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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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Effect of Nanopowder on Agricultural Expelling Insect

Nanomaterials have broad application potential in insect repellent agriculture. The following are some common examples of nano powders that may play a role in agricultural pest control:

 

  1. Silica nanoparticles(HW-A213): Silica nanoparticles are widely used in agriculture as an environmentally friendly pesticide. They can adsorb on the surface of insect shells, damage the protective layer of the insect body, and cause dehydration, suffocation, or death of the insect.

 

  1. Metal oxide nano powder: metal oxide nano powder, such as silicon dioxide (HW-T681&T689) and zinc dioxide (HW-Z713), has the effect of insecticide. They can kill insects by photocatalysis, activate the surface of nano powder by ultraviolet radiation, produce free radicals or oxides, and cause damage to insects.

 

  1. Carbon nanotubes(HW-C931): Carbon nanotubes have a large surface area and high mechanical strength. They can be used as carriers to load insecticides onto their surfaces and improve insecticidal efficacy by controlling release. In addition, carbon nanotubes can also be used as insect sensors to monitor and control pests by detecting chemical signals released by insects.

 

  1. Nano boron nitride(HW-L551): Nano boron nitride has excellent thermal conductivity and stability, and can be used to develop efficient fire-resistant materials. In agriculture, it can also be used as an insecticide to control pests through physical effects or interference with the normal physiological activities of insects.

 

  1. Nanographene(HW-C952): Nanographene is a nanomaterial with excellent conductivity and photothermal properties. It can be applied to the electric insecticidal mechanism, which kills pests by heating. Nanographene can generate high temperatures at lower currents, causing fatal damage to agricultural pests.

 

The application of nano powder in agricultural insecticide is mainly reflected in the use of nano pesticide. Nanopesticides are the use of nanotechnology to prepare pesticide active ingredients into nanoscale particles, in order to enhance their solubility, dispersibility, and activity, improve the effectiveness and utilization of pesticides, and ensure their safety and environmental friendliness. In addition, scientific and reasonable agricultural management and the application of comprehensive prevention and control measures remain the key to promoting sustainable agricultural development.

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Two common anti-UV materials: nano titanium dioxide (TiO2) and nano zinc oxide (ZnO)

Nano zinc oxide (ZnO) and nano titanium dioxide (TiO2) are two commonly-used oxide materials for UV resistance.

 

They have special optical and chemical properties at the nanoscale, making them important candidates in the field of UV resistance.

 

  1. Nanozinc oxide (ZnO), as an excellent ultraviolet shielding agent, shows good ultraviolet absorption properties in the ultraviolet spectrum range. It has high transmittance and excellent optical properties, so it is widely used in the preparation of anti-UVcoatings, fabrics and other products as it has a shielding effect on both UVA (long wave 320 ~ 400nm) and UVB (medium wave 280 ~ 320nm).

 

  1. Nanotitanium dioxide(TiO2)has excellent chemical stability, thermal stability and non-migration, strong achromatic and hiding power, low corrosiveness, good dispersibility, and is non-toxic, odorless and non-irritating, safe to use, and also has the function of sterilization and deodorization.

 

More importantly, nano titanium dioxide can not only absorb ultraviolet rays, but also emit and scatter ultraviolet rays, so it has strong UV resistance. Compared with the same dose of organic anti-UV agents, its absorption peak in the ultraviolet region is higher. Moreover, nano TiO2 has a blocking effect on both medium-wave and long-wave ultraviolet rays, unlike organic anti-UV agents that only have a shielding effect on medium-wave or long-wave ultraviolet rays. Researchers add light shielding agents, light stabilizers, etc. to achieve photoaging resistance of polymer material products, and rutile-type nano TiO2 is non-toxic and odorless to ultraviolet light UVA (315 ~ 400 nm) and UVB (280 ~ 315 nm) ) have a very good shielding effect, do not decompose or discolor after absorbing ultraviolet light, and have excellent stability and durability.

 

  1. The combined use of zinc oxidenano and titanium dioxide nano is also a common anti-UV strategy. Their combined use can give full play to their respective advantages and improve the anti-ultraviolet effect.

Since a single oxide absorbs ultraviolet light in a limited wavelength range, the preparation of UV-resistant nanocomposite oxides has attracted increasing attention from researchers.

