title: The role of heteropolysaccharides in developing oxidized cellulose nanofibrils.
abstract: A fundamental study was undertaken to determine the general role of heteropolysaccharides during the production of TEMPO-oxidized cellulose nanofibrils (TOCNs). Four major fiber resources, viz., fully bleached kraft pulps of softwood and hardwood varieties (pine, eucalyptus) and non-woods (bamboo, bagasse) were used because of their substantial morphological differences and relative abundance. The effect of heteropolysaccharides during TEMPO-mediated oxidation and high-pressure homogenization for TOCNs production was investigated under constant conditions. Most galactoglucomannans were removed during oxidation, whereas the majority of xylans were retained. The galactoglucomannans, however, non-beneficially consumed NaClO, the terminal TEMPO oxidant, while xylans adversely affected carboxylate group formation by limiting chemical accessibility to cellulose. However, lower xylans content led to more transparent and processable suspensions, while during mechanical processing, heteropolysaccharides supported nanofibrillation. The average length of the final TOCNs from eucalyptus, bamboo, bagasse, and pine were 290, 350, 360 and 370nm, respectively, with average widths of ∼4nm.
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Qijun
authors.initials: Q
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China. Electronic address: shyfu@scut.edu.cn.
authors.forename: Shiyu
authors.initials: S
authors.lastname: Fu
authors.affiliation: The Laboratory of Soft Materials & Green Chemistry, Departments of Chemistry, Wood & Paper Science, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Lucian A
authors.initials: LA
authors.lastname: Lucia
mesh_terms: D002264:Carboxylic Acids / Q000032:analysis; D002483:Cellulose, Oxidized / Q000032:analysis / Q000737:chemistry*; D004355:Drug Stability; D049329:Nanostructures / Q000737:chemistry*; D055620:Optical Phenomena; D012212:Rheology; D013696:Temperature
chemical_list: D002264:Carboxylic Acids; D002483:Cellulose, Oxidized
keywords: Heteropolysaccharides; Oxidized cellulose nanofibrils; TEMPO oxidation