silicon carbide whisker – Silver Nanoparticles Antimicrobial,Copper Oxide Nanoparticles,Gold Nanopowder

February 21, 2023February 21, 2023

Modification of Epoxy Resin by Silicon Carbide Whiskers (SiC-W)

Because of the small diameter, large aspect ratio, high strength, high modulus and excellent heat resistance, silicon carbide whiskers play a unique role in the modification of polymer materials. Epoxy resin has been widely used in various fields of the national economy because of its high strength, good adhesion, good thermal stability, high strength, and small shrinkage. SiC whisker modified epoxy resin can further improve its mechanical properties (strengthening and toughening), friction and wear resistance and antistatic properties.

Epoxy resin (EP) is one of the most widely used thermosetting polymer materials. It has excellent adhesion, thermal stability, electrical insulation, chemical resistance, high strength, small shrinkage, and low price and it’s widely used in various fields such as coatings, adhesives, light industry, construction, machinery, aerospace, electronic and electrical insulation materials, and advanced composite materials. However, due to the shortcomings of epoxy resin cured products such as high brittleness, low impact strength, easy cracking, and poor antistatic performance, its further applications are limited.

Epoxy resin glue is prepared by epoxy resin plus curing agent, filler and so on. It has the characteristics of high bonding strength, high hardness, good rigidity, acid, alkali, oil and organic solution resistance, and small curing shrinkage. At present, the bonding strength of epoxy adhesive is relatively high, but there are still some deficiencies in the bonding of some high-strength structures, and the bonding strength needs to be further improved.

Whiskers are fibers with extremely small diameters grown in the form of single crystals under special conditions. They have a highly ordered atomic arrangement structure, so they can approach the theoretical strength of valence bonds between atoms, and have great potential for strengthening epoxy adhesives. Many research results show that filling whiskers into epoxy resin matrix can effectively solve these shortcomings and greatly improve the comprehensive performance of epoxy resin.

Silicon carbide whisker is a cubic whisker whose crystal form is the same as that of diamond. It is currently the whisker with the highest hardness, the largest modulus, and the best heat resistance among whiskers. The crystal form is β-type, which has higher hardness, better comprehensive properties such as toughness and thermal conductivity, and is also one of the best reinforcing and toughening materials. It can significantly improve the toughness, flexural strength, hardness, wear resistance, and high temperature resistance, oxidation resistance, thermal conductivity, structural stability, thermal shock resistance, etc..

The silicon carbide whiskers treated with the coupling agent can be well and stably dispersed in the matrix, the whiskers are well infiltrated by the matrix, and the interface bonding strength is increased. Through this interface, the matrix and whiskers are connected as a whole. When the matrix is subjected to external force, the stress can be uniformly transmitted through this interface and absorb a large amount of energy. On the one hand, when a crack appears in the matrix, the whiskers bridge the surface of the broken crack, which can hinder the further development of the crack; on the other hand, if the crack encounters silicon carbide powders, if it wants to develop further, the crystal must be destroyed or removed. Whiskers have high strength and high modulus, and it takes a lot of energy to destroy or pull out the whiskers, and when the crack bypasses the whiskers, it develops further and causes more microcracks. And because the whiskers have a relatively large L/D, more energy needs to be absorbed, thereby significantly increasing the strength and toughness of the EP matrix.

December 10, 2015

About Antimicrobial Silver Nanoparticles

“Nano Silver” is “silver nanoparticles” is abbreviated or commonly known, refers to the particles of silver atoms, the particle size is generally in the range of 1-100 nm. Silver chunks of material surface having antibacterial properties already well known, the mechanism is located on the surface of the silver atoms in the oxygen environment may be slow oxidation, releasing free silver ions (Ag +), the silver ions with the wall of the bacteria mercapto binding, blocking the bacterial respiratory chain, eventually killing bacteria adhered to the surface of the material. For bulk material is silver, the oxidation process is extremely slow, the amount and rate of release of silver ions very low.

Some people are claiming for Silver Nanoparticles Antimicrobial and solutions to be bad without any proof. Dr. Flavin from the FDA actually stated that silver is in fact safe and can benefit the immune system.

