Osmotic and small-angle neutron scattering measurements on polyelectrolyte hydrogels swollen in physiological salt solutions

摘要

In recent years there has been an increased interest in the structure and thermodynamic properties of synthetic and natural polyelectrolyte gels. However, these studies have not addressed explicitly the thermodynamic conditions (i.e., pH, ionic strength, ionic composition, etc.) that occur in biological systems. Only few investigations have been performed on fully neutralized polyelectrolyte gels in salt solutions containing both monovalent and multivalent ions. Such systems are of great significance, both practically and scientifically (e.g., in drug delivery or also in understanding the mechanism of biological processes, where ion exchange plays a central role). Previously we found that the addition of multivalent cations to sodium polyacrylate gels is accompanied by a sudden and reversible volume transition.