( 5 ) nuclear energy. AgInCd alloy is important neutron control rod material. Pd-Ag , Pd-Ag-Au-Ni multi-hydrogen purification materials can be used for H 2 isotope purification and separation in thermal diffusion type hydrogen and oxygen purification equipment and nuclear fusion reactor Tamper Evident Cap,Tamper Proof Water Caps,Tamper Proof Cap,Tamper Evident Screw Cap Jiangyin First Beauty Packing Industry Co, ltd , https://www.cosmeticpacking.com
   Silver in the application of catalyst
Catalytic technology is one of the key technologies for the development of the chemical industry. 20 % to 30 % of the gross national product of developed countries comes directly from catalysis. Silver has many special applications in catalysts. Such as:
　　 Ag/Al 2 O 3 is used to oxidize ethylene to produce ethylene oxide or ethylene glycol. Silver Catalyst Converts Ethylene to Ethylene Oxide to make polyester fibers for the manufacture of sweaters, scarves, coats, shawls and other popular fabrics.
　　 KBr-Ag-Al 3 O 3 is used for the dehydrogenation of butane to butadiene.
A catalyst composed of metal Ag and Pd can greatly improve the production of formaldehyde.
DuPont uses Ag-Au mesh for formaldehyde oxidative dehydrogenation to formaldehyde.
　　 Ag/ zeolite catalysts are used in the production of formaldehyde, glacial acetic acid, nylon, acetaldehyde, hydrazine, etc., and silver catalysts containing yttrium ( Y ) can be used to improve and improve the aroma of perfumes and foods, the aroma of toothpaste, chewing gum and cigarettes, and drugs. Synthesis, etc.
Silver catalysts can be used to treat industrial waste gases containing sulfides.
Silver-containing catalysts are useful in the manufacture of high octane fuels for benzene.
The silver catalyst converts H 2 and CO 2 into syngas methane and ethanol (automobile fuel).
Silver X molecular sieves can be used as a gas dehydrogenation deoxidation.
Metal silver catalysts oxidize organics to CO 2 and water.
Acetone can also be produced by catalytic dehydrogenation of isopropanol on a silver catalyst. The amine is dehydrogenated with a silver catalyst to produce a nitrile ( RCN ). Silver compounds are widely used as catalysts for redox and polymerization.
Silver nitrate catalyzes the preparation of methyloxy rings from propylene. Silver perchlorate can be used to produce a polymer of butyl acrylate by dimethylformyl and to effect polymerization of methacrylic acid amide.
   Tetrafluoroboric acid silver may be used for cyclization of the amine propadiene Synthesis of 3-pyrroline. Silver carbonate is used alone or on a sub-acetyl plastic ( celite ) for the oxidation of methyl esters of D -fructose, ethylene, propylene triose and alpha -diol. Silver sulfate can reduce aromatic hydrocarbons to cyclohexane derivatives; it can also be used to oxidize organic matter to determine the chemical oxygen demand ( COD ) in wastewater samples . Pd-Ag thin catalysts are also widely used: for example, Pd-20Ag can be used for the conjugation reaction of 2 -rebutene dehydrogenation, hydrodemethanization of toluene or hydrogenation of benzene Pd-23Ag can be used for cyclohexane hydrogenation. Pd-25Ag hexane widely used in the dehydrogenation reaction of conjugated and hydrogen peroxide; Preparation of isoprene hydrogenation of 2 - methyl - 1 - butene; 2, 4 - hexadiene and 1, 5 - is Preparation of ethylene from diene, ethylbenzene from styrene, preparation of propionaldehyde semicarbazone from acrolein; dehydrogenation of cyclohexanol; dehydrogenation of n- butane to prepare dehydrogenation of 1 -butene and isobutane
Butene; 1 , 3 - butadiene and 1 -butene are hydrogenated to prepare butane and the like. Pd-35Ag can hydrogenate the hexene. Pd-40Ag, Pd-50Ag can dehydrogenate cyclohexane.
   The application of silver in medicine
   A. The application of silver in medicine
Biomedical materials are different from drugs, and their main therapeutic goals are not achieved by chemical reactions or metabolism in the body, but must meet the requirements of biological properties, ie biocompatibility. Silver is more widely used in medicine than gold.
   ( 1 ) Surgical silver: acupuncture with silver needles, silver thread sutured bone and connective tissue, silver drainage tube. Silver alloys are used for bone replacement (especially for skulls). Silver foil coated fresh wounds can speed up open wound healing. Ag-Pd alloys are widely used in devices such as optic nerve repair devices, ear foil nerve stimulation devices, spinal cord stimulation for incontinence, and spinal cord bending in children. The use of electric biostimulation ( Electrical Biostimulation ) promotes the growth of bones and skin with silver. [next]
( 2 ) Dental materials. Can be divided into dental casting alloys and dental amalgam . Casting silver-based dental alloys include: Ag-Cu-Sn , Ag-Cu-Sn-Zn , Ag-Cu-Zn-Ni , Ag-Pd , Ag-Pd-Au , Ag-In-Zn-Pd, etc. . Ag-Pd is used for dental trays and short span bridges. Dental amalgam is a repair filler for teeth. The old Ag-Sn amalgam alloy is no longer in use. Now, Ag-Cu-Sn amalgam is used to mix the alloy into spherical powder and irregular powder. The mixed powder is more compact and better. Carved for viscosity. High- lead silver alloy powders and mercury-free dental filling materials (such as Ag-Ga -based alloys and gallium alloy materials) have received much attention.
