Effects of hemicellulose composition and content on the interaction between cellulose nanofibers

In this study, cellulose nanofibers (CNFs) from softwood and hardwood kraft pulps were prepared with different hemicellulose contents, and the effects of the hemicellulose compositions and contents on the interaction between CNFs were studied. In addition, the effects of CNF interaction on the CNF dispersion stability and viscosity characteristics in the aqueous state were investigated. Using quartz crystal microbalance with dissipation, the results of the interaction analysis revealed that hemicellulose moderated the strength of the interaction between CNFs, and the intensity of the interaction changed according to the hemicellulose compositions. The interaction between galactoglucomannans was stronger than that between glucuronoxylans, and CNFs prepared from softwood pulp containing mainly galactoglucomannan showed stronger interaction between CNFs than those prepared from hardwood pulp containing mainly glucuronoxylan. The presence of hemicelluloses on the surface of CNFs improved the dispersion stability and increased the viscosity. However, the intensity of the interaction between CNFs, which is dependent on the type of hemicellulose, did not affect these properties. The properties of CNFs in the aqueous state are determined by not only the interaction between CNFs but also several factors such as the morphology of CNFs and physical properties of hemicelluloses.