Sunday, January 30, 2022

Eagle The bird

 Eagle

  The bird


 



 

 

  

  The eagle, one of the many large, heavy beaked, large-footed birds of prey belonging to the family Accipitridae (order Accipitriformes).  In general, the eagle is any bird of prey that is more powerful than the eagle.  An eagle resembles an eagle in construction and flight characteristics, but its full-winged (often crusted) head and strong legs are equipped with large curved dunes.  Another difference is in the eating habits: eagles live primarily on live prey.  They are keen for effective air pursuit but try to surprise and overwhelm their prey on the ground.  Like the owl, many people behead their prey.  Because of their power, the eagle has been a symbol of war and imperial power since the time of Babylon.  Examples are found in Greek and Roman ruins, coins and medals.




  Aquila nipalensis



 

  Related Topics: Bald Eagle Sea Eagle Hawk Eagle Hairy Eagle Serpent Eagle

 


  Eagles are monogamous.  They reunite for life and use the same nest each year.  They build nests in inaccessible places, laying a small clutch of eggs for six to eight weeks.  Adolescents gradually become adults, reaching adulthood in the third or fourth year.



  Britannica Quiz

  Animals: Fact or Fiction?

  Curiosity may have killed the cat, but the Concajos, Bluebacks, and Mustilds are alive and well in these questions!  These are just some of the amazing animals that stand out in this reality or fiction quiz.


  The harpy eagle, named after the unclean, deadly creature of Greek mythology (part female and part bird), is a large, powerful, crusted eagle from the tropical forests of South America and the South Pacific.  They nest in the tops of the tallest trees and hunt macaws, monkeys and sloths.  The Great Harpy Eagle (Harpia harpija), from southern Mexico to Brazil, is about 1 meter (3.3 feet) long and has a crown of deep feathers on its head.  His body is black at the top and white at the bottom except for the black chest straps.  It is becoming increasingly rare, especially in Mexico and Central America.  The New Guinea Harpyopsis novaeguineae is about 75 cm (30 inches) long.  It is grayish brown in color and has a long tail and a short but complete crust.  The Philippine eagle (Pithecophaga jefferyi) is very similar in appearance and habits.  It is about 90 cm (35 inches) long, brown at the top and white at the bottom, with long, narrow wings.  This is an endangered species.



  Harpy Eagle

  Harpy Eagle

  © Kenneth W. Funk / Ardia London


  Philippine eagle (Pithecophaga jefferyi)

  Philippine eagle (Pithecophaga jefferyi).




  The Harrier Eagle, six types of circuits from Europe, Asia and Africa (subfamily circuitini, snake eagles) are about 60 cm (24 inches) long and have short legs.  They build nests in tree tops and hunt snakes.


  Hawk eagles (Genra Spezstore, Speciesites, Loftus, and Heritas, subfamily Accipitrinae) are lightly made eagles with legs and large beaks and feet.  They hunt all kinds of small animals.  Members of the species Spizaetus - for example, the tropical American ornate hawk eagle (S. ornatus) - have short, broad, long tails, and decorative heads.  The Bonelli eagle (Hieraaetus fasciatus), of the Mediterranean region and parts of South Asia, is about 60 cm (24 inches) long, deep above and light below, has a broad tail band, and usually on the back.  Displays a white spot.



  The African marshal eagle (Polemaetus belicosus) is heavily formed, with a black throat and brown spots with white underparts.  It has a short, bloated tail and bright yellow eyes.  It is large and strong enough to kill wolves and small deer, but its usual food is birds such as birds and hirax.



  Marshall Eagle (Polemaetus belicosus)

  Martial eagle (Polemaetus belicosus) with prey.

  Frank W. Lane / Bruce Coleman Inc.


  In the winter in Hokkaido, Japan, visit the magnificent stellar sea eagle and the white-tailed sea eagle in search of food.

  Learn about Stellar's sea eagles and white-tailed sea eagles.

  


  Watch Stellar's sea eagles compete for food during the winter on Lake Kuril on Russia's Kamchatka Peninsula

  Stellar's sea eagles are competing for food in the Kamchatka Peninsula, Russia.

  , Mainz

 


  Sea eagles (sometimes called fish, or fishing, eagles, Haliaeetus species) are huge eagles that live along rivers, large lakes, and tidal waters around the world, except in South America.  Some reach 1 meter (3.3 feet) tall, the wingspan is almost double that.  They all have unusually high arched beaks and bare lower legs.  The undersides of the fingers become rough to catch the slippery prey.  These birds eat a lot of carcasses but sometimes they kill.  They snatch fish from the surface of the water and often loot their rival osprey.  The largest sea eagle is Stellar's H. pelagicus, the Far East of Korea, Japan and Russia (especially the Kamchatka Peninsula).  The wingspan of this bird is more than 2 meters (6.6 feet) and it can weigh up to 9 kilograms (20 pounds).  The only North American sea eagle is the bald eagle (H. leucocephalus) found in Canada and the United States and northern Mexico.  The white-bellied sea eagle (H. leucogaster), often found off the coast of Australia, stretches from New Guinea and Indonesia through Southeast Asia to India and China.  A well-known African species is the African eagle (H. vocifer), found along lakes, rivers and coastlines from southern Sahara to the Cape of Good Hope.



  White-bellied sea eagle (Haliaeetus leucogaster)

  The white-bellied sea eagle (Haliaeetus leucogaster) is catching fish.


  Fish eagle

  African fish eagle (Haliaeetus vocifer), wood, Botswana.

  Digital Vision / Getty Images




  The white-tailed sea eagle (H. albicilla), which belongs to the coastal areas of Europe, southwestern Greenland, the Middle East, Russia (including Siberia) and China, disappeared from the British Isles by 1918 and from much of southern Europe.  Were done  1950;  However, they began resettling Scotland via Norway in the 1950s and '60s.  By the early 21st century, more than 5,000 breeding pairs could be found throughout Northern Europe as a result of systematic reintroduction programs that began in the 1980's.  Currently, the Scottish population is over 150 birds, and a handful of sea eagles have been reintroduced to Ireland.



  Asian species include the gray-headed, or larger, fishing eagle (Ichthyophaga ichthyaetus) and the lesser fishing eagle (I. naga).


  Snake Eagles, or Snake Eagles, Spilornis (six species, subfamily Circaetinae), eat mostly snakes, including large venomous ones.  They are found in Asia.  Other birds called serpent eagles, especially the long-tailed members of the genus Dryotriorchis (e.g., African snake eagle) and Eutriorchis (e.g., endangered Madagascar snake eagle) are found in Africa.


  The Verreaux eagle (Aquila verreauxii) is an unusual bird of East and South Africa.  It is black with white rump and feather patches.  It grows to about 80 centimeters (31 inches) in length, and rests primarily on hierarchies.  The golden eagle.


  Editors of the Encyclopedia Britannica

  This article was recently revised and updated by John P. Reference.

  Sea eagle


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  Sea eagle

  The bird

  Alternative titles: Fish Eagle, Fishing Eagle


 

 

  By the editors of the Encyclopedia Britannica  See edit history

  Sea eagles, any of the various fish-eating eagles (especially the Haliaeetus species), of which the bald eagle is the most well-known.  Sea eagles (sometimes called fish eagles or fishing eagles) live along rivers, large lakes and tidal waters all over the world except South America.  Some reach 1 meter (3.3 feet) tall, the wingspan is almost double that.  They all have unusually high arched beaks and bare lower legs.  The undersides of the fingers become rough to catch the slippery prey.  These birds eat a lot of carcasses but sometimes they kill.  They snatch fish from the surface of the water and often loot their rival osprey.




  Fish eagle



 

  Related topics: Bald eagle White-bellied sea eagle White-tailed sea eagle Steeler's sea eagle African fish eagle

 


  In the winter in Hokkaido, Japan, see the magnificent stellar sea eagle and the white-tailed sea eagle in search of food.

  Learn about Stellar's sea eagles and white-tailed sea eagles.



  Watch the red-crowned cranes defending their food from Stellar's sea eagles on the Japanese island of Hokkaido

  Stellar's sea eagles are battling red-crowned cranes for food on the Japanese island of Hokkaido.

Wednesday, January 26, 2022

Tin Oxide

 Tin oxide (SnO2) belongs to the Transparent Conducting Oxide (TCO) family.


 



     Related Terms:

     Graphene nanorods nanovirus titanium dioxide zinc oxide indium pyruvicites oxide nanoparticles thin films

 

     Tin oxide content

     Marcelo Ornaghi Orlandi, In Tin Oxide Materials, 2020


   

     Tin oxide deserves special attention from material scientists because of its numerous uses.  Therefore, the idea of ​​this book was to create a unique place where professors, researchers and readers can get general and specific information about tin oxides and their uses.  In addition to the details of the most well-known tin oxide content (SnO2), lesser known phases, SnO and Sn3O4 properties will also be offered.  The purpose of inspiring this book was to bring together a team of experts working on tin oxide so that they could share their experiences and ideas with the scientific community.  The book begins with an introductory chapter that provides general information about the content of tin oxide, including the origin of the name, the world's largest mineral deposits, some of its physical and chemical properties, and the tin in our lives.  The role of oxides is involved.  The basics of tin oxide, including its crystal line structure, as well as its electrical and thermal properties, are provided in the following chapters, as are some methods of synthesis of tin oxide nanoparticles, 1D materials, and thin films.  The last part of the book explores the most important use of tin oxides in modern times.  I hope readers will enjoy visiting the chapters and discovering the beauty tin oxides that humans can provide.


 

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     The use of tin oxide-based materials in catalysis

     Pandian Manjunathan, Ganpati V Shanbhag, In Tin Oxide Materials, 2020


     Abstract

     Tin oxide is a versatile metal oxide due to its two properties.  The condition of the variable valence and the existence of defects in the oxygen space.  Therefore, tin oxide is potentially widely used in catalysis, electrolysis, solar energy conversion, antistatic coatings, transparent conductive electrodes, and electrochromic devices.  Tin oxide-based materials play an important role in catalysis due to hereditary acidity and the presence of redox characters.  Properties in tin oxide can be modified by introducing cation or anion species into its structure and interactions with other oxides.  This chapter focuses on the types of tin oxide-based materials, such as mesoporous and nano-tin oxides, alloys of metallic oxide (M-Sn-oxide), alloy oxides and tin oxides as catalysts, and their use in catalysis.  They are reported to be highly effective catalysts in a wide variety of reactions such as biomass conversion, biodiesel synthesis, glycerol conversion, prince reaction, and cyclic reaction.  In addition, the use of tin oxide-based materials as photocatalysts for degradation and hydrogen evolution reactions and their use as catalysts in photoelectrocatyles is further discussed.


 

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     Tin oxide electrodes in Li and Na ion batteries

     Hero Notohara, ... Osamo Moriguchi, In Tin Oxide Materials, 2020


     Abstract

     Tin oxide is a potential candidate for high-capacity electrode materials for Li-ion batteries.  However, its reactions with SnO2-Sn conversion and Sn-Li alloying / dealloying-based Li-ions are usually irreversible, leading to severe reduction in capacity during charge-discharge cycling.  Much research work has been devoted to overcoming this problem.  In this chapter, Section 14.1 provides a brief description of Li-ion batteries, and then introduces the basic charge / discharge feature of tin oxide with the problem of applying it to Li-ion batteries (Section 14.2).  Some methods for overcoming the problem with small size and morphology controls such as nanoparticles, nanotubes, and holo nano-spares are summarized (Section 14.3).  The development of compounds of tin oxide and carbon materials such as unsecured carbon, carbon nanotubes, and graphene sheets has been introduced more efficiently (Section 14.4).  In addition, the design of composite structures for high performance is also discussed.  The use of all-solid state Li-ion batteries and non-ion batteries based on tin oxide is also mentioned (Section 14.5).  The final section refers to the practical application of nanomaterials based on tin oxide.


