What is graphite oxide

graphite oxide is a compound of carbon , oxygen and hydrogen in varying proportions by graphite obtained with strong oxidizing agents. The bulk material is oxidized to a yellow solid with a C: O 2.1 to 2.9 , which retains the layered structure of graphite , but with a distance much larger and irregular.
the color of graphite oxide  remains yellow, water-soluble is very good, no precipitation. Content of dissolved more than 99% single, micro-chip the size of 1 to 5 microns, the thickness of about 0.8 to 1.2 nm. This product has many advantages:1. preparation of clear, mature technology, easy to write articles for scientific research;2. good water solubility, sheet size, uniform, controllable;3. no Suixiao particles, high-temperature graphene oxide powder prepared by small particles and more layers curl is not conducive to experiments carried out.
With hydrazine hydrate suspension to reduce some of the graphite oxide 100 ° C, 24 hours  , or by hydrogen peroxide plasma map some of the second action , [ 15 ] or pulsed xenon flash light is strong . [ 18 ] However , this approach will be less than 10 S / cm conductivity curve [ 18 ] and charge from a 200 cm2 / (V · S) orifice , from .5 to 30 cm2 / (V · S) for the electrons. These height values ​​as oxides , but there are smaller scale than the original graph several orders of magnitude lower . Atomic force microscopy showed that the carbon – oxygen layer is distorted , it ‘s a significant business within the oxide layer thickness of the rough , reduced after . These errors occurred in the Raman spectra of graphene .


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The Introduction of carboxyl graphene powder

Carboxyl graphene powder is yellow powder, soluble in water, 5% carboxyl content, carboxyl parameters have been out of the products, product performance is very good.
1) Since graphene has a very high specific surface area, leading to its reunion is very serious, difficult to disperse polar or non polar solvents.
We are completely solve the problem of dispersion of graphene, its application in composite materials cleared the way;
2) graphene oxide is graphene-modified intermediates, we have been carboxylated graphene surface carboxyl content of 5.0 wt.% Or so, greatly conducive to the next step of the application;
3) available in volume quantities of graphene oxide film (paper) and graphite film (paper);
4) can be ordered graphene or graphene oxide dispersion (polar or non polar solvents may be);
5) and the American elite to launch high-end modified graphene - amination of graphene and graphene-based thiol。

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The Introduction of CMK-3

CMK-3 over the CAC, adsorption capacity, adsorption rate, and equilibrium time is short, is a good adsorbent, while of the mesoporous carbon CMK-3 for phenol adsorption thermodynamics and kinetics. CMK-3 adsorption of phenol used Langmuir and Freundlich isotherm to describe the correlation is good, but more in line with Freundlich empirical formula. were used to simulate first-order reaction and second-order reaction model examined the adsorption kinetics and the calculation of these dynamics model rate constants. analog second-order reaction model and experimental data a good correlation between the respectively calculated thermodynamic parameters ΔG0, ΔS0 and ΔH0, results show that, CMK-3 for phenol adsorption process is endothermic and spontaneous .
Mesoporous carbon is a new type of non-silicon-based mesoporous materials with large specific surface area (up to 2500m2 / g) and pore volume (up to 2.25cm3 / g), is expected to catalyst, hydrogen storage materials, electrode materials and other aspects of important applications, so are people’s attention. In addition, mesoporous materials obtained by the double-layer capacitance charge storage material above the metal oxide particles assembled electric capacity, far higher than commercially available metal oxide double-layer capacitors.
And pure mesoporous silica materials, mesoporous carbon materials exhibit unique properties, high specific surface area, high porosity; pore size adjustable within a certain range; mesoporous shapes, hole wall composition, structure and nature of the adjustable; by optimizing the synthesis conditions can be high thermal stability and hydrothermal stability; synthesis is simple, easy to operate, no physiological toxicity. It is still in its attraction of fuel cells, molecular sieve, adsorption, catalysis, electrochemistry and other areas of potential applications. In recent years, mesoporous materials science has become an international cross-chemistry, physics, materials, biology and other disciplines cross one of the hot areas of research, development of materials science have become an important milestone.
Mesoporous material as a photocatalyst for the treatment of environmental contaminants is one of the hot research in recent years. For example, mesoporous TiO2 Bi Nami TiO2 (P25) has a higher photocatalytic activity, because the mesoporous structure with high surface area to improve contact with organic molecules, an increase of surface adsorbed water and hydroxyl, water and hydroxyl groups with the catalyst surface can be excited by light the reaction of hydroxyl radical hole, and hydroxyl radical degradation of organic matter is a strong oxidant, can put a lot of biodegradable organic matter is oxidized to CO2 and water and other minerals. In addition, the ordered mesoporous materials for selective doping can improve the optical activity of visible light photocatalytic degradation of organic waste to increase the efficiency.
Now widely used in domestic water chlorine disinfection process though killed all bacteria, but had chloroform, carbon tetrachloride, monochloroacetic acid and a series of toxic organic compounds, its serious “three letter” effects (cancer, teratogenic, mutagenic) has attracted international scientific and medical community’s attention. Through the pores of mesoporous materials received on the inner wall of the school γ-chloropropyl triethoxysilane, has been functionalized mesoporous CPS-HMS, the functional mesoporous molecular sieves to remove traces of chloroform in water results are obvious, the removal rate of up to 97%. After the treated water chloroform concentrations below the national standard, even lower than the drinking water standards.


