Radius of gyration determination

These observations were confirmed by the values of the radius of gyration determined from the Guinier plot (around 3 nm, see Table 4). SANS experiments on IL/oil microemulsions clearly demonstrate the formation of surfactant-stabilized dispersed nanodroplets with IL cores. 

The application of SEC-LS has heen discussed in a multitude of papers. Useful information can he found in References 2,3,47-57,76. Further details on SEC-LS are summarized as follows precision and accuracy of different LS detectors,"" " the formation of microgels,"" problems encountered in molar mass and radius of gyration determination, and the analysis of micellar systems. "" ... 

As should be expected, both (fg ) and r show the same dependence on the degree of polymerization or molecular weight. Since the radius of gyration can be determined experimentally through the measurement of viscosity or light scattering, it is through this quantity that we shall approach the evaluation of 1. 

Both the intrinsic viscosity and GPC behavior of random coils are related to the radius of gyration as the appropriate size parameter. We shall see how the radius of gyration can be determined from solution viscosity data for these... 

Random coils. Equation (9.53) gives the Kirkwood-Riseman expression for the friction factor of a random coil. In the free-draining limit, the segmental friction factor can, in turn, be evaluated from f. In the nondraining limit the radius of gyration can be determined. We have already discussed f in Chap. 2 and (rg ) in this chapter and again in Chapter 10, so we shall not examine the information provided by D for the random coil any further. 

Fig. 6 Radius of gyration as a function of particle weight for AX-I in several solvents. The single, non-aggregated chains has = 62000g/mol, determined with the percarbani-lated sample in dioxane [102]...

Hyperbranched poly(ethyl methacrylate)s prepared by the photo-initiated radical polymerization of the inimer 13 were characterized by GPC with a lightscattering detector [51]. The hydrodynamic volume and radius of gyration (i g) of the resulting hyperbranched polymers were determined by DLS and SAXS, respectively. The ratios of Rg/R are in the range of 0.75-0.84, which are comparable to the value of hard spheres (0.775) and significantly lower than that of the linear unperturbed polymer coils (1.25-1.37). The compact nature of the hyperbranched poly(ethyl methacrylate)s is demonstrated by solution properties which are different from those of the linear analogs. 

The mesh size was determined from an equivalent network, prepared from a mixture of protonated and deuterated precursors. The radius of gyration of the mesh strands was found to be 25 A, which is identical to the radius of gyration of the uncross-linked precursors. 

Models of the polymer coil are based on the end-to-end distance, which is generally not directly available as a quantitative feature. Coils in dilute solution can be characterized in terms of the radius of gyration, Rg, which is a statistical measure of the distribution of mass about the center of gravity or in terms of the hydrodynamic radius, Rh, that is usually determined through the use of Stokes law and a measurement of a drag coefficient or friction factor, /drag/ for the coil,... 

The radius of gyration (s ) of polymers is generally determined from lightscattering measurements on dilute polymer solutions and is a constant... 

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