Complaint
Graphene oxide is the oxide of graphene, generally denoted by GO, the color is brownish-yellow, firstly prepared by the improved Hummers method to get the slurry, and then freeze-dried to get the high-quality graphene oxide powder. GO not only contains SP2 hybridized carbon atoms, part of the carbon-carbon double bond is interrupted by the oxygen-containing functional groups, which becomes the SP3 hybridization; the surface of graphene oxide contains a large number of functional groups, such as -OH, -COOH, -O-, etc. These functional groups give graphene oxide some new properties, such as good dispersion, hydrophilicity, increased interaction with polymers and so on.
The most commonly used dispersant is deionized water, while ethanol,NMP, DMF, etc., can also be used as a dispersant for GO.
| Layers | Tap Density(g/cm3) | Specific surface area(m2/g) | Carbon content(%) | Oxide content(%) | particle size(D50=μm) | state | pH Value |
| 1~5 | <0.02 | 350~450 | 45~62 | 36~53 | <5μm | dispersion | 5~6 |
1, Graphene oxide-based materials provide surface modification active position and large specific surface area
2, Good dispersion in composite materials, in situ polymerization to prepare multifunctional composite materials with less agglomeration
3, High purity, less metal impurities
4, Adjustable oxidation degree, can be customized according to customer needs
1, Textile field: Graphene materials and ordinary textiles' effective combination, can make the textile retain their own performance ,meanwhile access to graphene' one or several special properties, such as conductive, flame-retardant, antibacterial, anti-ultraviolet ray, anti-electromagnetic radiation, magnetic therapy, anionic health care, etc., can be applied in the field of special protection, smart fabrics and so on;
2, Graphene photocatalytic materials: Graphene/titanium dioxide photocatalytic materials in the visible light or ultraviolet light has a strong reducing ability, stable chemical properties, can be formaldehyde, xylene, odor, bacteria, microorganisms, and other harmful organic matter completely decomposed into carbon dioxide and water. Graphene/titanium dioxide photocatalytic material can be applied to various photocatalytic sprays for air pollution treatment, such as applied to indoor air purification, formaldehyde removal, outdoor environment air purification, etc.; nano antimicrobial coatings; wastewater treatment, such as decomposition of organic matter in wastewater from paper mills, dyeing and printing factories, and chemical plants. The application prospect is broad.
3.Construction materials: Graphene construction materials are formed by using graphene as the core and compositing with other materials through its high strength and strain hardening properties. The characteristics of graphene flakes can be utilized to strengthen the thermal conductivity and strength of the material, while effectively reducing the density of the material. Usually in the concrete material to increase a strength level, a single square of concrete need to increase 30kg cement, if mixed with graphene, then to achieve the same strength level, can save cement about 10%. The advantages are high strength, good thermal conductivity, good emissivity and oxidation resistance.In 2018, a hospital in London, UK, applied a roof built with graphene material. This roof utilizes special 3D printing and steel structure, and through the high thermal conductivity of graphene material, the temperature inside the hospital will be drastically reduced in the summer, saving the hospital's air conditioning energy consumption.
4.Graphene anti-corrosion coatings: Graphene material in the sheet diameter is very small can still maintain a great diameter-thickness ratio, add a small amount of graphene in the coating on the line to effectively form a lap, the formation of a more complete shielding layer, delay the penetration of corrosive media, greatly reducing the permeability of chloride ions. Some practical applications show that when the amount of GO added is 0.5%, the chloride ion permeability of the coating can be reduced by 50%. On the other hand, the use of graphene's high conductivity, add a very small amount of zinc coating (<0.3%), the coating and zinc can form a conductive network, improve the utilization of zinc, so that the entire coating relative to the steel to become the "anode", and significantly improve the cathodic protection performance of the zinc primer.
