Polystyrene light scattering spectrum

The theoretical analysis of the scattered spectrum was first presented by Komarov and Fisher (3) and Pecora (4) independently in 1963. In 1964 the spectrum of laser light scattered by dilute solutions of polystyrene latex spheres was observed (5) and was foimd to exhibit a lineshape in good agreement with theory. In a typical scattering experiment (6) a monochromatic beam of radiation is incident on the material the wave vector is denoted as ko and the frequency by coo- The scattered radiation is recorded as a function of the scattering angle and frequency shift co, where... 

Borsali, et al. studied dynamic light scattering spectra of 970 kDa polystyrene 950 kDa polymethylmethacrylate toluene. PMMA and toluene form an isorefrac-five pair(70). Semiquanfitafive experimental tests were made of the theoretical work of Benmouna, et a/. (67). When neither polymer was dilute, the observed spectrum was biexponenfial, even though only one macrocomponent scatters light. The mode... 

Sun and Wang report a series of studies of polystyrene polymethylmethacrylate mixtures (in benzene, dioxane, and toluene, respectively) using light scattering spectroscopy as the major experimental technique(78-80). Both polymers were in general nondilute. Neither polymer is isorefiractive with any of the solvents. The objective was to study the bimodal spectra that arise under these conditions and to show that the two relaxation times and the mode ampUtude ratio can be used to infer diffusion and cross-diffusion coefiBcients of the two components. Experimental series varied both the total polymer concentration and the concentration ratio of the two components. The theoretical model predicts a biexponential spectrum. The experimental data were fitted by a bimodal distribution of relaxation rates or by a sum of two Williams-Watts functions. The inferred self-diffusion coefiBcients of both species fall with increasing polymer concentration. 

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