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About Stealth Materials and Related Nano Materials

Stealth materials, also known as absorbing materials, refer to a type of electromagnetic material that can absorb and attenuate incident electromagnetic waves, convert electromagnetic energy into heat energy, and consume it. They are widely used in military, aerospace, and security fields to reduce the detectability of targets in equipment such as electromagnetic wave detectors, radar systems, and infrared sensors.

 

The principle of stealth materials mainly includes two aspects:

 

Absorption: Stealth materials have the characteristic of highly absorbing electromagnetic waves, which can absorb most or specific wavelengths of light within the spectral range, thereby reducing reflection and scattering. This absorption characteristic can be achieved through appropriate material selection and design, such as using composite materials with absorbing agents or absorbing coatings.

 

Scattering: Stealth materials can change the propagation path of electromagnetic waves by causing them to scatter or refract in different directions, thereby reducing the echo signal of the target. This principle can be achieved through the design of nanostructures, microstructures, or multi-layer materials to alter the interaction between electromagnetic waves and materials.

 

The common nano powder used for stealth applications include iron oxide, nano silver, and so on. They have excellent absorption and scattering characteristics, effectively weaken or shield the reflection and echo signals of electromagnetic waves, and improve the stealth performance of targets. The following are some common applications of nano powders in stealth technology:

 

  1. Iron oxide nano powder: Iron oxide nano powder has excellent wave absorption performance, can absorb and scatter electromagnetic waves, and achieve stealth effect within a certain range.

 

  1. Carbon nanotubes: Carbon nanotubes have high conductivity and good absorption properties, which can absorb and dissipate electromagnetic waves over a wide frequency range. They are used to prepare composite materials with good stealth properties.

 

  1. Graphene: As a two-dimensional material with a single layer of carbon atoms, graphene has excellent electron transfer and absorption properties and can be used to prepare efficient invisible coatings or composite materials.

 

  1. Silver nanoparticles: Silver nanoparticles exhibit excellent absorption performance in the visible light range, capable of absorbing, scattering, or reflecting electromagnetic waves, achieving stealth effects.

 

The above-mentioned nano raw materials are all supplied by Hongwu Nano. Welcome to contact us for further information if you are interested in.

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The Global Market’s Demand for Nano Silver is Growing Rapidly

At present, nanotechnology is considered to be the most revolutionary technology, which has had a significant impact on social livelihoods through its multidisciplinary applications. Silver nanoparticles (AgNPs) is a metal nanoparticle material that has been widely researched and applied. At present, the global market’s demand and enthusiasm for silver nanoparticles (AgNPs) continues to increase.

Chinese scholars have discovered a new strategy of highly effective antibacterial nano-silver, sterilization does not produce drug resistance.

Professor He from the School of Chemistry and Chemical Engineering of Hefei University of Technology and Professor Cha from the School of Food and Bioengineering have successfully developed a nano-silver aqueous dispersion with weak acid response recombination function, which can be sprayed on the wound to achieve an efficient target for drug-resistant bacterial infections For treatment, it eliminates bacteria while not producing resistant bacteria, and thus proposes a new high-efficiency antibacterial strategy. Relevant results were published online in the “Advanced Functional Materials” magazine a few days ago.

Scientists hope that a material that they claim can kill bacteria and viruses can be used in masks to help deal with the new coronavirus pneumonia epidemic.

The main component of this material is nano-silver with antibacterial properties, which is prepared by using a melt-blown process. Alexander Zanovich Medvedev, who worked on the project, explained that this made polypropylene fibers with a diameter of 1 micron. Medvedev is currently in charge of the work of a laboratory of the Siberian branch of the Russian Academy of Sciences. It is not clear whether this research has been published in a peer-reviewed journal.

Medvedev said in a statement that he and his colleagues put the finished material on the inner layer of a conventional three-layer medical mask. The chief researcher of the Institute of Chemistry and Technology Nikolai Zakharovich Liakhov said that the researchers tested the performance of the mask against influenza A virus, staphylococcus and E. coli.

When the research team compared this new material with the material of ordinary masks, it was found that the number of viruses passing through the latter was 10,000 times higher.

