MUTUAL DIFFUSION IN AQUEOUS GEL SOLUTIONS

Concentration relations for mutual diffusion coefficients D(m)(C) in water of polyelectrolyte gelatin macromolecules at different temperatures were studied by optical interferometry. It is shown that D(m)(C) values are in agreement with scaling predictions and are similar to those observed for solutions of neutral macromolecules under theta-conditions. However, they are greatly influenced by the square-law term C2, having a correlation to the conventional scaling law D(m) is-proportional-to C, and the mobility of solution components is influenced by physical gelation processes under certain thermodynamic conditions. It is demonstrated that the temperature relation of the diffusion coefficient at infinite dilution D0(C --> 0) for the three gelating samples with various physico-chemical properties can be described by a universal function.