In this work, we studied the adsorption of modified cellulose nanocrystals onto solid surfaces by quartz crystal microbalance with dissipation monitoring (QCM-D). Cellulose nanocrystals obtained from tunicate (CNC) were modified at reducing end by amidation reactions. Two different functionalities were investigated: a polyamine dendrimer (CNC-NH₂), which interacts with gold surface by the amine groups; and a biotin moiety (CNC-Biot), which has a strong affinity for the protein streptavidin (SAV). QCM-D results revealed different adsorption behaviors between modified and unmodified CNCs. Hence, unmodified CNCs covered almost all the surface forming a rigid and flat layer whereas reducing end modified CNCs remained rather upright forming a hydrated and viscoelastic layer with lower surface coverage. The analysis of adsorption kinetics allowed the calculation of an apparent collision rate factor, which resulted 10-fold higher for unmodified CNCs compared to reducing end modified CNCs, therefore, demonstrating the different adsorption behavior.

Cellulose nanocrystals; amidation; reducing-end modification; Voight model; collision rate efficiency factor; rate constant