ICNF 2019 - 4th International Conference on Natural Fibers
Microscale natural fibers for large-scale nanotechnology
Director of WWSC Wallenberg Wood Science Center at KTH Royal Institute of Technology, Sweden
Lars Berglund is professor at the Royal Inst of Technology in Stockholm, and director of Wallenberg Wood Science Center, with an annual funding of 7 million euro. He has been a visiting researcher at Stanford University, Cornell University and Kyoto University. His research interest is in nanostructured composite materials; primarily those based on cellulose. An important challenge is transparent cellulosic nanomaterials, which also can serve as load-bearing engineering materials. Professor Berglund has published more than 200 journal papers, examined more than 20 PhD’s and is a member of the Royal Swedish Academy of Engineering Sciences. He holds an ERC Advanced Grant on Nanotechnologies for Transparent Wood.
The scientific impact of nano-cellulose research is difficult to exaggerate. From a comparably limited community around 10 years ago, the growth of the field has been such that it is now dominating many aspects of biopolymer, bio-composites and nanomaterials research. Recently, the first industrial products have been introduced in packaging, biomedical, hygiene and high-technology applications. Yet, the more sophisticated uses are still yet to come since processing challenges are still substantial. For instance, the viscosity is dramatically increased when a fine scale nanoparticle of high aspect ratio is dispersed in a liquid phase. In addition, gelation takes place at very low concentration since a continuous network may form early.
For this reason, it is of great interest to consider the potential of existing natural fibers in the context of nanotechnology. Those fibers are already processed at large industrial scale today. If one could exploit the unique nano-structural features of natural fibers, and yet utilize “microfiber” processing techniques, this would have great technical benefits.
Natural fibers have nano-structural cell wall characteristics. Cellulose in the form of nanoscale fibrils make up the plant cell wall. There is now a plethora of chemical modification methods which can be used to preserve the nanoscale features of the cell wall, such as high specific surface area, native cellulose preservation (high molar mass), controlled removal of lignins etc. Examples will be provided on how the mechanical properties of the fibers are influenced by careful chemical treatment of the cell wall. In addition, the potential of recycling, and functionalization, eg improved optical transmittance and new optical functionalities, are discussed.