Critical anomaly of complex shear modulus in polymer solutions: Viscoelastic suppression of order parameter fluctuation due to dynamic asymmetry

Abstract

The critical anomaly of the complex shear modulus has been studied for ideal polymer solutions in the frequency range from 1 Hz to 400 Hz. The logarithmic critical divergence is observed for both the real and imaginary parts of the complex shear modulus. It is found that the strength of the critical anomaly decreases with an increase in the degree of polymerization N, while the noncritical background increases with N, indicating the significance of the viscoelastic effect. The critical anomaly is likely suppressed by the viscoelastic effects through the spontaneous coupling between the stress field and the order parameter fluctuation.