Silver Nanoparticles are tiny particles of silver and are made with a very low application of electricity to pure silver. If the amount of electricity applied is too much, the silver particles will not be nano sized and it’s important that they are nanoparticles because they are small enough to affect viruses.

As far as the claims of silver being “toxic”. Have you ever seen any any effects from holding silver in your hand. The answer to that would be no. If silver were toxic, we couldn’t hold it with our bare hands safely.

In the air there are heavy metals like lead, mercury and cadmium we breathe in all the time. Most of this comes from industry and past weapons testing in the 1940’s and 1950’s. These metals also show up in our water supply. They are very dangerous metals and are proven to be toxic. Yet we are still alive.

Silver is not proven to be toxic at all.
There is a condition called argyria. This condition is real and used by organizations to scare people away. Argyria turns the skin a blue/gray color. This is caused from large amounts of impure silver build up in the skin. Impure silver has other material in it that is not supposed to be there like proteins, other metals, salt, etc.

The truth about argyria is that it is extremely rare. The only way to get argyria is to take poorly made impure silver solutions. Dr. Flavin, a former science assistant to the Director of Toxicology at the FDA, made a signed statement that says pure silver solutions are not toxic and admits that silver nanoparticles, are in fact proven to help the immune system. The link to this document is below.

All silver solutions should be nano sized and made from.999 pure silver. Any good pure silver nanoparticle solution provider will state the silver particle size and the ppm (parts per million) amount on the bottle or they will tell you if asked. Some companies have effectively made silver particles at.8 microns which is smaller than a nanoparticle.

Most providers will recommend taking 1/2 a teaspoon or smaller. Any silver that is not used by the body will be expelled through the urine when taken in small amounts.

Silver nano particles working the body.
The immune system can be preoccupied with other germs and bacteria. Even more if there is a virus present. When the immune system is working overtime, this can weaken the bodies defenses and allow germs, viruses and bacteria to grow since the immune system can’t keep up and kill them. This makes us sick.

The introduction of silver nanoparticles. Silver with positive charge viruses and harmful bacteria like negatively charged. Thus, when silver nanoparticles come into contact, it inhibits the viruses and bacteria, and kill them with natural anti-bacterial silver, antibiotics and anti-viral properties. When viruses and bacteria are put out of commission, which makes the natural immune system to grow and grow, what then take care of the rest. Very simple, but very effective.

November 23, 2015

Zinc Oxide Nanotechnology for Future

Nano Zinc Oxide is a new high for the 21st century, the function of high value-added fine inorganic chemical products. Its diameter is between 1100 nm, also known as ultrafine zinc oxide. Since the fine crystal grains, the surface electronic structure and crystal structure changes, resulting in a surface effect macroscopic objects do not have the volume effect, quantum size effect and macroscopic tunnel effect and high transparency, high dispersion characteristics. In recent years, we found that it demonstrated in catalysis, optics, magnetism, mechanics and so on a number of special features that make it in many areas of ceramics, chemicals, electronics, optics, biology, medicine and other important application value, can not have an ordinary zinc oxide compare specificity and purposes. Due to a series of nano zinc oxide rods are excellent and very attractive prospect, and therefore has become the focus of many research and development of nano-zinc oxide scientific and technical personnel concerned.

Nanotechnology is the science of constructing components, devices, materials and systems at a nanometer level which means “near-atomic.” The word “nano” is synonymous with one-billionth. So, in nanotechnology, the works and operations happen at the scale of 1/1,000,000,000 (one over one billionth) of a total meter. Such dimension or size is so small and thin. It is about 100,000 times smaller and slimmer than a strand of hair.

An atom, which is the building block of matter, is about this small. For instance, a DNA molecule, life’s blueprint and basic foundation of human genetics, is two nanometers in length. If a material is of this size, it is expected to have unique chemical and physical properties which are caused by several factors such as the significant increase in the surface area of the material as compared to its volume which happens when a particle becomes smaller.

Why is Nanotechnology Important?