For example, nano titania mainly has good absorption performance at 280~350nm, but its absorption at 350~400nm is weak. Although nano ZnO’s short-wave absorption performance is not as good as nano TiO2, it can provide very broad-spectrum protection and inhibit UVA.

The experimental results were found through the ultraviolet absorption spectrum of pure TiO2 and nano ZnO/TiO2 composite particles: at the same concentration, the ultraviolet transmittance of the system containing nano-TiO2 in the 280 ~ 322nm band is only 1%, and the ultraviolet transmittance in the 322 ~ 351nm band is only 1%. The transmittance is 1%~15%, the ultraviolet transmittance in the 351~400nm band is 15%~46%, and its ultraviolet transmittance in the 322~400nm band shows a linear upward trend; while the ultraviolet transmittance of nano-ZnO/TiO2 composite particles in the range of 280-351nm band is always 15%, and the transmittance in the 351 ~ 400nm band is only 15%-18%, the increase in ultraviolet transmittance is not significant.

It can be seen that the UV shielding performance of nano-TiO2 below 351nm is higher than that of nano-ZnO/TiO2, while above 351nm, the UV-shielding performance of nano-ZnO/TiO2 is much higher than nano-TiO2. Although the absorption of nano-ZnO/TiO2 in the UVB region is not as good as that of nano TiO2, its blocking effect on long-wave UVA is better than that of nano-TiO2. It can also be seen that the ultraviolet transmittance of the composite particles in the entire UVB and UVA bands is very small, always below 15%, knowing that this composite particle has a strong ability to shield ultraviolet rays.

 

To sum up, nano zinc oxide and nano titanium dioxide play an important role in the field of UV resistance. Their excellent performance and wide application make them key ingredients in protective products, providing effective protection for people’s health and safety.

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Nano Materials applied in flexible screens

The beauty of flexibility is everywhere. The development of flexible screens can be applied to all walks of life, make life more concise and convenient. Here are some nano materials that can be used for flexible screens:

ITO nanopowder

ITO (tin oxidation) transparent conductive film has become the most important touch layer material for display screens such as non -curved LCD and OLED due to many reasons such as good light transmission, low thickness, excellent hardness and electrical conductivity, and mature production process. However, ITO is a kind of crispy material, not suitable for the flexible touch layer that can be curved or even bent at will, and the cost is high.

Nano graphene, carbon nanotubes, silver nanowires, etc.

At present, the main substitutes for ITO materials are: nano graphene, carbon nanotubes, silver nano wires, and metal grids. Among them, nano graphene and carbon nanotubes are very good substitutes for ITO in terms of material itself. But graphene is still a bit far from mass production. The film made of nano -carbon tube is not as good as ITO in conductivity. Therefore, from the perspective of technology and market, metal grids and nano -silver technology will be the protagonist of recent development.

The metal grid technology mentioned here is the conductive metal mesh formed by using metal conductive materials such as silver and copper or oxides on PET and other thin film substrates. Its main advantage is that the cost of raw materials is low and good for winding. However, due to the problem of Morri interference ripples caused by good rate, yield and high -end high pixels, it is more suitable for applications with low resolution and relatively long -distance use. Desktop all -in -one machines, laptops and television products.

Nano -silver wire technology refers to applying nano -silver wire ink materials to PET or glass substrates, and then uses Laser lithography technology to portray the nano -level conductive network. Its main advantages are high rates, small line width, good conductivity and resistance, and disadvantages are high costs. And compared to metal grids, nano -silver materials have a small curvature radius, and the resistance changing rate of resistance during bending is small, plus the reasons for the width, so it is more suitable for high -resolution such as mobile phones, smart watches and bracelets. Use in close range scenes.

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Nano titanium oxide and silicon oxide are used for anti -wrinkle fabric treatment

Nano oxides have many amazing properties and are widely used in the textile fields such as antibacterial, deodorizing, and anti -ultraviolet rays, etc functioned textiles. Similarly, nano oxide configuration has also had a positive impact. Add nano titanium dioxide or nano silicon oxide(sio2 hydrophobic or hydrophilic) to the traditional system, to form nano-oxide anti-wrinkle tidal liquids at high speed, and anti -wrinkle arrangement of fabrics.

