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Dispersion method of nano silver powder

Because of the volume effect, surface effect, quantum size and other effects unique to nanomaterials, nano silver powder has many special uses. In the field of antibacterial medicine, silver nano particles are more likely to be in close contact with pathogenic microorganisms, thereby exerting greater biological effects. It has the characteristics of wide antibacterial range and long duration, and is a new type of nano material with broad application prospects.

 

Nanopowders have small particle size and high surface activity, and it is easy to agglomerate between particles. Ag nano powder is no exception. The agglomeration will affect the development and application of nano Ag particle and its derivatives. The key technology is solve the agglomeration and obtain a stable dispersion. In order to obtain nano silver materials that are compatible with the process formula and are easy to disperse, please refer to the following points:

 

  1. If the user is willing to provide the application details, Hongwu Nano can modify the silver nanowires in advance to improve the dispersion of silver accordingly.
  2. In general, the addition of surfactants and mechanical dispersion methods should be combined to achieve good dispersion effects.
  3. Commonly used mechanical dispersing equipments include: generally used in low viscosity systems such as water and organic solutions, high-speed dispersing machines and ultrasonic equipment can be selected. High-viscosity system (paste) can be selected pulp mill, surface mill, high-speed dispersion disc, ball mill, etc..
  4. The dried silver powder can be depolymerized and surface modified with a supersonic jet mill.
  5. Commonly used surfactants: polymer surfactants such as PVP, gum arabic, polyethylene glycol, polyvinyl alcohol, etc. These dispersants are recommended for water-based systems. Surfactants can be used in combination and can significantly improve the dispersion effect.
  6. Based on years of silver powder production experience and users’ feedback, Hongwu Nano has summed up practical nano silver powder dispersion methods and techniques. Currently we can provide untreated nanosilver powder, surface-modified nano-silver powder, nano-silver water dispersion(colloidalAg), etc. Tailor-made nano-silver series products according to customer requirements.
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Summary of the various applications of nano graphene on mobile phones

Graphene nanopowder  is a two-dimensional material. Carbon atoms are arranged in a hexagonal shape and are connected to each other to form a carbon molecule. Its structure is very stable. As the number of connected carbon atoms increases, the two-dimensional carbon molecule plane keeps expanding, and so does the molecule. A single layer of graphene nanoparticles is only one carbon atom thick, that is, 0.335nm, which is equivalent to 1/200,000 of the thickness of a hair. There will be nearly 1.5 million layers of graphene in 1 mm thick graphite. Graphene is the thinnest known material and has the advantages of extremely high specific surface area, superior electrical conductivity and strength. The existence of the above advantages is that it has a good market prospect. Various applications of nano graphene on mobile phones are as follows:

 

Screen

Graphene screens can use force sensors, bringing a new dimension to touchscreen technology. Furthermore, thanks to graphene’s high toughness, these new properties can be integrated into flexible screens, which are useful for wearable technology.

 

Phone case

Graphene is a high-strength material. Mixed with resins and plastics, or even just as a coating, graphene could be used to make safer helmets, stronger aircraft parts and more durable building materials. Combining graphene with a phone’s case could make it even stronger, and we might never have to worry about it falling off again!

 

Antennas and Communications

Graphene could boost optical data communications to unprecedented rates while reducing energy consumption and transmission errors. By 2020, the graphene flagship aims to link more than 400 gigabits of data per second. Graphene can also serve as the basis for flexible near-field communication (NFC) antennas, enabling new technologies such as electronic banknotes or smart wallets.

 

Sensors

Graphene sensors have many applications: linking to health sensors throughout our bodies, monitoring high-risk infections, oxygen and sugar levels, correcting our posture, and even helping us track neurological pathologies. Sensors can also detect and analyze our environment.

 

Processors and Electronics

Graphene’s electronic properties allow us to make faster and more reliable phone accessories. Graphene has high strength, conductivity, yet thin — just one atom thick, enabling thinner and faster microprocessors for smart products and the Internet of Things. Graphene and related materials are so flexible that devices can be integrated into textiles or even ‘stickers’ directly on the skin.

