Rheology of semi-dilute solutions of calf-thymus DNA

We study the theology of semi-dilute solutions of the sodium salt of calf-thymus DNA in the linear and nonlinear regimes. The frequency response data can be fitted very well to the hybrid model with two dominant relaxation times tau(0) and tau(1). The ratio (tau(0)/tau(1)) similar to 5 is seen to be fairly constant on changing the temperature from 20 to 30degreesC. The shear rate dependence of viscosity can be fitted to the Carreau model.