X-ray scattering study and molecular simulation of glass forming liquids: Propylene carbonate and salol

Wide angle x-ray scattering and classical molecular-dynamics simulations were employed to study structural and dynamic properties of two low-molecular weight glass-forming liquids, propylene carbonate, and salol. We observe pronounced changes in the liquid structure as a function of temperature in a wide temperature range bracketing the glass transition temperature. The experimental and simulation results compare the x-ray scattering from the liquid slightly and far above the experimental glass transition temperature, Tgexp. The simulations largely reproduce the characteristic behavior of the experimental x-ray intensities, which is interpreted in terms of clusterlike heterogeneities forming in the liquid as Tgexp is approached.