Hydrogen bonds dominated frictional stick-slip of cellulose nanocrystals

Chi Zhang; Sinan Keten; Dominique Derome; Jan Carmeliet

doi:10.1016/j.carbpol.2021.117682

Hydrogen bonds dominated frictional stick-slip of cellulose nanocrystals

Carbohydr Polym. 2021 Apr 15:258:117682. doi: 10.1016/j.carbpol.2021.117682. Epub 2021 Jan 23.

Authors

Chi Zhang¹, Sinan Keten², Dominique Derome³, Jan Carmeliet⁴

Affiliations

¹ Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, Raemistrasse 101, 8092, Zurich, Switzerland. Electronic address: zhangchi@student.ethz.ch.
² Department of Civil and Environmental Engineering, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208-3109, United States. Electronic address: s-keten@northwestern.edu.
³ Department of Civil and Building Engineering, Université de Sherbrooke, Sherbrooke, J1K 2R1, Québec, Canada. Electronic address: dominique.derome@usherbrooke.ca.
⁴ Chair of Building Physics, Department of Mechanical and Process Engineering, ETH Zurich, Raemistrasse 101, 8092, Zurich, Switzerland. Electronic address: cajan@ethz.ch.

PMID: 33593555
DOI: 10.1016/j.carbpol.2021.117682

Abstract

Crystalline cellulose, the most abundant natural polymer on earth, features exceptional physical and mechanical properties. Using atomistic simulation, this study reports the mechanical behavior of cellulose-cellulose nanocrystal hydrophilic interface and systematically examines the impact of loading direction, interfacial moisture, misalignment and surface types. The density, orientation or distribution of interfacial hydrogen bonds are shown to explain the series of findings presented here, including stick-slip behavior, stiffness recovery after an irreversible slip, direction-dependent behavior and weakening induced by hydration or misalignment. Correlation analysis shows that, regardless of the various loading conditions, the interfacial stress, shear velocity and interaction energy are strongly correlated with the density of interfacial hydrogen bonds, which quantitatively supports the central role of hydrogen bonding. Based on this correlation, the friction force rendered by a single hydrogen bond is inferred to be f_HB ∼1.3 E-10 N under a shearing speed of 1 m s^-1.

Keywords: Adhesion; Cellulose nanocrystal; Friction; Hydrogen bond; Interface; Stick-slip.