1. Chemical Identification and Structural Variety

1.1 Molecular Composition and Modulus Principle

(Sodium Silicate Powder)

Salt silicate, generally referred to as water glass, is not a single compound but a family of not natural polymers with the general formula Na two O · nSiO two, where n represents the molar ratio of SiO ₂ to Na two O– described as the “modulus.”

This modulus commonly ranges from 1.6 to 3.8, seriously influencing solubility, thickness, alkalinity, and sensitivity.

Low-modulus silicates (n ≈ 1.6– 2.0) include more salt oxide, are highly alkaline (pH > 12), and dissolve readily in water, creating viscous, syrupy fluids.

High-modulus silicates (n ≈ 3.0– 3.8) are richer in silica, less soluble, and commonly appear as gels or solid glasses that require warmth or pressure for dissolution.

In liquid remedy, salt silicate exists as a vibrant equilibrium of monomeric silicate ions (e.g., SiO FOUR ⁴ ⁻), oligomers, and colloidal silica fragments, whose polymerization level raises with focus and pH.

This structural versatility underpins its multifunctional roles throughout construction, production, and ecological engineering.

1.2 Production Methods and Business Types

Sodium silicate is industrially produced by merging high-purity quartz sand (SiO TWO) with soft drink ash (Na two CO ₃) in a heater at 1300– 1400 ° C, yielding a molten glass that is quenched and liquified in pressurized steam or warm water.

The resulting liquid item is filteringed system, concentrated, and standardized to particular densities (e.g., 1.3– 1.5 g/cm THREE )and moduli for different applications.

It is likewise offered as strong lumps, beads, or powders for storage stability and transportation effectiveness, reconstituted on-site when needed.

Worldwide production exceeds 5 million metric heaps every year, with significant usages in detergents, adhesives, foundry binders, and– most substantially– building and construction materials.

Quality assurance concentrates on SiO TWO/ Na two O proportion, iron web content (affects shade), and clarity, as pollutants can hinder establishing reactions or catalytic performance.

(Sodium Silicate Powder)

2. Devices in Cementitious Equipment

2.1 Alkali Activation and Early-Strength Development

In concrete technology, salt silicate works as an essential activator in alkali-activated products (AAMs), especially when combined with aluminosilicate forerunners like fly ash, slag, or metakaolin.

Its high alkalinity depolymerizes the silicate network of these SCMs, launching Si ⁴ ⁺ and Al THREE ⁺ ions that recondense right into a three-dimensional N-A-S-H (salt aluminosilicate hydrate) gel– the binding phase comparable to C-S-H in Rose city cement.

When included directly to normal Rose city cement (OPC) mixes, sodium silicate speeds up early hydration by boosting pore option pH, promoting rapid nucleation of calcium silicate hydrate and ettringite.

This leads to substantially lowered initial and last setting times and improved compressive strength within the first 24 hours– valuable in repair mortars, grouts, and cold-weather concreting.

Nonetheless, too much dose can create flash collection or efflorescence as a result of excess salt migrating to the surface and responding with atmospheric carbon monoxide two to create white salt carbonate down payments.

Optimal application commonly varies from 2% to 5% by weight of concrete, calibrated through compatibility screening with local materials.

2.2 Pore Sealing and Surface Hardening

Water down salt silicate solutions are commonly utilized as concrete sealants and dustproofer therapies for commercial floorings, stockrooms, and vehicle parking structures.

Upon penetration right into the capillary pores, silicate ions respond with cost-free calcium hydroxide (portlandite) in the concrete matrix to develop additional C-S-H gel:
Ca( OH) TWO + Na Two SiO FIVE → CaSiO THREE · nH ₂ O + 2NaOH.

This reaction densifies the near-surface area, minimizing leaks in the structure, enhancing abrasion resistance, and removing dusting triggered by weak, unbound fines.

Unlike film-forming sealers (e.g., epoxies or polymers), sodium silicate treatments are breathable, permitting dampness vapor transmission while blocking fluid access– essential for stopping spalling in freeze-thaw settings.

Numerous applications might be required for highly porous substratums, with curing periods in between layers to allow total response.

Modern formulations commonly blend sodium silicate with lithium or potassium silicates to reduce efflorescence and improve lasting security.