5.Graphene lubricant: Traditional lubricant additives usually contain sulfur, phosphorus and other elements, to bring greater harm to the environment, in order to create a green and efficient lubricant products, graphene has become the ideal choice, graphene lubrication and anti-wear performance is very excellent, when the number of layers of 2 ~ 3 layers, its friction is not zero but almost zero. Graphene lubricant can change the friction between the metal rotating parts into sliding between the layers of graphene sheets, and at the same time, it can also fill and repair the uneven pits on the metal surface to meet the dual needs of anti-wear and drag reduction, and prolong the service life of the engine. At the same time, based on graphene's antioxidant and anti-volatility, graphene lubricant can also save fuel and reduce carbon emissions, which is conducive to environmental protection. Currently several categories of graphene materials can achieve the effect of lubrication, but considering the problem of dispersion, the dispersion of graphene oxide is more advantageous.
6.Graphene antibacterial filter element: Graphene material has excellent bactericidal effect, it has corresponding resistance of more than ten kinds of bacteria such as Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Candida albicans and so on. Nanoscale graphene material due to the small size, its sharp edges will be like a sword into the bacteria, and eventually "kill" the bacteria. The larger micron-sized graphene material can surround the bacteria to achieve the effect of "cutting off their food", thus starving the bacteria to death, thus achieving the role of sterilization. Graphene oxide is added to the water filter, the inhibition rate of E. coli can reach more than 99.9%;
7.Graphene thermal conductive film: With the rapid development of consumer electronics products in the 5G era, electronic devices on the heat dissipation components of the heat expansion ability of the demand is higher and higher, graphene thermal conductive film is an important part of the electronic heat dissipation materials, graphene thermal conductive film is based on graphene as the raw material, the use of multi-layer graphene stacked into a high directional thermal conductive film, including protective film, one-sided adhesive, graphene film, double-sided adhesive and release film and so on. Graphene heat dissipation film has good heat transfer performance and excellent flexibility, light weight and other characteristics, as a new type of high thermal conductivity material has attracted much attention. At present, the mainstream preparation process is mainly to coat graphene oxide to form a self-supporting GO film, and then form a graphene foam film through high-temperature heat treatment, followed by calendering, punching and sticking, die-cutting and other processes, and ultimately form a highly thermally conductive graphene thermal conductive film. At present, the thermal conductivity of graphene thermal conductive film products on the market can reach 1500W/m-K stably
8.The field of health: Graphene inherent properties determine that it can produce a wavelength of 5 ~ 15μm range of far-infrared radiation energy, and 4 ~ 15μm of far-infrared light is essential for the survival of plants and animals, "the light of life", biological tissues, cells and molecules of the chemical bond vibration, resonance wavelengths are located in most of the 4 ~ 15μm wavelength band. Most of the resonance wavelengths are located in the 4~15μm band when the chemical bonding of biological tissues and cells vibrate, which is basically coincident with the far infrared rays radiated by graphene, thus producing "resonance absorption". Far infrared rays have a strong penetrating ability, not only to the surface of the object, but also can be transported to the object inside the heat, absorbed by the human body can penetrate the skin 3 ~ 5nm, is the temperature of the deep skin rises, to promote blood circulation, and play a role in health care.
9.Masterbatch manufacturing industry: Graphene and its graphene oxide doping can change the physical and mechanical properties of polymers, graphene masterbatch as an additive can effectively change the tension, deformation and impact resistance of plastics, and enhance the resistance to ultraviolet rays. The incorporation and concentration of graphene and its derivatives can change the physical and mechanical properties of the polymer to be processed. Addition of the masterbatch to different polymers more or less improves the final properties of the material, for example:
--Polypropylene (PP) with polypropylene-graphene masterbatch (MB-PP/GO) incorporation improves tensile strength (8%) and fracture rate (29%).
--Additive for polyethylene (PE) with polyethylene-graphene masterbatch (MB-PE/GO) improves tensile strength (17%), flexural strength and breaking strength (66%).
