The glass transition in colloidal suspensions of silica nanoparticles in a water-lutidine mixture: A photon correlation study.
Martinelli A., Baldi G., Capaccioli S., Caporaletti F., Dallari F., Grübel G., Valenti S., Zontone F., Monaco G.
Colloidal suspensions of silica nanoparticles in a water-lutidine mixture have been investigated for different volume fractions of nanoparticles across the glass transition using both X-ray photon correlation spectroscopy and multi-speckle dynamic light scattering. These experiments have allowed carrying out a detailed characterization of the density-density correlation function of these materials over an extended range of exchanged momentum, $q$. Moreover, the dynamical heterogeneities have been investigated via four-points correlation functions, and the comparison of the results obtained with the two experimental techniques has evidenced the advantages and the limits of this approach.