Cationic surfactants as a non-covalent linker for oxidised cellulose nanofibrils and starch-based hydrogels

Kazi M Zakir Hossain; Vincenzo Calabrese; Marcelo A da Silva; Saffron J Bryant; Julien Schmitt; Janet L Scott; Karen J Edler

doi:10.1016/j.carbpol.2019.115816

Cationic surfactants as a non-covalent linker for oxidised cellulose nanofibrils and starch-based hydrogels

Carbohydr Polym. 2020 Apr 1:233:115816. doi: 10.1016/j.carbpol.2019.115816. Epub 2019 Dec 31.

Authors

Kazi M Zakir Hossain¹, Vincenzo Calabrese¹, Marcelo A da Silva¹, Saffron J Bryant¹, Julien Schmitt¹, Janet L Scott², Karen J Edler³

Affiliations

¹ Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom.
² Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom; Centre for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom.
³ Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom; Centre for Sustainable Chemical Technologies, University of Bath, Claverton Down, Bath, BA2 7AY, United Kingdom. Electronic address: K.Edler@bath.ac.uk.

PMID: 32059878
DOI: 10.1016/j.carbpol.2019.115816

Abstract

Rheological properties of hydrogels composed of TEMPO-oxidised cellulose nanofibrils (OCNF)-starch in the presence of cationic surfactants were investigated. The cationic surfactants dodecyltrimethylammonium bromide (DTAB) and cetyltrimethylammonium bromide (CTAB) were used to trigger gelation of OCNF at around 5 mM surfactant. As OCNF and DTAB/CTAB are oppositely charged, an electrostatic attraction is suggested to explain the gelation mechanism. OCNF (1 wt%) and soluble starch (0.5 and 1 wt%) were blended to prepare hydrogels, where the addition of starch to the OCNF resulted in a higher storage modulus. Starch polymers were suggested to form networks with cellulose nanofibrils. The stiffness and viscosity of OCNF-Starch hydrogels were enhanced further by the addition of cationic surfactants (5 mM of DTAB/CTAB). ζ -potential and amylose-iodine complex analyses were also conducted to confirm surface charge and interaction of OCNF-starch-surfactant in order to provide an in-depth understanding of the surfactant-induced gel networks.

Keywords: Cationic surfactant; Cellulose nanofibrils; Rheology; Starch.