The University of Maine’s Forest Bioproducts Research Institute recently announced that it is building a pilot-scale plant to manufacture cellulose nanofibrils, a wood-based material of interest for its reinforcing properties and potential use in replicating synthetic plastics. This innovative project, involving six other universities and the Forest Products Laboratory (FPL), seeks to investigate wood at the nano-scale, which ranges from 1 to 100 nanometers.
One nanometer represents one-billionth of a meter, or roughly one-millionth the thickness of an American dime. Cellulose nanofibrils (CNFs) are one of the smallest components of wood that researchers have been able to work with, about 1,000 times smaller than paper fibers.
Zhiyong Cai, a project leader in engineered composite science at the FPL, has been involved in the UMaine research collaboration since last April when researchers started investigating the conversion of wood components into these unique nanomaterials. Cellulose nanofibrils (CNFs) can be incorporated into a variety of forest products thus increasing potential functionality, durability, and end-use performance.
Cellulose nanocrystals (CNC) are another highly sought-after wood-derived nanomaterial. Though related in size and strength characteristics to nanofibrils, these two wood-based nanomaterials differ in how they are produced. At its most simplistic, nanofibrils are produced through mechanical means, a sort of vigorous pounding impact process whereas nanocrystals are typically derived through chemical processes, essentially bathed in sulfuric acid to breakdown the basic constituents of wood for further use.
Real-world applications for cellulose nanofibrils include car parts, paint and coating additives, and in water filtration devices. Both CNFs and CNCs have potential in medical and electronic applications. The production of these nanomaterials in the United States, through pilot projects like the one at UMaine, will decrease dependency on foreign sources such as those developed in Japan and Germany. Increased domestic production will also provide sufficient quantities for greater practical testing and demonstration.
FPL has also recently purchased reactor equipment (two 100-gallon, one 1,000-gallon, and one 1,500 gallon glass lined reactor) and a filtration system, for the pilot-scale production of cellulose nanocrystals. Researchers at FPL hope to use the robust strength of CNC’s to produce high-performance composite materials, including applications requiring high clarity, such as bullet-proof glass for military vehicles.
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By James T. Spartz, FPL Public Affairs Specialist