TY - JOUR
T1 - Rheological investigation of specific interactions in Na Alginate and Na MMT suspension
AU - Zlopasa, Jure
AU - Norder, Ben
AU - Koenders, Eduard A B
AU - Picken, Stephen J.
PY - 2016/10/20
Y1 - 2016/10/20
N2 - 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.
AB - 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.
KW - Alginate
KW - Montmorillonite
KW - Physical gel
KW - Rheology
KW - Suspension
UR - http://www.scopus.com/inward/record.url?scp=84973111538&partnerID=8YFLogxK
UR - http://resolver.tudelft.nl/uuid:327f5d0b-1dab-4ab1-b43b-eb73c736b619
U2 - 10.1016/j.carbpol.2016.05.055
DO - 10.1016/j.carbpol.2016.05.055
M3 - Article
AN - SCOPUS:84973111538
SN - 0144-8617
VL - 151
SP - 144
EP - 149
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
ER -