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The Introduction of MCM-41

A technique called MCM-41 of ordered mesoporous materials, it is a new type of nano structure material, has featured six party in orderly arrangement, size uniform, pore diameter can be in 2-10 nm range continuous adjustment, high spicific surface etc. Characteristics. MCM-and from the traditional synthesis Molecule sieve synthesis is the biggest characteristic of the template, different, traditional zeolite synthesis of molecular sieve Molecule or small organic Molecule in a single molecular or metal ion for template agent and ZSM-5 as an example, the typical template, for four propyl amine ion, crystal is through the acid salt in the template, around the formation of condensation. And the synthesis of MCM-41 is different, it is in large Molecule molecular surfactants as a template,, template, alkyl chain generally more than 10 carbon atom, about the formation of it has already proposed two mechanism, and continue to improve and perfect. Compared with other zeolite materials, MCM-41 skeleton aluminum species are relatively poor thermal stability, in the roasting process, aluminum frame by frame fall off as a species skeleton aluminum species.
Pure silicon MCM-41 itself acid is very weak, as catalytic activity directly is low. Therefore, researchers often the modification, to increase its catalytic activity.
Modification methods include：
(1) synthetic skeleton structure with miscellaneous atomic MCM-41, coordination of the four central skeleton ion such as: A13 +, Cu2 + +, and Zn2 Fe3, +, and Ga3 + from anions and surface center, but through the protons or other transition metal ions to compete so as to form the catalytic activity center.
(2) using in heteropoly acid etc are method, made a series of applicable to different reaction of multiphase catalysts, such as: B acid hydrogen type MCM-41; Doping L acid type MCM-1; Mixed metal oxide alkaline or sexual MCM-41; Bear in PW12, SIW12, such as the PMo12 MCM-41 heterpoly acid; And in SO42 / bear TiO2, ZrO2 / SO42- such as solid super acid type MCM-41.
(3) MCM-41 hole assembly solid in transition metal complex molecules.


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What is Graphene oxide powder

Graphene oxide powder formerly called graphite oxide, graphitic oxide or graphitic acid, is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers.The maximally oxidized bulk product is yellow solid with C:O ratio between 2.1 and 2.9. It consists of loosely-bound layers, each being a two-dimensional arrangement of carbon atoms in the “chicken-wire” (graphene) pattern, with epoxide groups (bridging oxygen atoms) and hydroxyl groups attached to both sides.Graphene oxide has attracted much interest recently as a possible route for the large-scale production and manipulation of graphene, a material with extraordinary electronic properties. Graphene oxide itself is an insulator, almost a semiconductor, with differential conductivity between 1 and 5 x 10-3 S/cm at a bias voltage of 10 V. However, being hydrophilic, graphene oxide disperses readily in water, breaking up into macroscopic flakes, mostly one layer thick. In theory, chemical reduction of these flakes would yield a suspension of graphene flakes.
 These values are much greater than the oxide’s, but still a few orders of magnitude lower than those of pristine graphene. Inspection with the atomic force microscope shows that the oxygen bonds distort the carbon layer, creating a pronounced intrinsic roughness in the oxide layers which persists after reduction. These defects also show up in Raman spectrum of graphene oxide.Reduction methods have been developed that do not use chemical solutions and can be performed at room temperature. a consumer camera flash has been shown to decompose graphene oxide to graphene.
Based on the graphite oxide aperture adjustable nano porous materials preparation methods, to natural flake graphite as raw material, strong sulfuric acid and sodium nitrate for intercalated agent and potassium permanganate as the oxidant of the thermal and chemical intercalated processing; Then will get flake graphite oxide to ion solution after the freeze-drying get flake graphite oxide powder, or use of polarity of the organic solvent to flake graphite oxide to ion solution for solvent for flake graphite oxide organic solvent suspension; , then use direct modification method and construct the supramolecular method of flake graphite oxide powder or flake graphite oxide organic solvent in modified suspension, get flake graphite oxide based on the pore diameter of adjustable nano porous materials; The party of the nano porous materials legal system through covalent bond or metal coordination key connection building, pore structure stability, the use of the modifying molecule range, can be in a wide range of adjust its pore size.


