Effects of magnetite nanoparticles on the thermorheological properties of carrageenan hydrogels
authors Daniel-Da-Silva, AL; Loio, R; Lopes-Da-Silva, JA; Trindade, T; Goodfellow, BJ; Gil, AM
nationality International
journal JOURNAL OF COLLOID AND INTERFACE SCIENCE
author keywords thermoreversible sol-gel transition; carrageenan; magnetite; rheology
keywords KAPPA-CARRAGEENAN; MECHANICAL-PROPERTIES; GELS; SPECTROSCOPY; BEHAVIOR; DRUG; COMPOSITES; RELEASE
abstract The influence of magnetite (Fe3O4) nanoparticles on the theological properties Of kappa-, iota- and lambda- carrageenan gels has been investigated. Small amplitude oscillatory shear measurements were performed to study the effect of the presence of Fe3O4 nanoparticles with particle sizes of ca. 10 nm on the gel properties, as a function of carrageenan type, carrageenan concentration and magnetite load. The formation of Fe3O4 nanoparticles on the presence of biopolymer was observed to promote the gelation process and lead to stronger gels as indicated by an increase in the gel viscoelastic moduli and of the gelation temperature. This effect was more marked for kappa-carrageenan than for iota- and lambda-carrageenan and has been proposed to depend not only on Fe3O4 concentration but also on the concentration of potassium ions. A mechanism based on the combined effect of Fe3O4 nanoparticles and potassium ions was suggested, involving the adsorption of potassium ions on the negatively charged surface of the Fe3O4 nanoparticles, thus leading to an increase of the potassium ion concentration within the "carrageenan cages" containing the magnetite. This would, therefore, promote more extensive biopolymer helical aggregation, thus resulting in the formation of a stronger K-carrageenan gel in the presence of Fe3O4, as observed. Since iota- and lambda-carrageenan gels are known to be less sensitive to potassium ions concentration, the effect of precipitating Fe3O4 within these biopolymers is reduced. (c) 2008 Elsevier Inc. All rights reserved.
publisher ACADEMIC PRESS INC ELSEVIER SCIENCE
issn 0021-9797
year published 2008
volume 324
issue 1-2
beginning page 205
ending page 211
digital object identifier (doi) 10.1016/j.jcis.2008.04.051
web of science category Chemistry, Physical
subject category Chemistry
unique article identifier WOS:000257232100029
  ciceco authors
  impact metrics
journal analysis (jcr 2017):
journal impact factor 5.091
5 year journal impact factor 4.281
category normalized journal impact factor percentile 77.891
dimensions (citation analysis):
altmetrics (social interaction):



 


Sponsors

1suponsers_list_ciceco.jpg