 

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     Method of preparation of tin oxide particles using alkoxide precipitation

     Shuuichi Towata, ... Nobuyasu Mizutani, in Advanced Material '93, I, 1994


     Monodispersed tin oxide particles were prepared by hydrolysis of aloxide in a mixed solvent of n-octanol and acetonitrile.  As the solubility of the alkoxide in the mixed solvent decreased, a portion of the alkoxide was accelerated.  These emulsion particles were closely related to the preparation and development of solid oxide particles.  Monodispersed tin oxide particles were thought to be formed by emulsion of aloxide.  Monodispersed spherical tin oxide particles were approximately 0.3–0.7 قطرm in diameter.  The effects of water concentration, the role of estonitrile and N-actanol in solvents, and the age of aging in the form of tin oxide particles were investigated.  The hydrolysis rate of tin n-butoxide can be controlled in a mixed solvent of n-octanol and acetonitrile.  The best condition for preparation was established.  And, the mechanism of formation of this process was also discussed.


 

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     Tin oxide based thin film transistors and their circuits

     Hongtao Cao, Lingyan Liang, in Tin Oxide Materials, 2020


     15.5 TFTs and possible on tin oxides in circuits

     Tin oxides and their composite semiconductors have been used not only in displays but also in sensors, detectors, power transmissions, biosystems, synaptic devices, and many other emerging multifunctional devices and systems.  Despite advances over the past decade, there are still barriers to real application beyond optical displays.  Particular attention should be paid to aspects of future research and development: from materials (composite strategy, high-performance p-type oxide, newly designed n-type oxide blends with ultra-low electron efficient mass, ultra larger than IGZO  Wide band gap, narrow band gap - composite, mix between oxide and 2D material, and so on, fabric technique (vacuum based, solution based, direct print, etc.), material performance (all kinds of basic  Features), and device and system applications (passive or active devices, two or three or even multi-terminal devices, planar integration systems, 3D integration systems, etc.). Finally, future communication manufacturing costs of oxide-based materials  In this regard, tin oxide has natural benefits. Once these problems are resolved, oxide semiconductor based devices and systems promise to be used in everyday things. In this case,  The oxide family, the tin oxide, of course, will contribute to the development of humanity as it did in the C era.


 

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     Tin oxide structure and electronic structure

     Julia Seville, ... Graeme W. Watson, In Tin Oxide Materials, 2020


     Abstract

     Tin oxide materials are technically important materials for applications including catalysts, transparent conducting oxides, and battery materials.  The structure and electronic structure of these materials play a key role in determining their properties and applications.  In this chapter, we discuss the crystal line structure of SnO2, SnO, and Sn3O4, using both experimental data and computed data from Density Functional Theory (DFT).  , Discusses the electronic structure of these tons of oxide material by studying data from existing experimental studies using methods such as X-ray emission spectroscopy (XES), hard X-ray photoelectron spectroscopy (HAXPES).  X-ray absorption spectroscopy (XAS).  Electronic structures are further studied using different levels of DFT (general gradient estimation and hybrid DFT), in which band structures and state densities are used to clarify specific characteristics of electronic structures and compare them with experimental data.  Are used for  The effects of single pairing in SnO and Sn3O4 have also been highlighted and discussed.


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     Nano-formed semiconductor oxides formed by anodic oxidation of metal Sn

     Leszek Zaraska, ... Grzegorz D. Sulka, in Nanostructured Anodic Metal Oxides, 2020


     11.1 Introduction

     Tin oxides such as SnO2, SnO, and mixed valence oxides (Sn2O3 or Sn3O4) have been extensively researched due to their exceptional semiconductor properties that make them promising candidates for many innovative applications.  Band Gap (~ 3.6 eV) n-type semiconductor with high electronic conductivity and high optical transparency in visible range widely used as transparent electrode material in various devices including solar cells, 2 light emitting diodes, and others.  Is done  Electrical properties change significantly during oxidizing and reducing gases, SnO2 is still one of the most popular semiconductor materials used in gas sensors.  And acts as a support for other catalysts.  Mic conductors with a narrow band gap (2.5–3.4 eV) and high hole mobility including a variety of applications including optoelectronic and electronic devices, gas sensors, and catalysts.  , It offers even more optical capacity (875 mA h g − 1) than SnO2 (783 mA h g − 1g).  -Type semiconductor which, due to its very small band gap (2.3–2.8 eV), is able to absorb a wide range of visible light, which makes it a promising candidate for visible photocatalysts.  10–12 Finally, mixed phase systems such as SnO – SnO2 form p – n heterojunction, can demonstrate improved gas sensing performance 13,14 and photocatalytic activity.


     It is widely known that further improvements in the performance of semiconductors can be achieved by using nano-structural materials instead of their bulk counterparts, mostly (but not only) due to their extremely high area and limited size.  because.  Therefore, over the past decade, many studies have focused on the controllable synthesis of different nano-architectures of different tin oxides.  3,16,17 In this context, the process of electrochemical oxidation of metal substrates, a simple, inexpensive, and easily expandable method for the fabrication of nano-structured metal oxides, seems particularly interesting.  Despite a generation of oxide films per ton through anodic oxidation in 18–20 different electrolytes has been studied for decades, 21–24 the first work describing anodic formation.  Since the layers of nanoparticle tin oxide were published by Shin and co-workers, more than 60 papers have been published, most of which have produced nanoporous oxide films by anodizing different metal subsets in different electrolytes.  Has gone  26-28 However, this method has also been used to synthesize nano-structured tin oxide, such as with flower-like patterns 29 or nanoparticles.


     Therefore, in this chapter, we present for the first time a detailed overview of the most important achievements in the formation of various nano-structured tin oxides by simple anodic oxidation of metal tin.  Particular attention is paid to the requirements that must be met in order to obtain crack-free nanoparticles SnOx films, as well as efforts to control the synthesis of oxide layers with a precisely designed shape and texture.  Examples of practical use of nanostructured anodic tin oxides are also given.


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     Ionic conductivity of metal oxides: an essential property for all solid state lithium ion batteries

     C. Chen, ... P.H.L.  Newton, Metal Oxide-Based Thin Film Structures, in 2018


     16.1.12 SnO, SnO2, PbO, and PbO2

     Tin oxides, such as SnO and SnO2, have become increasingly popular as potential alternatives to conventional graphite anodes.  The main reason for this is that they show superior theoretical abilities (SnO: 875 mAh / g, SnO2: 782 mAh / g), which is superior to graphite (372 mAh / g).  It is well established that the reaction of tin oxide with Li + consists of two stages:


     (16.6) SnOx + 2xLi ++ 2xe− → Sn + xLi2Ox = 1,2

     (16.7) Sn + yLi ++ ye-↔LiySn0≤y≤4.4

     During the first discharge process, tin oxides in the form of Li2O and metal Sn will be lithium in the possible range of 0.95–1.2 V, as shown by Eq.  (16.6).  This phase is irreversible, which leads to the initial irreversible potential, but is necessary to obtain a completely reversible change from Sn to Li4.4Sn below 0.7 V (16.7).


     However, the massive expansion of more than 250% of the volume in the second phase results in severe polarization of the active substance, particle breakage, loss of contact, and ultimately poor stability of the cycling.  The common strategy is to wrap SnOx with carbonaceous materials [86,87] or to design a novel nanostructured SnOx [86,88,89].  At the same time, SnO2 thin films were reported to exhibit more reversible emission capabilities and longer cycle life than SnO2 powder electrodes.  SnO2 thin films are made as anodes in Li-ion batteries using several different techniques, including RF-magnetron sputtering [90,91], CVD [92], PLD [93], electrostatic spray deposition [94]  ], And the sol-gel method [95].


     Lead-based oxides (PbO and PbO2), like SnOx, have (de) lithium performance, which can be represented.


     (16.8) PbOx + 2xLi ++ 2xe− → Pb + xLi2Ox = 1,2

     (16.9) Pb + yLi ++ ye − ↔LiyPb0≤y≤4.4

     On the first discharge cycle, PbOx converts to Pb with the irreversible formation of Li2O.  Like SnOx's electrochemical behavior, the formation of Li2O will result in a large capacity loss in the first lithiation cycle.  Only LiyPb alloys (Eq. 16.9) can be inverted to a potential range of 0.1–0.6 V, giving a total storage capacity of 529 mAh / g for PbO and 493 mAh / g for PbO2.  ۔


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     Modified electrochemical sensors in metal oxide carbon nanotubes nanocomposite for toxic chemicals

     Piyush Kumar Sonkar, Velayachmi Ganesan, in nano-composite electrochemical sensors for toxic chemicals in metal oxide, 2021


     6.6 CNTs and tin oxide compounds

     Tin oxide (SnO2) is an important metal oxide in the field of electrochemistry because of its low cost and ability to reverse redox.  Developed by a nanocomposite electrochemical templating method based on SnO2 and cofunctionalized SWCNTs [80].  Electrochemical-assisted methods are used for the functionalization of SWCNTs with SnO2 (SWCNTs-SnO2).  Furthermore, electrode positions of metal nanoparticles were performed at SnO2 level.  Three different metal catalysts, palladium, platinum, and gold, were used to detect various toxic gases.  SWCNTs-SnO2-modified electrodes are sensitive to toxic gases such as NH3, NO2, H2, H2S, and water vapor [80].  Mendoza etc.  CNTs-SnO2 developed a composite film-based room temperature gas sensor.  It exhibited gas sensing properties for ethanol, methanol, and H2S up to ppm levels at room temperature and ambient pressure.  It heals itself in 1 minute without heat or other sources of energy [81].  The configuration of the electrochemical gas sensor and the sensing of the gases are shown in Figure 8.9.



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     Figure 8.9.  Sensor voltage response to alcohol vapor in cyclic exposure: (a) methanol and (b) ethanol.  Construction of gas sensing device (C).


     Reproduced with permission of F. Mendoza, D.M.  Hernández, V. Makarov, E. Febus, B.R.  Weiner, G. Morrell, Ton Dioxide Carbon Nanotubes Room Temperature Gas Sensors Based on Composite Films, Sense Actuators B190 (2014) 227–233.

 

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     Nanostructured thin films

     Lucina Gerzidzel, Mackay Krzyzewski, at Frontiers of Nanoscience, 2019


     3.1.1 SnO2, SnO1 <x <2 / CuPc

     Tin oxide structures are important components of the technology of various optoelectronic devices, such as OLED or PV as transparent conducting oxide electrodes [39,40].  In addition to the application of wide band gap (e.g. 3.6 eV [41]) stoichiometric SnO2, deviations from the ideal stoichiometric forms SnOx (1 <x <2) draw attention due to lack of oxygen or conductivity driven by impure dupents  does.  Crystallographic errors and additives lead to the creation of additional occupied electronic states in the band gap that affect the firm's level energy position and charge carrier concentration [42,43].  Both yield tin oxide layers, highly controlled vacuum conditions (e.g., epitaxial growth [44], accumulation of laser-affected chemical vapors [45], rheotaxial growth, and thermal or vacuum oxidation) [46,47]  ]), And more realistic.  Near mass production civil-gel technology [48], nano-structured inorganic-organic interfaces can form suitable ultrathane layers for construction.


