Rheology of Semi-dilute Solutions of Calf-thymus DNA

Abstract

We study the rheology 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 ${\tau }_{\circ }$ and ${\tau }_1$. The ratio $\frac{{\tau }_{\circ }}{{\tau }_1}\sim$ 5 is seen to be fairly constant on changing the temperature from 20${}^{\circ }$C to 30${}^{\circ }$C. The shear rate dependence of viscosity can be fitted to the Carreau model.

6 pages inclusive of 7 eps figures