 

Battery

Graphene can be used to improve the capacity, efficiency and stability of batteries. Graphene batteries can have higher energy storage and better performance in terms of service life and charging time. Graphene and related materials can also be used to improve the performance of other energy storage solutions, such as supercapacitors. Another role of graphene in graphene-based lithium-ion batteries is to improve heat dissipation.

 

Headphones/Speakers

Graphene could make headphones and speakers more energy-efficient and lighter, while producing better sound. As membranes become lighter, they are often too FL releasable and generate unnecessary vibration and noise. Graphene is flexible and strong, so distortion is reduced and people can enjoy their favorite music sources with unprecedented clarity!

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Carbon nanotubes used in polymer composites

Because carbon nanotubes have a similar structure to polymer materials (epoxy resin, polystyrene, polymethyl methacrylate, polyacetylene, nylon and polyurethane, etc.), it is easy to form an ideal interfacial bonding force when mixed, resulting in improved performance. The composite material exhibits excellent strength, wear resistance, electrical conductivity, antistatic properties and other properties that the polymer itself does not have.

1. The acidified carbon nanotubes were compounded with high-density polyethylene (HDPE), and the oriented carbon nanotubes/HDPE composites were prepared by mechanical blending method, which improved the yield strength and tensile strength of the composites. modulus.

2. The carbon nanotube/polytetrafluoroethylene composite material prepared by the customer has a reduced coefficient of friction and improved wear resistance.

3. A company uses carbon nanotubes to reinforced polyurethane composite materials, with a strength/weight ratio of more than 50%, to manufacture larger, stronger and lighter wind turbine blades, so that the power generation of wind turbines can reach more than 1.5MW.

4. Poly(3-octylthiophene)/carbon nanotube composites, the electrical conductivity is improved by 5 orders of magnitude.

5. Adding 8.5wt% single-walled carbon nanotubes to polystyrene-isoprene reduces the resistivity by 10 orders of magnitude.

6. Adding 2-3% of multi-walled carbon nanotubes to the plastic can greatly improve the electrical conductivity; dispersing carbon nanotubes in an epoxy resin, a small amount of addition can produce higher electrical conductivity. Adding 10% carbon nanotubes to engineering plastics such as polycarbonate and polyamide, the conductivity is much higher than other conductive fillers of the same kind. Based on this, the demand for carbon nanotubes in the plastics industry is increasing day by day. china professional carbon nanotube supplier –www.hwnanomaterial.com.

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Application of nano materials in the coating field

The nano raw materials used in the coating field are mainly divided into the following categories according to their functions: Photocatalytic nano-coatings, weather-resistant nano-coatings, high-mechanical properties nano-coatings, transparent heat-insulating nano-coatings, and conductive nano-coatings.

1.Photocatalytic Nanocoatings
Using the photocatalytic properties of Titanium dioxide nanoparticles, scientists have already carried out the protection of historical building relics. The researchers took advantage of the wide catalytic properties of nano-TIO2 that most of the Ca(OH)2 in the layer reacted with SO2 oxidized by OH to form CaSO4, which prevented the further erosion of buildings by SO2 and CO2 in the air, and effectively protected historical buildings. remains. In the application of photocatalytic decontamination and sterilization, CUxO/TIO2 nanocomposite products that can absorb visible light have been applied indoors.

2. Weather resistant nano coating
The high-energy damage of ultraviolet rays is the main culprit for the degradation and aging of organic matter in coatings. The small size effect of nano materials makes it have a strong absorption effect on ultraviolet rays, and the particle size of nanoparticles is much smaller than the wavelength of visible light, which ensures that the layer has good transparency. At present, the most widely used weather-resistant nano materials are nano-TIO2, ZNO, SIO2. Among them, TIO2 has excellent functions of absorbing, reflecting and scattering ultraviolet rays, so it is an ideal UV protectant. ZNO has good absorption and scattering effect on long-wave ultraviolet. SIO2 has extremely strong reflectivity to medium-wave and long-wave ultraviolet rays, and it can play a better shielding effect when added to coatings. Weather-resistant nano-coatings are widely used in building materials, cosmetics and art protection.