     The ideal interface between the thermally deposited 1-nm-thick SnO2 layer and the 5-nm-CuPc film was investigated by Hong et al.  [40].  The interface shown by the combined results of SRPES, NEXAFS, and UPS is electronically separated.  A small interface of 0.50 eV detects no chemical interaction at the Dupole CuPc-on-SnO2 junction.  SnO2-on-CuPc's inverted interface reflects a strong interface dupole effect reaching 0.65 eV [40].  For this construction, the authors said that the thermally absorbed Sn atoms spread in CuPc resulting in the formation of metal-organic Sn2CuPc compounds.  In support of this hypothesis, the authors point to additional vacuum conditions above the upper part of the Valence band as envisioned in Figure 8.3A, as well as nitrogen atoms in the Sn12-on-CuPc's N 1s SRPES spectrum.  With the traces of chemical reactions can be detected.  [40].  During the NEXAFS study, the shift of the peaks attributed to N 1s, π منت transfers by 0.25 eV was observed towards low photonic energy with respect to the CuPc-on-SnO2 ones for SnO2-on-CuPc.  At the same time, during high film development, as shown in Figure 8.3B and C, SnO2 increases the primary surface peaks produced by phthalocyanine by 0.15 and 0.25 eV by 0.15 and 0.25 eV.  Detected for -on-CuPc and CuPc-on-.  SnO2 junction, respectively.  It was attributed by Hong et al.  [40] To bend the band upwards which is only present on the CuPc side as shown in Figure 8.3D and E, [40] schematically through the energy band diagram.



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     Figure 8.3.  Ultraviolet photoelectron spectroscopy spectra of the Valence Band Max (VBM) region (A) for both SnO2-on-CuPc and CuPc-on-SnO2 interfaces.  Significant differences in SnO2 (upper spectrum) conditions may be triggered by Sn proliferation.  Sn12-on-CuPc and CuPc-on-SnO2 (B and C) C1s peak synchrotron radiation photo-emission spectroscopy spectra, respectively.  The top of the C 1s is marked in three components: scented carbon in benzene color (C – C), carbon attached to nitrogen atoms in pyrol rings (N – CN), and satellite of N – CN bonds.  The change in energy level that ΔE represents.  Schematic energy band diagram in two interfaces: SnO2-on-CuPc (D) and CuPc-on-SnO2 (E).  The hole injection barrier is shown as BH [40].  Homo, the most occupied molecular orbital band;  LUMO, the lowest nonlinear molecular orbital band.


     K. Hong, K. Kim, S. Kim, S.Y.  Reprint and tweak with permission.  Kim, J.L.  Lee, Jay-Z.  Chem C 115 (2011) 23107. Copyright (2011) American Chemical Society.

     The integrated effects of interface dupole and band bending allow the setting of a hole injection barrier as 0.60 and 0.95 eV for interface with CuPc up and down, respectively.  Finally, the difference in interfacial condition was confirmed during OLED operation, when the CuPc-on-SnO2 structure showed smaller operation voltage and greater light than the reverse one [40].


     Interfacial potential barrier parameters (such as changes in surface work function, bending of energy bands in the substrate, and changes in potential in organic coatings) can also be identified using total current spectroscopy.  TSC) Method [49]: The formation of the interface between polycrystalline line, thermally deposited SnO2 (500 nm-thick) and CuPc (up to 10 nm) overlayers was investigated by TSC investigations by Komolov et al.  [49].  Like Hong et al.  [40], they did not reveal a change in the energy level of the SnO2 substrate as a function of CuPc film development, which indicates a decrease in band bending in tin dioxide as a result of interaction with phthalocyanine molecules.  ۔  Furthermore, TSC revealed a decrease of 15 0.15 eV in CuPc work function during the development of the organic layer up to a thickness of 1.5 nm and then a continuous increase of 10 0.10 eV which saturated the 8 nm layer [49].  The authors interpret these results as the effect of negative charge transfer to inorganic substrate, emphasizing the donor role of CuPc molecules [49].


     The new characteristics of the formation of inorganic-organic interfaces are due to the combination of substochemometric civil-gel-formed SnO1 <x <2 oxide nanolizers due to the presence of (1) oxygen spaces and (2) CuPc ultrathan film.  Increased conductivity due to addition.  Space [48].  The chemical and electronic properties of the buried civil-gel SnOx / CuPc junction were examined in a non-destructive in-depth analysis based on ADXPS in collaboration with PYS [48].  A sudden change of 0.23 eV in the work function at the interface (shown in Figure 8.4A) was detected by PYS and assigned to the dupole effect of the interface [48].  Figure 8.4B presents the results of quantitative ADXPS analysis of the energy positioning of SnOx deep and shallow core surfaces near the C interface.  One can see the constant change towards the lower BE of about 0.50 eV and deep core O 1s, Sn 3d levels ∼0.20 eV.  This effect was explained by the charge transfer attached to the interface which led to the bending of the band upwards in the oxide and was not observed to form the interface between the CuPc nanolayer and the stoichiometric SnO2 form [40,49].  ۔  By CuPc, a shallow C 2p energy level shift was found (Fig. 8.4C): more binding energy around the oxide interface ∼0.5 eV and opposite the surface.  The intensity of CuPc's C 2p signal changes indicates that this level played a key role in the transfer of charge through the interface as part of CuPc's aromatic system.  Furthermore, as shown in Figure 8.4D, the change of C 2p variation towards the lower BE of phthalocyanine, resulting in deeper basal surfaces C 1s, N 1s, Cu 2p near the CuPc surface, as seen  Probably due to environmental oxidation [48].  Finally, the variation of the depth-dependent surfaces allowed the band-like outline of the building presented in Figure 8.4E and described the direction of negative charge transfer from the inorganic substrate to the organic overlay during the formation of the interface. [48]  ۔



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     Figure 8.4.  Photo emission reveals the spectroscopy spectrum of the naked civil-gel SnOx and SnOx / CuPc structures (A).  Inset represents the CuPc contribution extracted from the aggregate signal.  The ADXPS results of the basic level binding energy shift as a take-off angle (TOA) function for the species (B) related to the central SnOx;  Variation of energy level binding energy related to Valence band as a function of TOA (C);  CuPc-related energy level changes as a function of depth of information.  Inset: Binding the change of energy distance as a function of TOA for the basic levels (D) related to the main SnOx- and CuPc is not equal to any change from the initial value equal to 0 shift.  All the values ​​offered in the band-like diagram (E) eV representing depth-dependent variations in energy level alignment for the investigated SnOx / CuPc structure developed on the basis of two photo-emission experiments (E) [48].


     Reproduced (partially adapted) from M. Krzywiecki, L. Grządziel, A. Sarfraz, A. Erbe, Phys.  Cam Cam Physics 19 (2017) 11816. Posted by PCCP Owner Societies.

     For the case of SnO1 <x <2 nanolayers obtained using the RGVO technique, the configuration of the interface during the assembly of the ultrathin CuPc overlayer revealed some disruption in the transfer of charge through the junction [50].  Buried interface features monitored by depth and energy-soluble photo-emission modes: ADXPS and UPS.  Around the bare RGVO-SnOx surface, Sn 3d, O 1s, and Sn 4d core levels had no identifiable energy change except for a small change in the C 1s component as shown in Figure 8.5A [50].  The last mentioned ingredient is caused by contaminating organic matter, probably from carbon in the form of long alveolar chains, which is present on the surface of the RVVO ton oxide exposed to air.  The movement of carbon species towards higher BE near the surface may indicate the existence of a surface dopole-like or charging effect.  After collecting the CuPc thin film, studies showed no significant change in the energy position of the core surface on either side of the junction in the area of ​​the RGVO-SnOx / CuPc interface (Fig. 8.5B) [50].  However, the UPS detected a significant change in the working function of 0.4 eV between the two materials, as shown in Figure 8.5C and D, indicating the appearance of the interface dupole effect [50].  This effect revealed a rearrangement of the local electronic charge which was reflected in a possible sudden change in the interface [51,52].  Thus, as shown in the built-in band diagram (Fig. 8.5E), there was no extended (lengthwise) redistribution of mobile charge carriers in the organic layers, known as "band bending" or constant energy levels.  Conceived by shift, in order to achieve electronics.  Equilibrium with the alignment of the vertical surfaces on both sides of the contact [51].  The lack of mobile charge interaction was attributed to the presence of carbon absorbers in the interface that can pin energy levels.  Finally, away from the interface, in close proximity to the CuPc surface, the phthalocyanine-related base surfaces shifted to the lower BE as a result of the ambient air reaction of the 0.2 eV surface, which increased the absorption of oxidizing agents in the atmosphere.  Can provoke  Concentration in the underground area



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     Figure 8.5.  The ADXPS core level energy recorded with different take off angles (TOA) for Sn 3d5 / 2, O 1s, C 1s, and Sn 4d energy areas of RGVO-SnOx (A) is deeply dependent for CuPc /  Core Surface Energy Shifts RGVO-SnOx (B) Bare RGVO-SnOx Layers (C) and RGVO-SnOx / CuPc Structures (D) Energy Surface Outline (E) Energy Surface Positioning by Photo Emission Methods  UPS results presented by  Roman numerals in brackets correspond to sub-level (I) of RGVO-SnOx;  (II) - Area of ​​interaction with the surface environment of the naked RGVO-SnOx;  (III) RGVO-SnOx / CuPc interface;  (IV) -CuPc layer  (V) - CuPc - Region with Environmental Interaction.  All values ​​are given in eV [50].  RGVO, rheumatoid arthritis and vacuum oxidation.

    ۔

     As a result, research has focused on the effects of atmospheric oxide surface emissions on the creation of electronically efficient hybrid interfaces.  The presence of parasitic adsorbents will reduce the alignment of energy levels and impede the transfer of mobile charge.

Sunday, January 23, 2022

Wasserstoff

 Wasserstoff


 

 

  Wissenschaft

  Chemie

  Wasserstoff

  Chemisches Element

 


 

  Wasserstoff (H), eine farblose, geruchlose, geschmacklose, brennbare gasförmige Substanz, die das einfachste Mitglied der Familie der chemischen Elemente ist.  Das Wasserstoffatom besteht aus einem Kern, der ein Proton enthält, das eine Einheit positiver elektrischer Ladung enthält.  An diesem Kern hängt auch ein Elektron, das eine Einheit negativer elektrischer Ladung hat.  Unter normalen Bedingungen ist Wasserstoffgas eine lose Ansammlung von Wasserstoffmolekülen, wobei jedes Atompaar aus einem zweiatomigen Molekül, H2, besteht.  Die früheste wichtige chemische Eigenschaft von Wasserstoff ist, dass er Wasser mit Sauerstoff, H2O, verbrennt;  Tatsächlich leitet sich der Name Wasserstoff vom griechischen Wort ab, das „Wassermacher“ bedeutet.



  Chemische Eigenschaften von Wasserstoff



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  Schlüsselpersonen: Henry Cavendish Anton Lavoisier Otto Straw Anders Jonas Ingström Fritz Wolf Gang London

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  Obwohl Wasserstoff das am häufigsten vorkommende Element im Universum ist (dreimal häufiger als Helium, das zweithäufigste Element), macht es nur 0,14 % des Gewichts der Erdkruste aus.  Es kommt jedoch in großen Mengen als Teil des Wassers in Ozeanen, Packeis, Flüssen, Seen und der Umwelt vor.  Als Bestandteil unzähliger Kohlenstoffverbindungen ist Wasserstoff in allen tierischen und pflanzlichen Geweben sowie im Erdöl vorhanden.  Obwohl oft gesagt wird, dass Kohlenstoffverbindungen bekannter sind als jedes andere Element, ist es Tatsache, dass Wasserstoff in fast allen Kohlenstoffverbindungen vorhanden ist und mit allen anderen Elementen (mit Ausnahme einiger Elemente, Edelgase) eine Masse von Verbindungen bildet. es ist möglich, dass es mehr Wasserstoffverbindungen gibt.



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  Früher Wasserstoff findet seine hauptsächliche industrielle Verwendung bei der Herstellung von Ammoniak (einem Gemisch aus Wasserstoff und Stickstoff, NH3) und bei der Hydrierung von Kohlenmonoxid und organischen Verbindungen.



