On the temperature dependence of the elasticity of agarose gels

The elastic modulus E of agarose gels with different molecular weights are determined as a function of temperature. E increases slowly from 5°C up to a certain temperature Tmax, which depends on the molecular weight, and then decreases gradually at first and then rapidly. Tmax is shifted to higher temperatures with increasing molecular weight. E is discussed in terms of an entropic and an energetic contribution. The entropic part decreases while the energetic part increases with increasing temperature.