Difference between bamboo- and wood-derived cellulose nanofibers prepared by the aqueous counter collision method

Bamboo pulps whose crystalline and hierarchical structures differ from those of wood pulps were subjected to the aqueous counter collision (ACC) method, which makes it possible to overcome interfacial interactions between cellulose molecules in order to produce cellulose nanofibers (CNFs) and hence highlights differences between surface properties. At first, the CNFs derived from both bamboo and wood were compared in studies of the sedimentation behavior of 0.05% (w/w) aqueous CNF dispersions. Then, changes in mechanical properties of CNF sheets under various humidity conditions, as well as the CNF emulsion droplets formed by mixing with n-hexane, both of which were prepared from aqueous CNF dispersions, were examined. These investigations focusing on the interaction of CNFs with water indicated totally different inherent nature in the surface properties between bamboo and wood CNFs, which were prepared by the ACC method. Moreover, the different character in the two CNF emulsion droplets also indicates that the surface on bamboo-derived CNFs prepared by this method was likely to exhibit more hydrophobic properties than wood CNFs without any chemical modification.