Oil-in-oil Pickering emulsions stabilized by shigaite-like layered double hydroxide particles

In this work, we report the preparation of simple oil-in-oil emulsions using layered nanoparticles as stabilizers at the interface between silicone and castor oil. Layered double hydroxides with a shigaite-like structure presenting an ideal composition of [Mn6Al3(OH)18][(SO4)2Na].12H2O (S-Na/SO4) were prepared by co-precipitation with increasing pH, followed by particle surface grafting with octhadecyltrimethoxysilane (S-OTMS) in an apolar medium. The powder XRD, SEM, TEM, and specific surface area (BET) techniques showed that the structure and morphology of silane-grafted S-Na/SO4 remained practically unchanged. FTIR, EDS and ICP-OES analyses indicated that the silanes were successfully grafted onto the S-Na/SO4 surface. In addition, to maintaining their structure and morphology, these functionalized materials showed good performance in controlling the hydro-phobicity of the surface for application in oil-in-oil emulsions, improving their compatibility for the dispersion in non-polar liquids.

Automated summary

In this study, simple oil-in-oil emulsions were prepared using layered nanoparticles as stabilizers between silicone and castor oil. Layered double hydroxides with a shigaite-like structure were prepared by co-precipitation, followed by surface grafting with octadecyltrimethoxysilane in an apolar medium. The functionalized materials maintained their structure and morphology and showed good performance in controlling the hydrophobicity of the surface for application in oil-in-oil emulsions, improving their compatibility for dispersion in non-polar liquids.