 

Nano material is a new type of functional material that has a large surface area, many surface activity centers, and strong adsorption capacity. In recent years, the study of nano  titanium dioxide has been started in China. The addition of nano titanium dioxide effectively improves the anti -wrinkle effect of cotton fabrics, and at the same time greatly improves the strength of the fabric. When the content of nano -titanium dioxide is 0.1g/L, the anti -wrinkle performance and improvement of the fabric will be the best.

 

Real silk fabric has excellent hanging, soft luster, and special silk feeling, especially its good comfort and health effects. However, the silk fabric is easy to wrinkle when washing or wetting. In order to improve the rebound performance of real silk, many studies have been conducted at home and abroad. Studies have shown that nano -silicon oxide has many activity points , and its reaction activity is better than nano -titanium dioxide. On the surface of the experiment, the Malaysid Anid Anid anhydride anti -wrinkles can be used as a catalyst. In addition, the best process conditions for nano -silicon oxide as the anti -wrinkle system are: 2g/(50ml) of the Malay acid anhydride concentration, and the baking temperature of the roasting temperature It is 150C. This is realistic and economic value for improving the grade of textiles.

 

Apply unique function of nano powders to develop safe and efficient nano materials and used in textiles has great market prospects. The promotion and application of such technology is expected to give new economic growth points for textiles, medical and health materials, and health care products.

 

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Chinese Scientists Have Made Important Breakthroughs in The Field of Super-strong Carbon Nanotube Fibers

Carbon nanotubes are considered to be one of the strongest materials discovered by humans, with a Young’s modulus of over 1 TPa and a tensile strength of over 100 GPa (the specific strength is as high as 62.5 GPa/(g/cm3). ), more than 10 times stronger than T1000 carbon fiber. Theoretical calculations show that carbon nanotubes are currently the only material that has the potential to help us realize our dream of a space elevator.

How to maintain the excellent mechanical properties of a single carbon nanotube after assembling is the first problem that must be solved in the preparation of super strong fibers. However, the reported strength of carbon nanotube fibers is only 0.5–8.8 GPa, which is far lower than the theoretical strength of carbon nanotubes (>100 GPa). The main reason is that the carbon nanotubes that form fibers are short in length, and the units overlap each other by van der Waals force, which easily slips each other under the action of tension, and cannot fully utilize the inherent high strength of carbon nanotubes. In addition, structural defects and disordered orientations in carbon nanotubes will lead to the decrease of fiber strength. In contrast, ultra-long carbon nanotubes have lengths of centimeters or even decimeters and have perfect structures, consistent orientations, and mechanical properties close to the theoretical limit, which have great advantages in the preparation of ultra-strong fibers.

With the support of the national key R&D program “Nanotechnology”, Professor Wei Fei’s team of Tsinghua University and Professor Li Xide’s team have made a breakthrough in the field of super-strength carbon nanotube fibers. Preparation of ultralong carbon nanotube bundles for theoretical strength. By adopting the method of in-situ airflow focusing, the research team controllably prepared centimeter-scale continuous ultra-long carbon nanotube bundles with definite composition, perfect structure and parallel arrangement, ingeniously avoiding the above-mentioned limiting factors. By preparing ultralong carbon nanotube bundles containing different numbers of units, quantitatively analyzing the effects of their composition and structure on the mechanical properties of ultralong carbon nanotube bundles, a definite physical/mathematical model was established. A “synchronized relaxation” strategy is proposed to release the initial stress of carbon nanotubes in the tube bundle through nanomanipulation, so that it is in a narrow distribution range, and then the tensile strength of the carbon nanotube bundle can be increased to 80 GPa. The above is close to the tensile strength of a single carbon nanotube. The reported tensile strength of ultralong carbon nanotube bundles is superior to all other fiber materials found so far. This work reveals the bright prospect of ultra-long carbon nanotubes for the manufacture of super-strong fibers, and points out the direction and method for the development of new super-strong fibers.

 

As carbon nanotube suppliers, Hongwu Nanomaterial is providing several specs cnts as follows.

