Résumé
Soft Matter 6 (2010) 5605-5614 The effect of silica nanoparticles on transient microemulsion networks made
of microemulsion droplets and telechelic copolymer molecules in water is
studied, as a function of droplet size and concentration, amount of copolymer,
and nanoparticle volume fraction. The phase diagram is found to be affected,
and in particular the percolation threshold characterized by rheology is
shifted upon addition of nanoparticles, suggesting participation of the
particles in the network. This leads to a peculiar reinforcement behaviour of
such microemulsion nanocomposites, the silica influencing both the modulus and
the relaxation time. The reinforcement is modelled based on nanoparticles
connected to the network via droplet adsorption. Contrast-variation Small Angle
Neutron Scattering coupled to a reverse Monte Carlo approach is used to analyse
the microstructure. The rather surprising intensity curves are shown to be in
good agreement with the adsorption of droplets on the nanoparticle surface.