Supermolecular formations

When the cracks first appear, the propagation rate is small, and the stressed state is preserved until the fracture occurs. Mechanical force orients both the structural units and the macro- and supermolecular formations into directions parallel to the direction of the force. 

These findings are confirmed by study of the thermodynamic parameters of mixing of the cured epoxy resin with OP-20. At 6-7% content of surfactant, corresponding to the maximum surface tension of the polymer, a kink and an area of decrease of the Flory-Huggins parameter are observed in the dependence of X2,s on the surfactant concentration. This anomalous dependence can be explained in terms of the rearrangement of the intermolecular bonds in the polymer-surfactant system. With ED-20 initial resin, there are no extrema on the curve. Alteration of the macromolecular conformation affects the supermolecular structure of the polymer. Adding surfactant to ED-20 resin changes the form and causes a noticeable decrease of the size of the polymeric supermolecular formations. 

As mentioned in [7] irrespective of acid concentration in the initial solution, in the formed ChT-PVA film there takes place a decrease in the number of supermolecular formations and an increase in their size as compared with additive values. This fact is evidently due to the existing interpolymer interaction, i.e. the formation of ChT-PVA heteroaggregates which are known to be characterized by lower packing density and by great sizes. Thus, the introduction of the second polymer is likely to change the supermolecular... 

The layer stacks are in turn building blocks [50, 51] from which larger supermolecular formations are constructed (cf. Fig. 6.14). The detection and interpretation of the powerful zero emission for a number of smectic polymers (cf. Fig. 6.13a, left part of the diffraction pattern) and the analysis of the three-dimensional correlation functions YsW (Fig- 6.13b) allow us [50, 51] to postulate the formation of large cylindrical supermolecular formations fiem the layer stacks (cf. Fig. 6.14). 

Nowadays attention is turned also to the supermolecular level, that is, to the morphologic aspects, to the nature of interfaces, to the formation of new phases, or of particular aggregates (liquid crystals, gels, etc.). Interest has also been directed to the study of chain mobility for its influence on frictional properties of polymers. In recent years there have been many successful approaches to a microscopic theory (in contrast to a phenomenological approach) of the physi-comechanical behavior of macromolecular materials. 

The Primary Donor. - The radical-cation P+ In the bRC of purple bacteria and also in PS I the primary electron donors have been identified as (B)Chl dimers and EPR/ENDOR clearly showed that the unpaired electron and the positive charge - is (asymmetrically) distributed in a supermolecular orbital extending over both dimer halves (see sections 2.1,3.1). Dimer formation has the important consequence of charge delocalization and this stabilization of the primary donor radical-cation leads to a decrease of the oxidation potential. A fine tuning of the potential is possible through interactions with the environment, e.g. via H-bonds. 

Thus, varying thermodynamic quality of the solvent (by the use of various solvents and their mixtures or varying the temperature) one may appreciably affect the extent of inter- and/or intramolecular aggregation of the side groups. This, in turn, may definitely influence the formation of supermolecular organization of the mesophase in bulk polymeric samples. 

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