocene is now known.
Compounds of zinc | Organometallic compounds
In form of a thin film ZnO has been demonstrated in miniaturised high frequency thin film resonators, sensors and filters.
Zinc oxide | Piezoelectricity
ReO is unusual for an oxide because it exhibits very low resistivity. It behaves like a metal in that its resistivity decreases as its temperature decreases. At 300 K, its resistivity is 100.0 nΩ·m, whereas at 100 K, this decreases to 6.0 nΩ·m, 17 times less than at 300 K.
Rhenium trioxide | Physical properties
Zinc oxide nanoparticles are nanoparticles of zinc oxide (ZnO) that have diameters less than 100 nanometers. They have a large surface area relative to their size and high catalytic activity. The exact physical and chemical properties of zinc oxide nanoparticles depend on the different ways they are synthesized. Some possible ways to produce ZnO nano-particles are laser ablation, hydrothermal methods, electrochemical depositions, sol–gel method, chemical vapor deposition, thermal decomposition, combustion methods, ultrasound, microwave-assisted combustion method, two-step mechanochemical–thermal synthesis, anodization, co-precipitation, electrophoretic deposition, and precipitation processes using solution concentration, pH, and washing medium. ZnO is a wide-bandgap semiconductor with an energy gap of 3.37 eV at room temperature.
Zinc oxide nanoparticle | Introduction
Zinc -carnosine (beta"-alanyl--histidinato zinc) (N"-(3-aminopropionyl)--histidinato zinc), often simply called zinc carnosine, and also known as polaprezinc, is a mucosal protective chelate compound of zinc and -carnosine invented by Hamari Chemicals, Ltd. It is a quadridentate 1:1 complex of a polymeric nature. Although it contains 23% zinc and 77% -carnosine by mass, zinc carnosine is a molecule and not a mixture of zinc and -carnosine. It is an approved drug requiring a medical prescription in Japan and South Korea where it is clinically used to treat gastric ulcers. Clinical studies have also shown its efficacy for oral mucositis, esophagitis, proctitis, taste alteration and dermatitis during and after radiotherapy.
Zinc L-carnosine | Introduction
Zinc is a strong reducing agent with a standard redox potential of −0.76 V. Pure zinc tarnishes rapidly in air, rapidly forming a passive layer. The composition of this layer can be complex, but one constituent is probably basic zinc carbonate, Zn(OH)CO. The reaction of zinc with water is slowed by this passive layer. When this layer is corroded by acids such as hydrochloric acid and sulfuric acid, the reaction proceeds with the evolution of hydrogen gas. Zinc reacts with alkalis as with acids. With oxidants such as chalcogens and halogens, Zn forms binary compounds such as ZnS and ZnCl.
Compounds of zinc | Reactivity of metallic zinc
Depending on the heat treatment modes, the microstructure characteristic of ADI is obtained; it possesses the following specific feature: under certain conditions molybdenum evolutions are formed.
Ductile iron with special properties | Microstructure
The mechanical properties of 6063 depend greatly on the temper, or heat treatment, of the material.
6063 aluminium alloy | Mechanical properties
This phenomenon can be explained by the fact that the elastic modulus decreases with increasing interatomic separation: as temperature increases, the atomic vibrations also increase, resulting in a larger equilibrium interatomic separation. The mechanical strength is also rarely studied in Heusler compounds. One study has shown that, in off-stoichiometric NiMnIn, the material reaches a peak strength of 475 MPa at 773 K, which drastically reduces to below 200 MPa at 973 K. In another study, a polycrystalline Heusler alloy composed of the Ni-Mn-Sn ternary composition space was found to possess a peak compressive strength of about 2000 MPa with plastic deformation up to 5%.
Heusler compound | Mechanical Properties
Activators consist of various metal salts, fatty acids, as well as nitrogen-containing bases, the most important these being zinc oxide. Zinc actives many accelerants by coordination, for example causing thiuram to convert into ziram. Zinc also coordinates to the sulfur-chains of sulfurating agents, changing the most likely bond to break during cross-link formation. Ultimately, activators promote the efficient use of sulfur to give a high density of cross-links. Due to the low solubility of ZnO it is often combined with fatty acids such as stearic acid to form more soluble metallic soap, "i.e.", zinc stearate.
Sulfur vulcanization | Activators
Its antifungal effect is thought to derive from its ability to disrupt membrane transport by blocking the proton pump that energizes the transport mechanism.
