Methods of making graphene oxide and reduced graphene oxide are provided. The methods can include a simple one-pot synthesis of graphene oxide from a purified coal powder using a mild oxidizing acid. The methods provide for an improved, more cost-effective, and simpler process than conventional methods such as Hummers methods. In some aspects, placing the purified coal powder in the mild oxidation atmosphere includes contacting the purified coal powder with a mild oxidizing acid such as nitric acid, nitrous acid, sulfuric acid, phosphoric acid, benzoic acid, or a combination thereof. In some aspects, the mild oxidizing acid consists essentially of nitric acid. Graphene oxides and reduced graphene oxides prepared by the methods are also provided.

Provided are nanocrystalline graphene and a method of forming the nanocrystalline graphene through a plasma enhanced chemical vapor deposition process. The nanocrystalline graphene may have a ratio of carbon having an sp.sup.2 bonding structure to total carbon within the range of about 50% to 99%. In addition, the nanocrystalline graphene may include crystals having a size of about 0.5 nm to about 100 nm.

The present invention provides a paper ball-like graphene microsphere, a composite material thereof, and a preparation method therefor. Such paper ball-like graphene microspheres are obtained by chemically reducing graphene oxide microspheres to slowly remove oxygen-containing functional groups on the surface of the graphene oxide to avoid the volume expansion caused by rapid removal of the groups, thereby maintaining a tight bond between graphene sheets without separation; and removing the remaining small number of oxygen-containing functional groups and repairing defect structures in the graphene oxide sheets by means of high temperature treatment, such that the graphene structure becomes perfect at an ultrahigh temperature (2500 to 3000° C.), thereby further improving the bonding ability between the graphene sheets in the microspheres and achieving a dense structure.

A graphene dispersion liquid containing graphene dispersed in a dispersion medium is described, in which, in the graphene contained in the dispersion liquid, a proportion of graphene with a size in the plane direction of 500 nm or more and 1 μm or less is 30% or more on an area basis, and a proportion of graphene with a size in the plane direction of 10 μm or more and 50 μm or less is 30% or more on an area basis. The graphene dispersion liquid is in a stable dispersion state and forms a strong conductive path.

Provided herein are high throughput continuous or semi-continuous reactors and processes for manufacturing graphenic materials, such as graphene. Such processes are suitable for manufacturing graphenic materials at rates that are up to hundreds of times faster than conventional techniques, and have little batch-to-batch variation. Also provided herein are graphenic compositions of matter, including large, high quality and/or highly uniform graphene.

An example method includes providing coal and extracting the graphene from the coal. The graphene may be extracted using any suitable technique, such as the Hummers method, a modified Hummers method, or exfoliation of graphite. The graphene may include impurities or other electrical properties that depend at least partially on the composition of the coal. The method may further include forming a life science device from the graphene. The life science device may include, for example, a biosensor or a drug delivery system.

Provided herein are graphene nanoribbons with high structural uniformity and low levels of impurities and methods of synthesis thereof. Also provided herein are graphene nanoplatelets of superior structural uniformity and low levels of impurities and methods of synthesis thereof. Further provided herein are mixtures of graphene nanoribbons and graphene nanoplatelets of good structural uniformity and low levels of impurities and methods of synthesis thereof. The method includes, for example, the steps of depositing catalyst on a constantly moving substrate, forming carbon nanotubes on the substrate, separating carbon nanotubes from the substrate, collecting the carbon nanotubes from the surface where the substrate moves continuously and sequentially through the depositing, forming, separating and collecting steps. Further processing steps convert the synthesized carbon nanotubes to graphene nanoribbons, graphene nanoplatelets and mixtures thereof.

A method for improving processing speed, dimensional stability, and physical properties in extruded elastomers is herein disclosed, including the steps of mixing natural rubber with pristine graphene, the pristine graphene acting as a nucleating agent for strain induced crystallization of the natural rubber, and the pristine graphene inducing additional shear during mixing.

Methods include producing tunable carbon structures and combining carbon structures with a polymer to form a composite material. Carbon structures include crinkled graphene. Methods also include functionalizing the carbon structures, either in-situ, within the plasma reactor, or in a liquid collection facility. The plasma reactor has a first control for tuning the specific surface area (SSA) of the resulting tuned carbon structures as well as a second, independent control for tuning the SSA of the tuned carbon structures. The composite materials that result from mixing the tuned carbon structures with a polymer results in composite materials that exhibit exceptional favorable mechanical and/or other properties. Mechanisms that operate between the carbon structures and the polymer yield composite materials that exhibit these exceptional mechanical properties are also examined.

A method for producing graphene includes: a pretreatment process of drying and pulverizing a vegetable material to obtain a carbon source; a carbonization process of carbonizing the carbon source to obtain a carbide; and a purification process of removing an impurity containing silica from the carbide obtained in the carbonization process, wherein the carbonization process including a heating process of supplying an inert gas into a chamber and heating the carbon source in the chamber in a plasma atmosphere.