Nanotechnology is playing a very important role today and in the future to change and improve every aspect of human activities. Nanotechnology influences a lot of materials used for manufacturing important items. These materials include biomaterials, ceramics, metals and polymers. The new and improved materials formed through nanotechnology are the source of most important technological advances. As of today, nanotechnology is used on following commercial applications:

Sunscreen Lotion – Through zinc oxide particles which have a “nano” size, ultraviolet (UV) rays are absorbed and reflected. As a result, sunscreen lotions appear transparent and are smooth when applied. Before, a sunscreen lotion is white and really sticky. Through, nanotechnology, these lotions are more attractive to customers.

Self-cleaning and scratch proof window – This kind of window is actually coated with a special material that has distinctive chemical properties. Once the sun shines on these self-cleaning windows, the material starts to have a chemical reaction and results to breaking down the dirt on it. Also, if there is rain, no droplets are formed. The rainwater is evenly spread on the window panel and it washes away the dirt that was broken down. The nanoscale controls the thickness of the layer.

Stain-repellent cloth or fabric – This is actually a fabric made of dipped woven rolls of cotton fabric in liquid form that has trillions of nanotechnology fibers. The cotton is dried inside an oven that binds these infinitesimal fibers of the cotton thread. As a result, the fabric becomes resistant to liquid although its physical appearance does not change.

Bouncing tennis ball – These balls are specially coated with a nano-sized material. The molecular barrier of the ball that formed because of these minute particles traps the molecules of air, thus, making the tennis ball bouncier.

Other Remarkable Uses of Nanotechnology:

– Organic Light Emitting Diodes (OLEDs) – for monitor or TV screen displays
– Photovoltaic Film – for conversion of light to electricity
– Hip Joint – formed through biomaterials
– Bucky Tube Frame – this is light but remarkably very strong material
– Nano-particle paint – used to avoid corrosion
– Thermo-chromic glass – regulates light
– Magnetic Layers – used for compressed data memory storage
– Carbon Nanotube – fuel cells used to operate vehicles and electronics

In the future, nanotechnology can change the theories and applications we believe and use. The fields of manufacturing, information technology, electronics and communications have very advance future if nanotechnology is further enhanced.

November 6, 2015

Discovery of Silicon Carbide

Silicon carbide (SiC) with quartz sand, petroleum coke (or coal), wood chips (the production of green silicon carbide need to add salt) and other raw materials by high temperature resistance furnace smelting. Silicon carbide also exists in nature, rare mineral moissanite. Silicon carbide, also known as Moissanite. In contemporary C, N, B and other high-tech non-oxide refractory materials, and silicon carbide is the most widely used, most economical, can be called emery or refractory sand. China’s industrial production of silicon carbide is divided into two kinds of black silicon carbide, and green silicon carbide, are hexagonal crystals, a specific gravity of 3.20 – 3.25, the hardness of 2840 ~ 3320kg / mm2.

Silicon carbide was accidentally invented by Edward G. Acheson different field in 1891, while trying to manufacture artificial diamonds. A mixture of fine sand and charcoal brick is about the inner conductor resistance furnace carbon. Current passing through the furnace to bring the carbon in the coke and silica sand, a chemical reaction to form the compound of SiC and carbon monoxide gas. In the end you have a green and black crystal like components, these components after crushing and grinding into various sizes each use. The crystals were deeper, smaller purity. Some natural silicon carbide was found in Arizona Grand Canyon Diablo meteorite. Most of the sales to the worldwide silicon carbide is synthetic.

Acheson patented the method of making silicon carbide in 1893. Silicon carbide is also called carborundum because Acheson was trying to dissolve carbon in molten corundum (alumina) when this material was discovered,and now silicon dioxide nanoparticles is popular very much. It was first put to use as an abrasive and later used in electronic applications. It was also used as a detector in radios in 20th century. In 1907 LED was first produced by Henry Joseph Round by applying high voltage to silicon carbide crystals.

This chemical has low density, high strength, low thermal expansion, high thermal conductivity, high hardness, excellent thermal shock resistance, and fantastic chemical inertness. Due to its properties it is widely used in suction box covers, seals, bearings, ball valve parts, hot gas flow liners, heat exchangers, semiconductor process equipment and fixed and moving turbine components.