3. Nano coating with high mechanical properties
The characteristics of the filler directly determine the function and performance of the coating. The contact area between the nanoparticles and the organic matter in the coating is huge, and the bonding force is strong, which increases the mechanical properties of the organic layer, such as the hardness, impact resistance and wear resistance of the coating.
Research indicates that addition of nano-AL2O3, TIO2, SIO2, ZNO and other particles into coatings can significantly enhance the anti-scratch and wear-resistant properties of the coatings. This is widely used in automotive topcoats, furniture paints, lens complaints and other fields.

4. Transparent heat-insulating nano-coating
Nano metal oxide particles are selective to the solar spectrum and are ideal filler particles for nano coatings. Nano ATO tin antimony oxide, nano ITO indium tin oxide and nano zinc aluminum oxide have good barrier properties for near infrared. Nano TIO2, ZNO, FE2O3, etc. have a good barrier to ultraviolet rays. Evenly dispersing such nano-oxide particles into an organic solution can prepare nano-composite transparent thermal insulation coatings, which has a huge promotion effect on building energy conservation, emission reduction and environmental protection advocated by the state.

5. Conductive Nanocoatings
At present, nanoparticles such as nano-ATO, SNO2, TIO2, ZNO, FE2O3 have been used in electrostatic shielding nanocomposite coatings. The fillers are in contact with each other to form a conductive network, and the carriers move freely in the conductive network.
Another popular conductive material in the market is nano AZO, which is doped with Al2O3 in ZnO, has high temperature resistance, good electrical conductivity, strong high temperature stability and good radiation resistance. The product is a relatively cheap, cost-effective and environmentally friendly.

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Summary of the various applications of nano graphene on mobile phones

Graphene is a two-dimensional material. Carbon atoms are arranged in a hexagonal shape and are connected to each other to form a carbon molecule. Its structure is very stable. As the number of connected carbon atoms increases, the two-dimensional carbon molecule plane keeps expanding, and so does the molecule. A single layer of graphene is only one carbon atom thick, that is, 0.335nm, which is equivalent to 1/200,000 of the thickness of a hair. There will be nearly 1.5 million layers of graphene in 1 mm thick graphite. Graphene is the thinnest known material and has the advantages of extremely high specific surface area, superior electrical conductivity and strength. The existence of the above advantages is that it has a good market prospect. Various applications of graphene oxide powder on mobile phones are as follows:

Screen

Graphene screens can use force sensors, bringing a new dimension to touchscreen technology. Furthermore, thanks to graphene’s high toughness, these new properties can be integrated into flexible screens, which are useful for wearable technology.

Phone case

Graphene is a high-strength material. Mixed with resins and plastics, or even just as a coating, graphene could be used to make safer helmets, stronger aircraft parts and more durable building materials. Combining graphene with a phone’s case could make it even stronger, and we might never have to worry about it falling off again!

Antennas and Communications

Graphene could boost optical data communications to unprecedented rates while reducing energy consumption and transmission errors. By 2020, the graphene flagship aims to link more than 400 gigabits of data per second. Graphene can also serve as the basis for flexible near-field communication (NFC) antennas, enabling new technologies such as electronic banknotes or smart wallets.

Sensors

Graphene sensors have many applications: linking to health sensors throughout our bodies, monitoring high-risk infections, oxygen and sugar levels, correcting our posture, and even helping us track neurological pathologies. Sensors can also detect and analyze our environment.

Processors and Electronics

Graphene’s electronic properties allow us to make faster and more reliable phone accessories. Graphene has high strength, conductivity, yet thin — just one atom thick, enabling thinner and faster microprocessors for smart products and the Internet of Things. Graphene and related materials are so flexible that devices can be integrated into textiles or even ‘stickers’ directly on the skin.

Battery

Graphene can be used to improve the capacity, efficiency and stability of batteries. Graphene batteries can have higher energy storage and better performance in terms of service life and charging time. Graphene and related materials can also be used to improve the performance of other energy storage solutions, such as supercapacitors. Another role of graphene in graphene-based lithium-ion batteries is to improve heat dissipation.

