Researchers at the University of California, Davis have developed a high-yield method that utilizes the unique properties of cellulose nanofibrils (CNFs) to fabricate high-quality graphene from bulk graphite. This graphene can then be fabricated into graphene nanopapers, which have unique moisture and heat-sensing capabilities for applications in “smart” electronic devices and other uses.
Currently, graphene is employed in various applications, including electric circuits, solar cells and medical processes. Although graphene has many desirable properties in these applications, existing production processes for graphene typically yield low-quality or low volumes of graphene using excess surfactant or in organic liquids. A process for producing high-quality graphene in significant volumes is thus highly desirable.
Researchers at the University of California Davis have developed a robust, simple and fast process for exfoliating graphite to single-layer to few layer graphene. This process utilizes novel amphiphilic cellulose nanofibrils (CNFs) derived from readily available agricultural and food processing biomass that is non-toxic. Additionally, the fabrication process is aqueous and easily scalable for bulk graphene production. Graphene flakes produced from this method are stable in aqueous media without aggregation. By comparison, current techniques for fabricating graphene from bulk graphite at comparable concentrations require harsh organic compounds or significant quantity of surfactants and often result in graphene flakes that aggregate over time. The graphene flakes fabricated using CNFs can be readily formed into graphene nanopapers - which display unique moisture-responsive properties, as well mechanical strength and flexibility. The features of this graphene enable it to be beneficial for various applications such as electronics, pulp and paper products, and nano-composite products.