  Es gibt drei bekannte Wasserstoffisotope.  Die größte Anzahl von Wasserstoffisotopen ist 1, 2 und 3, die häufigste Masse ist 1 Isotop, das allgemein als Wasserstoff (Symbol H oder 1H) bezeichnet wird, aber auch als Protom bezeichnet wird.  Das Masse-2-Isotop, das das Zentrum eines Protons und eines Neutrons hat und als Deuterium oder schwerer Wasserstoff (Symbol D oder 2H) bezeichnet wird, macht 0,0156 % der normalen Wasserstoffmischung aus.  Tritium (Symbol T oder 3H) mit einem Proton und zwei Neutronen in jedem Kern ist ein Isotop der Masse 3 und enthält etwa 10-15 bis 10-16 % Wasserstoff.  Die Praxis, Wasserstoffisotope getrennt zu benennen, wird dadurch gerechtfertigt, dass sich ihre Eigenschaften erheblich unterscheiden.


  Paracelsus, Arzt und Chemiker, experimentierte im 16. Jahrhundert versehentlich mit Wasserstoff, als er bemerkte, dass beim Auflösen des Metalls in Säure ein brennbares Gas entsteht.  Das Gas war jedoch mit anderen brennbaren Gasen wie Kohlenwasserstoffen und Kohlenmonoxid vermischt.  1766 zeigte der englische Chemiker und Physiker Henry Cavendish, dass sich Wasserstoff, damals brennbare Luft, Phlogustin oder brennbares Prinzip genannt, von anderen brennbaren Gasen durch seine Dichte und die Menge an Säure unterscheidet, die er enthält. Cavendish bestätigte 1781 frühere Beobachtungen, dass Wasser wurde bei der Verbrennung von Wasserstoff gebildet, und Antoine-Laurent Lavoisier, der Vater der modernen Chemie, prägte das französische Wort Hydrogène, von dem die englische Form abgeleitet wurde.  1929 zeigten Carl Friedrich Bonhofer, ein deutscher physikalischer Chemiker, und Paul Hartik, ein österreichischer Chemiker, basierend auf früheren theoretischen Arbeiten, dass gewöhnlicher Wasserstoff eine Mischung aus zwei Arten von Molekülen ist, Orthowasserstoff und Parawasserstoff.  Aufgrund der einfachen Struktur von Wasserstoff lassen sich seine Eigenschaften relativ einfach theoretisch berechnen.  Daher wird Wasserstoff oft als theoretisches Modell für komplexere Atome verwendet und die Ergebnisse kompetent auf andere Atome übertragen.



  Physikalische und chemische Eigenschaften

  Die Tabelle listet die Haupteigenschaften von molekularem Wasserstoff H2 auf.  Extrem niedrige Schmelz- und Siedepunkte sind das Ergebnis schwacher Gravitationskräfte zwischen Molekülen.  Das Vorhandensein dieser schwachen intermolekularen Kräfte zeigt sich auch in der Tatsache, dass, wenn sich Wasserstoffgas in Richtung des maximalen Drucks bei Raumtemperatur ausdehnt, seine Temperatur ansteigt, während die Temperatur der meisten anderen Gase abnimmt  Nach thermodynamischen Prinzipien bedeutet dies, dass die radioaktiven Kräfte größer sind als die Gravitationskräfte zwischen den Wasserstoffmolekülen bei Raumtemperatur – sonst kühlt die Ausdehnung den Wasserstoff ab.  Tatsächlich herrschen bei 0,668,6 ° C Gravitationskräfte, und Wasserstoff kühlt ab, wenn er sich unter diese Temperatur ausdehnt.  Der Kühleffekt wird bei Temperaturen unterhalb von flüssigem Stickstoff (6196 °C) so deutlich, dass dieser Effekt genutzt wird, um die Flüssigtemperatur von Wasserstoffgas zu erhalten.


  Einige Eigenschaften von gewöhnlichem Wasserstoff und Deuterium

  Gewöhnliches Wasserstoff-Deuterium

  Atomarer Wasserstoff

  Ordnungszahl 1 1

  Atomgewicht 1,0080 2,0141

  Ionisationskapazität 13.595 Elektronenvolt 13.600 Elektronenvolt

  Elektronenzugehörigkeit 0,7542 Elektronenvolt 0,754 Elektronenvolt

  Atomspin 1/2 1

  Atomares magnetisches Moment (Atommagnet) 2,7927 0,8574

  Atomares Quadratmoment 0 2,77 (10−27) Quadratzentimeter

  Elektrisch negativ (Paling) 2.1 ~ 2.1

  Molekularer Wasserstoff

  Bindungsabstand 0,7416 Angström 0,7416 Angström

  Trennenergie (25 Grad Celsius) 104,19 kcal pro Mol 105,97 kcal pro Mol

  Ionisationskapazität 15,427 Elektronenvolt 15,457 Elektronenvolt

  Feststoffdichte 0,08671 Gramm pro Kubikzentimeter 0,1967 Gramm pro Kubikzentimeter

  Schmelzpunkt –259,20 °C – 254,43 °C

  Schmelztemperatur 28 Kalorien pro Mol 47 Kalorien pro Mol

  Flüssigkeitsdichte 0,07099 (–252,78 Grad) 0,1630 (–249,75 Grad)

  Siedepunkt –252,77 °C – 249,49 °C

  Dampftemperatur 216 Kalorien pro Mol 293 Kalorien pro Mol

  Kritische Temperatur –240,0 °C – 243,8 °C

  Kritischer Druck 13,0 Atmosphäre 16,4 Atmosphäre

  Kritische Dichte 0,0310 Gramm pro Kubikzentimeter 0,0668 Gramm pro Kubikzentimeter

  Verbrennungstemperatur des Wassers (g) −57,796 kcal pro Mol 9 59,564 kcal

  Wasserstoff ist für sichtbares Licht, Infrarotlicht und ultraviolettes Licht bis zu Wellenlängen von weniger als 1800 transparent.  Da sein Molekulargewicht geringer ist als bei jedem anderen Gas, ist die Geschwindigkeit seiner Moleküle bei jeder gegebenen Temperatur höher als bei jedem anderen Gas und es dehnt sich schneller aus als jedes andere Gas.  Dadurch wird kinetische Energie durch Wasserstoff schneller verteilt als durch jedes andere Gas.  Es hat zum Beispiel die höchste Wärmeleitfähigkeit.



  Das Wasserstoffmolekül ist das einfachste mögliche Molekül.  Es besteht aus zwei Protonen und zwei Elektronen, die durch elektrostatische Kräfte zusammengehalten werden.  Atome können wie Wasserstoff eine große Anzahl gespeicherter Energieniveaus haben.


  Orthowasserstoff und Parawasserstoff

  Es gibt zwei bekannte Arten von molekularem Wasserstoff (Ortho und Para).  Diese unterscheiden sich in den magnetischen Wechselwirkungen der Protonen aufgrund der Drehbewegungen der Protonen.  Bei Orthowasserstoff sind die Rotationen der beiden Protonen gleichsinnig verbunden, also parallel.  Bei Parawasserstoff sind die Spindeln gegenläufig geschaltet und damit parallel.  Die Spinausrichtung bestimmt die magnetischen Eigenschaften von Atomen.  Im Allgemeinen treten keine Mutationen von einem Typ zum anderen auf (d. h. Änderungen zwischen Ortho- und Paramolekülen), und Orthowasserstoff und Parawasserstoff können als zwei separate Modifikationen von Wasserstoff betrachtet werden.  Die beiden Formen können sich jedoch unter bestimmten Bedingungen ändern.  Das Gleichgewicht zwischen den beiden Formen kann auf viele Arten hergestellt werden.  Eine davon ist das Einbringen von Katalysatoren (zB Aktivkohle oder diverse paramagnetische Substanzen).  Die zweite Methode besteht darin, dem Gas einen elektrischen Strom zuzuführen oder es auf eine höhere Temperatur zu erhitzen.



  Die Konzentration von Parawasserstoff in einer Mischung, die ein Gleichgewicht zwischen den beiden Formen erreicht hat, hängt von der Temperatur ab, wie die folgende Abbildung zeigt:




  Grundsätzlich kann reiner Parawasserstoff bei der Temperatur von flüssigem Wasserstoff hergestellt werden, indem die Mischung mit Holzkohle gemischt wird.  Es wandelt den gesamten Orthowasserstoff in Parawasserstoff um.  Andererseits kann ortho-Wasserstoff nicht direkt aus der Mischung hergestellt werden, da die para-Wasserstoffkonzentration nie weniger als 25 % beträgt.


  Die beiden Formen von Wasserstoff haben leicht unterschiedliche physikalische Eigenschaften.  Der Schmelzpunkt von Parawasserstoff ist um 0,10 % niedriger als der einer 3:1-Mischung aus Orthowasserstoff und Parawasserstoff.  Der Dampfdruck auf flüssigem Parawasserstoff bei –252,77 °C beträgt 1,035 Atmosphären (ein Atmosphärendruck auf Meereshöhe unter Standardbedingungen, entspricht etwa 14,69 Pfund pro Quadratzoll), verglichen mit 1,000 Atmosphären 3: 1 Ortho-Para-Verbindungsdampfdruck.  Aufgrund der Dampfdrücke von para-Wasserstoff und ortho-Wasserstoff können diese Formen von Wasserstoff durch Niedertemperatur-Gaschromatographie getrennt werden, ein analytisches Verfahren, das es ermöglicht, dass verschiedene Atome und Molekülarten ihre unterschiedlichen Schwankungen aufweisen


  Wasserstoffreaktion

  Ein Wasserstoffmolekül spaltet sich in zwei Atome (H2 → 2H), wenn die Energie gleich oder größer als die Energie (dh die Energiemenge, die zum Aufbrechen der Bindung, die die Atome im Molekül zusammenhält) bereitgestellt wird.  Die Abbauenergie von molekularem Wasserstoff beträgt 104.000 Kalorien pro Mol – geschrieben 104 kcal/mol (Mol: Molekulargewicht wird in Gramm ausgedrückt, das sind bei Wasserstoff zwei Gramm).  Genügend Energie wird beispielsweise gewonnen, wenn das Gas einer weißglühenden Wolframfaser ausgesetzt wird oder wenn im Gas ein elektrischer Strom gebildet wird.  Wenn in einem System bei niedrigem Druck atomarer Wasserstoff erzeugt wird, gäbe es eine kritische Lebensdauer von Atomen, beispielsweise 0,3 Sekunden bei einem Druck von 0,5 mm Hg.  Kernwasserstoff ist sehr reaktiv.  Es verbindet sich mit den meisten Elementen zu Hydriden (z. B. Natriumhydrid, NaH) und reduziert Metalloxide, eine Reaktion, die das Metall in seinem ursprünglichen Zustand erzeugt.  Metalloberflächen, die sich nicht mit Wasserstoff zu stabilen Hydriden verbinden (z. B. Platin), lösen die Rekombination von Wasserstoffatomen zu Wasserstoffmolekülen aus und werden dadurch durch die bei dieser Reaktion freigesetzte Energie erwärmt.


  Molekularer Wasserstoff kann mit vielen Elementen und Verbindungen reagieren, aber die Reaktionsgeschwindigkeiten bei Raumtemperatur sind normalerweise so gering, dass sie fast nicht vorhanden sind.  Diese scheinbare Trägheit ist teilweise auf die hohe Abbauenergie des Moleküls zurückzuführen.  Bei höheren Temperaturen ist die Reaktionsgeschwindigkeit jedoch höher.