Nano-silver medical masks, using new nano silver antibacterial patented technology, developed and created the first reusable nano-silver non-woven medical masks in Guangdong Province. Based on the calculation of continuous wearing for 8 hours a day, the life cycle of a nano-silver non-woven mask can reach 7 days.

In addition to the conventional single-layer spunbonded non-woven fabric on both sides of the inside and outside, and the middle melt-blown non-woven fabric, the mask also contains a layer of nano-silver non-woven fabric, which has strong water absorption, releases high-activity silver ions, and kills bacteria and viruses. When breathing moist gas, it will release silver ions for a long time to kill bacteria.

The test results of the Hong Kong Polytechnic University wearing experiment show that after 8 hours of wearing, the total number of bacteria on the surface of this type of mask is still far below the range allowed by the national standard, and it can be used repeatedly; the test report of the NELSON laboratory approved by the US FDA shows that the The bacterial filtration rate of the type mask is over 99.7%. After 18-24 hours of continuous use, its bacterial content still does not exceed the range allowed by the national standard, and it can be used repeatedly for a long time.

The research team of Shanghai University has developed 6Cr16MoMA ultra-high hardness stainless steel containing nano-antibacterial silver, which has high strength plastic toughness and sterilization function. The core technology has been authorized by the national invention patent.

In 2017, the Antibacterial Material Testing Center of the Institute of Physics and Chemistry of the Chinese Academy of Sciences tested the antibacterial properties of the material and found that the antibacterial rates for E. coli and Staphylococcus aureus were both ≥99%. In 2019, after further testing by Shanghai Ingeer Testing Technology Service Company, the material has an antibacterial rate of 99.61% against Candida albicans and an antibacterial rate of Pseudomonas aeruginosa ≥99.99%. This stainless steel material not only has a high antibacterial rate, but also has excellent mechanical properties. It is used in the production of household kitchen knives. Its cutting performance is equivalent to that of high-end imported kitchen knives. It is much better than similar domestic products and is at the leading domestic level. Get latest nano silver price from https://www.hwnanomaterial.com.

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Knowledge about flake silver powder and grinding aids

The properties of flake silver powder are stable, and the particles are in surface or line contact, so the resistance is relatively low and the conductivity is good. Flake silver powder is one of the important materials for electronic components, and is widely used in electronic components such as membrane switches, filters, carbon film potentiometers, silver nanoparticles tantalum capacitors, and semiconductor chip bonding.

 

The key process for preparing flake silver powder is ball milling. The process of ball milling is more complicated. The quality of flake silver powder’s micro morphology, diameter-to-thickness ratio, and surface condition all depend on the ball milling process. The main influencing factors of ball milling include ball gradation, ball mill speed, ball-to-material ratio, ball milling time, type and amount of grinding aids, ball milling atmosphere, ball milling temperature and so on.

 

Different ball milling aids have different effects on the performance of the powder. If only absolute ethanol is used as the wet milling medium, the prepared silver powder particles are coarser and the silver flakes are larger, but they are very bright. Using oleic acid as the ball milling medium, the prepared powder is better in flakes and the color is silver gray. Using stearic acid as the ball milling medium, the prepared silver powder has a flake size and the color is silver gray. The color of the silver powder prepared by the compound auxiliary agent is bright gray.

 

The so-called grinding aids are chemical substances that can significantly improve the efficiency of crushing operations and reduce the energy consumption per unit of product. It includes organic and inorganic matters. The main purpose of adding a grinding aid is to improve the grindability of the material, reduce the interaction between particles and the adhesion of fine particles on the grinding medium, and provide the fluidity of the material in the mill, thereby improving the fineness and quality of the product.

 

There are mainly two views on the mechanism of action of grinding aids. One is the theory of “adsorption reduces hardness”, which believes that the adsorption of grinding aid molecules on particles reduces the surface energy of the particles or causes dislocations in the crystal lattice near the surface layer, thereby reducing the strength and hardness of the particles. The second is the theory of “pulp rheology adjustment”, which believes that the grinding aid reduces the viscosity of the pulp and promotes the dispersion of the particles by adjusting the rheological properties of the pulp and the surface electrical properties of the mineral particles. Both theories explain the mechanism of the grinding aid from a certain aspect, but the grinding aid acts on the powder in a highly complex ball milling environment, so it should be considered comprehensively.

