Critical phenomena in a binary mixture ofn−hexaneand nitrobenzene. Analysis of viscosity and light-scattering data

Extensive measurements were made of light scattering intensity, quasielastic spectral width, and shear viscosity of the binary-liquid system $n-\mathrm{hexane}$ and nitrobenzene in the critical region. The measurements cover both the critical isochore and some other isochores in the temperature range $T=1\mathrm{} \mathrm{mK} \mathrm{to} 30 \mathrm{K}$ around the consolute temperature. The scattering experiments were made at five different angles covering a range of wave-vector transfer $q$ from 3.5×${10}^4$ to 28.2×${10}^4$ ${\mathrm{cm}}^{-1\mathrm{}}$ with values of the scaling variable $q\xi$ ($\xi$ is the correlation length) spanning from 0.006 to 51. The data on viscosity and linewidth are analyzed in the light of recent theoretical predictions taking into account the background effects on the transport coefficients. The agreement between theory and the experiments is very good in the whole range of $q\xi$ when the background effect is included.