  Funken oder einige Strahlen können eine explosive Reaktion einer Mischung aus Wasserstoff und Chlor verursachen, um Chlorwasserstoff zu erzeugen, wie durch die Gleichung H2 + Cl2 → 2HCl gezeigt wird.  Das Gemisch aus Wasserstoff und Sauerstoff reagiert mit einer messbaren Geschwindigkeit von knapp über 300 °C, gemäß den Gleichungen 2H2 + O2 → 2H2O.  Solche Verbindungen, die 4 bis 94 % Wasserstoff enthalten, entzünden sich beim Erhitzen auf 550 ° –600 ° C oder bei Kontakt mit Katalysatoren, Funken oder Flammen.  Besonders heftig ist die Explosion eines 2:1 Gemisches aus Wasserstoff und Sauerstoff.  Nahezu alle Metalle und Nichtmetalle reagieren bei hohen Temperaturen mit Wasserstoff.  Bei hohen Temperaturen und Drücken reduziert Wasserstoff die Oxide der meisten Metalle und vieler Metallsalze in Metallen.  Zum Beispiel Reaktion von Wasserstoffgas und Eisenoxid, Herstellung von metallischem Eisen und Wasser, H2 + FeO, Fe + H2O;  Wasserstoffgas reduziert Palladiumchlorid unter Bildung von Palladiummetall und Chlorwasserstoff, H2 + PdCl2 → Pd + 2HCl.



  Wasserstoff wird von vielen Übergangsmetallen bei hohen Temperaturen absorbiert (Scandium, 21, Kupfer, 29 % Etrium, 39, Silber, 47 % Hafnium, 72, Gold, 79);  Und aktinoide Metalle (über Actinium, 89, Laurensium, 103) und Lanthanoid-Reihen (Lanthan, 57, über Lithium, 71), um harte, legierungsartige Hydride zu bilden.  Sie werden oft als interstitielle Hydride bezeichnet, weil sich das Metallkristallgitter in vielen Fällen einfach ausdehnt, um den gelösten Wasserstoff unverändert aufzunehmen.


  Wasserstoffverbindung

  In einigen harmonisch gebundenen Hydriden ist ein Wasserstoffatom gleichzeitig durch zwei separate elektronegative Atome verbunden, die dann als Wasserstoffbrücken bezeichnet werden.  Zu den stärksten Wasserstoffbrückenbindungen gehören kleine, stark elektronegative negative Atome von Fluor (F), Sauerstoff und Stickstoff.  Im Bifluorid-Ion HF2− bindet das Wasserstoffatom zwei Fluoratome.  In der Eiskristallstruktur ist jedes Sauerstoffatom von vier anderen Sauerstoffatomen umgeben, dazwischen befinden sich Wasserstoffatome.  Wenn Eis schmilzt, brechen einige Wasserstoffbrückenbindungen und die Struktur bricht mit zunehmender Dichte zusammen.  Wasserstoffbrückenbindungen sind in der Biologie wichtig, weil sie eine wichtige Rolle bei der Bestimmung der Bildung von Molekülen spielen.  Die helikalen (spiralförmigen) Konfigurationen einiger großer Molekülketten, wie z. B. in Proteinen, werden durch Wasserstoffbrückenbindungen zusammengehalten.  Umfangreiche Wasserstoffbindungen im flüssigen Zustand erklären, warum die Siedepunkte von Fluorwasserstoff (HF), Wasser (H2O) und Ammoniak (NH3) von ihren schweren Analoga Chlorwasserstoff (HCl), Schwefelwasserstoff (H2S) und vielen mehr abweichen.  Phosphin (PH3).  Die zum Aufbrechen von Wasserstoffbrückenbindungen und zum Ermöglichen der Verdampfung erforderliche thermische Energie ist nur bei hohen Siedetemperaturen verfügbar.



  Ganz anders verhält sich Wasserstoff in einer starken Säure wie Salzsäure (HCl) oder Salpetersäure (HNO3).  Wenn sich diese Säuren in Wasser auflösen, trennt sich Wasserstoff in Form eines Protons, H +, vollständig von dem negativ geladenen Ion, dem Anion (Cl− oder NO3−), und tritt mit Wassermolekülen in Wechselwirkung.  Das Proton bindet fest an ein Wassermolekül (hydratisiert), um ein Axoniumion (H3O +, manchmal auch als Hydroniumion bezeichnet) zu bilden, das wiederum Wasserstoff an andere Wassermoleküle bindet, was die Anzahl der H2O-Moleküle angibt, die in Formeln wie H enthalten sind (H2O) n + Index n).  Die Reduktion von H + (Reduktion ist die chemische Veränderung, bei der ein Atom oder Ion ein oder mehrere Elektronen erhält) kann als Halbreaktion dargestellt werden: H ++ e− → 1 / 2H2.  Die zum Herbeiführen dieser Reaktion erforderliche Energie kann als Reduktionspotential ausgedrückt werden.  Das Wasserstoff-Reduktionspotential wird per Konvention als Null angesehen, und alle Metalle mit negativem Reduktionspotential werden berücksichtigt, dh Metalle, die leicht reduziert werden können (leichter oxidiert werden; → Zn, −0,763 Volt) – können im Prinzip Wasserstoff entfernen aus stark saurer Lösung: Zn + 2H + → Zn2 + + H2.  Metalle mit positivem Reduktionspotential (z. B. Silber: Ag + + e− → Ag, + 0,7995 Volt) werden an wässrige Wasserstoffionen gebunden.

Saturday, January 22, 2022

Stickstoff

 Flüssiger Stickstoff siedet bei Raumtemperatur.

  Stickstoff ist für das Leben auf der Erde unerlässlich.  Es ist Bestandteil aller Proteine ​​und kommt in allen lebenden Systemen vor.  Stickstoffverbindungen sind in organischen Stoffen, Lebensmitteln, Düngemitteln, Sprengstoffen und Giften enthalten.  Stickstoff ist lebensnotwendig, kann aber auch umweltschädlich sein.


 

 

  Benannt nach dem griechischen Wort Nitron, für „lokales Soda“ und für die Gene „Bildung“, ist Stickstoff das fünfthäufigste Element im Universum.  Nach Angaben des Las Alamos National Laboratory besteht die Luft auf der Erde zu 78 % aus Stickstoffgas.  Andererseits enthält die Atmosphäre des Mars nur 2,6 % Stickstoff.


  In seiner gasförmigen Form gilt Stickstoff als farblos, geruchlos und im Allgemeinen inert.  Laut Los Alamos ist Stickstoff in seiner flüssigen Form auch farb- und geruchlos und sieht aus wie Wasser.


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  Ordnungszahl (Anzahl der Protonen im Kern): 7

  Atomsymbol (im Periodensystem der Elemente): N

  Atomgewicht (durchschnittliches Atomgewicht): 14,0067

  Dichte: 0,0012506 Gramm pro Kubikzentimeter

  Schritt bei Raumtemperatur: Gas

  Schmelzpunkt: minus 321 Grad Fahrenheit (minus 210 Grad Celsius)

  Siedepunkt: Negativ 320,42 F (minus 195,79 C)

  Anzahl der Isotope (Atome desselben Elements, die eine unterschiedliche Anzahl von Neutronen enthalten): 16, davon 2 stabil

  Die häufigsten Isotope: Stickstoff-14 (Häufigkeit: 99,63 %)

 


  Nitrogen General-fmv, Andrei Marincas Shutterstock)

  Düngerkomponente

  Nach Angaben des Los Alamos National Laboratory wurde Stickstoff 1772 vom Chemiker und Arzt Daniel Rutherford entdeckt, als er Sauerstoff und Kohlendioxid aus der Luft entfernte, was darauf hinweist, dass Restgas Organismen oder Verbrennung nicht unterstützen würde.  Andere Wissenschaftler, darunter Carl Wilhelm Shell und Joseph Priestley, arbeiteten an demselben Problem und nannten Stickstoff „verbrannte“ Luft oder Luft ohne Sauerstoff.  1786 nannte Antoine Laurent de Lavoisier Stickstoff „Azote“, was „unbelebt“ bedeutet.  Es basierte auf der Beobachtung, dass es Teil der Luft ist und das Leben selbst nicht unterstützen kann.



  Eine der wichtigsten Verbindungen des Stickstoffs ist Ammoniak (NH3), das im sogenannten Haber-Bosch-Verfahren hergestellt werden kann, bei dem Stickstoff mit Wasserstoff reagiert.  Farbloses Ammoniakgas mit starkem Geruch lässt sich leicht in Stickstoffdünger verflüssigen.  Tatsächlich werden etwa 80 % des produzierten Ammoniaks als Düngemittel verwendet.  Es wird auch als Kühlgas verwendet.  Bei der Herstellung von Kunststoffen, Textilien, Pestiziden und Farbstoffen;  Und in der Aufräumlösung, so das New York State Department.


 

 

  Stickstoffkreislauf

  Der Stickstoffkreislauf, in dem Luftstickstoff in verschiedene organische Verbindungen umgewandelt wird, ist der wichtigste natürliche Prozess zur Erhaltung von Lebewesen.  Während des Kreislaufs wirken Bakterien im Boden oder „fixieren“ Luftstickstoff zu Ammoniak, der für das Pflanzenwachstum benötigt wird.  Andere Bakterien wandeln Ammoniak in Aminosäuren und Proteine ​​um.  Dann fressen die Tiere Pflanzen und fressen Eiweiß.  Stickstoffverbindungen kehren durch tierische Exkremente in den Boden zurück.  Bakterien wandeln überschüssigen Stickstoff wieder in Stickstoffgas um, das wieder in die Atmosphäre freigesetzt wird.


  Um Pflanzen schneller anzubauen, verwenden die Menschen Stickstoff in Düngemitteln.  Der übermäßige Einsatz dieser Düngemittel in der Landwirtschaft hat jedoch verheerende Folgen für die Umwelt und die menschliche Gesundheit, da er zur Verschmutzung des Grundwassers und der Oberflächengewässer beiträgt.  Laut der US-Umweltschutzbehörde (EPA) ist die Lebensmittelverschmutzung durch überschüssigen Stickstoff und Phosphor in Luft und Wasser eines der am weitesten verbreiteten, kostspieligsten und herausforderndsten Umweltprobleme.


  Umgang mit Ungleichgewichten

  Laut Randy A. Dalgreen, Professor für Bodenkunde an der University of California, Davis, liegt eine Lösung für das Problem des überschüssigen Stickstoffs darin, das Bewusstsein der Landwirte für nachhaltige Landwirtschaft, ökologischen Landbau und Umweltfragen zu schärfen.


  „Die Idee wäre, zu versuchen, die Verwendung dieser kommerziellen Düngemittel zu eliminieren und stattdessen organische Abfälle zu verwenden“, sagte er und fügte zum Beispiel tierische Abfälle hinzu.  Ein weiterer Schritt wäre die Verwendung von Soft-Release-Düngemitteln mit Kunststoffbeschichtungen, und anstatt Stickstoff sofort freizusetzen, wird Stickstoff während der Vegetationsperiode freigesetzt “, sagte Stickstoff aus kunststoffbeschichteten Düngemitteln. Der Versuch, die Emissionen anzupassen. Pflanzenanforderungen “, sagte er.


  Mikrobiologen der University of Alberta in Kanada und der Universität Wien in Österreich haben eine andere Lösung gefunden.  Im August 2017 gaben Forscher bekannt, dass sie eine Ammoniak oxidierende Mikrobe namens Nitrospera anopenata identifiziert hatten.


  Laut Forschern ist Nitrospira inopinata ein Ammoniumschwamm, der bei der Oxidation von Ammonium in der Umwelt fast jede andere Art von Bakterien und Archäologen (Einzeller) hinterlässt.  Da dieses Bakterium ein so wirksames Oxidationsmittel ist, kann es dabei weniger Lachgas produzieren.


