Colloidosomes are an interesting class of microcapsules derived from Pickering emulsions, which are stabilised by either thermal annealing1, polyelectrolyte adsorption1, gel trapping2 or covalent cross-linking3, 4 in order to lock in the initial particle super-structure. Recently, the permeability of such microcapsules has been assessed via dye release studies5. Unfortunately, the release of model water-soluble dyes from colloidosomes into the aqueous continuous phase typically occurs within a few hours5, whereas industrial applications demand retention of actives over time scales of many months/years for useful product shelf-lives. For spherical Pickering emulsifiers such as latexes, there is also an intrinsic geometric packing problem. Bausch et al. have shown experimentally that packing a monolayer of near-monodisperse  latex particles onto spherical oil droplets inevitably leads to the formation of at least twelve packing defects or 'scars'6. Moreover, the intrinsic free volume within amorphous vinyl polymers such as polystyrene most likely precludes latex-based colloidosomes from offering a sufficiently impermeable barrier to prevent the premature release of small molecules. In principle, such technical problems can be overcome by using crystalline, non-spherical Pickering emulsifiers such as clay nanoparticles.

Clay-based colloidosomes

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.