Dynamic light scattering probes of structure instabilities in foamed substances

摘要

The results of experimental study of the foam structure evolution at various temperatures using correlation analysis of backscattered laser light are presented. Shaving foam was used for preparation of the phantom samples. It was found that for the later stages of structure evolution the significant spread of the local estimates of intensity correlation time is characteristic. This feature is interpreted in terms of the increasing probability for burst-like processes associated with local changes in the bubble configurations. The statistics of the local estimates of intensity correlation time is analyzed. The possible contribution of the sampling volume effect on the observed fluctuations of the correlation time is considered using the results of Monte-Carlo simulations of probed light transport in the medium.