Dynamics during thermoreversible gelation of the polysaccharide schizophyllan

The β‐1.3/1.6 glucan schizophyllan is a fungal polysaccharid that is known to suppress tumor growth. Addition of sorbitol to aqueous solutions of schizophyllan led to a thermoreversible formation of optically transparent gels. The gelation process was followed by low amplitude oscillatory shear as well as by static and dynamic light scattering. Power law behavior of storage modulus G ′(ω) and loss modulus G ″(ω) was found at the gel temperature with an exponent n = 0.5. However, no power law was found for the time correlation functions as measured by dynamic light scattering. Two separated relaxation modes were found above and below the gel transition. The slow mode diverged below the gel temperature indicating a second critical point related to heterogeneities in the gel.