In today’s world it is commonly used in abrasives such as grinding, water-jet cutting, sandblasting etc. Particles of the silicon carbide are used in sandpaper. It is also found in various automobile parts such as brake disks due to its resistance to extreme temperatures. The compound is also used in the mirror of the astronomical telescope because of its rigidity and hardness and thermal conductivity. It is also used to melt glass and non-ferrous metals, production of ceramics, float glass production, steel production, as catalyst support, graphene production etc.

It is also used as a gemstone in jewelery and is referred to as “moissanite” and is similar to diamond in its hardness with a Mohs hardness rating of 9. It is much more resistant to heat and lighter than diamonds and hence has more shine, sharper facets. It has also become a very popular diamond substitute.

September 14, 2015

Applications of Carbon NanoTubes

If you are an engineer, and hope to establish something, it will last a long time, to take the final element of abuse, and even can withstand 5 hurricane, as well as can be; how would you do it?

Perhaps you would want a material that is stronger than steel, flexible and yet, harder than diamonds; indeed and that is what she said. No more viagra needed? But in all seriousness can you image a real legitimate use for this type of material? How about replacing wooden dams in flood prone areas or cement dams in Earthquake prone regions? How about a car that you could play bumper cars with and never lose, the ultimate urban assault vehicles? Speaking of urban assault and the war in Iraq which is similar to the Los Angeles Freeways, how about a Humvee made out of that kind of material. Yah that would save our Troops from roadside bombs and murderous cowardice International Terrorists indeed. What if you were making these units out of a material that was ten times lighter than steel and 250 times the strength?

Single-walled Carbon Nanotubes (SWNTs) are ideal systems for investigating fundamental properties in one-dimensional electronic systems and have the potential to revolutionize many aspects of nano/molecular electronics. Scanning tunneling microscopy (STM) has been used to characterize the atomic structure and tunneling density of states of individual SWNTs. Detailed spectroscopic measurements showed one-dimensional singularities in the SWNT density of states for both metallic and semiconducting nanotubes. The results obtained were compared to and agree well with theoretical predictions and tight-binding calculations. SWNTs were also shortened using the STM to explore the role of finite size, which might be exploited for device applications. Segments less than 10 nm exhibited discrete peaks in their tunneling spectra, which correspond to quantized energy levels, and whose spacing scales inversely with length. Finally, the interaction between magnetic impurities and electrons confined to one dimension was studied by spatially resolving the local electronic density of states of small cobalt clusters on metallic SWNTs. Spectroscopic measurements performed on and near these clusters exhibited a narrow peak near the Fermi level that has been identified as a Kondo resonance. In addition, spectroscopic studies of ultrasmall magnetic nanostructures, consisting of small cobalt clusters on short nanotube pieces, exhibited features characteristic of the bulk Kondo resonance, but also new features due to their finite size.

Well as an engineer you would be making bridges, nuclear power plants, ships, airplanes, cars, buildings and swimming pools out of it. You would be thinking of Space Shuttles, Lunar Colonies, Satellites, iPods and even the levees in New Orleans, but the more you thought about it, you would say; Golf Clubs, fishing poles and snow boards; boy you do need a vacation don’t you? Yes and they you would be re-designing the Château, ski lift and making yourself a new snow mobile too.

You would water pipes, oil pipelines, aqueducts and Space Needles out of the stuff. You are a true American entrepreneur I can tell, so I am thinking you wish to make flag poles, Washington Monument and even the Statue of Liberty out of this stuff. Oh, did I tell you that this material could conduct electricity and even remain invisible to the naked eye? Oh, there goes your engineering mind again, underground Internet lines; high-tension power lines and ditch those lightning prone telephone wires too. Well, I guess we agree that Carbon Nanotubes are the material of the future then. Think on this.

August 12, 2015

An Introduction of Silicon Carbide Whisker

Silicon carbide whiskers is a little flawed, there is a certain aspect ratio of single crystal fibers, it has a very good temperature resistance and high strength. Mainly used for applications requiring high temperature high-strength material toughening occasions. Such as: aerospace materials, high-speed cutting tool. Currently, with high cost performance.