  Die neuen Erkenntnisse, die in der Fachzeitschrift Nature veröffentlicht wurden, könnten erhebliche Auswirkungen auf die Erforschung des Klimawandels haben.  Die Forscher bereiten sich darauf vor, das Bakterium durch eine Vielzahl praktischer Anwendungen zu testen, die den Ammoniumgehalt im Boden, im Wasser und in der Umwelt senken könnten.  Laut der University of Alberta können einige dieser Anwendungen Änderungen an unserem Trinkwasser, Abwasserbehandlung und Staubbehandlung umfassen.


  Wer wusste

  Obwohl der Begriff "Stickstoff" im Englischen verwendet wird, um sich auf das Element zu beziehen, wird der laoische Begriff "azote" immer noch im Französischen verwendet, und seine Form ist in "azoto" auf Italienisch oder "azot" auf Polnisch vorhanden. ۔

  Laut der Royal Society of Chemistry wird flüssiger Stickstoff häufig als Kältemittel verwendet, um beispielsweise Spermien, Eizellen und andere Zellen zu lagern, die in der medizinischen Forschung oder in Fruchtbarkeitskliniken verwendet werden.

  Flüssiger Stickstoff wird auch verwendet, um Lebensmittel schnell einzufrieren und ihren Geschmack, ihre Textur, Feuchtigkeit und ihr Aroma zu bewahren.

  Laut dem Jet Propulsion Laboratory enthält Titan (der größte Saturnmond) 95 % Stickstoff aus der Atmosphäre.

  Stickstoffgas spielt eine Rolle bei der Entstehung der Polarlichter – einer natürlichen Lichterscheinung am Himmel, die vor allem in den arktischen und antarktischen Regionen zu sehen ist – die auftritt, wenn Elektronen, die sich schnell durch den Weltraum bewegen, unsere Atmosphäre erreichen und mit Sauerstoff und Stickstoff kollidieren .  NASA

  Stickstoffgas kann durch Erhitzen einer wässrigen Lösung von Ammoniumnitrat (NH4NO3) gewonnen werden, einem festen Kristall, der üblicherweise in Düngemitteln verwendet wird.

  Nach Angaben der Royal Society of Chemistry werden nach dem Heber-Verfahren jährlich etwa 150 Tonnen Ammoniak produziert.

  Nach Angaben der Royal Society of Chemistry wurde Stickstoff in Form von Ammoniumchlorid, NH4Cl, im alten Ägypten durch Erhitzen tierischer Exkremente, einer Mischung aus Urin und Salz, hergestellt.

  Nitroglycerin, ein heftiger Sprengstoff, der bei der Herstellung von Dynamit verwendet wird, ist eine ölige, farblose Flüssigkeit, die Stickstoff, Sauerstoff und Kohlenstoff enthält.

  Zusätzliche Berichterstattung von Tracy Pedersen, Live Science Assistant.


  Zusätzliche Ressourcen


  Diese Website erklärt, was passiert, wenn man versucht, verschiedene Substanzen in flüssigen Stickstoff zu geben.

  Diese Infografik beschreibt die Stickstoffverschmutzung in der Chesapeake Bay.

Friday, January 21, 2022

Eisen

 Eisen


    Sektionen und Medien

    Verbindungen

    Die wichtigsten Oxidationsstufen von Eisen sind +2 und +3, obwohl mehrere Zustände +4 und +6 bekannt sind.  Die Tendenz zur relativen Stabilität der Oxidationszustände zwischen den Elementen der ersten Übergangsreihe für das elementare Eisen setzt sich fort, außer dass es keinen legierungs- oder chemisch kritischen Zustand gibt, in dem der Oxidationszustand des Eisens seine Wertigkeit hat Anzahl von  Schalenelektronen, acht;  Die bekannteste Oxidationsstufe ist +6, was selten und unbedeutend ist.  Sogar die Oxidationsstufe +3, die an der Position von Chrom im Periodensystem wichtig ist, verliert gegenüber der Position +2 an der Eisenposition an Boden.  Im +2-Zustand werden Eisenverbindungen als Eisen bezeichnet und enthalten hellgrüne Fe2 + -Ionen oder komplexe Ionen.  Eisenverbindungen im +3-Zustand werden Eisen(III) genannt und enthalten Fe3+-Ionen (die je nach Ausmaß der Hydrolyse von gelb über orange bis braun reichen) oder komplexe Ionen.




    Drei Sauerstoffverbindungen des Eisens sind bekannt: Eisenoxid, FeO;  Eisenoxid, Fe2O3;  Und Ferrosphärenoxid oder Ferroferrioxid, Fe3O4, das unter +2- und +3-Oxidationsbedingungen Eisen enthält.  Eisenoxid ist ein grünes bis schwarzes Pulver, das hauptsächlich als Glasschmiermittel verwendet wird.  Es kommt in der Natur als mineralischer Abfallit vor und kann durch Erhitzen der Eisenverbindung unter Luftabschluss oder durch Übertragung von Wasserstoff auf Eisenoxid hergestellt werden.  Eisenoxid ist ein rotbraunes bis schwarzes Pulver, das in der Natur als Mineral Hämatit vorkommt.  Es kann durch künstliches Entzünden einer beliebigen Eisenverbindung in der Luft hergestellt werden.  Eisenoxid ist die Grundlage einer Reihe von Farben, die von Gelb bis zu einer roten Farbe reichen, die als venezianisches Rot bezeichnet wird.  Die fein gepuderte rote Form, oft als Jewellers Rouge bezeichnet, wird zum Polieren von Edelmetallen und Diamanten sowie in der Kosmetik verwendet.  Eisenoxid bildet zahlreiche Hydrate mit variablen Strukturen und Verbindungen.  Eine häufige Form ist Eisenrost, der durch die kombinierte Einwirkung von Feuchtigkeit, Kohlendioxid und Luftsauerstoff auf metallisches Eisen entsteht.  Dieser Prozess läuft in zwei Stufen ab: Zunächst löst sich das Eisen in der Luft und die aus Kohlendioxid gebildete saure Lösung bildet Eisen(II) und setzt Wasserstoff frei.  Zweitens oxidiert Sauerstoff aus der Luft Eisen(II)-eisen, um hydratisiertes Eisen(III)-oxid zu bilden.  Ferrophorisches Oxidmineral wird als Magnetit in Form von magnetischen, schwarzen oder rötlich schwarzen Kristallen gefunden.  Es wird durch dampfendes glühendes Eisen hergestellt.  Oxid wird häufig in Materialien mit Ferrit, hoher magnetischer Permeabilität und hohem elektrischem Widerstand verwendet, die in Beschichtungen für computerspezifische Speicher und Magnetbänder verwendet werden.  Es wird auch als Schmier- und Poliermittel verwendet.



    Die Einwirkung von Schwefelsäure auf Eisen führt zur Bildung von zwei Schwefelverbindungen: Eisensulfat, FeSO4, allgemein erhältlich als Heptahydrat FeSO4 ∙ 7H2O.  Und Eisensulfat, Fe2 (SO4) 3.  Eisen(II)-Sulfat-Heptahydrat, im Handel bekannt als grüner Glaskörper oder Capras, wird als Nebenprodukt industrieller Prozesse erhalten, bei denen Eisenmetalle verwendet werden, die mit Schwefelsäure behandelt wurden.  Es dient als Ausgangsstoff bei der Herstellung verschiedener anderer Eisenverbindungen und als Reduktionsmittel.  Es wird auch zur Herstellung von Tinten, Düngemitteln und Pestiziden sowie zum Galvanisieren von Eisen verwendet.  Eisen(III)-sulfat wird in großem Umfang durch Zugabe von Schwefelsäure und einem Oxidationsmittel (wie Salpetersäure oder Wasserstoffperoxid) zu einer heißen Lösung von Eisen(II)-sulfat hergestellt.  Es wird zur Herstellung von Eisenalaun und anderen Eisenverbindungen verwendet.  Als Gerinnungsmittel in der Wasserreinigung und Abwasserbehandlung;  Und als Beizmittel (Fixiermittel) beim Textilfärben und -bedrucken.



    Eisen bildet neben Chlor eine weitere Gruppe industriell wichtiger Verbindungen: Eisen(II)-chlorid, FeCl2;  Und Eisenchlorid, FeCl3.  Eisenchlorid wird erhalten, indem trockenes Chlorwasserstoffgas über glühendes Eisen geleitet wird, um gelbgrüne, zarte (feuchtigkeitsabsorbierende) Kristalle zu bilden.  Es kann auch in hydratisierter Form, FeCl2 ∙ 4H2O, durch Auflösen von metallischem Eisen in Salzsäure hergestellt werden.  Es wird in der Farbstoffindustrie als Beiz- und Reduktionsmittel verwendet.  Eisenchlorid wird normalerweise aus Eisenchlorid durch Chlorid- oder Salpetersäureverfahren hergestellt.  Es wird zur Herstellung vieler anderer Eisenverbindungen und als Chlorierungsmittel für Silber, Kupfer und einige organische Verbindungen verwendet.  Die Behandlung einer Lösung von Fe3 + mit dem komplexen Hexacyanoferrat-Ion [Fe (CN6)] 4− erzeugt einen tiefblauen Niederschlag, der als Persisches Blau bezeichnet wird.  Dieses Öl hat einen leicht rötlichen Farbton und wird in Farben, Lacken und Linien verwendet.


    Zahlreiche Eisenverbindungen haben sich als medizinisch nützlich erwiesen.  Eisengluconat, Fe (C6H11O7) 2 ∙ 2H2O, und Eisenpyrophosphat, Fe4 (P2O7) 3 ∙ xH2O, gehören beispielsweise zu den Verbindungen, die am häufigsten zur Behandlung von Anämie verwendet werden.  Zur Förderung der Wundheilung werden verschiedene Eisen(III)-Salze aufgetragen, die als Gerinnungsmittel wirken.


    Dieser Artikel wurde kürzlich von Eric Gregerson überprüft und aktualisiert.


Thursday, January 20, 2022

Sulfuric Acid

 

 


  

  Sulfuric acid

  You may have had many sulfuric acid experiments.  Didn't you  So, has it ever been put in water?  no!  never ever!  but why?  Let's find out  In the next section, we will read all about sulfuric acid and its properties.  Then we will look at its use.  So let's start with what it is.


 

  Introduction to P Block Elements


  Introduction to the Carbon Family


  Fluorine abnormal behavior


  Percent free SO3 in Oleum




  What is sulfuric acid?

  Sulfuric acid, also spelled sulfuric acid or H2SO4, is an odorless, colorless, oily liquid.  Also, it is very corrosive.  Another name for it is the Isle of Wight.  Due to its wide applications, it is called the 'King of Chemicals'.  Furthermore, we can find it in both shared and independent situations.




  Browse more topics under P-block elements.

  Introduction to P Block Elements

  Some important compounds of carbon and silicon

  Carbon tendency and unusual properties

  Trends and properties of boron and aluminum

  Ammonia

  Chlorine

  Dinitrogen

  Dioxin

  Boron Family: Group 13 Elements

  Carbon Family: Group 14 Elements

  Group 15 elements

  Group 16 elements

  Group 17 elements

  Group 18 elements

  Hydrogen chloride

  Interhalogen compounds

  Nitric acid and nitrogen oxides

  Halogen oxy acids

  Phosphorus oxo acids

  Sulfur oxo acids

  Ozone

  Phosphine

  Phosphorus - Allotropic forms.

  Phosphorus halides

  Simple oxides

  Sulfur - Allotropic forms.

  Sulfur dioxide

  The process of preparation of sulfuric acid

  In general, there are two techniques for industrial production of sulfuric acid.  They are:


  Lead chamber operation

  Contact process

  Now let's look at these processes in detail.


  1) Contact process

  There are three main stages in the communication process.


  Step-I: Production of Sulfur Dioxide

  Sulfur dioxide is produced by heating sulfur or sulfide metals.  For example, iron pirates in excess of air.


