Formation and relaxation kinetics of starch-particle complexes
Journal article, 2016

© The Royal Society of Chemistry.The formation and relaxation kinetics of starch-particle complexes were investigated in this study. The combination of cationic nanoparticles in suspension and anionic starch in solution gave rise to aggregate formation which was studied by dynamic light scattering, revealing the initial adsorption of the starch molecules on the particle surface. By examining the stability ratio, W, it was found that even in the most destabilized state, i.e. at charge neutralization, the starch chains had induced steric stabilization to the system. At higher particle and starch concentrations relaxation of the aggregates could be seen, as monitored by a decrease in turbidity with time. This relaxation was evaluated by fitting the data to the Kohlrausch-Williams-Watts function. It was found that irrespective of the starch to particle charge ratio the relaxation time was similar. Moreover, a molecular weight dependence on the relaxation time was found, as well as a more pronounced initial aggregated state for the higher molecular weight starch. This initial aggregate state could be due to bridging flocculation. With time, as the starch chains have relaxed into a final conformation on the particle surface, bridging will be less important and is gradually replaced by patches that will cause patchwise flocculation. After an equilibration time no molecular weight dependence on aggregation could be seen, which confirms the patchwise flocculation mechanism.

surface sizing

starch

nanoparticles

Colloidal behavior

interactions

Author

Frida Iselau

Chalmers, Chemistry and Chemical Engineering

Tuan Phan Xuan

Chalmers, Physics, Condensed Matter Physics

G. Trefalt

University of Geneva

Aleksandar Matic

Chalmers, Physics, Condensed Matter Physics

Krister Holmberg

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Romain Bordes

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry, Applied Surface Chemistry

Soft Matter

1744-683X (ISSN) 1744-6848 (eISSN)

Vol. 12 47 9509-9519

Subject Categories

Materials Chemistry

Chemical Sciences

Areas of Advance

Materials Science

DOI

10.1039/C6SM01312K

More information

Latest update

6/15/2018