Role of sonication pre-treatment and cation valence in the sol-gel transition of nano-cellulose suspensions.

ABSTRACT: Sol-gel transition of carboxylated cellulose nanocrystals has been investigated using rheology, SAXS, NMR and optical spectroscopies to unveil the distinctive roles of ultrasound treatments and addition of various cations. Besides cellulose fiber fragmentation, sonication treatment induces fast gelling of the solution. The gelation is independent of the addition of cations, while the final rheological properties are highly influenced by the type, concentration and sequence of the operations since the cations must be added prior to sonication to produce stiff gels. The gel elastic modulus was found to increase proportionally to the ionic charge rather than the cationic size. In cases where ions were added after sonication, SAXS analysis of the Na⁺ hydrogel and Ca²⁺ hyd

SUBMITTER: Maestri CA 

PROVIDER: S-EPMC5593908 | biostudies-literature | 2017 Sep

REPOSITORIES: biostudies-literature