Zinc pyrithione | Mechanism of action
Hydrolysis explains why basic salts such as basic zinc acetate and basic zinc carbonate, Zn(OH)(CO)•HO are easy to obtain. The reason for the hydrolysis is the high electrical charge density on the zinc ion, which pulls electrons away from an OH bond of a coordinated water molecule and releases a hydrogen ion. The polarizing effect of Zn is part of the reason why zinc is found in enzymes such as carbonic anhydrase. No fluoro complexes are known, but complexes with the other halides and with pseodohalides, [ZnX] and [ZnX] can be prepared. The case of the thiocyanate complex illustrates the class A character of the zinc ion as it is the N-bonded isomer, [Zn(NCS)]in contrast to [Cd(SCN)] which is S-bonded.
Compounds of zinc | Complexes
Its mechanism of action is oxygen radical scavenging, anti-oxidation, and acceleration of gastrointestinal wound healing. It exhibits ROS-quenching activities. It can remain in the stomach without rapid dissociation and adhere specifically to ulcerous lesions, after which -carnosine and zinc are released to heal the ulcer. It has been shown to stimulate mucus production and to maintain the integrity of the gastric mucosal barrier. It maintains homeostasis of the gastric mucosa by prostaglandin-independent cytoprotective effects due to anti-oxidative membrane stabilizing actions, and it promotes the repair of damaged tissues by wound healing action. It exerts cytoprotection through regulating heat shock proteins and chemokines, and by stabilizing mast cells.
Zinc L-carnosine | Gastrointestinal
The material can be used in inner ear ossicles, ocular prostheses, electrical insulation for pacemakers, catheter orifices and in numerous prototypes of implantable systems such as cardiac pumps. Aluminosilicates are commonly used in dental prostheses, pure or in ceramic-polymer composites. The ceramic-polymer composites are a potential way to filling of cavities replacing amalgams suspected to have toxic effects. The aluminosilicates also have a glassy structure. Contrary to artificial teeth in resin, the colour of tooth ceramic remains stable Zirconia doped with yttrium oxide has been proposed as a substitute for alumina for osteoarticular prostheses. The main advantages are a greater failure strength, and a good resistance to fatigue.
Bioceramic | Mechanical properties and composition
The table below is a summary of the key physical properties of the group 12 elements. The data for copernicium is based on relativistic density-functional theory simulations. Zinc is somewhat less dense than iron and has a hexagonal crystal structure. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C. Above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a fair conductor of electricity. For a metal, zinc has relatively low melting (419.5 °C, 787.1 F) and boiling points (907 °C). Cadmium is similar in many respects to zinc but forms complex compounds.
Group 12 element | Physical and atomic properties
The compound is a prototypical zinc dithiocarbamate, a broad class of coordination complexes with the formulae Zn(RNCS), where R can be varied. Such compounds are produced by treating zinc and dithiocarbamate (RNCS), as illustrated with dimethyldithiocarbamate: Annually, approximately 1.9 million pounds of the active ziram ingredient are used. Ziram is often sold in powder or granule form. Zinc bis(diethyldithiocarbamate) complexes degrade thermally to give zinc sulfide.
Zinc bis(dimethyldithiocarbamate) | Chemistry
Zinc chloride has the ability to react with metal oxides (MO) to give derivatives of the formula MZnOCl. This reaction is relevant to the utility of ZnCl solution as a flux for soldering — it dissolves oxide coatings, exposing the clean metal surface. Fluxes with ZnCl as an active ingredient are sometimes called "tinner's fluid". Typically this flux was prepared by dissolving zinc foil in dilute hydrochloric acid until the liquid ceased to evolve hydrogen; for this reason, such flux was once known as "killed spirits". Because of its corrosive nature, this flux is not suitable for situations where any residue cannot be cleaned away, such as electronic work.
Zinc chloride | As a metallurgical flux
The sheets are held together by hydrogen bonding from OH groups of one sheet to Cl anions of adjacent sheets, and to interstitial HO groups. The [Zn(OH)] octahedra have four long equatorial bonds (at 2.157 Å) and two short apical bonds (at 2.066 Å). This apical shortening is a result of the bond-valence requirements of the coordinating OH groups and the connectivity of polyhedra in the structure. The equatorial OH groups [O(1)H] are coordinated by two Zn(1) cations and one Zn(2) cation, whereas the apical OH groups [O(2)H] are coordinated by three Zn(1) cations. As Zn(1) is six-coordinated and Zn(2) is four-coordinated, the local bond-valence requirements require the Zn(1)-O(1) bonds to be considerably longer than the Zn(1)-O(2) bonds.
