MS03-P07 Scanning electron diffraction reveals the crystalline microstructure of Cellulose Nano Crystals Tom Willhammar (Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden) Duncan Johnstone (Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, United Kingdom) Yingxin Liu (Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden) Lennart Bergström (Department of Materials and Environmental Chemistry, Stockholm University, Stockholm, Sweden) Paul A. Midgley (Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, United Kingdom)email: tom.willhammar@mmk.su.seAll living plants contain cellulose as a crucial part of their structures. It possesses a complex structural diversity, including chirality. The combination of its fascinating structural features and its impressive properties in terms of specific strength and stiffness has triggered the engineering of cellulose-based materials with tailored mechanical and optical properties.
 
Scanning electron diffraction (SED) is an emerging method developed for the transmission electron microscope (TEM), following developments in electron optics and fast and sensitive detectors. By scanning a small electron probe, down to 1 nm in size, across the specimen and for each raster point a 2D electron diffraction pattern is acquired. In this way it is possible to build up a map revealing the ordering of the atoms in the sample with nanometer resolution. This method is opens up exciting opportunities for specimens, which are very beam sensitive and are difficult to study by other methods.
 
In this study, SED has been used to shed light on the microstructure of cellulose nanocrystals (CNCs) and to study the local ordering of the polysaccharide chains in the CNCs. Based on mapping of twisted CNCs it is possible to follow the ordering of the chains e.g. as the crystals are twisting.
 
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Keywords: electron diffraction, cellulose, polymer