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What is Graphene oxide paper

Graphene oxide paper or paper produced graphite oxide composite graphite oxide . The material has exceptional stiffness and strength , due to the inherent strength of the backbone and the two-dimensional graphene layer structure intertwined distributed load . Starting materials water-dispersed graphene oxide films, which often includes a graphene layer. Chemical bonding of these films may , leading to the development of additional new material . As raw materials , graphene oxide paper, is an electrical insulation ; However , you can transfer the property to make this conductor or semiconductor , and not at the expense of its mechanical properties. Detailed study of graphite oxide and p. There Kohlschutter later date can be traced back to 1918.

Researchers have developed a very simple way to convert ordinary graphite particles into very thin , but superstrong sheets, stronger than steel and carbon fiber as a flexible but more expensive . This finding will produce a new type of material and other industrial application of anti-corrosion coatings , electronic components , batteries, fuel cells .

Oxidation graphite papers can be system and solutions and phase alkyl modification, and the latter is clearly the process becomes slower. Gallery spacing, physical thickness and the quality of the thesis amine modification, increase physical adsorption removal amine, can directly interpolated alkyl chain length of related. Although after the modification of the paper tensile strength increases slightly amine length decreases, their “effective oxidation graphite modulus remain the same basic, suggesting that, graphite oxide is the only contribution to the stiffness of the modified paper amine.

 

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Graphene oxide dispersions can build the biggest concentration of 2mg/ml solution of graphene oxide, graphene oxide solution is prepared by the oxidation of graphene thin films derived from precipitation does not occur.The graphene has a very high specific surface area, leading to its reunion is very serious, difficult to Polar and non polar solvents dispersed. In all of these solvents , all of the stratum corneum is divided into individual graphite oxide materials , single-layer graphene oxide film group , was achieved. Exhibited dispersed graphene oxide sheets between the long-term stability and a few hundred nanometers and several microns large , a similar situation dispersed graphene oxide in water。

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The Introduction of graphene oxide

The graphite oxide , formerly known as oxide or graphitic acid is a compound of carbon , oxygen and hydrogen in varying proportions by graphite obtained with strong oxidizing agents. The bulk material is oxidized to a yellow solid with a C: O 2.1 to 2.9 , which retains the layered structure of graphite , but with a distance much larger and irregular.
The bulk material is dispersed in the basic solutions to monomolecular sheets to produce a graph similar to graphene known , form a single layer of graphite. Graphene sheets were used to prepare a paper as a solid material , and have recently attracted considerable interest as a possible intermediary graph. But by 2010 this target in the distant future , this method since graphs with many chemical and structural defects .

With hydrazine hydrate suspension to reduce some of the graphite oxide 100 ° C, 24 hours  , or by hydrogen peroxide plasma map some of the second action ,  or pulsed xenon flash light is strong .  However , this approach will be less than 10 S / cm conductivity curve  and charge from a 200 cm2 / (V · S) orifice , from .5 to 30 cm2 / (V · S) for the electrons. These height values ​​as oxides , but there are smaller scale than the original graph several orders of magnitude lower . Atomic force microscopy showed that the carbon – oxygen layer is distorted , it ‘s a significant business within the oxide layer thickness of the rough , reduced after . These errors occurred in the Raman spectra of graphene .