Silicon carbide whisker belong to a diamond crystal, is now synthesized whiskers highest hardness, modulus maximum, maximum tensile strength, heat resistance temperature of the highest whiskers products, divided the α type and β type two forms, which is superior to α-type β-type and has a higher hardness (Mohs hardness of 9.5 and above), better toughness and conductivity, wear resistance, high temperature, particularly resistant to earthquake , corrosion resistance, radiation has been applied on and engine, high-temperature turbine rotor, special parts on aircraft, missiles shell.

Cubic silicon carbide whisker whiskers, and belong to a diamond crystal, is now synthesized whiskers highest hardness, modulus maximum, maximum tensile strength, heat resistance temperature of the highest whiskers products, divided the α type and β type in two forms, including β-type performance than α type. β type than the α type having a higher hardness (Mohs hardness of 9.5 and above), better toughness and conductivity, wear resistance, high temperature, especially earthquake-resistant, corrosion-resistant, resistant to radiation, have housing in aircraft, missiles on and engine, high-temperature turbine rotor, has been applied on special parts.

Silicon carbide is extremely anisotropic crystal growth is achieved by a catalyst on the basis of silicon carbide particles on the surface along the crystal growth of the short fibers, there are two main methods currently producing a gas phase reaction method and a solid material, which method is more solid material It is economical and suitable for industrial production.

Japan and the United States show the synthesis of silicon carbide of a high enthusiasm, in terms of reducing costs and improving the quality of work done a lot of research. Ramsey and other American to amorphous silica as silicon source rice husk species (obtained from burning carbonized rice husk), were mixed in pulverized petroleum coke carbonized rice husk and powder sintering to produce a silicon carbide products. Japan Tanaka and other acid-boiled rice husk, cleaning, carbonation, sintering and other steps to obtain high-purity silicon carbide products.

The first production of silicon carbide whiskers of manufacturers, production of silicon carbide whiskers is a high strength beard shape (one-dimensional) single crystal, high strength, high modulus, and many other excellent mechanical properties, it is widely used in metal matrix, ceramic matrix composite. Mainly used in ceramic cutting tools, high temperature components in the field of aerospace, main bearing strong, large mud pumps, etc. Add to this new material has obtained a more excellent high temperature components, wear resistance, widely used as a structural material in aviation, aerospace, automotive, machinery, petrochemical and other, known as the king of whiskers said. In particular, it has a special significance in the automotive, aerospace engines, housing and so on.

In addition, it was added as an enhanced component plastic matrix, metal matrix or ceramic matrix and play a role in enhancing toughening, high thermal conductivity Sic use of nano materials, high insulation resistance, as large scale integrated circuit substrates in the electronics industry and packaging materials. As an optical material information in the television show, fields of modern communications and the Internet with a high value.

Silicon carbide whiskers in the manufacture of high-strength plastic, metal and ceramic applications work, you can speed up the upgrading of key traditional products. As the nano-silicon carbide whiskers of outstanding features, it has a special role in the aerospace industry industry sectors, namely in aircraft, missile applications and engine housing, the high temperature turbine rotor, special components, military industry and so it huge demand for civilian industry.

August 4, 2015

Comparisons of Mineral Makeup

Mineral foundations have increased in popularity over the years as people have been drawn to the idea that it’s more natural, therefore kinder to and more comfortable on your skin. Though many people think this just includes powder foundations, liquid formulas can be mineral foundation too.

They call them mineral make up. They call them pure. They say they have only “good things” in them. Is this true? And how do they compare in price? Let’s compare apples to apples. I’ve listed all the well know brands of mineral cosmetics, compared their ingredients, their cost, and their actual cost per gram. Although each company offers several products such as foundations, blushes, eye shadows, etc, I’ve chosen the most popular – foundations – as a basis of comparison. I’ve stacked them against Purely Cosmetics to see how each holds up against the other.