1.Single walled carbon nanotube,SWCNTs, D 2nm, L 1-2um, 91%;

2.Single walled carbon nanotube,SWCNTs, D 2nm, L 5-20um, 91%;

 

3.Multi walled carbon nanotube, MWCNTs, D 10-30nm, L 1-2um,99%;

4.Multi walled carbon nanotube, MWCNTs, D 10-30nm, L 5-20um,99%;

5.Multi walled carbon nanotube, MWCNTs, D 30-60nm, L 1-2um,99%;

6.Multi walled carbon nanotube, MWCNTs, D 30-60nm, L 5-20um,99%;

7.Multi walled carbon nanotube, MWCNTs, D 60-100nm, L 1-2um,99%;

8.Multi walled carbon nanotube, MWCNTs, D 60-100nm, L 5-20um,99%;

  1. functionized cnts(-COOH, -OH, -NH2, Ni plated, graphited)
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Some Functional Materials in Electronic Paste

Electronic paste is made by mixing functional materials with conductive binders or dispersants. It usually has a high concentration of solid particles dispersed in a stable liquid medium for easy coating, spraying, printing, and other operations in the manufacturing process of electronic devices. Its main applications are in printed electronics, solar cells, and nano electronic devices. The following are several main functional materials used for preparing electronic pastes:

 

  1. Metal powder: Metal powder is commonly used as a conductive material in electronic pastes, including silver powder, copper powder,silver copper powder, aluminum powder, etc. They have good conductivity and can be used to prepare conductive components and electrodes.

 

  1. Oxide powder: Oxide powder is commonly used as a dielectric or semiconductor material in electronic paste. For example, ZnO(HW-Z713)powder, TiO2(HW-T681,T685,T689)powder, lithium niobate powder can be used to prepare insulation layers or semiconductor materials for electronic components.

 

  1. Semiconductor nanoparticles: It isa type of material with special electrical and optical properties, often used for specific functional applications in electronic pastes. For example, indium tin oxide (ITOHW-V751) nanoparticles are widely used in the preparation of transparent conductive films.

 

  1. Carbonnano materials powders: Carbon based materials such as graphene powder （HW-C963, C966, C968) and carbon nanotubes have excellent conductivity and mechanical properties, and can be used to prepare high-performance electronic devices.

 

  1. Functional additives: In addition to the main functional materials mentioned above, auxiliary functional additives like surfactants, antioxidantsand rheological modifiers are often added to electronic paste to improve their performance and stability.

Hwnanomaterial supply the materials mentioned above, with reliable and stable product quality and excellent price. Welcome to contact us for further info.

 

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Nano Zirconia: Performance, Applications Potential in Consumer Electronics

Nano Zirconia has excellent performance, wide application fields, and great development potential in the field of consumer electronics.

Nano Zirconia has excellent physical properties such as high strength, high temperature resistance, wear resistance, insulation insulation, and expansion coefficients, as well as outstanding performance for its nano size with excellent chemical properties such as corrosion resistance and high conductivity and high -scale surface area, high processing accuracy, strong oxygen storage capacity. It is widely used in structural devices, oxygen sensors, joints, etc; and in the background of consumer electronics in the development of the next generation of backboards, ceramic materials ( ZrO2, YSZ) have great potential.

  1. The backplane and intelligent wearable devices are expected to usher in the era of zirconia ceramics.

The 5G era requires a faster signal transmission speed and will adopt a spectrum above 3GHz, which has shorter wavelength of its millimeter. Compared with the metal backboard, the ceramic backboard has no interference to the signal. The ceramic material combines the characteristics of the shape of the glass, no signal shielding, and high hardness. Yes, it is very suitable for wearable devices and mobile phone backboards.

Among all ceramic materials, in addition to high -strength, high hardness, acid -alkali -resistant corrosion resistance and high chemical stability, the zirconia ceramics have the characteristics of anti -scratch -resistant, no signal shielding, excellent heat dissipation performance, and good appearance effects. Therefore, it has become a new type of mobile phone body after plastic, metal, and glass. At present, the application of zirconia ceramics in mobile phones is mainly two parts: backboard and fingerprint recognition cover.

With the well -known domestic mobile phone manufacturers Huawei and Xiaomi  launching zirconia ceramic backplane phones, the market heat has gradually increased, which has opened the curtain of oxidation and infiltration of mobile phone backplane materials.