 

According to experiments, the amount of ball milling aids added has a great relationship with the bulk density. With the increase in the amount of ball milling aids, the bulk density of the powder continues to decrease. When the amount of ball milling aids is over 1.5%, the bulk density of the powder gradually increases, so the amount of ball milling aids can be considered to be controlled around 1.5%.

 

Hongwu Nano produces flake silver powder with low bulk density and normal bulk density. In addition, customers for different applications have different requirements for whether to wash off the grinding aids, and we can deal with them accordingly. Get nano silver price from us quickly!

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Yttria stabilized zirconia powder Application

HW provide 3YSZ,5YSZ,8YSZ powder, size available from nano to micron size. Also can do customization. Below is the ,man application of Yttria stabilized zirconia powder.

 

  1. 1. Yttria stabilized zirconia powderas refractory material, widely used in Electronic ceramic bearing plate burning, glass, metallurgy molten metal.

 

  1. Due to yttrium stable nanometer zirconium oxide powder’s high oxygen ionic conductivity and ideal stabilityin REDOX atmosphere, it isa kind of ideal electrolyte has been widely applied in the field of solid oxide fuel cell, has the good market application prospect and commercial value.

 

  1. Yttrium stabilized zirconia powder has the characteristics of strong thermal shock resistance, high temperature resistance, good chemical stability and outstanding material composite. Yttrium stabilized zirconia powder and other materials (Al2O3, SiO2) composite, can greatly improve the performance parameters of the material and improve its fracture toughness, bending strength. Therefore, Yttrium stabilized zirconia powderis not only used in the field of structural ceramics and functional ceramics, but also in improving the surface properties of metal materials (thermal conductivity, thermal shock resistance, high temperature oxidation resistance, etc.).

 

  1. Yttrium stabilized zirconia with high hardness and wear resistance, has been widely usedin the field of grinding medium and grinding tool, such as ball mill and ball mill interior lining and wear parts, wire drawing die, etc.

 

  1. Used in functional ceramics, structural ceramics, especially electronic ceramics, bio-ceramics (such as: denture), we havea 3YSZ powder Specialized for dental use.

 

  1. Yttria stabilized zirconiapowder use in piezoelectric elements, oxygen-sensitive resistors, bulk capacitors, solid oxide fuel cells (SOFC) and oxygen sensors.

 

  1. Yttria stabilized zirconiapowder use as artificial gem materials, abrasive materials

 

  1. The additionof Yttria stabilized zirconia increase the ceramic structure toughness strength, the surface finish is good, and ceramic dense compact, resistant to beat.

 

Future information, pls feel free to contact us.

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Silver Nanoparticles For Printable Electronics And Medical Application

Silver nanoparticles have attracted extensive research interest because of unusal optical, electronic, and chemical properties which depend on their size, shape,composition, crystallinity, and structure. They have been widely exploited for use as microelectronic materials, antibacterial materials, catalystic materials and sensor materials due to these unique properties.

Silver nanoparticles used in electronic device application are generally prepared by chemical reduction methods.Using these methods, silver nanoparticles with spherical,cubic, wire. amd triangular shapes have been manufactured.

Silver nanopaticles are widely incorporated into wound dressings, and are used as an antiseptic and disinfectant in medical applications and in consumer goods. Silver nanoparticles have a high surface area per unit mass and release a continuous level of silver ions into their environment. The silver ions are bioactive and have broad spectrum antimicrobial properties against a wide range of bacteria. By controlling the size, shape, surface and agglomeration state of the nanoparticles, specific silver ion release profiles can be developed for a given application.

We supply silver nanoparticles in 20nm,30-50nm, 50-80nm or more bigger, particle size is adjustable. Contact us for further information.

Related reading: nano diamond powder Silver Nanoparticles Antimicrobial