Any ingredient marked in bold contains a non-pure, non-earth mineral. Some even worse: parabens are preservatives that are thought to be linked to breast cancer and early aging of the skin. Bismuth oxychloride is a filler that is a by-product of lead and copper processing and is irritating to the skin.Copper Oxide Nanoparticles is good for you!

This is lengthy, but you’ll find some real eye openers. Your favorite mineral makeup is most likely listed here, as I’ve compared Bare Escentuals, Jane Iredale, GLO Minerals, Sheer Cover, Laura Mercier, Youngblood, PUR Minerals, L’Oreal, and Neutragena to Purely Cosmetics.

Note about micronized particles: The use of micronized titanium dioxide is controversial. Some research indicates that micro-size particles do stay on the surface of the skin and do not enter the bloodstream, while others question the long-term safety of using nanoparticles. Studies have shown that it is possible for micronized titanium dioxide particles to penetrate cells and eventually lead to DNA damage following sun exposure. Asthmatics and others with repiratory problems should be cautioned about using loose powders with micronized ingredients as they are easily airborne. Micronized particles are liked by some mineral makeup companies because they provide a smooth coverage and adhere easily. The smaller the particle, the more sheer and natural looking the application. On the flip side, micronized particles cannot provide medium to full coverage for those who need to cover life’s imperfections.

July 23, 2015

Information of Silicon Dioxide Nanoparticles

Since nanomaterials are a heterogeneous group of substances used in various applications, risk assessment needs to be done on a case-by-case basis. Here the authors assess the risk (hazard and exposure) of a glass cleaner with synthetic amorphous silicon dioxide (SAS) nanoparticles during production and consumer use (spray application). As the colloidal material used is similar to previously investigated SAS, the hazard profile was considered to be comparable. Overall, SAS has a low toxicity. Worker exposure was analysed to be well controlled. The particle size distribution indicated that the aerosol droplets were in a size range not expected to reach the alveoli. Predictive modelling was used to approximate external exposure concentrations. Consumer and environmental exposure were estimated conservatively and were not of concern. It was concluded based on the available weight-of-evidence that the production and application of the glass cleaner is safe for humans and the environment under intended use conditions.

Silicon Oxide(SiO2) Nanopowder, silicon dioxide nanoparticles or nanodots are high surface area particles. Nanoscale Silicon Oxide Nanoparticles or Silica Particles are typically 5 – 100 nanometers (nm) with specific surface area (SSA) in the 25 – 50 m 2 /g range. Nano Silicon Oxide Particles are also available in Ultra high purity , high purity, coated, hydrophilic, lipophilic and dispersed forms. They are also available as a nanofluid through the AE Nanofluid production group. Nanofluids are generally defined as suspended nanoparticles in solution either using surfactant or surface charge technology. Nanofluid dispersion and coating selection technical guidance is also available. Other nanostructures include nanorods, nanowhiskers, nanohorns, nanopyramids and other nanocomposites. Surface functionalized nanoparticles allow for the particles to be preferentially adsorbed at the surface interface using chemically bound polymers.

Development research is underway in Nano Electronics and Photonics materials, such as MEMS and NEMS, Bio Nano Materials, such as Biomarkers, Bio Diagnostics & Bio Sensors, and Related Nano Materials, for use in Polymers, Textiles, Fuel Cell Layers, Composites and Solar Energy materials. Nanopowders are analyzed for chemical composition by ICP, particle size distribution (PSD) by laser diffraction, and for Specific Surface Area (SSA) by BET multi-point correlation techniques. Novel nanotechnology applications also include Quantum Dots. High surface areas can also be achieved using solutions and using thin film by sputtering targets and evaporation technology using pellets, rod and foil.. Research into applications for Silicon Oxide nanocrystals includes use as a dielectric coating, in solar cell applications, as a high temperature insulator, as a gas sensor and for use in other coatings, plastics, polymers and wire and further research for their potential electrical, optical, imaging, and other properties Silicon Oxide Nano Particles are generally immediately available in most volumes. Additional technical, research and safety (MSDS) information is available.

