title: Understanding nanocellulose chirality and structure-properties relationship at the single fibril level.
abstract: Nanocellulose fibrils are ubiquitous in nature and nanotechnologies but their mesoscopic structural assembly is not yet fully understood. Here we study the structural features of rod-like cellulose nanoparticles on a single particle level, by applying statistical polymer physics concepts on electron and atomic force microscopy images, and we assess their physical properties via quantitative nanomechanical mapping. We show evidence of right-handed chirality, observed on both bundles and on single fibrils. Statistical analysis of contours from microscopy images shows a non-Gaussian kink angle distribution. This is inconsistent with a structure consisting of alternating amorphous and crystalline domains along the contour and supports process-induced kink formation. The intrinsic mechanical properties of nanocellulose are extracted from nanoindentation and persistence length method for transversal and longitudinal directions, respectively. The structural analysis is pushed to the level of single cellulose polymer chains, and their smallest associated unit with a proposed 2 × 2 chain-packing arrangement.
authors.affiliation: Department of Health Science and Technology, ETH Zurich, Schmelzbergstrasse 9, LFO E23, Zurich 8092, Switzerland.
authors.forename: Ivan
authors.initials: I
authors.lastname: Usov
authors.affiliation: Department of Health Science and Technology, ETH Zurich, Schmelzbergstrasse 9, LFO E23, Zurich 8092, Switzerland.
authors.forename: Gustav
authors.initials: G
authors.lastname: Nyström
authors.affiliation: Department of Health Science and Technology, ETH Zurich, Schmelzbergstrasse 9, LFO E23, Zurich 8092, Switzerland.
authors.forename: Jozef
authors.initials: J
authors.lastname: Adamcik
authors.affiliation: Department of Health Science and Technology, ETH Zurich, Schmelzbergstrasse 9, LFO E23, Zurich 8092, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Handschin
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden.|Wallenberg Wood Science Center, KTH, Teknikringen 56, Stockholm 10044, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Schütz
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Fall
authors.affiliation: Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, Stockholm 10691, Sweden.
authors.forename: Lennart
authors.initials: L
authors.lastname: Bergström
authors.affiliation: Department of Health Science and Technology, ETH Zurich, Schmelzbergstrasse 9, LFO E23, Zurich 8092, Switzerland.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Mezzenga