Viscoelastic Effects on the Diffusion Properties of Curdlan Gels

The diffusion properties of curdlan gels were characterized against its viscoelastic behavior. With increased junction zones involved in rigid crosslinks in higher concentration gels, the three-dimensional structure of curdlan is characteristic. As the gel concentration increases, the intermolecular crosslinking and apparent viscosity increase, reducing mobility of the polymer chains with slower release rates. The scaling laws confirmed that curdlan gel network structure corresponds to that of polymer chains in a good solvent at the semi-dilute regime. Diffusion of the entrapped agent in 6% gels resembled pseudo-controlled release behavior, and a further increase in gel concentration might produce microspheres that support a sustained release.