Selective Intermacromolecular Complexation

In biological systems, a macromolecular chain effectively selects a complementary one to form an intermacromolecular complex. In this way, very specific functionalities become effective. Synthetic polymers can also form intermacromolecular complexes, but the ability of a synthetic polymer to select only one objective polymer as in biological systems has not yet been realized, except for several specific systems of pairs of polymers which include one of the complementary base pairs of nucleic add individually, e.g. po y(A)-poly(U) and poly(I)-poly(C) (see Sect. 3.3). The intermacromolecular complex formation of synthetic polymers is controlled by many factors such as interaction forces, solvent, ionic strength, temperature, pH, etc. Moreover, the cooperative and concerted interactions of each active site play an important role in complex formation. These phenomena suggest that the selective intermacromolecular complexation can be realized under suitable conditions. 

Selective interchain macromolecular complexation is described as follows  

Pj and P3 can interact with P2 individually to form the intermacromolecular complex. However, when three polymer components coexist under suitable conditions, only P3 preferentially forms a complex with P2 in this system. 

PHMPA PMAA PVPo DMSO PHMPA-PMAA Solvation 

PVPo PMAA PEO H20 (2) PVPo-PMAA Concerted effect 

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The selective intermacromolecular complexation based on the difference of the chain length of PEO is also shown in Table 24. It has already been pointed out that a cooperative interaction between macromolecules is a very important factor in the formation of intermacromolecular complexes. This phenomenon is explained by Eq. (60). 

As mentioned previously, selective intermacromolecular complexation is realized by the control of the difference of the total bond energy between each pair of polymers. Therefore, if P can interact with P2 more strongly than P3 does, the interchain macromolecular substitution reaction of P3 and P3 takes place on the addition of Pj to the P2-P3 complex solution. In these systems, it is expected that a cooperative interchain macromolecular substitution reaction of the type... 

As a result, a study of such selective intermacromolecular complexation and substitution reaction would be expected to clarify the fundamental phenomenon of the specific polymer reaction in biological systems and the polymer effects of synthetic macromolecules. 

Moreover, intermacromolecular complex formation is applied to selective recovery of organic and metallic ions. For example, as shown in Table 27, Cu2+ ion is much more effectively precipitated by the polyelectrolyte complex than by one of its components520. Furthermore, polyelectrolyte complexes including some metal ions have been studied in recent years (see Sect. 3.2.). Crown ethers can bind certain cations they especially exhibit high affinity to K+. Smid et al.S21) synthesized poly(vinylbenzo-[18]-crown-6). Such polymers containing crown ether with K+ behave like polycations in solution and can interact with polyanions such as poly(carboxyHc acid) to generate a kind of polyelectrolyte complexes. Moreover, PAA may interact with the ether oxy-... 

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