Concentration segment distribution

A comparison between the Eg values listed in tables I and II with theoretical Gg values is not possible at present, since for calculation of Gg one needs to know the polymer-solvent interaction parameter as a function of Na2S04 concentration. Moreover, an assumption must be made about the segment distribution of the adsorbed layer. In the absence of such information, it is not possible to calculate Gg. However, the values of Eg obtained from rheology (tables I and II) are reasonable, considering the approximation made and the crude model used for calculating Es. 

We always applied the polymeric ligands in concentrations below those for homogeneous segmental distribution. In other words we dealt with separate polymer coils containing the active centers, which... 

We have thus considered relatively simple irreversible phenomena in the solution of flexible chain polymers. Through use of the segment distribution functions several different theories are reviewed in a somewhat unified way. It is clear now what will be our next task to improve the existent theories. Apart from the transport phenomena discussed in this paper, however, there are more complicated cases. For instance, treatment of the concentration dependence of the specific viscosity requires further development. We hope to discuss such cases in the near future. 

In Fig. 16, the average size R of an annealing PE star (specified as the first moment of the end segment distribution) is plotted as a function of the salt concentration, 0ion (Ps, for different values of the bulk pH. A maximum is observed for pH < pK. ... 

By the sequential polymerization of TrMA to either DMA or MMA (or vice versa), the subsequent hydrolysis and methylation of the resulting block copolymer should yield stereoblock polymers of PMMA. Polymer architecture can be controlled with selection of either monofunctional or bifunctional initiators. Segment distribution can be controlled by initiator and monomer concentrations. 

According to M.C. Williams, in concentrated solutions intermo-lecular interactions are developed, whose intensity derive from both the potential function and chain segments distribution. Without specifying the nature of intermolecular forces, the author started from the theory of the polymer solutions equilibrium, elaborated by M. Fixman [1008], and proposed the following relation ... 

Eq. 1 is no longer valid. To account for the nonuniform segment distribution, the general theory for dilute solutions, where the chemical potential of the solvent is expressed in virial form, has to be considered. Fortunately, it has been found that the change in chemical potential of the polymer with increasing dilution is so small that it does not have any appreciable effect on its equilibrium melting temperature [12]. For practical purposes, Eq. 1 is obeyed over the complete concentration range of dilutions. 

Figure 4. A series of SANS data and their fits for Pluronic P84 micellar solutions at 40 C. The fits in absolute intensity scale use an sticky hard sphere model for the inter-particle structure factor and a ctp-and-gown model for the form factor. The same stickiness and polymer segmental distribution are used to fit the entire series of SANS data in this graph simutaneously by varying only the polymer concentrations. This indicates that the microstructure of self-associated micelles is independent of the polymer concentration.

To characterize the structure of adsorption layer, it is very important to know the profile of density of segment distribution. In many works, the ultimate goal was to predict the concentration profile,( )(z), in the interfacial region as a function of the distance z from the interface. For many years, att ts were made to derive the structure of polymer layers from some theory. In this case, each chain is submitted to an average potential which is a combination of... 

We may divide the range of c into three the dilute, semidilute, and concentrated regimes. The first and second ones are concerned roughly with c below and above c, respectively. In the semidilute regime, the solution appears to be macroscopi-cally uniform, but the segment density is still quite low. In other words, the segment distribution is not microscopically... 

We assume that polymer molecules consist of a large number of chain segments of equal length, joined by flexible links. Each link then occupies one site on the lattice. The solution has to be sufficiently concentrated that the occupied lattice sites are distributed at random, rather than having them clustered together in a non-random way. 

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