Embrapa Agroenergy (Brasília, DF) developed methods to extract nanometric fiber from cellulose that can grant different properties to the materials already used in the industry or originate new ones. For instance, the scientists were able to use such nanofiber to reinforce natural rubber, forming nanocompounds. Such innovation assets are part of Embrapa Agroenergy's Technology Showcase. The first of such nanofibers' characteristics to draw attention are related to sustainability: they are biodegradable and, as they are extracted from plant cellulose, they have a renewable source. They are either white-colored or transparent, show resistance to traction (being stretched) and a large surface area. Such characteristics can be transferred to the materials to which they are added. The large surface area is a property that facilitates the adhesion of particles - of a drug, for example. In turn, resistance to traction has the material not stretch so easily. It was mostly such resistance characteristic that the scientists sought by adding nanofiber to natural rubber. “We have proven, through microscopy, mechanical testing and other methods, that rubber adheres to the cellulose nanofiber, resulting in a reinforcement effect”, reports the researcher from Embrapa Agroenergy Leonardo Fonseca Valadares, who leads the work. Currently, the main application of rubber is to manufacture tires. The resistance is conferred by a process called vulcanization, which makes rubber lose the biodegradability it had as product of natural origin. The nanocompound obtained by the Embrapa team still has lower resistance than vulcanized rubber, but it keeps the rubber biodegradable. Enzymes to produce nanofiber To get to the nanofibers, first it is necessary to separate the cellulose from other plant components. There is a well established methodology for that purpose, used in the industry that processes eucalyptus and pinus to manufacture paper. Embrapa's team, however, uses other biomasses, basically waste, such as African oil palm stalks and sugarcane bagasse. The challenge was overcome and scientists were able to purify cellulose and generate paper in a laboratory. The group then continued and developed methods based on mechanical and chemical techniques to extract nanofibers from cellulose. But the group also innovated by using enzymes, biological substances that are not commonly used in nanotechnology. Valadares explains that the main motivation to invest in enzymes was to obtain a process that is friendlier both to the environment and to workers' health. The chemical process of extracting nanofibers uses high concentrations of sulfuric acid, a toxic product that requires special corrosion-proof equipment in the production unit. Enzymes originate from living beings and are biodegradable and atoxic. On the other hand, they have a high cost, and enzyme-based processes require much more time. The mechanical process is also a toxicity-free option, but it spends a lot of energy and does not generate nanofibers properly, but a net of fibers instead. The new materials of the bioeconomy The types of materials that nanofibers are going to generate will depend on where the market is headed, especially the bioeconomy. Besides natural rubber, the researchers have also been combining nanofibers with other materials. “I anticipate applications of high added value that make the most of nanofibers' characteristics”, Valadares states. He believes that they can contribute to enhancing value in the cellulose production chain. The cellulose pulp extration industry is enormous. Brazil, the world's fourth largest producer, produced 18.77 million tons of the commodity in 2016. However, cellulose currently has a smaller range of applications when compared to oil. The latter generates a nearly countless number of products - from fuels that leave the refineries costing less than a dollar to chemical specialties whose value exceeds the thousands of dollars per gram. By investing in nanofibers, the Embrapa team aims to offer options to have the cellulose production chain in Brazil expand its range of products. The group is now committed to establishing conditions to scale up production, which can be done in partnership with companies. Embrapa Agroenergy has bet on open innovation to speed up the development of technologies and insert them in the market. The research center has worked on the development of solutions for a less oil-dependent economy, as it has obtained not only biofuels but also chemical and material products from the biomass generated by farmlands. Learn more about Embrapa Agroenergy's Technology Showcase. Translation: Mariana Medeiros