Headphones/Speakers

Graphene nanopowder could make headphones and speakers more energy-efficient and lighter, while producing better sound. As membranes become lighter, they are often too FL releasable and generate unnecessary vibration and noise. Graphene is flexible and strong, so distortion is reduced and people can enjoy their favorite music sources with unprecedented clarity!

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Graphene oxide for heavy metal pollution control

Heavy metals generally refer to more than 60 elements with a density of more than 4 or 45 elements with a density of more than 5. However, because the toxicity of different heavy metals in water and soil is very different, in the field of environmental science, people usually pay attention to vanadium, chromium and nickel. , cobalt, copper, zinc, cadmium, tin, mercury, lead and other metal ions. Heavy metal ions can accumulate in the human body and lead to poisoning, cancer and damage to the nervous system, so it is particularly important to do a good job of heavy metal pollution control.

Graphene oxide  is a carbon nano material prepared from natural graphite with a structure similar to carbon nanotubes. Compared with the adsorption capacity of activated carbon, carbon nanotubes and graphene materials for low-concentration lead-containing wastewater, the adsorption capacity of graphene oxide for lead is as high as 800 mg/g, which is much higher than that of activated carbon, which is 60 to 120 mg/g. It has extremely strong regeneration capacity, and the adsorption capacity drops only 5 to 10% after repeated adsorption/elution cycles.

Why does graphene oxide have such a strong heavy metal adsorption capacity? There are two reasons: one is that graphene oxide is a two-dimensional nano material with a thickness of one atomic layer, and its specific surface area can theoretically reach 2600 square meters/g, which is the largest among all carbon nano materials; During the preparation process, a large number of active groups such as carboxyl group, carbonyl group, hydroxyl group, epoxy group, etc. are formed on its surface. Therefore, graphene oxide has the most basic elements required for an excellent adsorbent: a sufficiently large specific surface area and a sufficiently high density of surface functional groups.

The use of graphene oxide material can reduce the discharge concentration of lead-containing wastewater in the lead-acid battery industry from the current 100-1000ppb to 1-10ppb, increase the lead recovery rate to 95%-99%, and reduce the total environmental discharge of lead by 90% compared with the existing technology. %. The achievement can be effectively extended to other heavy metal pollution systems such as cadmium, nickel, arsenic, copper, chromium, and radioactive elements, and has considerable economic and social benefits. https://www.hwnanomaterial.com/

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Application of Nano-materials in Plastic Modification

Organic/inorganic nanocomposites formed by inorganic fillers dispersed in a general plastic matrix with nano size are called nanoplastics. In nanocomposites, nanoplastics have excellent properties such as high strength, heat resistance, high barrier properties, flame retardancy and excellent processability because of the nano size effect, large specific surface area and strong interfacial bonding of the dispersed phase, which is a new high-tech new material.

Application of nano materials in plastic modification:

(1) Anti-aging properties of reinforced plastics
The anti-aging performance of polymer directly affects its service life and working environment, especially for agricultural plastics and plastic building materials, which is an indicator that requires high attention. The ultraviolet wavelength in sunlight is 200~400nm, and the ultraviolet light in the 280~400nm band can break the polymer molecular chain, and never make the material age. Nano oxides powder, such as nano alumina(Al2O3), titanium dioxide(TiO2), silicon dioxide(SiO2), etc., have good absorption characteristics for infrared and microwave. Proper mixing of nano-SiO2 and TiO2 can absorb a large amount of ultraviolet rays, thereby making the material anti-aging.

(2) Improve the processing performance of plastics
Some high polymers, such as ultra-high molecular weight polyethylene with a viscosity average molecular weight of more than 150, have excellent comprehensive performance, but due to their extremely high viscosity, it is difficult to form and process, thus limiting their popularization and use. Taking advantage of the small friction coefficient between the layers of layered silicate sheets, the ultra-high molecular weight polyethylene and layered silicate are fully mixed to make nano rare earth / ultra-high molecular weight polyethylene composite material, which can effectively reduce the ultra-high molecular weight polyethylene. The entanglement of ethylene molecular chains reduces the viscosity and plays a good lubricating role, thus greatly improving its processing performance.