--Additives to polyethylene terephthalate (PET) with polyethylene terephthalate-graphene masterbatch (MB-PET/GO) improve moisture resistance, increase tensile strength (72.2%) and improve impact resistance.
--Additive for polycarbonate (PC) with polycarbonate-graphene masterbatch (MB-PC/GO) improves moisture resistance and increases rupture resistance (276%).
Q: What is graphene oxide?
A: Graphene oxide (GO) is a two-dimensional material in which oxygen-containing functional groups are introduced into the graphene skeleton. The introduction of oxygen-containing functional groups, on the one hand, destroys the ideal π-electron conjugated structure of graphene, changing it from a conductor to an insulator. On the other hand, these functional groups also confer functions such as hydrophilicity, so that graphene oxide can form stable colloids in water and some low molecular weight alcohols. Using these chemically active functional groups, covalent bonding of graphene oxide with other materials can also be realized.
Q: What are the categories of graphene materials?
A: According to the different preparation processes, graphene materials can be divided into two categories: graphene oxide and graphene, and graphene can be divided into graphene nanosheets prepared by physical method, usually denoted by GNP, and reduced graphene oxide prepared by redox method, usually denoted by rGO, according to the different preparation processes.
Q: Can graphene oxide dispersion be used directly?
A: It can be used directly after opening, if it has been placed for a long time, it can be used after ultrasonic dispersion for 5~10min, the ultrasonic time should not be too long, after the ultrasonic time is too long, the temperature of the water bath rises, and graphene oxide is easy to deoxidize, resulting in poor dispersion effect.
Q: Graphene oxide can be dispersed into which agents?
A: Graphene oxide can be stably dispersed in water due to a large number of oxygen-containing functional groups, in addition, ethanol, acetic acid, NMP, DMF and so on are also good dispersants of graphene oxide.
Q: How to store the unused graphene oxide dispersion after opening?
A: It is recommended to be stored in a ventilated and dry environment at a temperature not higher than 35ºC, do not contact with metals, vitamin C, NaHSO3, NaBH4 and other reducing reagents when storing, and keep it sealed at low temperature after opening.
Q: What is the particle size of graphene oxide?
A: At present, the particle size of our graphene oxide products is less than 5μm, if you need other sizes, please contact us for customization.
Q: Is the smaller the particle size of graphene oxide, the better the dispersibility?
A: The dispersibility of graphene oxide has a little relationship with the particle size, but there is no direct influence on the relationship, the more critical influencing factor is the degree of oxidation as well as the dispersing technology, the oxygen content of more than 20% of the GO has been able to meet the normal dispersion needs.
Q: Graphene oxide dispersed in water is acidic or alkaline?
A: Graphene oxide is weakly acidic when dispersed in water due to its acidic oxygen-containing functional groups. Some GO dispersions on the market that are more acidic are due to incomplete cleaning and high content of impurity ions.
Q: Can graphene oxide be stabilized under alkaline condition?
A: Weakly alkaline conditions can be stable, but pH more than 11 is prone to agglomeration, because the adsorption of graphene oxide and metal ions under strong alkaline conditions changes the zeta potential of the lamellae, resulting in mutual attraction between the lamellae. In addition, it is easy to deoxidize under heating condition in alkaline solution, resulting in poor dispersion of the product.
Q: Why is the color of graphene oxide dispersion different from graphene dispersion?
A: According to the different concentration, graphene oxide dispersion shows brownish yellow to blackish brown from low to high concentration respectively. The reason for the color of graphene oxide is the destruction of its conjugated structure during the preparation process, the opening of the optical band gap, the hanging unsaturated bonds and the joint action of oxygen-containing functional groups. Graphene with a perfect conjugated structure does not have an optical band gap, and by destroying the conjugated structure or narrowing the conjugated structure, graphene can absorb or emit a certain range of wavelengths of light. Graphene oxide has suspended unsaturated double bonds and other color-generating groups, together with the oxygen-containing functional groups of the color-assisting groups, the corresponding color is produced.