3. Industrial Applications Beyond Building

3.1 Factory Binders and Refractory Adhesives

In steel casting, salt silicate serves as a fast-setting, not natural binder for sand mold and mildews and cores.

When mixed with silica sand, it develops a stiff structure that holds up against liquified steel temperatures; CARBON MONOXIDE two gassing is commonly used to instantaneously treat the binder using carbonation:
Na ₂ SiO TWO + CARBON MONOXIDE ₂ → SiO ₂ + Na ₂ CO SIX.

This “CO ₂ process” makes it possible for high dimensional accuracy and rapid mold turnaround, though residual salt carbonate can cause casting problems otherwise effectively aired vent.

In refractory linings for heaters and kilns, salt silicate binds fireclay or alumina accumulations, offering initial environment-friendly strength before high-temperature sintering establishes ceramic bonds.

Its inexpensive and simplicity of use make it crucial in small shops and artisanal metalworking, despite competitors from organic ester-cured systems.

3.2 Cleaning agents, Drivers, and Environmental Utilizes

As a building contractor in laundry and industrial detergents, sodium silicate barriers pH, prevents rust of washing maker parts, and puts on hold dirt particles.

It works as a precursor for silica gel, molecular filters, and zeolites– products used in catalysis, gas separation, and water softening.

In environmental engineering, sodium silicate is employed to maintain polluted soils through in-situ gelation, incapacitating heavy metals or radionuclides by encapsulation.

It also operates as a flocculant aid in wastewater therapy, boosting the settling of put on hold solids when incorporated with metal salts.

Arising applications consist of fire-retardant coatings (forms insulating silica char upon home heating) and easy fire protection for wood and textiles.

4. Security, Sustainability, and Future Overview

4.1 Taking Care Of Considerations and Ecological Influence

Salt silicate solutions are highly alkaline and can trigger skin and eye irritation; correct PPE– consisting of gloves and safety glasses– is important during handling.

Spills must be neutralized with weak acids (e.g., vinegar) and had to stop dirt or waterway contamination, though the compound itself is safe and biodegradable in time.

Its main environmental problem lies in raised sodium content, which can impact soil structure and marine communities if launched in big amounts.

Contrasted to artificial polymers or VOC-laden options, sodium silicate has a low carbon impact, stemmed from plentiful minerals and requiring no petrochemical feedstocks.

Recycling of waste silicate solutions from industrial processes is significantly practiced via rainfall and reuse as silica resources.

4.2 Innovations in Low-Carbon Building And Construction

As the building sector looks for decarbonization, salt silicate is main to the growth of alkali-activated concretes that remove or drastically lower Rose city clinker– the source of 8% of global carbon monoxide two discharges.

Research concentrates on optimizing silicate modulus, integrating it with option activators (e.g., sodium hydroxide or carbonate), and customizing rheology for 3D printing of geopolymer frameworks.

Nano-silicate diffusions are being checked out to boost early-age stamina without raising alkali web content, reducing long-lasting sturdiness threats like alkali-silica reaction (ASR).

Standardization efforts by ASTM, RILEM, and ISO goal to develop performance criteria and style standards for silicate-based binders, increasing their adoption in mainstream framework.

Basically, sodium silicate exemplifies how an old product– utilized considering that the 19th century– continues to progress as a cornerstone of sustainable, high-performance product science in the 21st century.

5. Supplier

TRUNNANO is a supplier of boron nitride with over 12 years of experience in nano-building energy conservation and nanotechnology development. It accepts payment via Credit Card, T/T, West Union and Paypal. Trunnano will ship the goods to customers overseas through FedEx, DHL, by air, or by sea. If you want to know more about Sodium Silicate, please feel free to contact us and send an inquiry.
Tags: sodium silicate,sodium silicate water glass,sodium silicate liquid glass

All articles and pictures are from the Internet. If there are any copyright issues, please contact us in time to delete.

Inquiry us [contact-form-7]

1.1 The 2H and 1T Polymorphs: Structural and Electronic Duality

(Molybdenum Disulfide)

Molybdenum disulfide (MoS TWO) is a layered transition metal dichalcogenide (TMD) with a chemical formula including one molybdenum atom sandwiched in between two sulfur atoms in a trigonal prismatic sychronisation, creating covalently adhered S– Mo– S sheets.

These specific monolayers are stacked up and down and held together by weak van der Waals forces, allowing easy interlayer shear and exfoliation to atomically thin two-dimensional (2D) crystals– a structural attribute main to its diverse functional roles.