(3) Improve the toughness and strength of plastics
The emergence of nano materials provides a new method and approach for the enhancement and toughening of plastics. Small particle size dispersed phase has relatively few surface defects and more unpaired atoms. The ratio of the number of atoms on the surface to the total number of atoms increases sharply with the decrease of the particle size. The crystal field environment and binding energy of the surface atoms are different from those of the internal atoms, and they have great chemical activity. The micronization of the crystal field and the increase of active surface atoms greatly increase the surface energy, so it can be closely combined with the polymer substrate and has good compatibility. When subjected to external force, the ions are not easily separated from the substrate, and can better transmit the external stress. At the same time, under the interaction of the stress field, more micro-cracks and plastic deformation will be generated inside the material, which can cause the substrate to yield and consume a large amount of impact energy, thereby achieving the purpose of strengthening and toughening at the same time. Commonly used nanomaterials include nano silicon carbide(SiC), silicon carbide whiskers(SiC-W), nano aluminum oxide(Al2O3), multi-walled carbon nanotubes(MWCNTs), etc.

(4) The addition of nanomaterials enables the functionalization of metal nanoparticles have heterogeneous nucleation, which can induce the formation of certain crystal forms that impart toughness to the material. Polypropylene was filled with low melting point metal nanoparticles, and it was found that it can act as a conductive channel and strengthen and toughen the polypropylene. At the same time, its low melting point also improves the processing performance of the composite material.

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Learn about Thermally Conductive Aluminum Nitride（ALN）

Introduction:
Aluminum nitride AlN is the only stable compound of Al and N, and is the semiconductor with the largest energy gap in the III-V group. Aluminum nitride atoms are combined by covalent bonds, which have good chemical stability and high melting point. At the same time, it has high mechanical strength and good electrical insulation properties. It is a piezoelectric material. It has good injection molding properties, can be used in composite materials, has good matching with semiconductor silicon, good interface compatibility, and can improve the mechanical properties and thermal conductivity and dielectric properties of composite materials.

Product advantages:
The particle size distribution is concentrated,
Good dispersion,
Low metal impurity content,
Low oxygen content,
Low coefficient of thermal expansion,
Strong hydrolysis resistance.

The particle size is complete (nano-level aluminum nitride 100-200nm, 300-500nm, 1-2um, 3-5um, 10um, etc.), and surface treatment can be done according to customer requirements.

Application direction of thermally conductive aluminum nitride powder:
Special for CPU thermal silica gel system;
Special for plastic system;
Special for epoxy resin system;
High thermal conductivity filler of thermal grease and thermal grease;
High thermal conductivity filler of thermal conductive glue, thermal conductive silicone sheet, epoxy resin thermal conductive potting glue;
High thermal conductivity filler of thermally conductive engineering plastics;
Packaging materials, high temperature lubricants, adhesives;
High thermal conductivity fillers for radiators, heat-dissipating paints, and heat-dissipating inks;
Manufacture of insulating and thermally conductive fillers for high thermal conductivity integrated circuit substrates (MCPCB, FCCL);
High thermal conductivity filler of thermal interface material (TIM);
Crucible metal smelting, evaporation boat, ceramic cutting tools, cutting tools, microwave dielectric materials;
Manufacturing high thermal conductivity aluminum nitride ceramic substrates and various ceramic products.

Aluminum nitride ALN powder should be sealed and stored in a dry and cool environment. It should not be exposed to the air for a long time to prevent agglomeration due to moisture, which will affect the dispersion performance and use effect. Surface treatment can be done according to user requirements.

If you need further inquiries about aluminum nitride powder, you can consult our sales staff online.

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Comprehensively understand the heat conduction material hexagonal boron nitride HBN

1. What is boron nitride?
Boron nitride is a crystal (BN) composed of nitrogen atoms and boron atoms, and its chemical composition is 43.6% boron and 56.4% nitrogen.

