Light Scattering, Classical: Size and Size Distribution Characterization
Particle Size Analysis
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Berry, G. C. 2006. Light Scattering, Classical: Size and Size Distribution Characterization. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
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The use of classical, or time-averaged, light scattering methods to characterize the size and size distribution of macromolecules in dilute solutions or particles in dilute dispersions is discussed. The necessary scattering relations are presented systematically, starting with three cases at infinite dilution: the scattering extrapolated to zero angle, the scattering at small angle, and the scattering for arbitrary angle, including the inversion of the scattering data to estimate the size distribution. The relationships needed to effect an extrapolation to infinite dilution from data on dilute solutions are also discussed. These are followed by remarks on light scattering methods, and the concluding sections give examples for several applications. The Rayleigh–Gans–Debye (RGD) approximation is usually appropriate in the scattering from dilute polymer solutions and is also adequate for the scattering from dilute dispersions of small particles. The approximation is assumed when appropriate, but more complete theories are introduced where necessary, as in the use of the Mie–Lorentz theory for large spherical particles.