Silicon (Si) atomic and molecular weight, atomic number and elemental symbolSilicon (atomic symbol: Si, atomic number: 14) is a Block P, Group 14, Period 3 element with an atomic weight of 28.085. Silicon Bohr MoleculeThe number of electrons in each of Silicon’s shells is 2, 8, 4 and its electron configuration is [Ne] 3s2 3p2. The silicon atom has a radius of 111 pm and a Van der Waals radius of 210 pm. Silicon was discovered and first isolated by Jöns Jacob Berzelius in 1823. Silicon makes up 25.7% of the earth’s crust, by weight, and is the second most abundant element, exceeded only by oxygen. The metalloid is rarely found in pure crystal form and is usually produced from the iron-silicon alloy ferrosilicon. Elemental Silicon Silica (or silicon dioxide), as sand, is a principal ingredient of glass, one of the most inexpensive of materials with excellent mechanical, optical, thermal, and electrical properties. Ultra high purity silicon can be doped with boron, gallium, phosphorus, or arsenic to produce silicon for use in transistors, solar cells, rectifiers, and other solid-state devices which are used extensively in the electronics industry.The name Silicon originates from the Latin word silex which means flint or hard stone.

May 26, 2015

Types of Chemical Heater and Silicon Carbide Whisker

Silicon Carbide is the only chemical compound of carbon and silicon. It was originally produced by a high temperature electro-chemical reaction of sand and carbon. Silicon carbide is an excellent abrasive and has been produced and made into grinding wheels and other abrasive products for over one hundred years. Today the material has been developed into a high quality technical grade ceramic with very good mechanical properties.It is used in abrasives,refractories,ceramics,and numerous high-performance applications. Silicon carbide whisker can also be made an electrical conductor and has applications in resistance heating, flame igniters and electronic components. Structural and wear applications are constantly developing.

Chemical heater and etch process are important terms that must be learned by people and businesses in the semiconductor industry. In this article, I am sharing about the types of chemical heaters used in the wet process system as well as the silicon nitride etch process.

Types of chemical heater

Quartz – Gas Heater — a system that is designed to meet the growing demand for heated high purity gasses. It has the capacity of heating a wide range of gases including: Ammonia (NH3), Helium (He), Argon (Ar), Hydrogen (H2), Arsine (AsH3),Hydrogen Bromide (HBr), Boron Trichloride (BCl3),Hydrogen Chloride (HCl), Carbon Dioxide (CO2), Nitrogen (N2),Carbon Monoxide (CO), Chlorine (Cl2), Nitrous Oxide (N2O), Oxygen (O2),Disilane (Si2H6), Sulfur Dioxide (SO2),Methylsilane (SiH3CH3)

Quartz – Fluid Heater — used in the semiconductor industry and its traditional application includes recirculation loop, either as the sole head source or a combination of a heated quartz tank.

SiC – HF & KOH Heater — designed for heating HF (hydrofluoric acide), KOH (potassium hydroxide), and other high PH chemistries. It uses high purity Silicon Carbide (SiC) as a heat transfer material because it has excellent heat transfer properties and eliminates the risk of contamination due to Teflon breakdown.
Interesting Facts about the Silicon Nitride Etch process

To be able to achieve the greatest etch rates and best selectivity, the phosphoric acid should have the highest ratio of water at a given temperature. For as long as the boil point is maintained, the etch rate of both Si3N4 and SiO2 can be precisely controlled.

Maintaining a boiling solution is one of the challenges in the etch process. When phosphoric acid is heated, the water solution begins boiling off. When temperature is not maintained, it affects the etching process as the acid concentration increase. Wet etch companies use a standard temperature controller to maintain temperature, but the water concentration will decrease and will change the etch rates. As a solution, wet etch process engineers use water addition system.

A technology called closed “reflux” system is used and it is created above the bath using condensing collar and a lid – this is to minimize water addition.

The chemical fumes and high temperatures that Nitride Etch tanks are subjected to are known to decrease bath life substantially by attacking the sealant that prevents liquid and fumes from entering the heater area. This problem has been addressed through the use of aquaseal.

Quartz Nitride Reflux system is engineered to address the unique needs of the silicon nitride etch process. It gives the following benefits to customers: process uniformity, lot-to-lot repeatability, prevents stratification.