Isotropic Gels of Cellulose Nanocrystals Grafted with Dialkyl Groups: Influence of Surface Group Topology from Nonlinear Oscillatory Shear
Journal article, 2023

Attractive (non-self-assembling) aqueous cellulose nanocrystal (CNC) suspensions were topologically tailored into isotropic gels through the surface grafting of dialkyl groups. We thus focus on the influence of CNC concentration, including for pristine CNC, surface linker branching, branching degree, and the influence of side group size and branch-on-branch surface-grafted groups. The resulting mobility and strength of interaction in particle-particle interaction mediated by the surface groups was investigated from a rheological point of view. The emphasis is on nonlinear material parameters from Fourier-transform rheology and stress decomposition analysis. The results show that nonlinear material parameters are more sensitive than linear viscoelastic parameters to the onset of weakly interconnected networks in pristine CNC isotropic suspensions. All surface-modified CNC suspensions resulted in isotropic gels. The nonlinear material parameters were found to be broadly sensitive to CNC concentration, branching, degree of branching and surface-grafted linkers’ length. However, the length of the grafted chains and the degree of branching were the primary factors influencing the nonlinear material response. Furthermore, the results showed evidence of two strain amplitude ranges with distinct nonlinear signatures that could be attributed to the disruption of weak network connection points and to distortions of more dense (aggregate) network regions, respectively.

Author

Sylwia Wojno

Chalmers, Industrial and Materials Science, Engineering Materials

Wallenberg Wood Science Center (WWSC)

Amit Kumar Sonker

Chalmers, Industrial and Materials Science, Engineering Materials

Wallenberg Wood Science Center (WWSC)

Jelka Feldhusen

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Gunnar Westman

Wallenberg Wood Science Center (WWSC)

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Roland Kádár

Chalmers, Industrial and Materials Science, Engineering Materials

Wallenberg Wood Science Center (WWSC)

Langmuir

07437463 (ISSN) 15205827 (eISSN)

Vol. 39 18 6433-6446

Subject Categories

Physical Chemistry

Polymer Technologies

DOI

10.1021/acs.langmuir.3c00210

PubMed

37096902

More information

Latest update

3/7/2024 9