Elasticity at Swelling Equilibrium of Ultrasoft Polyelectrolyte Gels: Comparisons of Theory and Experiments

We have studied the elasticity of low volume fraction hyaluronic acid polyelectrolyte gels in swelling equilibrium as a function of salt concentration and strand length. By measuring the shear modulus at different salt concentrations for a constant volume fraction, and for different volume fractions at constant salt concentrations, we uniquely identify the physical parameters responsible for swelling, the chain hydrophobicity, χ, and the degree...