Abstract
Nanocelluloses occur under various crystalline forms that are currently being selectively used for a wide variety of high performance materials. In the present study, two cellulose nanofibers (CF-I) were mercerized by alkaline treatment (CF-II) without degradation, the same molar mass of 560,000 g/mol was measured. Both samples were acid hydrolyzed, leading to cellulose nanocrystals in native (CNC-I) and mercerized (CNC-II) forms. This study focuses on the detailed characterization of these two nanoparticle morphologies (light and neutron scattering, TEM, AFM), surface chemistry (zetametry and surface charge), crystallinity (XRD, 13C NMR), and average molar mass coupled to chromatographic techniques (SEC–MALLS-RI, A4F-MALLS-RI), revealing variations in the packing of the crystalline domains. The crystal size of CNC-II is reduced by half compared to CNC-I, with molar masses of individual chains of 41,000 g/mol and 22,000 g/mol for CNC-I and CNC-II, respectively, whereas the same surface charge density is measured. This study gives an example of complementary characterization techniques as well as results to help decipher the mechanism involved in mercerization.