Mixing state of tert-butyl alcohol and water mixtures studied by small-angle and wide-angle X-ray scattering

Small-angle X-ray scattering measurements have been carried out on tert-butyl alcohol(TBA)-water mixtures at 20, 28, 40 and 55 degree C. The temperature effects in the concentration fluctuation and the Kirkwood-Buff parameters have been studied. Debye's correlation length has also been determined for each temperature. With the increase of temperature, the fluctuation becomes larger and the correlation length becomes longer, which indicates that the microscopic demixing of the mixture proceeds as the temperature is raised. With the result of radial distribution function obtained from wide-angle X-ray scattering, the temperature and concentration dependence of the mixing state of the TBA-water solution is discussed