   ( 3 ) Silver has applications in diagnosis and analysis. Silver staining is useful in diagnostics, and its sensitivity is 100 times higher than other methods . Silver can be used for prenatal diagnosis and pathological monitoring of fetal malformations, changes in pathogenic physiology, diagnosis of genetic disease chromosomes, identification of hormonal and urinary polypeptide levels, and evaluation of drug treatment, as well as for the analysis of natural foods. Silver protein analysis provides clear images for the identification of other proteins using the " fingerprint protein " . Silver complexes can be used to determine and observe the smallest building blocks of human cells for the diagnosis of cancer and to indicate multiple sclerosis. antibodies present disease, to accurately identify the abnormal protein by electrophoresis. tropism of silver nitrate used for early diagnosis of breast cancer estrogen. made of Ag
The film is used to determine the concentration of glucose in the urine and to diagnose the disease. Biosensors can be used to measure syphilis antibodies and measure blood type and O 2 and CO 2 concentrations and pH values ​​in blood using Ag/AgCl electrodes .
   ( 4 ) Silver halide fiber CO 2 laser scalpel. The silver halide polycrystalline fiber [AgClxBr(1-x)] (0 ≤ X ≤ 1) has good infrared spectral signal and mid-infrared laser energy performance. China's newly developed silver halide fiber CO 2 laser scalpel has been clinically applied in the oral cavity, throat, gynecology, anorectal and other aspects. After completing the clinical application, it will enter the industrialization stage.
   ( 5 ) Medical imaging X- ray film, CT film, and MRI film.
    B. Application of silver in medicine
   ( 1 ) Silver in traditional Chinese medicine: Some Chinese medicine formulas have silver foil in their composition. Some Chinese herbal medicines also contain trace amounts of non-silver silver. For example, the content of silver in raw radix is 4.615 μg/g .
   ( 2 ) Soluble silver salts: such as silver nitrate and silver citrate. The most commonly used soluble silver salt is silver nitrate, which can be used as astringent, irritating or caustic drug. Its action is related to the concentration and duration of the deep liquid. Solid bar-shaped silver nitrate (containing 1 to 3 % AgCl ) Or different concentrations of silver nitrate solution can be used to remove sputum, internal sputum, internal buds and the like. Silver citrate can be used to treat burns and skin diseases. Eye drops in the eyelids of newborns can be prevented from being infected with streptococcus by using 1 % silver nitrate solution.
   (3) insoluble compound: such as an oxide, a halide salt (oxide, iodide). Colloidal silver can be used as a cream to treat burns and skin infections.
   ( 4 ) Silver sulfadiazine and silver fluoride: This is a major medical silver. It is used to treat burns and African sleeping sickness.
   ( 5 ) Silver sol: such as AgI (Neosilvol) colloidal solution and strong protein Protargol (Strong) and soft silver protein Argyrol (mild) and Crede plaster (including the silver) can be used as an effective topical anti-infective. Colloidal silver is used for gynecological washing and disinfection.
   ( 6 ) Electron-generated silver ion technology ( EGSI ). The experiments have proved that all types of bacteria, Gram-positive bacteria, Gram-negative bacteria and various aerobic and anaerobic bacteria have obvious anti-infective effects and have broad-spectrum antibacterial effects.
   10 . Silver series antibacterial material
Silver series antibacterial materials are a class of inorganic antibacterial materials. The inorganic silver-loaded antibacterial material has the characteristics of persistence, durability, broad spectrum, good heat resistance, high safety and resistance to drug resistance.
Silver series antibacterial materials are silver antelope group apatite, silver sodium zirconium phosphate, silver zeolite, silver sodium borosilicate, silica, titanium dioxide, copper, silver and the like.
Silver-coated materials are widely used, and many practical products can be developed.
The antibacterial material with the basic composition of sodium zirconium phosphate and silver is applied to: antibacterial PE , PP , ABS and other film products, refrigerator lining, washing machine lining, bacteria-proof mildew packaging materials, antibacterial ceramics, bathtub, face washer , toilets, tiles, paints, magnetic teeth, antibacterial products, containers, tableware, food containers, etc. [next]
Silver-loaded zinc zeolite. Can be used for antibacterial fiber products, non-woven fabrics, underwear, footwear, cars, aircraft seat cushions, medical show white coats, bed sheets, etc. Antibacterial PE, PP, ABS and other film products, PE film and other products such as aluminum alloy.
Sodium borosilicate silver. Can be used for bacteria, PE , PP , ABS and other film products, antibacterial glass products, fiber products, antibacterial paper, silk and so on.
Titanium dioxide silica silver copper . A soil fungicide is available.
