The electric thermal noise has been measured in two aging materials, a colloidal suspension (Laponite) and a polymer (polycarbonate), presenting very slow relaxation towards equilibrium. The measurements have been performed during the transition from a fluid-like to a solid-like state for the gel and after a quench for the polymer. For both materials we have observed that the electric noise is ...

Adequate clay minerals considerably affect the macroscopic mechanical behavior of water even at concentrations of a few percent. Thus when 2 wt. % laponite clay mineral nanoparticles are added to water, the resulting colloidal suspension after some time takes on the semisolid characteristics of a jellylike material at room temperature. Cold neutron time-of-flight spectroscopy data are in agreem...

Nanofluids, stabilized suspensions of nanoparticles typically < 100 nm in conventional fluids, are evolving as potential enhanced heat transfer fluids due to their better thermal conductivity, increase in single phase heat transfer coefficient and significant increase in critical boiling heat flux. In the present paper, we investigate the overall thermal resistance of a closed two-phase thermos...

We study the rotational diffusion of aging Laponite suspensions for a wide range of concentrations using depolarized dynamic light scattering. The measured orientational correlation functions undergo an ergodic to nonergodic transition that is characterized by a concentration-dependent ergodicity-breaking time. We find that the relaxation times associated with rotational degree of freedom as a ...