The sol-gel transition probed by the dynamics of latex particles studied by QELS

The use of spherical probe particles to investigate the viscoelastic properties of polymer solutions has been suggested for a long time. We present, in this paper, an analysis of quasi-elastic light scattering results from latex probe particles during gelation of a gelatin solution. We show that by focusing on the short-time and long-time behavior of the autocorrelation function, it is possible to simply interpret our data in terms of the divergence of the viscosity and emergence of a shear elastic modulus near the gel point. With our crude analysis, we were able to grasp the critical behavior of gelation and obtain the two critical exponents of the transport properties.