 

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The use of graphite oxide powder

graphite oxide powder as an antimicrobial to restore the application materials, including nano-specific reduction of graphene oxide suspension or reduction of graphene nano-oxide film as an antibacterial material applications. Reduction described in nano-graphene oxide suspension, including the preparation of pre-oxidation of graphite, pre-oxidation products of the separation, re-oxidation, oxidation products of the purification, the reduction of oxidation products. Reduction described in nano-graphene oxide film is the use of the 0.22μm PVDF membrane filtration as described in the nano-graphene oxide suspension to restore the system. Use of the invention of nano-graphene oxide as an antimicrobial to restore the application materials can be nano-graphene oxide as an additive reduction is made with antimicrobial properties of antibacterial coating made ​​of a product or material, used in medical and daily life.Dispersed in organic solvents, oxidation behavior graphène different effects. Such as oxidized graphite manufacturing, N-méthyl-2-pyrrolidone N-diméthylformamide dispersed, tétrahydrofurane, built with ethylene glycol,. In all these solvents, ozone layer, the cornea is divided into different materials, graphite oxide, an oxide film layer graphène Group has been achieved. Scattered between the leaves graphène oxidation www.gammachina.cn and nanomètres hundreds of long-term stability and large, micron similar graphène oxide dispersed in water. ) These results must be easy to manipulate and handle the process with graphène materials with different environments.Based on the graphite oxide aperture adjustable nano porous materials preparation methods, to natural flake graphite as raw material, strong sulfuric acid and sodium nitrate for intercalated agent and potassium permanganate as the oxidant of the thermal and chemical intercalated processing; Then will get flake graphite oxide to ion solution after the freeze-drying get flake graphite oxide powder, or use of polarity of the organic solvent to flake graphite oxide to ion solution for solvent for flake graphite oxide organic solvent suspension; , then use direct modification method and construct the supramolecular method of flake graphite oxide powder or flake graphite oxide organic solvent in modified suspension, get flake graphite oxide based on the pore diameter of adjustable nano porous materials; The party of the nano porous materials legal system through covalent bond or metal coordination key connection building, pore structure stability, the use of the modifying molecule range, can be in a wide range of adjust its pore size.

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The Introduction of graphite oxide powder

Graphite oxide powder with its small thermal expansion, and thermal conductivity, thermal shock resistance and chemical stability, and many other advantages and to fit for the steel smelting harsh environment refractory raw material, but graphite in the water and wettability, dispersion sent in air shortcomings, such as easy oxidation limits its further applications. This papers to the inorganic salt (nitric acid aluminum, oxygen chlorinated zirconium, three chlorinated titanium) as raw material, the rare in graphite nanocolloidal suspension of non-uniform application into nuclear technology, make hydrolysis product (hydration oxide deposits to micron grade flake graphite surfaces, the washing and drying and heat treatment, the graphite/oxide compound preparation powder. This paper mainly of composite powder preparation process condition and performance. Through the coated rate, oxidation weightlessness rate, morphology observation, grain size and specific surface area and analysis found that, non-uniform nucleation process of pH value, coating solution temperature, the cladding precursors concentration on the several factors of graphite surface coating layer have important influence on the form.

Dispersion behavior of graphene oxide in different organic solvent impact . As-prepared graphite oxide may be dispersed , N-dimethylformamide, N-methyl-2-pyrrolidone, tetrahydrofuran , ethylene glycol . In all of these solvents , all of the stratum corneum is divided into individual graphite oxide materials , single-layer graphene oxide film group , was achieved. Exhibited dispersed graphene oxide sheets between the long-term stability and a few hundred nanometers and several microns large , a similar situation dispersed graphene oxide in water . These results should be easy to handle and deal with the graphene-based materials used in different environments .

 

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The Introduction of Graphene oxide paper

Graphene oxide paper or paper produced graphite oxide composite graphite oxide . The material has exceptional stiffness and strength , due to the inherent strength of the backbone and the two-dimensional graphene layer structure intertwined distributed load . Starting materials water-dispersed graphene oxide films, which often includes a graphene layer. Chemical bonding of these films may , leading to the development of additional new material . As raw materials , graphene oxide paper, is an electrical insulation ; However , you can transfer the property to make this conductor or semiconductor , and not at the expense of its mechanical properties. Detailed study of graphite oxide and p. There Kohlschutter later date can be traced back to 1918.

Researchers have developed a very simple way to convert ordinary graphite particles into very thin , but superstrong sheets, stronger than steel and carbon fiber as a flexible but more expensive . This finding will produce a new type of material and other industrial application of anti-corrosion coatings , electronic components , batteries, fuel cells .

