Aging mechanism in model Pickering emulsion.

We study the stability of a model Pickering emulsion system using fluorinated oil and functionalized silica nanoparticles. A special counter-flow microfluidic set-up was used to prepare monodisperse oil droplets in water. The wettability of the monodisperse silica nanoparticles (NPs) could be tuned by surface grafting and the surface coverage of the droplets was controlled using the microfluidic setup.

Spheres growing on a sphere: a model to predict the morphology yields of colloidal molecules obtained through a heterogeneous nucleation route.

Through the heterogeneous nucleation of polymer nodules on a surface-modified silica particle, the high-yield achievement of hybrid colloidal molecules with a well-controlled multipod-like morphology was recently demonstrated. However, as the formation mechanism of these colloidal molecules has not been completely understood yet, some opportunities remain to reduce the tedious empirical process needed to optimize the chemical recipes. In this work, we propose a model to help understand the formation mechanism of almost pure suspensions of well-defined colloidal molecules.

Nucleation of silica nanoparticles measured in situ during controlled supersaturation increase. Restructuring toward a monodisperse nonspherical shape.

The first stages of the nucleation and growth of silica nanoparticles are followed in situ using both SAXS and Raman spectroscopy. Coupling these two techniques allows the determination of the fractions of soluble and solid silica as a function of the reaction time. SAXS also enables demonstrating that major modifications of the structure occur after the initial precipitation period, inducing an increase of the precipitate density.

Light-responsiveness of C12E6/polymer complexes swollen with dodecane.

The association behavior of light-responsive azobenzene modified poly(sodium acrylate)s (AMPs) with C(12)E(6) (hexa-oxyethyleneglycol n-dodecyl ether) surfactant micelles swollen with dodecane was investigated using dynamic light scattering, UV spectrophotometry, and capillary electrophoresis techniques. AMPs complexes with oligoethyleneglycol n-alkyl ether show promising properties as emulsifiers for the light-triggered control of inversion of emulsions and the present work aims at giving new insights with respect to the nature of their photoresponse. Depending on the dodecane amount, the size of the spherical surfactant micelles was varied with radii ranging from 4 to 8 nm.

SAXS exploration of the synthesis of ultra monodisperse silica nanoparticles and quantitative nucleation growth modeling.

The production of highly monodisperse nanoparticles of precisely controlled size is a very important research field. It has important applications notably for the optical properties of nanoparticles (e.g.