MoS ₂ exists in multiple polymorphic types, one of the most thermodynamically steady being the semiconducting 2H phase (hexagonal balance), where each layer displays a direct bandgap of ~ 1.8 eV in monolayer form that transitions to an indirect bandgap (~ 1.3 eV) wholesale, a phenomenon essential for optoelectronic applications.

In contrast, the metastable 1T stage (tetragonal symmetry) embraces an octahedral sychronisation and acts as a metallic conductor due to electron donation from the sulfur atoms, allowing applications in electrocatalysis and conductive compounds.

Stage shifts in between 2H and 1T can be caused chemically, electrochemically, or with strain engineering, supplying a tunable system for designing multifunctional gadgets.

The capability to support and pattern these stages spatially within a single flake opens pathways for in-plane heterostructures with distinctive electronic domain names.

1.2 Flaws, Doping, and Side States

The efficiency of MoS ₂ in catalytic and digital applications is very conscious atomic-scale flaws and dopants.

Inherent point flaws such as sulfur vacancies work as electron benefactors, increasing n-type conductivity and acting as energetic websites for hydrogen development reactions (HER) in water splitting.

Grain boundaries and line problems can either hamper charge transportation or develop localized conductive pathways, depending on their atomic arrangement.

Regulated doping with change metals (e.g., Re, Nb) or chalcogens (e.g., Se) permits fine-tuning of the band structure, provider focus, and spin-orbit coupling results.

Especially, the sides of MoS two nanosheets, especially the metal Mo-terminated (10– 10) sides, display dramatically greater catalytic activity than the inert basal plane, inspiring the style of nanostructured catalysts with made the most of edge exposure.

( Molybdenum Disulfide)

These defect-engineered systems exemplify just how atomic-level control can change a normally taking place mineral right into a high-performance functional material.

2. Synthesis and Nanofabrication Techniques

2.1 Mass and Thin-Film Manufacturing Techniques

Natural molybdenite, the mineral form of MoS TWO, has actually been utilized for years as a strong lubricating substance, however modern applications demand high-purity, structurally controlled artificial types.

Chemical vapor deposition (CVD) is the dominant approach for creating large-area, high-crystallinity monolayer and few-layer MoS two films on substratums such as SiO TWO/ Si, sapphire, or flexible polymers.

In CVD, molybdenum and sulfur forerunners (e.g., MoO six and S powder) are vaporized at heats (700– 1000 ° C )controlled atmospheres, making it possible for layer-by-layer development with tunable domain name dimension and orientation.

Mechanical peeling (“scotch tape technique”) remains a benchmark for research-grade samples, producing ultra-clean monolayers with minimal flaws, though it does not have scalability.

Liquid-phase peeling, entailing sonication or shear blending of bulk crystals in solvents or surfactant services, generates colloidal diffusions of few-layer nanosheets ideal for finishes, compounds, and ink formulas.

2.2 Heterostructure Combination and Device Patterning

Real possibility of MoS ₂ arises when incorporated into upright or side heterostructures with various other 2D products such as graphene, hexagonal boron nitride (h-BN), or WSe two.

These van der Waals heterostructures enable the style of atomically specific gadgets, including tunneling transistors, photodetectors, and light-emitting diodes (LEDs), where interlayer charge and energy transfer can be crafted.

Lithographic pattern and etching methods allow the manufacture of nanoribbons, quantum dots, and field-effect transistors (FETs) with network sizes to tens of nanometers.

Dielectric encapsulation with h-BN secures MoS ₂ from environmental destruction and decreases charge scattering, significantly boosting carrier movement and gadget security.

These construction advancements are crucial for transitioning MoS two from lab interest to viable component in next-generation nanoelectronics.

3. Useful Characteristics and Physical Mechanisms

3.1 Tribological Actions and Strong Lubrication

Among the earliest and most long-lasting applications of MoS ₂ is as a dry strong lubricant in severe environments where liquid oils fall short– such as vacuum, high temperatures, or cryogenic problems.

The low interlayer shear toughness of the van der Waals gap allows very easy gliding in between S– Mo– S layers, leading to a coefficient of rubbing as reduced as 0.03– 0.06 under optimum problems.

Its efficiency is further improved by strong attachment to metal surfaces and resistance to oxidation up to ~ 350 ° C in air, beyond which MoO five development raises wear.