Oxidation graphite papers can be system and solutions and phase alkyl modification, and the latter is clearly the process becomes slower. Gallery spacing, physical thickness and the quality of the thesis amine modification, increase physical adsorption removal amine, can directly interpolated alkyl chain length of related. Although after the modification of the paper tensile strength increases slightly amine length decreases, their "effective oxidation graphite modulus remain the same basic, suggesting that, graphite oxide is the only contribution to the stiffness of the modified paper amine.

 

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The Introduction of graphene oxide dispersions

Graphene oxide dispersions can build the largest concentration of 2 mg / ml of graphene oxide , graphene oxide solution of graphene oxide films prepared from the precipitation does not occur.

Dispersion behavior of graphene oxide in different organic solvent impact . As-prepared graphite oxide may be dispersed , N-dimethylformamide, N-methyl-2-pyrrolidone, tetrahydrofuran , ethylene glycol . In all of these solvents , all of the stratum corneum is divided into individual graphite oxide materials , single-layer graphene oxide film group , was achieved. Exhibited dispersed graphene oxide sheets between the long-term stability and a few hundred nanometers and several microns large , a similar situation dispersed graphene oxide in water . These results should be easy to handle and deal with the graphene-based materials used in different environments .

 

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graphene oxide for sale

The graphite oxide , formerly known as oxide or graphitic acid is a compound of carbon , oxygen and hydrogen in varying proportions by graphite obtained with strong oxidizing agents. The bulk material is oxidized to a yellow solid with a C: O 2.1 to 2.9 , which retains the layered structure of graphite , but with a distance much larger and irregular.
The bulk material is dispersed in the basic solutions to monomolecular sheets to produce a graph similar to graphene known , form a single layer of graphite. Graphene sheets were used to prepare a paper as a solid material , and have recently attracted considerable interest as a possible intermediary graph. But by 2010 this target in the distant future , this method since graphs with many chemical and structural defects .

With hydrazine hydrate suspension to reduce some of the graphite oxide 100 ° C, 24 hours [ 9 ] , or by hydrogen peroxide plasma map some of the second action , [ 15 ] or pulsed xenon flash light is strong . [ 18 ] However , this approach will be less than 10 S / cm conductivity curve [ 18 ] and charge from a 200 cm2 / (V · S) orifice , from .5 to 30 cm2 / (V · S) for the electrons. These height values ​​as oxides , but there are smaller scale than the original graph several orders of magnitude lower . Atomic force microscopy showed that the carbon - oxygen layer is distorted , it 's a significant business within the oxide layer thickness of the rough , reduced after . These errors occurred in the Raman spectra of graphene .

 

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ZSM-12 for sale

Product name is ZSM-12, alumina than 60 to 150 years, surface area (m2 / g) frequency 340, crystallinity relative frequency (%), 95 residual sodium (%) is more than 0.1, the loss is the ignition (%) than 5.

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ZSM-11 for sale

Product Name:ZSM-11
Description:ZSM-11 zeolite is a high silica ZSM series, a member of the tetragonal, belonging to Pentasil zeolite, ten dollars from the oval ring made ​​of three-dimensional straight channels intersect.
Characteristics and Applications
ZSM-11 zeolite has a very unique crystal structure, the crystal structure of alumina is high, the crystal surface with a clear role and strong hydrophobic surface acidity, it is important to good shape-selective adsorbent and catalyst. For toluene - methanol alkylation, xylene isomerization and toluene disproportionation reaction.

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SBA-3 for sale

Product Name: SBA-3

Description:SBA-3 is a quaternary ammonium salt as the template in the synthesis of acid system with two-dimensional hexagonal mesoporous silicon-based molecular sieve. The material and the basic system of mesoporous materials synthesized in the different, the difference lies in its neutral or nearly neutral framework for the oxidation of silicon, instead of negatively charged silicate.
Characteristics and Application:
SBA-3 molecular sieves with regular pore structure, narrow pore size distribution, high surface area and better thermal stability of water in organic molecules, biological macromolecules adsorption and catalysis has wider applications. Can be applied to acid-base catalysis, redox catalysis, polymerization catalysis, protein separation, biosensors, biochips and electrochemical energy storage in the material; can also be used for environmental science and engineering of porous adsorbents, such as adsorption of heavy metal ions To remove the radioactive atoms, ions and removal of toxic waste from industrial adsorption recovery of useful substances.
Sealed.
This product is not toxic, but improper use can cause respiratory, eye slight stimulation, direct contact may cause dry skin. Recommended to wear masks and gloves when using.

