Globular polymers

Enzymes are compact, globular polymers. Vinyl polymers are extended structures with high intrinsic viscosities. For example, polyvinylpyrrolidone has an intrinsic viscosity of 22 ml g whereas comparable values for pro-... 

I would like to mention a geometrical feature of many enzymes that Professor Klotz s synzymes do not show. The active sites of most enzymes are located in clefts or channels, that is, in concave parts of the molecule. Synzymes are globular polymers and therefore do not show the concavity that is especially important for stereospecificity. 

Aharoni and coworkers characterized 59 Denkewalter s cascade macromolecules 4 by employing classical polymer techniques viscosity determinations, photo correlation spectroscopy (PCS), and size exclusion chromatography (SEC). It was concluded that at each tier (2 through 10) these globular polymers were, in fact, monodisperse and behaved as nondraining spheres. The purity of these molecules was not ascertained and the dense packing limits were either not realized or simply not noted. 

The first reported preparation of capillary columns containing MIPs utilised a thermally initiated dispersion polymerisation procedure [58], The functional monomer MAA and the cross-linking monomer EDM A were used. Agglomerates of micrometre-sized globular polymer particles were claimed to be prepared in situ in the capillary. Molecular imprinting of L-phenylalanine anilide, pentamidine and benzamidine was undertaken. A pH-dependent retardation of pentamidine over benzamidine in the pentamidine capillary was observed, while the opposite. 

This expression is useful for globular polymers of radius R. Also, the spherical model is the form that is approached as branching in a polymer molecule increases (6). 

Figure 4.32 Polyanions on vesicle surfaces do not disturb the membrane structure, but globular polymers disrupt the membrane. ...

In order to interpret the reflectance spectrum, modeling of the interface is the key issue. For example, in the simulation above, we tacitly made some assumptions. One is that the change of the optical properties of the substrate and refractive index of the solution immediately adjacent to the film surface are independent of potential and the presence of the film. The use of the Fresnel model with optical constants is based on the assumption that the phases in the three-strata model are two-dimen-sionally homogeneous continua. However, if the adsorbed molecule is a globular polymer which possesses a chromophore at its core, a better model of the adsorption layer would be a homogeneously distributed point dipole incorporated in a colorless medium. To gain closer access to the interpretation of the spectrum, a more precise and detailed model would be necessary. But this may increase the number of adjustable parameters and may demand a too complex optical treatment to calculate mathematically. Moreover, one has to pile up approximations, the validity of which cannot easily be confirmed experimentally. 

Synthetic glycopolymers of various architectures have been prepared in recent years using the fast development of controlled polymerization techniques and the very efficient coupling reactions in polymer analogous approaches. Both, linear and globular polymer structures that have been obtained by synthesizing dendritic, starlike, or micelle-like structures or nanogels have received much attention. 

RHEOLOGICAL VOLUMINOSITY AT A CERTAIN CONCENTRATION VOc OF GLOBULAR POLYMERS WITH RIGID... 

Although polymerisations may not be excluded, they will not be discussed here, most globular polymers being formed by condensation processes. 

Above it was remarked that the interlinked systems form, to a certain extent, a transition between the linear and the globular polymers. On these grounds their properties may be expected to be somewhere between those of the two systems mentioned, and this can actually be observed. 

Figure 5.11 Schematic representation of conformation of random-coil- and globular polymers at interfaces.

R. Cush, D. Dorman, and P. S. Russo. Rotational and translational diffusion of tobacco mosaic virus in extended and globular polymer solutions. Macromolecules, 37 (2004), 9577-9584. 

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