Polyelectrolyte complexes salt stability

Izumrudov, V.A., Zhiryakova, M.V. and Kudaibergenov, S.E. (1999) Controllable stability of DNA-containing polyelectrolyte complexes in water-salt solutions. Biopolymers, 52, 94-108. 

In general, depending on the nature of the polyelectrolytes, the response of a PEC to subsequent addition of salt may be quite different (see also [82-85]). The authors of [86] propose to use the different salt stability of the ionic binding to separate polyelectrolyte components from mixtures via complex formation with oppositely charged macroions. 

Dautzenberg H, Jaeger W (2002) Effect of charge density on the ftnmation and salt stability of polyelectrolyte complexes. Macromol Chem Phys 203 2095-2102... 

A polyelectrolyte complex was formed by synthesising an N-dodecylated chitosan, from dodecyl bromide and chitosan, and assembling with DNA. Atomic force microscopy was used to examine the thermal stability of the DNA embedded in the polyelectrolyte complex. From this it was seen that the incorporation of the dodecylated chitosan enhanced the thermal stability of DNA, due to encapsulation of DNA in the chitosan. The dissociation of the complex induced by small molecular salts was investigated. The ability of Mg2+ to break the polyelectrolyte complex is greater than that of Na+ and K+. From the atomic force microscopy images it can be seen that the DNA is well protected by the dodecylated chitosan from nuclease. The polyelectrolyte complex can be used as a gene delivery carrier. 21 refs. 

Fig. 4 Stability diagram of polyelectrolyte complexes as a function of the ionic strength for systems where (a) t rj Texp and (b) t > texp- On the horizontal axis is the composition of the mixture given. On the vertical axis is the salt concentration (Csan). The L region indicates a liquid state, and the G region the glassy (quenched) state S indicates soluble polyelectrolyte complexes. In the N region, no complexation occurs [1]. (a) is a slight modification of the diagram proposed by Kovacevic et al. [31]...

Polyelectrolyte (polyionic) complexes between macromolecular acids and bases or their salts. They are stabilized mainly by ionic bonds. The complex of poly(meth-acrylic acid) and polyvinylpyridine24,25 and complexes of biopolymers with synthetic polyelectrolytes26 are examples of such complexes. 

The surface of O/W emulsions, which are stabilized by surface active salts of polyelectrolytes, usually carries a negative charge. O/W emulsions are formed if the interfacial film consists of a molecular complex with an oil-soluble component and an ionizable water-soluble component (25). The simple oriented-wedge theory of... 

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