Gel Point Investigation of a Chitosan System Using Fourier Transform Rheometry and Multi‐Frequency Excitation

In this study, the sol‐gel transition temperature of a thermosensitive chitosan system was measured using SAOS, in‐real time FTR and multi‐frequency SAOS excitation. From FT analysis, we found that the intensity of the harmonics stayed constant while the chitosan system remained in the solution state, while it increased passed the gelation point. Multi‐frequency SAOS excitation was also carried out using a summation function of sine waves that allowed performing the measurements in the LVR. This last technique could determine the unique (frequency independent) critical sol‐gel transition temperature, and was found to be less tedious than the application of the traditional Chambon and Winter's method.