2. What are the classifications of boron nitride?

According to the crystal type, boron nitride is divided into hexagonal boron nitride, cubic boron nitride, rhombohedral boron nitride and wurtzite boron nitride. However, the current research on boron nitride mainly focuses on the two crystal forms of hexagonal boron nitride and cubic boron nitride. Hongwu Nano mainly focuses on the production and supply of hexagonal boron nitride powder, which includes three categories: nanometer, submicron and micron.

3. What are the physical and chemical properties of hexagonal boron nitride?
The crystal structure of hexagonal boron nitride has a similar layered structure of graphite, which is a white powder that is loose, lubricating, easy to absorb, and light in weight. The theoretical density is 2.29g/cm3, the Mohs hardness is 2, and the chemical properties are extremely stable. The product has high humidity resistance, and the temperature can reach 2800℃ when used in nitrogen or argon. It not only has a low thermal expansion coefficient, but also a high thermal conductivity. It is not only a good conductor of heat, but also a typical electrical insulator. The thermal conductivity of BN measured at 300k using high-purity single crystal is 730w/mk.

4. How is hexagonal boron nitride prepared?
There are many synthetic methods for hexagonal boron nitride, but the basic principle is that the boron source and the nitrogen source are heated and refined together. Hexagonal boron nitride is the most commonly used form of boron nitride. Its preparation methods include borax-urea method, hydrothermal synthesis method, chemical vapor deposition method and precursor method.
Compared with the process flow of various methods, it is not difficult to produce boron nitride, but the process conditions of each process have a great impact on the quality and output of the product. In order to reduce costs and improve quality, Hongwu Nano believes that several issues that must be paid attention to through production practices are: the purity and proportion of raw materials, the influence of reaction temperature and time, the influence of washing methods and the influence of drying processes. Of course, production equipment, production environment, etc. will have an impact to a certain extent.

5. What are the main application areas of hexagonal boron nitride?
Evaporation boat ceramic products;
LED thermally conductive packaging materials;
Boron nitride ceramic parts;
Additives for plastics and refractory materials;
Metallurgical stripping machine;
Lubricant
Thermal shielding materials in the aerospace field;
Atomic reactor structural materials;
Cosmetic fillers;
Laser anti-counterfeiting aluminized trademark hot stamping material.

If you need further inquiries about hexagonal boron nitride product information, please contact us online.  https://www.hwnanomaterial.com

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Application of Nano-silver Materials In The Field of Textile Functional Finishing Antibacterial, Antistatic, Anti-electromagnetic Radiation

The application of nano-silver materials to the field of textile functional finishing and the development of multi-functional, high-value-added fabrics will create huge economic and social benefits in the future textile industry. Nano-silver is a new type of nano-material that is under in-depth research and rapid development. It has broad application prospects in the textile industry due to its broad-spectrum and long-lasting anti-bacterial properties/anti-electromagnetic radiation properties/conductivity and absorption of some ultraviolet rays.

 

Application in natural fiber yarn and fabric

The fabrics made of natural fibers have good moisture absorption and are mostly porous fibers, which can provide enough water for the growth of bacteria. At the same time, the surrounding environment can also provide oxygen for the growth of bacteria and promote the reproduction of bacteria. Nano-silver has broad-spectrum and long-lasting antibacterial properties. At present, the antibacterial application of nano-silver in natural fibers is mainly for yarns and fabrics, and the antibacterial function is mainly obtained through finishing.

 

Nano-silver antibacterial finishing of yarn is generally aimed at cotton yarn or wool. For example, on the basis of puffing and pretreatment of cotton yarn with sodium hydroxide, tannic acid-reduced silver ammonia solution is used to load nano-scale silver particles in the micro gaps of the fiber to make The nano-silver particles and fibers are loaded on the yarn through coordination bonds, so that the silver-loaded cotton yarn has good antibacterial and washing resistance.

 

Under acidic conditions, using nano silver sol and acid dyes to dye wool yarns and antibacterial finishing at the same time, not only can improve the dye uptake, color fastness and flexibility of wool yarns, but also make wool yarns have good antibacterial properties.

