2017/05/19 by Cecilia Ada Maestri, Michela Abrami, S. Hazan +9 · 37 citations
Agricultural and Biological Sciences · Chemistry · Materials Science · Physics and Astronomy · #Advanced Cellulose Research Studies #Cationic polymerization #Cellulose #Chemical engineering #Chemistry #Chromatography #Composite material #Elastic modulus #Ion #Ionic bonding #Materials science #Organic chemistry #Polymer chemistry #Polysaccharides Composition and Applications #Polysaccharides and Plant Cell Walls #Rheology #Scattering #Self-healing hydrogels #Small-angle X-ray scattering #Sonication #Valence (chemistry) #cond-mat.mtrl-sci
paper · pdf · doi:10.1038/s41598-017-11649-4
published in Scientific Reports 7(1), 11129 (Nature Portfolio) · 17 apges, 11 figures
arxiv created 2017/05/19 · openalex publication_date 2017/09/05 · arxiv updated 2019/03/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 Ca 2+ hydrogel indicated the presence of structurally ordered domains in which water is confined, and 1H-NMR investigation showed the dynamics of water exchange within the hydrogels. Conversely, separated phases containing essentially free water were characteristic of the hydrogels obtained by sonication after Ca 2+ addition, confirming that this ion induces irreversible fiber aggregation. The rheological properties of the hydrogels depend on the duration of the ultrasound treatments, enabling the design of programmed materials with tailored energy dissipation response.