MoS two is commonly made use of in aerospace systems, air pump, and weapon elements, typically applied as a covering using burnishing, sputtering, or composite incorporation into polymer matrices.

Recent studies show that moisture can deteriorate lubricity by boosting interlayer adhesion, triggering study into hydrophobic layers or crossbreed lubes for better environmental security.

3.2 Digital and Optoelectronic Reaction

As a direct-gap semiconductor in monolayer kind, MoS ₂ exhibits strong light-matter interaction, with absorption coefficients exceeding 10 five centimeters ⁻¹ and high quantum return in photoluminescence.

This makes it ideal for ultrathin photodetectors with rapid action times and broadband level of sensitivity, from noticeable to near-infrared wavelengths.

Field-effect transistors based on monolayer MoS two show on/off ratios > 10 ⁸ and service provider flexibilities approximately 500 centimeters ²/ V · s in put on hold samples, though substrate interactions normally limit functional values to 1– 20 centimeters TWO/ V · s.

Spin-valley coupling, a repercussion of solid spin-orbit communication and broken inversion symmetry, makes it possible for valleytronics– an unique standard for info encoding utilizing the valley degree of flexibility in energy room.

These quantum sensations setting MoS two as a prospect for low-power reasoning, memory, and quantum computer aspects.

4. Applications in Power, Catalysis, and Arising Technologies

4.1 Electrocatalysis for Hydrogen Evolution Reaction (HER)

MoS two has actually emerged as an encouraging non-precious option to platinum in the hydrogen advancement reaction (HER), a key process in water electrolysis for environment-friendly hydrogen manufacturing.

While the basic aircraft is catalytically inert, edge sites and sulfur vacancies show near-optimal hydrogen adsorption totally free power (ΔG_H * ≈ 0), comparable to Pt.

Nanostructuring techniques– such as developing vertically lined up nanosheets, defect-rich films, or drugged crossbreeds with Ni or Co– optimize energetic site thickness and electrical conductivity.

When integrated right into electrodes with conductive sustains like carbon nanotubes or graphene, MoS ₂ attains high present densities and long-lasting security under acidic or neutral conditions.

Further improvement is achieved by stabilizing the metallic 1T phase, which improves innate conductivity and subjects extra active sites.

4.2 Adaptable Electronic Devices, Sensors, and Quantum Tools

The mechanical flexibility, openness, and high surface-to-volume ratio of MoS ₂ make it perfect for adaptable and wearable electronics.

Transistors, reasoning circuits, and memory gadgets have actually been demonstrated on plastic substrates, making it possible for bendable displays, health and wellness screens, and IoT sensing units.

MoS TWO-based gas sensing units display high sensitivity to NO ₂, NH SIX, and H TWO O due to charge transfer upon molecular adsorption, with reaction times in the sub-second array.

In quantum modern technologies, MoS ₂ hosts local excitons and trions at cryogenic temperature levels, and strain-induced pseudomagnetic areas can catch service providers, enabling single-photon emitters and quantum dots.

These developments highlight MoS ₂ not only as a useful product yet as a system for exploring fundamental physics in lowered measurements.

In summary, molybdenum disulfide exhibits the convergence of classical products science and quantum design.

From its old role as a lubricating substance to its modern-day implementation in atomically thin electronic devices and power systems, MoS two continues to redefine the boundaries of what is feasible in nanoscale materials style.

As synthesis, characterization, and combination strategies advancement, its influence across science and modern technology is positioned to expand also additionally.

5. Provider

TRUNNANO is a globally recognized Molybdenum Disulfide manufacturer and supplier of compounds with more than 12 years of expertise in the highest quality nanomaterials and other chemicals. The company develops a variety of powder materials and chemicals. Provide OEM service. If you need high quality Molybdenum Disulfide, please feel free to contact us. You can click on the product to contact us.
Tags: Molybdenum Disulfide, nano molybdenum disulfide, MoS2

All articles and pictures are from the Internet. If there are any copyright issues, please contact us in time to delete.

