The characterization in relation to shape and particle size of alumina and rutile
suspensions was performed. The intrinsic viscosity exhibited the presence of nonspherical
aggregates in both suspensions although TEM images showed non
monodisperse spherical shape of alumina particles. DLS indicated the existence of
particle aggregates for both systems. In all cases, the increase in thermal conductivity
with respect to the base fluid is verified. The thermal conductivities obtained
experimentally were compared with three mathematical models, which yielded lower
values than those measured. From rheological measurements and by means of the
Peclet number defined in colloidal suspensions, values of thermal conductivity were also
proposed.