 

 

According to reports, some scholars now use the reducibility and stability of the fabric itself to reduce the nano-silver particles in situ on the fabric, so that the fabric has good antibacterial and washing resistance. For example, Ma Tingfang uses the reducibility and dispersibility of cellulose macromolecules to reduce the silver nitrate solution in situ to prepare nano silver antibacterial cotton fabric, which has excellent antibacterial effect and washing resistance. After 20 cycles of washing, the antibacterial fabric will affect the large intestine. The inhibitory rates of Bacillus and Staphylococcus aureus are still as high as 98.5% and 94.3%, respectively. Majid Montazer and others also successfully used the reducibility and stability of cellulose to reduce Torrance reagent (silver ammonia solution) to synthesize nano silver. After the fabric treated with nano silver was washed for 30 times, the antibacterial performance was almost unchanged.

 

In addition, some scholars compound nano-silver with other substances, using inorganic-organic compounding method or inorganic-inorganic compounding method, to prepare compound such as nano-silver/polysaccharide quaternary ammonium salt (HACC), nano-silver/titanium dioxide, etc. Compound, and then padding and finishing the fabric to obtain functional textiles with multiple functions. Wang Haiyun prepared silver-loaded nano-TiO2 antibacterial agent in an inorganic-inorganic compounding method and used it for the finishing of cotton fabrics, so that the cotton fabric obtained the dual antibacterial functions of silver ion elution antibacterial and TiO2 photocatalytic antibacterial, and two kinds of antibacterial The effects promote each other, making the antibacterial effect far better than a single antibacterial agent with the same content.

 

Application in synthetic fibers and fabrics

Three types of synthetic fibers such as nylon, acrylic, and polyester are widely used. At present, the application research of nano-silver in synthetic fibers is mainly aimed at these three types of fibers and fabrics. The manufacturing of synthetic fiber functional fabrics mainly includes two methods: spinning functional fibers and finishing, specifically including blending spinning method, dipping (rolling) method and magnetron sputtering method. The direct-spun functional fiber has a long-lasting effect, but the technology is complex and the cost is high; the finishing agent is simple and convenient to use, and is suitable for most fiber textiles. The cost is low, but the washing resistance is relatively low.

 

(1) Blending spinning method

The blending spinning method is to add nano silver particles in the fiber manufacturing process to blend and spin the fiber to make the final fabric have corresponding functions. The blending spinning process has no pollution to the environment and is widely used. Zhang Hua uses ultra-fine hemp rod core powder to prepare nano silver particles and spun them into antibacterial multifunctional nylon. When the powder content is 2%, nylon fiber not only has excellent antibacterial properties, high strength, and good elasticity. , It also has the ability of far-infrared emission and negative oxygen ion release, and the spinnability also meets the requirements.

 

The antibacterial polyester masterbatch is prepared by blending the silver-loaded nano-zinc oxide antibacterial agent treated with T-aminopropyl triethoxysilane and polyester, which is added to the polyester skin layer, and the core-type antibacterial polyester is produced by spinning. This fiber has excellent antibacterial properties, and the sterilization rate of Escherichia coli and Staphylococcus aureus is above 99%.

 

(2) Dipping (rolling) method

Although the blending spinning method is environmentally friendly, it is difficult to prepare a spinnable spinning solution. In contrast, the dipping (rolling) process is relatively simple. Yu Qiaozhen treated the nano-silver particles to polyester fabrics by dipping, and studied its effect on the antistatic properties of the fabrics, and found that nano-silver treatment can effectively improve the antistatic capabilities of polyester fabrics; and different treatment methods have endless effects on the fabrics. Similarly, for example, the effect of the one-bath method in which nano-silver particle treatment and dyeing are performed at the same time is significantly better than the two-step method in which dyeing is followed by finishing.