Inquiry us [contact-form-7]

Advanced structural ceramics, due to their special crystal framework and chemical bond qualities, reveal efficiency benefits that steels and polymer products can not match in severe environments. Alumina (Al Two O TWO), zirconium oxide (ZrO TWO), silicon carbide (SiC) and silicon nitride (Si six N ₄) are the four major mainstream design ceramics, and there are vital distinctions in their microstructures: Al ₂ O six comes from the hexagonal crystal system and relies upon strong ionic bonds; ZrO two has 3 crystal forms: monoclinic (m), tetragonal (t) and cubic (c), and acquires special mechanical residential properties with phase change toughening mechanism; SiC and Si Three N ₄ are non-oxide ceramics with covalent bonds as the main part, and have stronger chemical stability. These architectural differences directly lead to substantial differences in the preparation procedure, physical buildings and design applications of the four. This short article will systematically examine the preparation-structure-performance connection of these four porcelains from the viewpoint of products scientific research, and explore their potential customers for industrial application.

(Alumina Ceramic)

Prep work process and microstructure control

In terms of preparation process, the 4 porcelains show evident distinctions in technical routes. Alumina ceramics make use of a fairly typical sintering process, typically making use of α-Al two O five powder with a pureness of more than 99.5%, and sintering at 1600-1800 ° C after dry pushing. The trick to its microstructure control is to prevent abnormal grain growth, and 0.1-0.5 wt% MgO is usually included as a grain limit diffusion prevention. Zirconia porcelains require to introduce stabilizers such as 3mol% Y TWO O ₃ to keep the metastable tetragonal phase (t-ZrO ₂), and use low-temperature sintering at 1450-1550 ° C to stay clear of extreme grain growth. The core process difficulty hinges on precisely controlling the t → m stage transition temperature level window (Ms point). Given that silicon carbide has a covalent bond proportion of up to 88%, solid-state sintering needs a heat of greater than 2100 ° C and relies on sintering help such as B-C-Al to form a liquid phase. The response sintering method (RBSC) can accomplish densification at 1400 ° C by penetrating Si+C preforms with silicon thaw, however 5-15% totally free Si will certainly stay. The prep work of silicon nitride is the most complicated, typically using general practitioner (gas pressure sintering) or HIP (warm isostatic pressing) processes, including Y TWO O FOUR-Al two O six collection sintering aids to create an intercrystalline glass stage, and warm therapy after sintering to crystallize the glass phase can significantly enhance high-temperature efficiency.

( Zirconia Ceramic)

Comparison of mechanical residential properties and enhancing mechanism

Mechanical residential or commercial properties are the core analysis indications of architectural ceramics. The four sorts of materials reveal completely various conditioning systems:

( Mechanical properties comparison of advanced ceramics)

Alumina mostly counts on fine grain conditioning. When the grain size is reduced from 10μm to 1μm, the stamina can be raised by 2-3 times. The superb toughness of zirconia originates from the stress-induced stage change device. The stress field at the fracture pointer activates the t → m stage change accompanied by a 4% volume expansion, resulting in a compressive tension shielding impact. Silicon carbide can enhance the grain boundary bonding strength with solid option of components such as Al-N-B, while the rod-shaped β-Si six N four grains of silicon nitride can produce a pull-out result comparable to fiber toughening. Split deflection and bridging contribute to the enhancement of strength. It is worth keeping in mind that by building multiphase ceramics such as ZrO TWO-Si Six N Four or SiC-Al ₂ O ₃, a variety of strengthening devices can be coordinated to make KIC exceed 15MPa · m ¹/ TWO.

Thermophysical properties and high-temperature actions

High-temperature security is the crucial advantage of structural ceramics that differentiates them from traditional products:

(Thermophysical properties of engineering ceramics)

Silicon carbide displays the best thermal administration efficiency, with a thermal conductivity of approximately 170W/m · K(equivalent to aluminum alloy), which is due to its basic Si-C tetrahedral structure and high phonon propagation rate. The low thermal development coefficient of silicon nitride (3.2 × 10 ⁻⁶/ K) makes it have outstanding thermal shock resistance, and the critical ΔT worth can reach 800 ° C, which is especially appropriate for duplicated thermal biking settings. Although zirconium oxide has the greatest melting factor, the conditioning of the grain border glass phase at heat will cause a sharp drop in stamina. By embracing nano-composite technology, it can be raised to 1500 ° C and still maintain 500MPa toughness. Alumina will certainly experience grain limit slip above 1000 ° C, and the addition of nano ZrO two can create a pinning result to prevent high-temperature creep.