Zinc chloride hydroxide monohydrate | Structure
Once this is done, we can measure the corresponding pressure applied during compression. The shorter the distance between the punches, thickness, the greater the pressure applied during compression, and sometimes the harder the tablet. Tablets need to be hard enough that they don't break up in the bottle, yet friable enough that they disintegrate in the gastric tract. Tablets need to be strong enough to resist the stresses of packaging, shipping and handling by the pharmacist and patient. The mechanical strength of tablets is assessed using a combination of (i) simple failure and erosion tests, and (ii) more sophisticated engineering tests.
Tablet (pharmacy) | Tablet properties
With this change, three properties worsened: "Water absorption" changed from 10% to 15%, "Resistance to water hydrostatic head" changed from 750mm to 600mm and "Oil repellency" changed from 5-6 to 0.
Ventile | Technical detail
Benzotriazole is one such species used to protect copper. For lubrication, zinc dithiophosphates are common - they deposit sulfide on surfaces. The suitability of any given chemical for a task in hand depends on many factors, including their operating temperature.
Corrosion inhibitor | Types
Compounds of the type Zn(SCNR) are dimeric, i.e. their proper formula is [Zn(SCNR)]. Each Zn center is in a distorted pentacoordinate site, with four Zn-S bonds of 2.3 Å length and one Zn---S interaction >2.8 Å in length. Mono-zinc derivatives are obtained by adding strong ligands (L) such as amines, which give adducts Zn(SCNR)L.
Zinc bis(dimethyldithiocarbamate) | Structure
Evans:
Organozinc compound | Zinc acetylides
Because the cathode does not change properties during discharge, terminal voltage is quite stable until the cell approaches exhaustion. Power capacity is a function of several variables: cathode area, air availability, porosity, and the catalytic value of the cathode surface. Oxygen entry into the cell must be balanced against electrolyte water loss; cathode membranes are coated with (hydrophobic) Teflon material to limit water loss. Low humidity increases water loss; if enough water is lost the cell fails. Button cells have a limited current drain; for example an IEC PR44 cell has a capacity of 600 milliamp-hours (mAh) but a maximum current of only 22 milliamps (mA).
Zinc–air battery | Discharge properties
As of 2011 there were no known human illnesses resulting from any engineered nanoparticles.
Zinc oxide nanoparticle | Introduction
Typically, as the elasticity of the biomaterial increases, the ultimate tensile strength will decrease and vice versa. One application where a high-strength material is undesired is in neural probes; if a high-strength material is used in these applications the tissue will always fail before the device does (under applied load) because the Young's Modulus of the dura mater and cerebral tissue is on the order of 500 Pa. When this happens, irreversible damage to the brain can occur, thus it is imperative that the biomaterial has an elastic modulus less than or equal to brain tissue and a low tensile strength if an applied load is expected.
Biomaterial | Mechanical Properties
Other applications are in electrical batteries, small non-structural castings, and alloys such as brass. A variety of zinc compounds are commonly used, such as zinc carbonate and zinc gluconate (as dietary supplements), zinc chloride (in deodorants), zinc pyrithione (anti-dandruff shampoos), zinc sulfide (in luminescent paints), and dimethylzinc or diethylzinc in the organic laboratory.
Zinc | Introduction
The following is a list of both physical and chemical properties:
Indolizine | Properties
Zinc hydroxide Zn(OH) is an inorganic chemical compound. It also occurs naturally as 3 rare minerals: wülfingite (orthorhombic), ashoverite and sweetite (both tetragonal). Like the hydroxides of other metals, such as lead, aluminium, beryllium, tin and chromium, Zinc hydroxide (and Zinc oxide), is amphoteric. Thus it will dissolve readily in a dilute solution of a strong acid, such as HCl, and also in a solution of an alkali such as sodium hydroxide.
Zinc hydroxide | Introduction
This produces zinc sulfide, together with large amounts of hot gas, heat, and light.
Zinc | Other industrial uses
In a sealed glass tube with inert atmosphere, this yields zinc nitride, ZnN.
Zinc azide | Properties
Zinc molybdate is an inorganic compound with the formula ZnMoO. It is used as a white pigment, which that is also a corrosion inhibitor. A related pigment is sodium zinc molybdate, NaZn(MoO). The material has also been investigated as an electrode material. In terms of its structure, the Mo(VI) centers are tetrahedral and the Zn(II) centers are octahedral.
Zinc molybdate | Introduction
In vapor deposition processes, zinc and oxygen are transported in gaseous form and react with each other, creating ZnO nanostructures. Other vapor molecules or solid and liquid catalysts can also be involved in the reaction, which affect the properties of the resultant nanostructure . To directly create ZnO nanostructures, one can decompose zinc oxide at high temperatures where it splits into zinc and oxygen ions and when cooled it forms various nanostructures, including complex structures such as nanobelts and nanorings. Alternatively, zinc powder can be transported through oxygen vapor which react to form nanostructures . Other vapours such as nitrous oxide or carbon oxides can be used by themselves or in combination.
