Polysaccharide gel

112 with permission. (C) (a) A plot of the intensity changes of C-6 and C-3 signals (%) in curdlan against temperature with reference to those obtained in the presence of 0.3 M NaOH. (b) a plot the C-3 13C chemical shift against temperature. From Ref. 9. 

---

The high molecular weight of the polysaccharide molecules is the most important and limiting factor for any cross-linking reaction, such as the gelation process. The importance of a high molecular weight has been proved for practically every polysaccharide gel mixture and is therefore not discussed in detail (7, 9, 11, U, 19),... 

Xanthan has several undesirable properties. It ordinarily forms microgel particles that can plug permeability(137), it is expensive relative to other natural polysaccharide gel agents, and it resists degradation by ordinary gel breaker additives. These features have kept xanthan applications in fracturing gels to a minimum. Some literature(138) on xanthan has appeared. 

T. Coviello, P. Matricardi, and F. Alhaique, Drug delivery strategies using polysaccharidic gels, Expert Opin. Drug Deliv., 3 (2006) 395 -04. 

Streptomycin, chemistry of, 3, 337-384 Structural chemistry, of fungal polysaccharides, 23, 367-417 of the hemicelluloses, 14, 429-468 Structure, molecular, of cellulose, 19, 219-246 of dextran, 15, 341-369 of glycogens, 12, 261-298 of polysaccharide gels and networks,... 

These structures and conformations of polysaccharide molecules and their intermolecular associations give polysaccharide solutions, polysaccharide dispersions, and polysaccharide gels their special properties in biologic systems and in industrial usage. The ease with which polysaccharides dissolve is related to their conformation and structure in many the same ways as is their solution behavior. 

Diffusion of water in polysaccharide gels (dextran and sephadex G hydrogels) were measured [54] over a range of diffusion time (A=30-300 ms), and the restricted diffusional behavior was analyzed using a planar semipermeable barrier model [55]. 

---