Polymer globule

Fig. 37 The phase diagram of a polymer globule in terms of the virial coefficients A2 and A3. (Schematically reproduced from Ref. [363])... 

Fig. 12 Schematic representation of the CDSD copolymerization process in the cases when one of the comonomers is selectively absorbed by a polymer globule (top) or adsorbed on a surface (bottom), a Growing chains diming the copolymerization (reaction zone around the growing chain end is marked with a dashed line) resulting copolymers in b globular (adsorbed) and c coil-like states. Regions where absorbed (adsorbed) monomers dominate are shown in gray...

Recent studies showed that amphiphilic properties have to be taken into account for most water-soluble monomer units when their behavior in water solutions is considered. The amphiphilic properties of monomer units lead to an anisotropic shape of the polymer structures formed under appropriate conditions, which is confirmed both by computer simulation and experimental investigations. The concept of amphiphilicity applied to the monomer units leads to a new classification based on the interfacial and partitioning properties of the monomers. The classification in question opens a broad prospective for predicting properties of polymer systems with developed interfaces (i.e., micelles, polymer globules, fine dispersions of polymer aggregates). The relation between the standard free energy of adsorption and partition makes it possible to estimate semiquantitatively the distribution between the bulk and the interface of monomers and monomer units in complex polymer systems. 

In this section, we consider the intramolecular liquid-crystalline ordering of the relatively small macromolecules, we will see that the properties of the globules in this case (small globules) are not universal. As already noted in the introduction, the analysis of the structure of small globules requires the use of the formalism of the self-consistent theory of polymer globules proposed by Lifshitz in Ref,23). 

Fig. 3 AFM image of Pd/PPX nanocomposite a Phase-contrast image dark regions are polymer spherulites and light spots are Pd nanoparticles located at the boundaries between polymer globules, b Cross-section A-A, Profile maximums correspond to Pd particles embedded into the boundary surfaces between the polymeric globules...

SnOi) are isolated and the interparticle distance varies from 5 to 100 nm (Fig. 5). Slightly above the percolation threshold the metal particles (Sn) form continuous filaments of varying diameter, but the maximal diameter never exceeds that of the single metal nanoparticle. Beyond the percolation threshold, the nanoparticles form aggregates located on the boundaries between the polymer globules. 

A series of samples of nanocomposites of Ti and PPX with different Ti content has been synthesized (Table 3). AFM analysis shows that the inorganic phase comprises nanoparticles of 10-20 nm in diameter, which are homogeneously distributed between the polymer globules (Fig. 8). 

Poly(ethylene oxide)s are the only water-soluble polymers which can be terminally functionalized and from which we can obtain complexes bound to the polymer tail. Thereby, several problems encountered in producing conventional polymer-immobilized catalysts can be obviated. The metal complexes synthesized retain the properties of, on the one hand, homogeneous low molecular weight metal complexes, and on the other, poly(ethylene oxide)s or ethylene oxide-propylene oxide block copol)miers. Among these properties are, first of all, water solubility and also the ability to concentrate nonpolar substances in polymer globules or micelles formed by polymer ligands. 

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