Directa Plus, based in the ComoNext Technological Park, was founded in 2005 and has been developing a technological platform able to produce graphene-based materials in large volumes. “We are paying specific attention to product engineering,” explains company president and CEO Giulio Cesareo, “and all our products are aimed at offering different ‘degrees’ of graphene to satisfy the needs of specific applications. The first module to be inaugurated in ComoNext is able to produce 30 tons of graphene materials per year.”

Cesareo made the announcement during the launch of the Italian Council for Eco Innovation, and Directa Plus is currently one of the 10 leading SMEs to stand out for innovation in cleantech.

Patented, scalable and sustainable process

“The company has developed a patented, scalable and sustainable process from an environmental and economic point of view to generate graphene-based products,” says Richard Youngman, who is Managing Director Europe/Asia of Cleantech Group Inc.

The four types of graphene-based materials that will be produced at Directa are: Basic G+, which is a super-expanded graphite; Ultra G+, a fine nanographite powder; Liquid G+, a highly concentrated water-based pristine dispersion of graphene nanoplatelets (GNPs); and Pure G+, a powder of pristine GNPs.

“Each of these products has its own applications and markets,” says Cesareo “The company’s production process comprises several steps that transform 3D graphite microstructures into 2D graphene. Products ready for commercialization are made at each step of the process.”

Directa’s pristine GNPs contain only a small amount of lattice defects, he explains. They are up to 10 µm long and less than 3–5 nm thick. They are also highly crystalline, and this, together with their high aspect ratio makes them ideal for use in high-performance composites.

The G+ manufacturing process is continuous, simple and low cost. In brief, it involves chemical intercalation of natural graphite followed by thermal plasma expansion. “This method increases the interlayer distance in graphite to its extreme limits so that it forms super-expanded graphite flakes from which GNPs can then be obtained by a mild post-plasma treatment,” Directa Plus scientific committee member Roman Sordan told nanotechweb.org. “We carry out a final exfoliation step, designed to fine tune the morphology of the GNPs in liquid media, such as water or organic solvents. The liquid dispersion can also be dried to produce an anhydrous form of GNP powder. The entire process is patented.”

Objectives and applications

Directa Plus’ objectives are to add value to its potential customer products by keeping costs low, improving product performance and incorporating new functionalities into the finished materials. The main applications areas are:

• Water and air purification: absorbing hydrocarbons, for example, in oil spill clean-ups (see GEnIuS project for more information) and absorbing certain pollutants.
• Textiles: flame-retardant materials that could replace toxic flame retardants; smart textiles that can conduct electricity or shield electromagnetic radiation; and thermally conducting materials for dissipating waste heat from computer chips and other electronic components.
• Elastomers: as super-additives for improving the mechanical properties of tyres – for example, by deceasing rolling resistance while preserving grip; thermally conductive silicones for dissipating heat in light-emitting diodes.
• Resins for carbon-fibre (CF) composites: the addition of small amounts of pristine GNPs can substantially increase the mechanical properties of these composites and adhesion between resins and the composites. Such a strategy would increase the life cycle of the final product.

During the Graphene Factory opening event, the first products powered by G+ will be revealed, added Cesareo. “For example, there will be a CF bike wheel with a tyre containing pristine GNPs. Vittoria Group, an industrial partner, and the largest manufacturer of bicycle tyres will be presenting these products.”