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MCM-48 for sale

Product Name : MCM-48
Description: Molecular sieve MCM-48 mesoporous molecular sieves are M41S series with uniformity of about 2.6 nm diameter and about two separate three-dimensional helical pore network structure. % Characteristics and Applicati.
Mesoporous molecular sieves of MCM-48 type were prepared by conventional hydrothermal and novel room temperature syntheses. Scanning electron microscopy (SEM) studies have shown that nonagglomerated uniform spheres of size ca. 0.5 μm were obtained by the room temperature method. Internal pore structure was studied by X-ray diffraction (XRD), transmission electron microscopy (TEM), and high-resolution nitrogen and argon adsorption. Pore size distributions were calculated from low-temperature nitrogen and argon adsorption isotherms by the nonlocal density functional theory (NLDFT) method. A novel approach to calculating the pore wall thickness of MCM-48 from XRD and gas adsorption isotherms was employed. The approach utilizes intrinsic symmetry of MCM-48 pore structure, cubic Ia3d space group, revealed by XRD and combines the results of the pore size distribution analysis with general geometrical relations between structural parameters of the gyroid minimal surface. The pore wall thickness of MCM-48 calculated from both nitrogen and argon adsorption data was found to be ca. 8−10 Å, in good agreement with the estimates obtained from TEM.

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MCM-41 for sale

Product Name: MCM-41
Description:MCM-41 is a quaternary ammonium salt as a template, were prepared in alkaline conditions, with a hexagonal ordered pore structure and long-range order of mesoporous molecular sieve. The Si-Al ratio can be adjusted from 20 to infinity, the aperture size can be synthesized with different conditions between 2 ~ 5 nm in the regulation.
Characteristics and Applications
MCM-41 molecular sieves with uniform pore size is a long-range ordered mesoporous materials with high BET surface area, large adsorption capacity, uniform in the pore structure characteristics of the residue catalytic cracking, hydrogenation of heavy oil, lubricating oil hydrogenation , Alkylation, olefin polymerization, CO2 and CH4 in the separation of acid catalysis and separation process in the petrochemical industry has considerable potential applications in heterogeneous catalysis, ion exchange, sensing technology, and Advanced Inorganic Materials for Adsorption and Separation And other fields have a higher value.

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ZSM-5 for sale

ZSM-5 - Zeolite Socony Mobil – 5, (structure type MFI – mordenite framework inverted) is an aluminosilicate zeolite mineral belonging to the pentasil family of zeolites. Its chemical formula is Na_nAl_nSi_96–nO₁₉₂·16H₂O (0<n<27). Patented by Mobil Oil Company in 1975, it is widely used in the petroleum industry as a heterogeneous catalyst for hydrocarbon isomerization reactions.
ZSM-5 is composed of several pentasil units linked together by oxygen b ridges to form pentasil chains. A pentasil unit consists of eight five-membered rings. In these rings, the vertices are Al or Si and an O is assumed to be bonded between the vertices. The pentasil chains are interconnected by oxygen bridges to form corrugated sheets with 10-ring holes. Like the pentasil units, each 10-ring hole has Al or Si as vertices with an O assumed to be bonded between each vertex. Each corrugated sheet is connected by oxygen bridges to form a structure with “straight 10-ring channels running parallel to the corrugations and sinusoidal 10-ring channels perpendicular to the sheets.”Adjacent layers of the sheets are related by an inversion point. The estimated pore size of the channel running parallel with the corrugations is 5.4–5.6 Å. The crystallographic unit cell of ZSM-5 has 96 T sites (Si or Al), 192 O sites, and a number of compensating cations depending on the Si/Al ratio, which ranges from 12 to infinity. The structure is orthorhombic (space group Pnma) at high temperatures, but a phase transition to the monoclinic space group P2₁/n.1.13 occurs on cooling below a transition temperature, located between 300 and 350 K.
ZSM-5 catalyst was first synthesized by Argauer and Landolt in 1972. It is a medium pore zeolite with channels defined by ten-membered rings. The synthesis involves three different solutions. The first solution is the source of alumina, sodium ions, and hydroxide ions; in the presence of excess base the alumina will form soluble Al(OH)₄^– ions. The second solution has the tetrapropylammonium cation that acts as a templating agent. The third solution is the source of silica, one of the basic building blocks for the framework structure of a zeolite. Mixing the three solutions produces supersaturated tetrapropylammonium ZSM-5, which can be heated to recrystallize and produce a solid.
ZSM-5 has a high silicon to aluminum ratio. Whenever an Al³⁺ cation replaces a Si⁴⁺ cation, an additional positive charge is required to keep the material charge-neutral. With proton (H⁺) as the cation, the material becomes very acidic. Thus the acidity is proportional to the Al content. The very regular 3-D structure and the acidity of ZSM-5 can be utilized for acid-catalyzed reactions such as hydrocarbon isomerization and the alkylation of hydrocarbons. One such reaction is the isomerization of meta-xylene to para-xylene. Within the pores of the ZSM-5 zeolite, para-xylene has a much higher diffusion coefficient than meta-xylene. When the isomerization reaction is allowed to occur within the pores of ZSM-5, para-xylene is able to traverse along the pores of the zeolite, diffusing out of the catalyst very quickly. This size-selectivity allows the isomerization reaction to occur quickly in high yield.
ZSM-5 has been used as a support material for catalysis. In one such example, copper is deposited on the zeolite and a stream of ethanol is passed through at temperatures of 240 to 320 °C as a vapour stream, which causes the ethanol to oxidize to acetaldehyde; two hydrogens are lost by the ethanol as hydrogen gas. It appears that the specific pore size of ZSM-5 is of benefit to this process, which also functions for other alcohols and oxidations. The copper is occasionally combined with other metals, such as chromium, to fine tune the diversity and specificity of the products, as there is likely to be more than one. Acetic acid is an example of one possible byproduct from hot copper oxidation.


