Applications of Prism‐Cell Light‐Scattering Spectrometer to Particle Sizing in Polymer Solutions

A prism‐cell light‐scattering spectrometer has been modified to accept both a diode‐array detector for measurements of angular distribution of scattered intensity and a photomultiplier tube for measurements of time‐dependent intensity‐intensity correlation function. This spectrometer permits the practice of light scattering at small scattering angles down to a few degrees. Here we make a brief study of the reliability of characteristic linewidth distributions obtained by several methods of analysis on the correlation data, which correspond to a reasonably broad unimodal distribution. Then the prism‐cell light‐scattering spectrometer is used to characterize a polymer solution consisting of two different molecular weights. To obtain characteristic linewidth distribution, the correlation data are analyzed by both the constrained regularization method (CONTIN) and the maximum‐entropy method (MEM).