Acetyl-based apatite. It can be used for anti-mold and anti-bacterial PP , PVC , PE and other film products, ship decoration, industrial circulating water anti-bacterial engineering, coating film, etc.
Compounds such as silver triazole, silver thiosalicylate and silver glycyrrhizinate also have good antibacterial and bactericidal effects.
The inorganic antibacterial agent is a contact agent for elements, element ions and functional groups such as Ag , Cu , Zn , S , As and Ag + , Cu 2+ , SO 3 2+ , AsO 2 - and the like. The elemental Ag has a so-called microdynamic effect ( Oligodynamiceffict ) which kills microorganisms such as bacteria, molds, spores and fungi that come into contact with it. A variety of metal ions have antibacterial effects The order of action is:
　　 Ag > Hg > Cc > Cd > Cr > Ni > Pd > Co > Zn > Fe .
However, Hg , Cd , Pd and Cr have residual toxicity to human body. Ni , Co and Cu are not stained in the fiber and should not be used in fibers. In fact, the metal antibacterial agents commonly used for chemical transformation are Ag , Zn and Compound. The antibacterial effect of silver is related to its own valence state, which is decelerated in the following order:
　　 Ag 3+ > Ag 2+ > Ag +
The high-valent silver has a very high reduction potential and can cause atomic oxygen in the surrounding space to have an antibacterial effect. Ag+ can strongly attract the sulfhydryl groups of the enzyme eggs in the bacteria and bind them quickly, so that the necessary enzymes lose their activity and cause the bacteria to die. The mechanism is as follows:
　　　　 SH 　　　　　　　　 SAg
Enzyme 　　 + 　 2Ag+ 　 = enzyme + 　 2H+
　　　　 SH 　　　　　　　　 SAg
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   Silver series antibacterial materials can form a large industry.
   Common inorganic desiccant
   In order to keep the medicine dry or to dry the produced gas, a desiccant must be used. There are three types of commonly used desiccants: one is acid desiccant, concentrated sulfuric acid, phosphorus pentoxide, silica gel, etc.; the second type is alkaline desiccant, solid caustic soda, lime and soda lime (sodium hydroxide and hydroxide) a mixture of calcium) and the like; third category is neutral drying agent such as anhydrous calcium chloride, anhydrous magnesium sulfate and the like. The properties and uses of commonly used desiccants are as follows: [next]
   1. Concentrated H 2 SO 4 : has strong water absorption and is commonly used to remove moisture in a gas which does not react with H 2 SO 4 . For example, it is often used as a drying agent for gases such as H 2 , O 2 , CO , SO 2 , N 2 , HCl , CH 4 , CO 2 , and Cl 2 .
   2 , anhydrous calcium chloride: because of its low cost, strong drying ability is widely used. It has a fast drying speed and can be regenerated with a dehydration temperature of 473K . It is generally used to fill dryers and drying towers, dry medicines and various gases. Can not be used to dry ammonia, alcohol, amines, acyl, ketones, aldehydes, esters, etc.
   3. Anhydrous magnesium sulfate: It has strong drying ability and generates MgSO 4 ·7H 2 O after water absorption . It has a fast water absorption effect, high efficiency and low cost, and is a good desiccant. Often used to dry organic reagents.
   4 , solid sodium hydroxide and soda lime: fast water absorption, high efficiency, low price, is an excellent desiccant, but can not be used to dry acidic substances. The party is used to dry gases such as hydrogen, oxygen, ammonia and methane.
   5 , color changing silica gel: commonly used to keep the instrument and balance dry. It turns red after water absorption. The failed silica gel can be used after drying and regeneration. The amine, NH 3 , O 2 , N 2 and the like can be dried .
   6 , activated alumina ( Al 2 O 3 ): large water absorption, fast drying, renewable ( 400 -500K baking).
   7 , anhydrous sodium sulfate: drying temperature must be controlled in
   8. Calcium sulfate: H 2 , O 2 , CO 2 , CO , N 2 , Cl 2 , HCl , H 2 S , NH 3 , CH 4 and the like can be dried .
   From the above, it can be seen that the desiccant for some gases can be selected as follows.
   Gas name            Common desiccant Gas name    Common desiccant
      CO 　　　 Concentrated H 2 SO 4 , CaCl 2 , P 2 O 5 　 　　 H 2 S 　　　　 CaCl 2
   CO 2 　　　 CaCl 2 , concentrated H 2 SO 4 , P 2 O 5 　 　　 N 2 　　　　　 Concentrated H 2 SO 4 , CaCl 2 , P 2 O 5
       Cl 2 　　　 CaCl 2 , concentrated H 2 SO 4 　 　　　　    　 NH 3 　　　 CaO , KOH or soda lime
      H 2 　　 　 CaCl 2 , P 2 O 5 　　　　　　　　 NO 　　　 Ca(NO 3 ) 2
      HBr 　　　 CaBr 2 , ZnBr 2 　　　　　　     　 O 3 　　　　     　 CaCl 2
     HCl 　 　 CaCl 2 , concentrated H 2 SO 4 　 　　　　　 SO 2 　　　           Concentrated H 2 SO 4 , CaCl 2 , P 2 O 5
      HI 　　　 CaI 2