 

Some researchers have explored a new type of finishing method that allows nano-silver particles to be bonded to the surface of the fiber through chemical bonding, so that the bond between nano-silver and the fiber is stronger. For example, the researchers amidoxim part of the acrylic fiber to make the fiber surface with chelating groups, which can be complexed with silver ions, and then use formaldehyde solution to reduce the silver ions to obtain nano-silver composite acrylic fiber. The killing rate of Staphylococcus aureus and Bacillus subtilis exceeds 99.99%, the antibacterial performance is good, and the original physical properties of the fiber have no obvious changes.

 

(3) Magnetron sputtering method

In order to avoid the waste liquid disposal problem of the dipping (rolling) method, some researchers used the radio frequency magnetron sputtering method to sputter nano-silver film on the surface of the fabric. The magnetron sputtering method is to charge a proper amount of argon in a high vacuum, and apply a DC voltage between the cathode (columnar target or flat target) and the anode (the wall of the coating chamber) to ionize the argon gas, and the argon ions are accelerated and bombarded by the cathode On the surface of the cathode target, the atoms on the surface of the target are sputtered and deposited on the surface of the substrate to form a thin film. This method has the advantages of strong bonding force between the coating layer and the substrate, and the coating layer is dense and uniform.

 

Application in industrial textiles

The application objects of nano-silver in industrial textiles are mainly non-woven fabrics, laminated composite fabrics and composite materials.

 

(1) Application in non-woven fabrics

The use of nano-silver to finish the non-woven fabric can obtain antibacterial properties and anti-electromagnetic radiation properties, which can be widely used in medical, sanitation, automotive interiors, electromagnetic shielding materials and other fields. Similar to synthetic fibers, the nano-silver finishing methods of non-woven fabrics also include blending spinning method, dipping (rolling) method and magnetron sputtering method, the principle of which is the same as described above. Hong Jianhan uses magnetron sputtering at room temperature to deposit nano-silver films on the surface of polyester spunbonded nonwovens to make the fabrics resistant to electromagnetic radiation. As the thickness of the nano-silver films increases, the shielding effect of electromagnetic waves is enhanced. This method expands the application field of nonwoven fabrics, and can be used to develop antistatic materials, conductive materials, electromagnetic shielding materials and fiber sensors.

 

The nano silver antibacterial agent is highly uniformly dispersed and implanted in the spinning solution to blend and spin, so that the fabric can obtain higher stability, antibacterial performance and washing resistance, and then obtain nano silver antibacterial spunlace nonwoven rolls and nano silver Antibacterial needle punched non-woven fabric rolls.

 

Its most extensive application field is the production of medical and sanitary products, such as nano-silver antibacterial masks, antibacterial wipes, medical bed sheets, medical wipes, etc. The latter’s market applications are also very broad, such as automobile compartment/indoor air conditioning antibacterial filter media, clothing linings, etc. , Antibacterial insoles, shoe materials, etc.

 

Application in laminated composite fabric

Laminated composite fabrics are ideal materials for civilian sportswear, cold-proof clothing, field work clothes, military combat uniforms, labor protective clothing and other products. The nano-silver finishing of composite laminated fabrics is mainly achieved by dipping or blending spinning. Researchers at Zhejiang Sci-Tech University used a cross-shaped cross-section polyester fiber material containing nano silver particles as an antibacterial modifier as the outer layer of the fabric, and combed cotton yarn with better moisture absorption as the inner layer of the fabric, using the changes in the fabric structure , Combined with advanced finishing technology, the fabric has multiple functions such as moisture absorption, perspiration, and antibacterial.

 

(3) Application in composite materials

 

The silver/polymer nanocomposite material not only has the excellent characteristics of nano silver and polymer, but also gives the material some new functions, so that it has broad application prospects in many fields such as textiles, electronics, and biomedicine.

 

Conclusion

As a new type of material, nano-silver is used in many fields, especially the textile industry is closely related to people’s lives, which has aroused the interest of many researchers. At present, the application of nano-silver in the textile industry is mainly to obtain antibacterial, antistatic, and anti-electromagnetic radiation functions. As people’s requirements for textile products increase, nano-silver will be increasingly used in functional fabrics, and its application prospects in the textile industry will become broader.