Interactions of structurally different hemicelluloses with nanofibrillar cellulose

Both cellulose nanofibrils and hemicelluloses are promising renewable alternatives for sustainable composite materials. Nanofibrils can enhance the material properties and modified hemicelluloses can be used to functionalize nanofibrillar cellulose. For optimum performance the interactions between the components have to be known. In this work the interactions between cellulose nanofibrils prepared from hardwood and softwood kraft pulps without chemical or enzymatic modification and well characterized hemicelluloses from different origins were studied. The sorption and the layer properties were quantified in the aqueous state using quartz crystal microbalance with dissipation (QCM-D). The results verified that hemicelluloses have a natural affinity towards cellulose nanofibrillar substrates. Comparison of nanofibrils prepared from hardwood and softwood kraft pulp reveal that the different hemicellulose concentration and composition of the nanofibrillar cellulose affects the adsorption of hemicelluloses. However, the hemicellulose structure affected the adsorbed layers even more significantly than the origin of the cellulose nanofibrils. (C) 2011 Elsevier Ltd. All rights reserved.