Polysaccharide counterion interaction

SUVs have also been stabilized by coating their outer surfaces with chitin [328], polylysine [329-332], polyelectrolytes [333], and polysaccharides [334]. Advantage has also been taken of electrostatic interactions to attract oppositely charged polyelectrolytes to outer SUV surfaces and subsequently polymerize them in situ [335-339]. These systems have been referred to as liposomes in a net [72]. A particularly telling example is the attachment of a two-dimensional polymeric network either to the inner or to the outer surfaces of SUVs by ion exchanging the vesicle counterions with oppositely charged polymerizable short-chain counterions and their subsequent polymerization (Fig. 42) [340-342]. 

Forces between DNA Double Helices. The repulsion and attraction of DNA is the molecular interaction most studied to date. In simple salts, repulsion is again exponential with decay rates of 2.8 3.3 A (II). Unlike forces between polysaccharides, the coefficient of the force depends on the type of cationic counterion, even though electrostatic double layer repulsion is low enough to suggest that the helix is largely neutralized by ion association. 

Pass G., Phillips G.O., WadlocK D.J., Morley R.G. "Interaction of Sulfated Polysaccharides with counterions", chapt. 17 of Carbohydrate Sulfates, R.G. Schweiger Ed., Am. Chem. Soc. Symp. 1878, 77. 

In this chapter we review the solution properties of K-carrageenan and its interaction with starch and non-starch polysaccharides in aqueous media. We stress the importance of the sol-gel transition and gelation mechanism of K-carrageenan p>articularly the effect of temperature, polysaccharide concentration and external counterions on the transition and the interaction of K-carrageenan with other pwlysaccharides. Given the economic importance of K-carrageenan, we also discuss its viscoelastic behavior and microstructure as well as actual and potential applications in foods. 

---