STRUCTURAL-PROPERTIES OF PARTIALLY CHARGED POLY(ACRYLIC ACID) GELS ASPROBED BY LIGHT-SCATTERING

We report results of static light scattering for partially charged gel s at different swelling degrees and different ionization degrees. We m easured both the ensemble-average and the rms fluctuations of the scat tered intensity by scanning through various positions in the gel. It i s shown that the dynamic concentration fluctuations are, to the first order, the same as in semi-dilute solutions at the same concentration. The excess of scattering of the gel with respect to the solutions ari ses mainly from frozen-in scattering domains with spatial extent less than approximately 300 angstrom.