  S (sulfur) + O2 (oxygen) + Δ (heating) → SO2 (sulfur dioxide)


  4FeS (iron pyrites) + 7O2 (oxygen) + Δ (heating) → 2Fe2O3 (ferric oxide) + 4SO2 (sulfur dioxide)


  Step-II: Formation of Sulfur Trixide

  Sulfur dioxide is then oxidized with atmospheric oxygen in sulfur trioxide using V2O5 as a catalyst.


  2SO2 (sulfur dioxide) + O2 (oxygen) + V2O5 (catalyst); SO3 (sulfur trioxide)


  Step-III: Converting Sulfur Trixide to Sulfuric Acid

  Then, sulfur trioxide is broken down into 98% sulfuric acid to provide oleum.  Another name for oleum is pyrosulfuric acid.  The oleum is then diluted with water to give the desired concentration of sulfuric acid.


  SO3 (sulfur trioxide) + H2SO4 (sulfuric acid-98%); H2S2O7 (pyrosulfuric acid / oleum)


  H2S2O7 (Pyrosulfuric acid / Oleum) + H2O (Dilution) → 2H2SO4 (sulfuric acid)


  2) Lead chamber process

  Lead chamber operation is one of the most common manufacturing techniques.  This results in about 50-60 B grade acids.  In this process, we use wet SO2 in the presence of nitrogen oxides.  As a result, it oxidizes with oxygen in the air and forms sulfur trioxide.  This is how the reaction is expressed.


  2SO2 + O2 → 2SO3


  Sulfur trioxide is then made to react with water to obtain H2SO4.  This is how the reaction is expressed.


  SO3 + H2O → H2SO4


  Physical properties of sulfuric acid

  Sulfuric acid is a thick, colorless and oily liquid.

  Its specific gravity is 1.84 at 298 K.

  The boiling point of acid is 611 K.  The boiling point and thickness of this chemical is due to hydrogen bonding.

  This strong chemical reacts with water which releases a lot of heat.  That way, you should never add water to H2SO4.  Instead, you should add the acid to the water, slowly, stirring appropriately.

  Chemical properties of sulfuric acid

  Sulfuric acid is a strong diabetic acid.  In addition, it occurs in water solution in two stages, diprotic and ionises.

  This chemical is highly corrosive, reactive and soluble in water.  It has high oxidizing power and thus acts as a strong oxidizing agent.

  There are very few fluctuations.  Because of this, it plays a role in the production of more volatile acids than their comparable salts.

  Concentrated sulfuric acid is a very strong dehydration agent.  Thus this chemical is used to dry many wet gases which do not react with acids.

  It also draws water from natural compounds like starch.

  Because it is a good oxidizing agent, it can oxidize non-metals as well as metals.  In addition, it reduces sulfur dioxide itself.

  Some common reactions to sulfuric acid

  Hot concentrated sulfuric acid oxidizes copper to copper sulfate.

  Cu + 2H2SO4 → CuSO4 + SO2 + H2O


  Concentrated sulfuric acid gives hydrogen chloride from sodium chloride.  In addition, it releases hydrogen fluoride from calcium fluoride.

  CaF2 + H2SO4 → CaSO4 + 2HF


  It burns glucose, sugar and starch into carbon.

  C12H22O11 + (H2SO4) → 12C + 11H2O


  Example solved for you

  Question: Write the basic uses of sulfuric acid.


  Answer: The uses of sulfuric acid are:


  It is a common chemical in the preparation of fertilizers.  For example ammonium sulfate and superphosphate.

  We use it to make colors, shades and colors.

  It is a common chemical in the manufacture of explosives.  For example, TNT.

  Other essential chemicals require the presence of sulfuric acid.  Without sulfuric acid, we can't get this chemical.  For example hydrochloric, phosphoric and nitric acid.  It is also essential for sodium carbonate.

  We use it as part of petroleum refining.

  It acts as a pickling agent.

  It is common as chemical laboratory agent, dehydration agent and oxidizing agent.


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Calcium Oxide

Calcium oxide

   Chemical compound

   Alternative titles: Lime, Quick Lime


 


   Lime deposits

   Depth of limestone in relation to annual rainfall.  Lime deposits (CaCO3) that can block the entry of plant roots are found deeper in the soil profile where there is a higher average annual rainfall than the season where there is less water to transport lime through the soil.  Is.

   Encyclopedia Britannica, Inc.

   Learn about this topic in these articles:

   Various references

   Time measurement

   In the soil: time

   The accumulation of soil and lime in the soil profiles as a result of their displacement towards the bottom is also an indication of aging.  For example, older soils that are formed on low calcium deposits tend to produce better than smaller soils on E and Bt horizons (as well as thin A horizons).


 

 

   Disadvantages: Physical and chemical properties.

   … Nodules (Los Doll) and Lime Layers (Calcium).  Lime forms rotary tubular encroachments with rotten plant roots, fisher fillings, and similar pathways in loess.


 

   Application

   In calcium: compounds

   Calcium oxide, CaO, also called lime or especially quick lime, is a white or grayish-white solid that is made by frying calcium carbonate in large quantities to expel carbon dioxide.  At room temperature, CaO will absorb carbon dioxide from the atmosphere spontaneously;


 

   Cement

   In Cement: History of Cement

   The materials used included limestone and volcanic ash, which reacted slowly with water to form a hard mass.  This led to the construction of Roman mortar and concrete cementing materials more than 2,000 years ago and later construction work in Western Europe.


 

   Coal burning

   Use of coal: Fluidized bed

   * Coal, limestone dissolves in calcium oxide (CaO), which then reacts with most of the SO2 emitted from burning coal in bed to produce calcium sulphate (CaSO4).  CaSO4 can be removed as a solid by-product for use in a variety of applications.  In addition, partially consumed calcium;


 

   Glass

   In glass: The structure of commercial glass

   The addition of lime (calcium oxide, or CaO), which is supplied by limestone, makes the glass insoluble again, but too much makes the glass subject to dewatering - that is, crystals within certain temperature limits.  Description of line steps.  The best synthesis is about 75% silica, 10% lime, and 15%.


 

   In industrial glass: silica based

   … Soda ash), and lime, or calcium oxide (CaO ؛ usually derived from roasted limestone).  Other ingredients can be added to this basic formula to achieve different properties.  For example, by adding sodium fluoride or calcium fluoride, a translucent but opaque product called opal glass can be obtained.


 

   In industrial glass: chemical compounds

   Limestone is obtained from limestone (calcium carbonate) or dolomite (calcium magnesium carbonate) when magnesium oxide is also required.  In the past it was customary to add about 0.25% arsenic oxide and 0.5% sodium nitrate to help fix or remove the glass.


 

   In unstructured solids: melting and extinguishing

   … = 1) Similar to Pure Calcium Oxide (CaO) and Pure Aluminum Oxide (Al2O3), deeper at least in the Tf-versus-x curve near the center of the compound boundary.  Although neither calcium oxide nor aluminum oxide can easily form glass, glass is easily formed from mixed compounds.  For relevant reasons;


 

   Portland Cement

   In cement: compound

   Lime compounds (calcium oxide, CaO) mixed with silica (silicon dioxide, SiO2) and alumina (aluminum oxide, Al2O3).  Lime is obtained from calcareous (lime-containing) raw materials, and other oxides are obtained from an argilisis (clay) material.  Additional raw materials such as silica sand, iron oxide (Fe2O3)


 

   In cement: chemical composition

   … C4AF, where C stands for Calcium Oxide (Lime), S stands for Silica, A stands for Alumina, and F stands for Iron Oxide.  Non-composite lime and magnesia are also present in small amounts, along with small amounts of alcohol and other elements.


 

   پوزولانا

   In Pozzolana

   * (Pozulan) powder with hydrated lime.  Roman engineers used two parts of the weight of pozzolan mixed with one part of lime to reinforce mortar and concrete in bridges and other masonry and brick work.  During the third century BC the Romans used pozzolana instead of sand in concrete and


 

   Soda lime glass

   In soda lime glass

   … And 9% lime (calcium oxide), with very small amounts of various other compounds.  Soda acts as a flow to reduce the temperature at which silica melts, and lime acts as a stabilizer for silica.  Soda Lime Glass Cheap, Chemically Stable, Reasonably Hard and Extreme;


 

   In unstructured solids: Properties of oxide glasses

   * Strong oxides, such as lime (CaO) and magnesia (MgO), make glass more durable.  Most commercial glass contains soda-lime-silica mixture and is manufactured in large quantities for plate and sheet glass, containers and light bulbs.


 

   Steel making

   In steel: slag

   Add slag (calcium oxide ؛ CaO) as a flow to form slag.  Burned lime itself has a high melting point of 2,570 ° C (4,660 ° F) and therefore solidifies at steel-making temperatures, but when it is mixed with other oxides, they all combine.  Melts ...


 

   Sugar production

   In Sugar: Explanation

   * Free from the addition of heat, lime, and flocculation aids.  Lime is a suspension of calcium hydroxide, often in a solution of sucrose, which forms a calcium secretion compound.  Heat and lime kill the enzymes in the juice and neutralize the pH by raising the natural acid level from 5.0–6.5;


 

   Alumina


   Sections and media

   Home

   science

   Chemistry

   Alumina

   Chemical compound

   Alternative titles: Aluminum oxide


   Cite

   More

   By the editors of the Encyclopedia Britannica  See edit history

   Alumina, also called aluminum oxide, is a synthetic aluminum oxide, Al2O3, a white or almost colorless crystalline substance used as a starting material for smelting aluminum metal.  It also acts as an active agent in a wide range of advanced ceramic products, raw materials and chemical processing.




   Ambiguous alumina



   View all media

   Related Topics: Corundum Table Alumina Synthetic Corundum Activated Alumina Calcined Alumina

   View all relevant content


   Alumina is made from bauxite, a naturally occurring ore containing a variable amount of hydrates (containing water) aluminum oxide.  Free Al2O3 is a mineral found in nature in the form of corundum and its precious stones, sapphires and rubies.  They can be synthesized from alumina and are sometimes even known as alumina, but the term is more appropriately limited to materials used in aluminum metallurgy, industrial ceramics, and chemical processing.



   Translucent alumina.

   Translucent alumina.  With the use of magnesia as a sintering aid, the pores expand from the material and remain at the boundaries between the grains, contributing to the translucency.

   (Above and between) W.H.  Rhodes and GC R.W.  Weaver (eds.) In Cahn and M.B., Encyclopedia of Materials Science and Engineering, Supplementary Vol.  3, © 1993 Pergamon Press  (Below) General Electric Company


   Read more on this topic

   Aluminum processing: aluminum oxide

   Aluminum oxide is present in many different crystallographic forms, of which corundum is the most common.


   Some alumina are still produced by melting bauxite in electric furnaces, in a process designed for the abrasive industry in the early 20th century, but most are now extracted from bauxite by Bayer process, which began in 1888.  Developed for the aluminum industry.  Bayer process bauxite is crushed, mixed with sodium hydroxide solution, and aluminum hydroxide is sown with crystals to accelerate.  Hydroxide is heated in a kiln to extract water and produce a variety of granular or powdery alumina, including activated alumina, smelter grade alumina, and calcined alumina.



   Activated alumina is an unsafe, granular substance used as a substrate for catalysts and as an absorbent to extract water from gases and liquids.  Simulator grade alumina makes up 90% of all manufactured alumina.  It is transported to aluminum plants, where it is electrolyzed to aluminum metal.  Calcined alumina is manufactured in a variety of ceramic products, including spark plug insulators, integrated circuit packages, bone and dental implants, laboratory equipment, sandpaper grits and grinding wheels, and refractory linings for industrial furnaces.  These products showcase the properties for which alumina is known, including low electrical conductivity, chemical attack resistance, high strength, extreme hardness (Mohs hardness scale 9, highest rating 10), and high melting.  Location (approximately 2,050 ° C, or 3,700 ° F).


