Capsules from Pickering emulsion templates

Abstract

Following the resurgence of interest in particle-stabilised or Pickering emulsions recently, the preparation of capsules from such templates has become feasible. We review some of the recent activity in this area and focus on both the methods used to reinforce the particle shell and the applications of these novel capsules, which may be empty or liquid-filled. The methods reported include interfacial polymerisation or crystallisation, interfacial cross-linking, the use of a sacrificial template, formation of polymer layers, gelation and evaporation from multiple emulsions. Potential applications are in the areas of wastewater treatment, perfume encapsulation, drug/dye release and as self-healing coatings.

Catalysis in Pickering emulsions

“…67 Recently, Bago Rodriguez and Binks reviewed methods to form capsules from Pickering emulsion templates including the sol-gel process. 89 Fig. 3(f) shows the appearance of a TEOS-treated micron sized w/o emulsion droplet stabilized by silica nanoparticles.…”

Electric-field-induced deformation, yielding, and crumpling of jammed particle shells formed on non-spherical Pickering droplets

“…[2][3][4] Droplets densely covered with particles (referred to as Pickering droplets) constitute Pickering emulsions and Pickering emulsion gels, [5][6][7] and can be used to produce particle capsules. [8][9][10] Such emulsions and capsules are promising for many applications, particularly in the pharmaceutical and food industries, [11][12][13] as well as in the oil industry and biofuel processing. 14,15 Moreover, particle-covered droplets facilitate the fabrication of new materials [16][17][18] and can be designed to form novel adaptive structures.…”

Pickering emulsion‐templated ionotropic gelation of tocotrienol microcapsules: effects of alginate and chitosan concentrations and gelation process parameters

“…Specifically, the capsules are formed via a two-stage process in which a bioactive compound-loaded Pickering emulsion would initially be prepared and subsequently subjected to a polymerization process to immobilize the particles at the oil-in-water (O/W) interface, thereby strengthening the wall of the emulsion droplets for a better support to the final structure. 2 By coupling both emulsification and gelation processes, porous and semipermeable microcapsules with tunable properties could be obtained. Xu et al 3 demonstrated the application of this coupling approach to encapsulate lysozyme into alginate microcapsules by utilizing biomimetic mineralized calcium carbonate (CaCO 3 ) particles to form its Pickering emulsion template.…”