title: Cellulose Nanofibers from Softwood, Hardwood, and Tunicate: Preparation-Structure-Film Performance Interrelation.
abstract: This work reveals the structural variations of cellulose nanofibers (CNF) prepared from different cellulose sources, including softwood (Picea abies), hardwood (Eucalyptus grandis × E. urophylla), and tunicate (Ciona intestinalis), using different preparation processes and their correlations to the formation and performance of the films prepared from the CNF. Here, the CNF are prepared from wood chemical pulps and tunicate isolated cellulose by an identical homogenization treatment subsequent to either an enzymatic hydrolysis or a 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-mediated oxidation. They show a large structural diversity in terms of chemical, morphological, and crystalline structure. Among others, the tunicate CNF consist of purer cellulose and have a degree of polymerization higher than that of wood CNF. Introduction of surface charges via the TEMPO-mediated oxidation is found to have significant impacts on the structure, morphology, optical, mechanical, thermal, and hydrophobic properties of the prepared films. For example, the film density is closely related to the charge density of the used CNF, and the tensile stress of the films is correlated to the crystallinity index of the CNF. In turn, the CNF structure is determined by the cellulose sources and the preparation processes. This study provides useful information and knowledge for understanding the importance of the raw material for the quality of CNF for various types of applications.
authors.affiliation: Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, KTH , Teknikringen 56-58, 10044 Stockholm, Sweden.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, KTH , Teknikringen 56-58, 10044 Stockholm, Sweden.|Valmet AB , 85194 Sundsvall, Sweden.
authors.forename: Carl
authors.initials: C
authors.lastname: Moser
authors.affiliation: Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, KTH , Teknikringen 56-58, 10044 Stockholm, Sweden.
authors.forename: Mikael E
authors.initials: ME
authors.lastname: Lindström
authors.affiliation: Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, KTH , Teknikringen 56-58, 10044 Stockholm, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Henriksson
authors.affiliation: Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, Royal Institute of Technology, KTH , Teknikringen 56-58, 10044 Stockholm, Sweden.|Research Institute of Sweden, RISE, Bioeconomy/Biorefinery and Energy , Drottning Kristinas väg 61, 11486 Stockholm, Sweden.
authors.forename: Jiebing
authors.identifier: http://orcid.org/0000-0002-4521-1122
authors.initials: J
authors.lastname: Li
keywords: cellulose nanofibers (CNF); comparison; correlation; film; hardwood; softwood; tunicate