Structure of polysaccharide gels.

Gels can be formed from a range of biopolymers, based on various types of physical or chemical crosslinks. Alginates form gels in aqueous Ca2+-containing solutions by lateral association of chain segments. Lately, the effect of adding free guluronic acid blocks on the gelation kinetics, swelling response and gel strength has been studied. Using rheology, scattering techniques and ultramicroscopy the fractal dimension and junction zone multiplicity of the gels are investigated. The same experimental procedures are used to study gels made from other biopolymers, i.e. (1,3)-β-D-glucans, chitosan and xanthan.

References:

• Small-angle X-ray scattering study of local structure and collapse transistion of (1,3)-β-D-glucan-chitosan gels.
  Sletmoen, M., Stokke, B.T. and Geissler, E.
  J. Chem. Phys. 125 (2006) 054908-1-6.
• Swelling, mechanical properties and effect of annealing of scleroglucan gels
  Aasprong, E., Smidsrød, O., and Stokke, B.T.
  Carbohydrate Polymers 60 (2005) 363-378.
• Small-angle X-ray scattering and rheological characterization of alginate gels. 3. Alginic acid gels
  Draget, K., Stokke, B.T., Yuguchi Y., Urakawa, H. and Kajiwara, K.,
  Biomacromolecules 4 (2003) 1661-1668.