Polyion interchange

Reactions of polyion interchange involve the transfer of the polyion chain, incorporated in the polymer complex, to another polyion present in the solution (Kabanov et al., 1985). These processes are... 

Reactions of polyion interchange (A) polyion exchange resulting in uniform distribution 162... 

Polyion Interchange Reactions Involving Micellar IPECs. 155... 

One of the very characteristic features of IPECs is their ability to participate in so-called polyion interchange (exchange and substitution) reactions, previously investigated for aqueous mixtures of oppositely charged linear PEs by Kabanov... 

In particular, by means of fluorescence measurements with the use of 4 -(aminomethyl) fluorescein-labeled PMANa and PS- -PMANa (PMA Na and PS-ft-PMA Na, respectively) they studied the following polyion interchange reactions ... 

The authors explained the observed differences in the rates of such polyion interchange reactions in terms of the collision model [95]. This model considers the transfer of the GPE from the original to the added HPE to proceed via a short-living intermediate ternary complex. Such a ternary complex is formed due to the diffusion-controlled approach and interpenetration of the HPE species occupied by chains of GPE and of free HPE species. Because the electrostatic and steric repulsions upon the approach and interpenetration of the reacting species for the coil/micelle combination (2a, 2b) and, especially, for the micelle/micelle combination (3a, 3b) are obviously much stronger than for the coil/coil combination (la, lb), the rates of the polyion interchange reactions show a pronounced decrease in the abovementioned order. 

The ability to participate in polyion interchange reactions is one of the basic properties of IPEC [10-13] ... 

Nevertheless, while PEI easily participates in polyion interchange reactions, PTBA chains at elevated temperatures (40-60 °C) are fixed in IPEC species even at a relatively high ionic strength, apparently, due to intra-IPEC interaction of bulky hydrophobic groups. 

Figure 9.5 Reactions of poly ion interchange (A) poly ion exchange resulting in uniform distribution of polycation among DNA chains (B) polyion substitution resulting in recognition of the scDNA and release of the 1DNA in a free form.

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