Structure and rheological properties of model microemulsion networks filled with nanoparticles

TL;DR

This study investigates the structure and flow behavior of model microemulsion networks stabilized by surfactants and polymers, incorporating silica nanoparticles to assess their effects on rheology and network structure.

Contribution

It introduces a detailed analysis of microemulsion networks with nanoparticle incorporation, combining scattering techniques and Monte Carlo simulations to understand their rheological and structural properties.

Findings

Rheological properties follow simple percolation laws.

Silica nanoparticles significantly alter network rheology up to 9% volume fraction.

Small Angle Neutron Scattering confirms network structure and nanoparticle dispersion.

Abstract

Model microemulsion networks of oil droplets stabilized by non ionic surfactant and telechelic polymer C18-PEO(10k)-C18 have been studied for two droplet-to-polymer size ratios. The rheological properties of the networks have been measured as a function of network connectivity and can be described in terms of simple percolation laws. The network structure has been characterised by Small Angle Neutron Scattering. A Reverse Monte Carlo approach is used to demonstrate the interplay of attraction and repulsion induced by the copolymer. These model networks are then used as matrix for the incorporation of silica nanoparticles (R=10nm), individual dispersion being checked by scattering. A strong impact on the rheological properties is found for silica volume fractions up to 9%.