Macromolecules/macromolecular systems

Stepanek P, Kondk C, Sedldcek B (1985) In Sedlacek B (ed) Physical optics of dynamic phenomena and processes in macromolecular systems. Proceedings of the 27th microsymposium on macromolecules, de Gruyter, Berlin, p 271... 

The copolymer-based systems possessing the core-shell structure in solutions are known and studied rather well (see, e.g., [14-16]). These copolymers in aqueous media tend to form polymeric micelles, which are often considered as promising drug delivery nano-vehicles [ 17,18], i.e., these macromolecular systems are not only of scientific, but also of considerable applied significance. Among such systems there are interesting examples, whose properties are very similar to the properties that should be inherent in the protein-like copolymers. All of these macromolecules possess the primary structure of... 

Interest in optically active polymers arose from analogy with macromolecules of biological origin. In addition, there was the hope to obtain new information to clarify the stereochemical features of synthetic polymers this, in fact, did come about. Attempts to direct the course of polymerization using chiral reagents had been made already prior to the discovery of stereospecific polymerization. It was only after the 1950s, however, that the problem of polymer chirality was tackled in a rational way. The topic has been reviewed by several authors (251-257). In this section I shall try to illustrate three distinct aspects the prediction of chirality in macromolecular systems, the problems regarding the synthesis of optically active polymers, and polymer behavior in solution. 

The recommendations embodied in this document are concerned with the terminology relating to the structure of crystalline polymers and the process of macromolecular crystallization. The document is limited to systems exhibiting crystallinity in the classical sense of three-dimensionally periodic regularity. The recommendations deal primarily with crystal structures that are comprised of essentially rectilinear, parallel-packed polymer chains, and secondarily, with those composed of so-called globular macromolecules. Since the latter are biological in nature, they are not covered in detail here. In general, macromolecular systems with mesophases are also omitted, but crystalline polymers with conformational disorder are included. 

Many, but not all, macromolecules are created by the mutual chemical chain reactions of small molecules called monomers and the arising species contain repeated small units, mers. In that case they are designated oligomers or polymers depending on their molar mass. This means that all oligomers and polymers can be called macromolecular substances but not all macromolecular substances are of oligomeric or polymeric nature (lignin, humin substances, etc.). Properties of macromolecular systems depend on... 

Mattice WL, Suter UW (1994) Conformational theory of large molecules The rotational isomeric state model in macromolecular systems, Wiley, New York Moritani T, Fujiwara Y (1973) J Chem Phys 59 1175 Nagai KJ (1959) J Chem Phys 31 1169 Nagai KJ (1962) J Chem Phys 37 490 Natta G, Corradini P, Ganis P (1962) J Polym Sci 58 1191 Suter UW (1981) Macromolecules 14 523 Viswanadhan VN, Mattice WL (1987) Macromolecules 20 685 Volkenstein M (1958) J Polym Sci 29 441 Volkenstein MV (1951) Dokl Akad Nauk SSSR 78 879... 

The interest in macromolecular systems containing defined topological bonds, such as polyrotaxanes 7, multicatenanes 8, polycatenanes 9, poly[2]catenanes 10, and polymeric catenanes 11, is dual. First, these macromolecules represent daunting synthetic and characterization challenges which deserve attention in their own... 

Isomorphism in macromolecular systems may be defined as the statistical substitution, within a single crystalline phase, between monomer units differing either in chemical structure or in conformation or in configuration. The distribution of the different monomer units needs not to be totally random. As we shall see, there are examples of isomorphous systems consisting of a mixture of different homopolymer chains. In these cases the randomness is confined to the macromolecules... 

Another experimental method that has been used to determine orientational correlation functions in macromolecular systems is based on measurements of the time-dependence of the depolarization of fluorescence 26 From these measurements rotational diffusion coefficients and the shape of the rotating macromolecule have been determined.27... 

Sufficient experimental and theoretical data have been already obtained permitting us to consider the molecular recognition ability, a fundamental property of macromolecular systems this property manifests itself under interactions where simple synthetic macromolecules (homo- and copolymers) participate, if they result in the formation of a polycomplex, i.e., a compound of the following type... 

Our treatment of basic principles of water-solute relationships involves a bottom-up approach that begins with a basic physical-chemical analysis of how fundamental water solute interactions have set many of the boundary conditions for the evolution of life. We discuss how the properties of macromolecules and micromolecules alike reflect selection based on such fundamental criteria as the differential solubilities of different organic and inorganic solutes in water, and the effects that these solutes in turn have on water structure these are two closely related issues of vast importance in cellular evolution. With these basic features of water-solute interactions established, we will then be in a position to appreciate more fully why regulation of cellular volume and the composition of the internal milieu demands such precision. We then can move upwards on the reductionist ladder to consider the physiological mechanisms that have evolved to enable cells to defend the appropriate solutions conditions that are fit for the functions of macromolecular systems. This multitiered analysis is intended to help provide answers to three primary questions about the evolution and regulation of the internal milieu ... 

In these aggregation phenomena, the formation of intermacromolecular complexes is attributed to the fact that macromolecules with complementary binding sites interact with each other almost stoichiometrically in solution due to certain secondary binding forces. In this review, the formation of complementary complexes in synthetic macromolecular systems is mainly discussed. 

Russell TP, Mayes AM, Kunz MS (1994) In Teramoto A, Kobayashi M, Norisuye T (eds) Ordering in Macromolecular Systems p. 217. Springer, Berlin Mayes AM, Russell TP, Bassereau P, Baker SM, Smith GS (1994) Macromolecules 27 749... 

The effects of macromolecules other than surfactants on the rates of organic reactions have been investigated extensively (Morawetz, 1965). In many cases, substrate specificity, bifunctional catalysis, competitive inhibition, and saturation (Michaelis-Menten) kinetics have been observed, and therefore these systems also serve as models for enzyme-catalyzed reactions and, in these and other respects, resemble micellar systems. Indeed, in some macromolecular systems micelle formation is very probable or is known to occur, and in others mixed micellar systems are likely. Recent books and reviews should be consulted for a more detailed description of macromolecular systems and for their applicability as models for enzymatic catalysis and other complex interactions (Morawetz, 1965 Bruice and Benkovic, 1966 Davydova et al., 1968 Winsor, 1968 Jencks, 1969 Overberger and Salamone, 1969). 

Dendritic architectures have attracted the interest of many scientists recently. The aesthetically pleasing tree-like moleeules combine advanced synthesis and unique properties with the prospects of supramolecular technologies. The guest-host properties of these well-defined macromolecules are of great interest, because they resemble the interactions of small molecules with biomacromolecules like proteins, and they are able to close the gap between the traditional supramolecular interactions of smaller molecules and the interactions in larger (phase-separated) macromolecular systems. In recent years a large number of interesting results have been reported, in which supramolecular interactions and dendritic architectures are combined. 

Chain rigidity can cause partial ordering of the macromolecules. While flexible macromolecules yield amorphous solutions and melts in which the individual coils interpenetrate each other, semiflexible macromolecular systems order in nematic domains [43],... 

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