Rayleigh factors

Scattering powers are conventionally represented in terms of the Rayleigh factor defined as... 

Figure 8. Rayleigh factor as a function of the square of the scattering vector for But 27, But 24, But 22, and 1. Key q, units of scattering vector, (fan) 1.

Figure 9. Inverse square root of the difference of the Rayleigh factors of cross-linked [R(l)] and uncross-linked [R(0)] samples as a function of square of the...

The growth rate R(q), not to be confused with the Rayleigh factor R(q), Is always negative for metastable mixtures, as expected. For unstable mixtures, R(q) becomes positive for fluctuations of a sufficiently long wavelength that q < q, exhibits a maximum at... 

A simple way to determine the relationship between molecular weight and intensity of scattered light is to recast Equation (4.4) by defining an optical constant K using Equation (4.5) and Ro, the Rayleigh factor (Equation (4.6)). 

In the simplest case Equation (4.6) relates the Rayleigh factor to the molecular weight in the absence of solvent-macromolecule and macromolecule-macromolecule interactions. The molecular weight is determined from the slope of a plot of the Rayleigh factor versus weight concentration of macromolecules, c. 

In the case of macromolecule-macromolecule interactions, the relationship between the Rayleigh factor and weight concentration of macromolecules is complicated by the fact that the coefficient B is needed to account for this effect (Equation (4.7)). 

According to the fluctuation theory of light scattering (Flory 1953), the relationship between the Rayleigh factor and the physical characteristics of the macromolecules in solution is expressed in the following general form ... 

The correction of absorption depends on the geometry of the cell and the scattering volume. Different relationships have been proposed to correct the Rayleigh factor measured with conventional goniometers, in which the detector rotates around the sample m a horizontal plane (Brice et al. 1953, Forss et al. 1967, Pla et al. 1977). With LALLS (low angle laser light scattering) pho-... 

The vertical, Rv(0), and horizontal Rh(0), Rayleigh factors are calculated from Eq. (2), and the excess Rayleigh factor, corrected for anisotropy, is finally obtained from Eq. (7). 

Kaye W, McDaniel JB (1974) Low-angle laser light scattering - Rayleigh factors and depolarization ratios Appl Opt 13 1934-1937... 

Conventionally, the excess light scattered per unit volume at angle 6 from the transmitted beam, e, is reported as a Rayleigh factor (or ratio). 

Now the molecular weight (M, ) of the solute is related to the Rayleigh factor by the following expression,... 

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