Rheological investigation of specific interactions in Na Alginate and Na MMT suspension

Rheological investigation of specific interactions in Na Alginate and Na MMT suspension

Zlopasa, J. (TU Delft Materials and Environment)
Norder, B. (TU Delft ChemE/Advanced Soft Matter; TU Delft ChemE/O&O groep)
Koenders, E.A.B. (TU Delft Materials and Environment)
Picken, S.J. (TU Delft ChemE/Advanced Soft Matter)

2016-10-20

Here we report on a study of a rheological behavior of sodium alginate and montmorillonite suspension. We find that viscoelastic behavior of this suspension is dramatically affected with increasing volume fraction of montmorillonite platelets. Addition of montmorillonite generally leads to gel formation, which is attributed to interactions of montmorillonite and alginate via H-bonding and attraction between the positive edges of the platelets and the anionic backbone of the biopolymer. A critical concentration for the measured system was observed at 20 wt.% montmorillonite, where a crossover to a gel-like structure was detected. The observed gel has a rubber plateau, which develops further with higher montmorillonite concentration. In this physical gel the relaxation maximum was detected, which is associated with the breaking and reformation of the bonds between the platelets and the biopolymer. For this transient behavior, we find that a Maxwell type viscoelasticity quite well describes the relaxation time and the observed G'-G" crossover. We believe that this gel-like behavior plays an important role in formation of highly ordered nanostructures that develop during the drying of these bio-nanocomposite suspensions.

Alginate
Montmorillonite
Physical gel
Rheology
Suspension

http://resolver.tudelft.nl/uuid:327f5d0b-1dab-4ab1-b43b-eb73c736b619

https://doi.org/10.1016/j.carbpol.2016.05.055

2017-10-20

0144-8617

Carbohydrate Polymers, 151, 144-149

Institutional Repository

journal article

© 2016 J. Zlopasa, B. Norder, E.A.B. Koenders, S.J. Picken