Mixed gels - Physical Gels from Biological and Synthetic Polymers - page 322

Figure 10.19 X-ray KGM (1:1) mixed gel, X-ray

wavelength 0.154 nm. Reprinted with permission from Ridout et al.( 1998 ) © 1998 Elsevier.

fibre diffraction pattern for 100% stretched deacetylated acetan -

10.7 Conclusions

As we have shown, studies on mixed gels cover a wide range of techniques and systems.
For the segregative gels, microscopy and scattering techniques have been applied,
whereas for the systems, perhaps understandably, studies have also included

a number of more specialized molecular techniques. Much of the work on the mixed
polysaccharide systems seems to be driven by efforts to establish the rather idealized
models. Mixed-gel formation occurs through various mechanisms including segregation,
aggregation and synergy; a precise knowledge of both the structure of junctions and the
kinetics of the phase separation at larger scales is necessary in order to classify the
underlying processes. Multi-distance scale studies such as rheology, microscopy and
scattering on the same samples are required. Despite this dif

' molecular '

culty, many of the systems
discussed here have proved of great value commercially and, we have no doubt, will
continue so to do.

References

Amici, E., Clark, A. H., Normand, V., Johnson, N. B., 2000. Biomacromolecules 1 , 721 - 729.
Amici, E., Clark, A. H., Normand, V., Johnson, N. B., 2001. Carbohydr. Polym. 46 , 383 - 391.
Amici, E., Clark, A. H., Normand, V., Johnson, N. B., 2002. Biomacromolecules 3 , 466 - 474.