ZnO nanostructures | Chemical vapor deposition (CVD)
In its monomeric form, zinc pyrithione has two of the anions chelated to a zinc centre with a tetrahedral geometry. In the solid state, it forms a dimer in which each zinc centre adopts a trigonal bipyramidal geometry with two of the anions acting as bridging ligands coordinated through the oxygen atoms in the axial positions. In solution, the dimers dissociate via scission of zinc-oxygen bonds to each bridging ligand. Further dissociation of the monomer into its constituents can occur and is undesirable as the complex is more potent in medical applications; for this reason, zinc carbonate can be added to formulations as it inhibits the monomer dissociation.
Pyrithione | Applications
The zinc dissolves in the hydroxide solution to form zincate, consuming hydroxide in the process. half of the hydroxides are replenished by the hydration and reduction of the copper oxide.
Edison–Lalande cell | Chemistry
The silicon content limits the solubility of zinc in copper in the α-phase. In the given alloy the maximum amount of silicon at a very high zinc content is added. The consequence is that the α-phase crystallized silicon supersaturated when it comes to high cooling rates of the alloy. As a result the α-solid solution does not disintegrate, which leads to the described high mechanical properties.
Silicon tombac | Metallurgical aspects
ZnBr · 2HO is prepared by treating zinc oxide or zinc metal with hydrobromic acid. The anhydrous material can be produced by dehydration of the dihydrate with hot CO or by reaction of zinc metal and bromine.
Zinc bromide | Production
Unlike traditional steel or titanium, this material dissolves in organisms at a rate of roughly 1 millimeter per month and is replaced with bone tissue. This speed can be adjusted by varying the content of zinc. Amorphous CaZnMg alloy exhibits extremely poor corrosion resistance. Wang "et al." reported that the said amorphous alloy completely disintegrated after no more than 3 hours exposure in biocorrosion environment. In static distilled water at room temperature, Dahlman "et al." also reported destructive corrosion reactions of the same material, decomposing into a multiphase powder. Ca-BMGs with higher Zn contents as reported by Cao "et al." showed an elastic modulus in the range of 35–46 GPa, and a hardness of 0.7–1.4 GPa.
Bioabsorbable metallic glass | Properties
Hexagonal and zincblende polymorphs have no inversion symmetry (reflection of a crystal relative to any given point does not transform it into itself). This and other lattice symmetry properties result in piezoelectricity of the hexagonal and zincblende ZnO, and pyroelectricity of hexagonal ZnO. The hexagonal structure has a point group 6 mm (Hermann-Mauguin notation) or C (Schoenflies notation), and the space group is P6mc or C. The lattice constants are "a" = 3.25 Å and "c" = 5.2 Å; their ratio "c/a" ~ 1.60 is close to the ideal value for hexagonal cell "c/a" = 1.633. As in most group II-VI materials, the bonding in ZnO is largely ionic (Zn–O) with the corresponding radii of 0.074 nm for Zn and 0.140 nm for O.
Zinc oxide | Structure
In anhydrous zinc acetate the zinc is coordinated to four oxygen atoms to give a tetrahedral environment, these tetrahedral polyhedra are then interconnected by acetate ligands to give a range of polymeric structures. In contrast, most metal diacetates feature metals in octahedral coordination with bidentate acetate groups. In zinc acetate dihydrate the zinc is octahedral, wherein both acetate groups are bidentate.
Zinc acetate | Basic properties and structures
However, it has lower young’s modulus and fracture toughness with brittle nature. Hence, it is required to produce a biomaterial with good mechanical properties.
Mechanical properties of biomaterials | Introduction
Related oxides are also known such as NaZnO, NaZnO, NaZnO.
Sodium zincate | Oxozincates
In medicine it is used together with oral rehydration therapy (ORT) and an astringent.
Zinc sulfate | Medicine
Further evidence for covalency is provided by the high solubility of the dichloride in ethereal solvents, where it forms adducts with the formula ZnClL, where L = ligand such as O(CH). In the gas phase, ZnCl molecules are linear with a bond length of 205 pm.
Zinc chloride | Structure and properties
Generally, these pads are made from porous polymeric materials with a pore size between 30-50 μm, and because they are consumed in the process, they must be regularly reconditioned. In most cases the pads are very much proprietary, and are usually referred to by their trademark names rather than their chemical or other properties.
Chemical-mechanical polishing | Physical action