   The hardness of alumina can be improved by adding zirconia particles or silicon carbide whiskers, making it suitable for industrial cutting tools.  Also, generally opaque materials can be made translucent by adding a small amount of magnesia.  Translucent alumina is used as a gas container in high pressure sodium vapor street lamps.



   Translucent alumina.

   Sodium vapor lamp with cylindrical envelope of translucent alumina containing hot gases.

   (Above and between) W.H.  Rhodes and GC R.W.  Weaver (eds.) In Cahn and M.B., Encyclopedia of Materials Science and Engineering, Supplementary Vol.  3, © 1993 Pergamon Press  (Below) General Electric Company

 


 



   Lime deposits

   Depth of limestone in relation to annual rainfall.  Lime deposits (CaCO3) that can block the entry of plant roots are found deeper in the soil profile where there is a higher average annual rainfall than the season where there is less water to transport lime through the soil.  Is.

   Encyclopedia Britannica, Inc.

   

Monday, January 17, 2022

Paint

 





For some, a clean car isn’t enough. It needs to be closer to perfection.


A deep cleaning of your vehicle’s paint, including correcting the imperfections in the clear coat, then applying a layer of protection, can make your car look like new.


Once complete, you'll have a layer of protection on your paint. If done right, the vehicle will look better, feel smoother (why are you touching the paint? Stop that!), and shine brighter. Sunglasses sold separately.


Properly detailing a car isn’t an hour-long endeavor. Depending on the condition of the paint, it could take anywhere from a morning to a lifetime; that shine is addictive. With the right time, equipment, and practice, a vehicle can sit in the sun and never reflect paint swirls, hazing, or scratches.


Based on more than 25 years of detailing vehicles (and boats), along with six years of professional detailing experience, here are my recommended steps to properly clean, correct, and protect your vehicle’s paint.


 



How to detail your car like a pro


Precautions and warnings


The risks of scratching, marring, or damaging a vehicle while detailing it are severe. Taking a power tool or abrasive chemicals to a vehicle’s finish increases those risks exponentially. The result could be a marred finish or worse, burning through the clear coat. Then you’ll have a dull spot showing exposed paint, like an open wound.


Following the right process is the start, but trial and error is required to truly master the art of detailing. Practicing on an old hood, body panel, or car no one cares about is advised.


The hardness of clear coats varies by automaker. Vehicles with softer clear coats will be easier to work with and imperfections will buff out quicker. With experience you’ll spot consistent trends and learn that, in general, the clear coats of Japanese vehicles are softer, Germans are harder, and Americans are thicker.


Jewelry and watches should be ditched before starting. Sorry, Honey, the wedding ring needs to come off temporarily. Belts should either be ditched or the buckle should be covered 100% by a shirt.


 



How to detail your car like a pro


Equipment


You’ll need clean microfiber towels, paint clay, liquid spray detailer, bug/tar remover, an orbital buffer or rotary polisher with a backing plate, polishing and cutting pads, liquid paint compound, wax, an LED headlight, and bright lights. A good portion of this stuff can be purchased locally at the auto parts store or a home improvement store, but buying online opens a world of choices with typically higher quality products.


All this equipment can be had for less than $1,000, or you could easily spend ten times that amount. It’s an investment in your vehicle. Except for the lighting and hardware, a lot of this stuff will need to be replaced over time.


 



How to wash a car like a pro


Wash, then detail


The vehicle has to be completely clean from any road grime and debris. Sand, rain spots, pollen, bird droppings, and any other dirt have to go. Here’s a handy guide on the proper way to wash your car.



How to detail your car like a pro


Location, location, location


Detailing should be done inside, or at a minimum under some sort of structure that protects the vehicle from sunlight and debris. A well-lit garage is the ideal location.


LED lighting has made it much easier to to shine a lot of light on a car. A 10,000-lumen LED light bulb costs less than $100. I have three 10,000-lumen bulbs in my garage. My wife will tell you it’s like looking at the sun. Imperfections in the paint can hide in the shadows and darkness, but ithey can’t escape the sun or bright LED lights.


 



How to detail your car like a pro


Process


Detailing is a panel-by-panel, section-by-section process. Work the vehicle from top to bottom, front to back, starting with the hood. Leave the bottom quarter of the vehicle—lower bumpers, doors, moldings, rear bumper—for last during each step as that’s where the most dirt lives.



How to detail your car like a pro

Clay, for cars


After washing the car, clean the clear coat with clay. Skip this step and you’ll swirl dirt and contaminants that you can’t see onto the clear coat.


Some clays are softer and stickier, making them easier to use, while some are harder and less enjoyable to work with. While some bars are as light as 60 or 80 grams, most are 100 grams. I prefer a larger 120+ gram bar to ensure I have more clay to work with.


Using liquid detailer, spray a section of the hood and rub the clay bar in side-to-side motions across the clear coat. For the Jeep Grand Cherokee shown here, I broke the hood into four sections. A 2-foot by 2-foot section is typical. Once you’ve gone over the entire section a few times, stop, fold the clay into itself half a dozen times or so to work the dirt and contaminants into the center of the clay. Dry the panel with a microfiber towel, and feel the paint.



How to detail your car like a pro


If it’s not perfectly smooth, go over it again. Putting your fingers in a thin Ziploc bag and running them over the paint increases the sensation and allows you to better feel contaminants in the paint.


Repeat the process across the entire vehicle. Start with the hood, and move on to the front fenders, A-pillars, roof, door uppers, rear fenders, and trunk/hatch. Next, move on to the lower bumpers, rockers, and moldings. Never use the clay without folding it into itself half a dozen times or so after a panel and never use a clay bar that’s been dropped on the ground or otherwise contaminated. Never reuse a clay bar. One clay bar for one vehicle.


Remaining bits


The paint’s now clean, but what if you see tar or stubborn baked-on bug guts? Grab a can of bug and tar remover and remove it with a microfiber rag. Real tough stuff can be treated with chemicals such as Goof Off or even lacquer thinner, but these are harsh; touch the wrong part and a piece of trim or decal might droop or lose its shine. Proceed with extreme caution. You don't need to clay bar these areas again as any contaminants the clay would remove have already been removed.


 



How to detail your car like a pro


Paint correction: Decision time


My grandfather used to say, “God only made so much land.” He was right, and automakers only put so much clear coat on a vehicle. Before you correct a vehicle’s paint there are some important questions that need to be answered. Is this vehicle a daily driver that hauls the kids to soccer practice? Is this a supercar or hypercar? Is this a classic? Does this vehicle have single-stage paint? Is this car headed to a concours event that will be judged? The answers to these questions impact the next steps.


You have to decide what level of correction is desired. Play the long game for most vehicles. There are only so many times a high touch area (hood, fenders, rear pillars, etc,) can be corrected before the clear coat runs out. Every time you detail a vehicle and correct its paint it should look better than the last time as you’re building off your previous work. However, that also means you're removing clear coat each time. It’s unwise to go for perfection every time as you’ll run out of clear coat.


Show cars headed to concours events or sports cars/hypercars/supercars that will rarely be driven or are about to be fully wrapped in protective film should be made perfect.



How to detail your car like a pro


Measure before you cut


Before correcting the paint it’s important to know roughly how much clear coat is on the surface. Between primer, paint, and clear coat, most vehicles have about 4 to 5 mils of coating, though some have a bit more based on the painting process. About a third of that, or 1.5 to 2 mils on average, is the clear coat. The vehicle shown, my Jeep Grand Cherokee, had a thicker coating that measured between 6.8 and 8.8 mils depending on the panel.


A paint depth gauge costs as little as $20, though the more you spend the more accurate and better quality the gauge will be. Get one and measure a few spots on each panel to get a feel for the depth of the coating on your vehicle. This process can show you areas where you have to be careful due to a thinner clear coat.


If a vehicle has been detailed many times, especially by someone without experience, it’s likely there’s less clear coat. A mistake during correction could result in blowing through the clear coat.



How to detail your car like a pro


Time to correct


Unless you’re trying to fix a scratch you’ll be correcting the paint on your entire vehicle. Otherwise, you’ll have one shiny, swirl-free panel on a marred car. My Jeep is a daily driver and I wasn't aiming for perfection, just correction to remove swirls, hazing, and micro-scratches.


Correcting your car’s paint is akin to sanding. You’re rubbing a grit on the clear coat to reduce or remove imperfections. Both the pad and compound you use will have grits and cutting and finishing properties. Sometimes it's necessary to start with rougher grits and work your way to a finer grits. Foam, microfiber, or wool pads can all get the job done. I prefer foam.


Paint correction can be done by hand with a microfiber rag or pad, but it’ll take far longer and require a lot more energy than using an orbital buffer. It’ll also be harder, though not impossible, to produce the same results. Tools help.


Choose the first grit for your pad—on the Jeep I used a foam light cutting pad—and attach the pad to the orbital or rotary buffer backed by a backing plate. Put three or four fingernail-sized dots of rubbing compound on the pad—I used a 1,200-grit fast-cutting compound—turn the speed dial to three or four, and place the buffer on the panel you intend to work on. Only now you can turn on the buffer. Applying mild, even pressure, move the buffer across the panel's surface in vertical, then horizontal, then diagonal lines. Scratches, swirls, hazing, and mars go in all directions and just like Pokemon Go you want to try and catch them all. When complete, remove the compound by wiping the surface with a microfiber rag.


Stop.



How to detail your car like a pro


Now check your work with an LED flashlight. Look directly at it and from side angles to check the progress. It’s important to check each section after these passes. Rinse and repeat section-by-section, panel-by-panel for the entire vehicle. Yes, you can do taillights and headlights. Yes, you can do chrome. But it’s important to know what compound and pads you are using on these things and ensure it’s the same grit level that you want for the clear coat.


Correcting is done in stages, just like sanding. If a vehicle’s clear coat is in rough shape and this is a car that is being made perfect it will likely take multiple rounds of correcting with multiple compounds and pads.



How to detail your car like a pro


Polish and protect


Congratulations! You’ve corrected your vehicle’s clear coat and hopefully not burned through it. Now it’s time to polish and apply protection to your vehicle’s finish.


Just like the correction stage, this can be done by hand with a microfiber towel or pad, but it’ll take far longer and it will be hard to produce the same results as an orbital or rotary buffer.


At this point, evaluate where compounding and correcting has left your finish.


If the finish could use one more step, a cleaner wax can be applied with a very mild finishing and polishing pad on the orbital buffer or rotary polisher. This will add another layer of protection while helping clean up a few tiny scratches.


The last step is to apply a wax or sealant with a fine finishing pad on the buffer. This provides no correction and instead applies a layer of protection that adds a brilliant shine.


Wheels!


You aren’t done yet. Wheels need love too. Some vehicles have painted wheels while others have steel, chrome, or painted alloys. It's important to protect your wheels and to choose the right product based on the wheel finish. If they are painted you might want to correct them so they shine just as brightly as the paint. This is typically done by hand, but some wheels are large enough or have enough surface area that a smaller buffer can be used.


 



How to detail your car like a pro


Clean up


You’re hot, sweaty, and tired, but the job’s not done. Wax dust covers your vehicle’s glass, chrome, grille, and other bits. Don’t go through all this work only to leave a sloppy look.


Wipe down the glass with a clean microfiber rag to remove all the dust. Then clean it with an ammonia-free glass cleaner. Wipe down the grille, lights, and trim bits with a microfiber rag. Make sure there’s no wax left behind on any seals, rubber gaskets, or in cracks and crevices such as door handles.


Now you're done!


Enjoy a beautiful, shiny, and protected finish and repeat these steps every 6-12 months to keep your car looking shiny all the time.


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