Effects of fibre dimension and charge density on nanocellulose gels

Llyza Mendoza, Thilina Gunawardhana, Warren Batchelor, Gil Garnier

Research output: Contribution to journalArticleResearchpeer-review

18 Citations (Scopus)

Abstract

Hypothesis: Carboxylated cellulose nanofibres can produce gels at low concentrations. The effect of pulp source on the nanocellulose fibre dimension and gel rheology are studied. It is hypothesised that fibre length and surface charge influence aspects of the gel rheological properties. Experiments: TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)- mediated oxidised cellulose nanofibres from never-dried hardwood and softwood pulp and containing different charge levels were produced and characterized. Steady-state and dynamic rheological studies were performed to ascertain the effects of pulp type on gel behavior and properties. Findings: Nanocellulose fibres extracted from softwood (SW-TOCN) and hardwood (HW-TOCN) pulp exhibit similar widths but different length dimensions as shown via AFM analysis. Rheological measurements show that the dynamic moduli (G′ and G′′) of nanocellulose gels are independent of pulp source and are mostly influenced by fibre concentration. Differences in the steady-state behavior (i.e. viscosity) at constant surface charge can be attributed to differences in fibre length. Increasing the surface charge density influences the critical strain and the viscosity at the percolation concentration (0.1 wt%) due to higher electrostatic interactions.

Original languageEnglish
Pages (from-to)119-125
Number of pages7
JournalJournal of Colloid and Interface Science
Volume525
DOIs
Publication statusPublished - 1 Sep 2018

Keywords

  • Atomic force microscopy
  • Fibre dimension
  • Gel
  • Nanocellulose
  • Rheology
  • TEMPO-mediated oxidation

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