Chemical security and rust actions

In a corrosive setting, the four sorts of porcelains show considerably various failing systems. Alumina will liquify externally in strong acid (pH <2) and strong alkali (pH > 12) remedies, and the rust price increases significantly with increasing temperature level, getting to 1mm/year in steaming focused hydrochloric acid. Zirconia has excellent resistance to not natural acids, yet will certainly go through reduced temperature deterioration (LTD) in water vapor environments over 300 ° C, and the t → m phase change will certainly lead to the formation of a microscopic fracture network. The SiO two safety layer based on the surface area of silicon carbide provides it excellent oxidation resistance listed below 1200 ° C, however soluble silicates will certainly be produced in molten antacids steel atmospheres. The deterioration behavior of silicon nitride is anisotropic, and the rust price along the c-axis is 3-5 times that of the a-axis. NH ₃ and Si(OH)₄ will certainly be created in high-temperature and high-pressure water vapor, causing product bosom. By optimizing the composition, such as preparing O’-SiAlON porcelains, the alkali deterioration resistance can be enhanced by more than 10 times.

( Silicon Carbide Disc)

Typical Design Applications and Situation Studies

In the aerospace field, NASA makes use of reaction-sintered SiC for the leading edge components of the X-43A hypersonic airplane, which can withstand 1700 ° C wind resistant heating. GE Air travel utilizes HIP-Si ₃ N four to make wind turbine rotor blades, which is 60% lighter than nickel-based alloys and enables greater operating temperatures. In the medical area, the crack stamina of 3Y-TZP zirconia all-ceramic crowns has gotten to 1400MPa, and the service life can be reached more than 15 years with surface gradient nano-processing. In the semiconductor market, high-purity Al two O five porcelains (99.99%) are made use of as cavity materials for wafer etching equipment, and the plasma rust rate is <0.1μm/hour. The SiC-Al₂O₃ composite armor developed by Kyocera in Japan can achieve a V50 ballistic limit of 1800m/s, which is 30% thinner than traditional Al₂O₃ armor.

Technical challenges and development trends

The main technical bottlenecks currently faced include: long-term aging of zirconia (strength decay of 30-50% after 10 years), sintering deformation control of large-size SiC ceramics (warpage of > 500mm elements < 0.1 mm ), and high production expense of silicon nitride(aerospace-grade HIP-Si three N ₄ gets to $ 2000/kg). The frontier advancement directions are focused on: ① Bionic structure layout(such as covering layered framework to boost sturdiness by 5 times); two Ultra-high temperature sintering technology( such as spark plasma sintering can achieve densification within 10 minutes); six Smart self-healing porcelains (containing low-temperature eutectic phase can self-heal splits at 800 ° C); ④ Additive manufacturing technology (photocuring 3D printing accuracy has actually reached ± 25μm).

( Silicon Nitride Ceramics Tube)

Future development trends

In a thorough comparison, alumina will still control the standard ceramic market with its expense advantage, zirconia is irreplaceable in the biomedical area, silicon carbide is the recommended material for extreme environments, and silicon nitride has great prospective in the field of high-end tools. In the next 5-10 years, with the combination of multi-scale architectural guideline and intelligent production technology, the performance limits of engineering ceramics are expected to attain brand-new breakthroughs: for example, the layout of nano-layered SiC/C porcelains can attain toughness of 15MPa · m 1ST/ ², and the thermal conductivity of graphene-modified Al two O five can be raised to 65W/m · K. With the development of the “double carbon” method, the application range of these high-performance ceramics in new power (fuel cell diaphragms, hydrogen storage space materials), environment-friendly production (wear-resistant parts life raised by 3-5 times) and other areas is expected to keep an ordinary yearly growth rate of more than 12%.

Distributor

Advanced Ceramics founded on October 17, 2012, is a high-tech enterprise committed to the research and development, production, processing, sales and technical services of ceramic relative materials and products. Our products includes but not limited to Boron Carbide Ceramic Products, Boron Nitride Ceramic Products, Silicon Carbide Ceramic Products, Silicon Nitride Ceramic Products, Zirconium Dioxide Ceramic Products, etc. If you are interested in si3n4 bearing, please feel free to contact us.(nanotrun@yahoo.com)

All articles and pictures are from the Internet. If there are any copyright issues, please contact us in time to delete.

Inquiry us [contact-form-7]