  1. Advanced aging and consumption upgrades will increase the penetration rate of oxidation dentures and the market space is broad.

Due to its good biological performance, aesthetics and stability, zirconia ceramic materials are widely used in the field of dental repair. With the intensification of global aging and the improvement of living standards and the attention of the whitening of teeth, the global denture market scale has continued to expand. The penetration rate of oxidation ceramics in the denture materials is expected to further increase, and the market space in the field of domestic oxidation in the field of righteousness will continue to grow.

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Application of TiO2 Nanotubes in Denitrification Field

TiO2 nanotubes have a high specific surface area (greater than 300m2/g). The specific surface area of ​​the catalyst has an important influence on the catalytic performance, so TiO2 nanotubes were used as the denitration catalyst carrier, and the manganese oxide/TiO2 nanotube denitration catalyst was prepared by loading manganese oxide by the equal impregnation method. The catalyst showed good low temperature denitration. performance, especially in the temperature range of 100-220 °C, the denitration activity is almost 100%.

Manganese oxide has relatively high catalytic activity in low-temperature denitration (electrons on 3D orbitals are very easy to migrate). Using TiO2 nanotubes with high specific surface as a carrier can improve the dispersion of manganese oxide and promote more catalytically active sites. At the same time, the mass transfer process of the reaction is improved; on the other hand, TiO2 nanotubes have strong anti-sulfur poisoning ability. In addition, the active sites of amorphous manganese oxide in the catalyst were uniformly dispersed on the surface of the carrier and the increase of Lewis acid content jointly promoted the improvement of catalyst performance.

The application of TiO2 nanotubes with large specific surface area in the catalytic reaction of low-temperature denitration is of great significance to expand the field of denitration.

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Silicon carbide whiskers can significantly improve the service life of resin diamond grinding wheels

The diamond grinding wheel uses diamond abrasive as raw material, and uses metal powder, resin powder, ceramics and electroplated metal as binders respectively. The circular bonded abrasive tool with a through hole in the center is called diamond grinding wheel (alloy grinding wheel).

The resin-bonded diamond grinding wheel generally has a low life and cannot meet the requirements of advanced numerical control machine tools. The short life is mainly due to the poor wear resistance of the resin bond itself or the low holding force on the diamond, which causes the diamond abrasive particles to fall off prematurely during the grinding process. Therefore, how to improve the wear resistance of the resin bond and improve the holding force of the resin on the diamond has become the key to improving the service life of the resin bond diamond grinding wheel.

The addition of silicon carbide whiskers can greatly improve the strength, hardness, heat resistance, polishing, etc. of the bond and the grinding wheel. Silicon carbide whiskers have unique mechanical and physicochemical properties such as high hardness, high strength (toughness), and excellent wear resistance, so they are widely used in metals, ceramics, plastics, etc.

Strengthening and toughening of materials and composite materials to improve the strength of composite materials and prevent shrinkage and deformation. The shape of silicon carbide whiskers is like needles, especially its Webster hardness is close to diamond and has good toughness and wear resistance, and compared with abrasive grains, even if the diameter is the same as the grain size of abrasive grains, there are whiskers of a certain length that are combined with The agent has a relatively large bonding area and bonding strength, which greatly improves the service life of the grinding wheel.

The β-type micron-sized silicon carbide whiskers produced by Hongwu Nano have the characteristics of high purity and good morphology, and are the preferred materials for strengthening and toughening of various metal-based, ceramic-based and resin-based composite materials. Its strengthening and toughening effect and scope of application are unmatched by other materials.

Beta silicon carbide whiskers are needle-like single crystals. As an atomic crystal, it has low density, high melting point, high strength, high modulus, low thermal expansion rate, and excellent characteristics such as wear resistance, corrosion resistance, high temperature resistance, oxidation resistance, etc. It is mainly used for metal base, ceramic base , Reinforcement and toughening of resin-based composite materials, significantly improve the properties of composite materials.

Its main physical performance indicators are as follows:
Whisker diameter Diameter: 0.1-2.5um
Whisker Length: 10-50um
Density: 3.2g/cm2
Hardness: 9.5 Mobs
Modulus Modulus: 480GPa
Tensile Strength Strength of extension: 20.8Gpa
Tolerable temperature: 2960℃