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graphene oxide dispersions for sale

Product Name:graphene oxide dispersions

Description:The product can build the biggest concentration of 2mg/ml solution of graphene oxide, graphene oxide solution is prepared by the oxidation of graphene thin films derived from precipitation does not occur.The graphene has a very high specific surface area, leading to its reunion is very serious, difficult to Polar and non polar solvents dispersed. Oxidized graphene graphene is a modification of the intermediates, we have been carboxylated graphene surface carboxyl content 5.0 wt.% or so, greatly conducive to its next application; bulk supply of graphene oxide film (paper) and the graphite film (paper); can be ordered graphene or graphene oxide dispersion (polar or non-polar solvents may be.

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Flake graphite with high purity for sale

Flake graphite with high purity is suitable for the preparation of graphene.The flake graphite has good electric and thermal conductivity, resistance to corrosion, and superior chemical stability, is very suitable for the preparation of graphene. The size is 100 mesh.Graphite has a layered, planar structure. In each layer, the carbon atoms are arranged in a hexagonal lattice with separation of 0.142 nm, and the distance between planes is 0.335 nm. The two known forms of graphite, alpha (hexagonal) and beta (rhombohedral), have very similar physical properties (except that the graphene layers stack slightly differently).The hexagonal graphite may be either flat or buckled. The alpha form can be converted to the beta form through mechanical treatment and the beta form reverts to the alpha form when it is heated above 1300 °C. The layering contributes to its lower density

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Nano-graphite for sale

Nano-graphite is synthesized by the detonation of high power explosive mixing with graphite which is put into a chamber. During the process of detonation, high temperature and pressure can be caused. Under this condition, large amount of dissociative carbon atom integrate into nano-sized graphite.  By advanced processing technologies, we make the Nano graphite powder with excellent quality. The average particle size is about 40-500 nm, and the purity is above 99.5%.
The application of  nano graphite powder is versatile, such as super lubricant, energy-storing, high conductor, diamond, etc. The details are as follow:

●For the feature of small and homogeneous particle dimension, can be used as nano-scaled compound-material or compound-paint additive.

 ●For the feature of high-purity and high specific surface area make it better to be hydrogen storage material than other materials.

 ●For the feature of high thermal-stability, electric/anti-corrosion performance and thermal-conduction features make it to be good electric and thermal conductive material.

●Additive to lubricant can diminish the friction coefficient and improve the ability of antifriction, resistance to ultimate-pressure and resistance to high temperature 

Features:

● Small and homogeneous particle dimension

● High specific surface area , porous structure

● High thermal-stability and good performance of electriconduction and heatconduction

● Good performance of lubrication, anti-corrosion and thermal conductivity

 

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