Probe diffusion in gels

The diffusion constant of probe molecules in the poly(acrylamide) gel is measured at various concentrations of the acrylamide using probe molecules that have different molecular weights. It is found that the normalized diffusion coefficients of the probe molecules are superposed onto a single master curve when the results are plotted as a function of a variable ${\mathit{M}}^{1/3}$ ${\mathrm{\phi }}^{3/4}$. The results indicate the scaling function of the form D/${\mathit{D}}_0$=f(x), where x=R/ξ. © 1996 The American Physical Society.