Rayleigh Linewidth of the Light Scattered from Flexible Polymers in Solution

Abstract

The linewidth of the Rayleigh scattered light from flexible polymers is calculated on the basis of Rouse model. In general, the contributions from translational diffusion and intrachain molecular motion are interrelated, but, for usual cases where the size of molecule is comparable to or less than the wave length of the incident light, the result is approximately expressed as a simple superposition of separate effects. The linewidth due to the translational motion decreases with decreasing scattering angle, whereas the linewidth due to the intrachain molecular motion remains constant. The ratio of magnitudes of these two effects is overwhelmingly large, and the effect of intrachain molecular motion seems almost indetectable.