摘要
An accurate molecular characterization, molar mass and size distributions, of 10 hyaluronan (HA) samples was performed by using a multi-angle light scattering detector connected on-line to a size exclusion chromatographic system. The dynamic viscosity η of the HA solutions was investigated using a rotational viscometer. On monitoring the sample dynamic viscosity for up to 5 h, a small however constant increase of the η value was observed, indicating rheopectic behavior of all 10 HA solutions. Addition of ascorbic acid to the HA solutions caused significant changes in the rheological properties of the samples investigated. The change of η values in the course of time was explained by the redox reactions (caused by the added ascorbate) that occur during the dynamic viscosity monitoring.