TEMPO-oxidised cellulose nanofibrils; probing the mechanisms of gelation via small angle X-ray scattering

DOI: 10.1039/C8CP00355F

Authors: Julien Schmitt (University of Bath) , Vincenzo Calabrese (University of Bath) , Marcelo A. Da Silva (University of Bath) , Saskia Lindhoud (University of Bath) , Viveka Alfredsson (Lund University) , Janet L. Scott (University of Bath) , Karen J. Edler (University of Bath)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Physical Chemistry Chemical Physics , VOL 44

State: Published (Approved)
Published: May 2018
Diamond Proposal Number(s): 3691 , 16364

Abstract: The structure of dispersions of TEMPO-oxidised cellulose nanofibrils (OCNF), at various concentrations, in water and in NaCl aqueous solutions, was probed using small angle X-ray scattering (SAXS). OCNF are modelled as rod-like particles with an elliptical cross-section of 10 nm and a length greater than 100 nm. As OCNF concentration increases above 1.5 wt%, repulsive interactions between fibrils are evidenced, modelled by the interaction parameter νRPA > 0. This corresponds to gel-like behaviour, where G′ > G′′ and the storage modulus, G′, shows weak frequency dependence. Hydrogels can also be formed at OCNF concentration of 1 wt% in 0.1 M NaCl(aq). SAXS patterns shows an increase of the intensity at low angle that is modelled by attractive interactions (νRPA < 0) between OCNF, arising from the screening of the surface charge of the fibrils. Results are supported by ζ potential and cryo-TEM measurements.

Subject Areas: Chemistry, Materials


Instruments: I22-Small angle scattering & Diffraction

Added On: 31/05/2018 10:40

Documents:
C8CP00355F.pdf

Discipline Tags:

Physical Chemistry Soft condensed matter physics Chemistry Materials Science

Technical Tags:

Scattering Small Angle X-ray Scattering (SAXS)