A reevaluation of the viscosity exponent for binary mixtures near the consolute point

A reevaluation of the critical exponent of the viscosity anomaly for binary mixtures close to the consolute point is presented. Using published data we make a systematic, consistent study in which corrections due to shear gradients and frequency effects are included and the effect of the functional form for the background viscosity is critically examined. The result is that the value of the exponent is generally found to be larger than reported and larger than the most recent theoretical predictions.