Layered clay minerals, synthetic layered double hydroxides and hydroxide salts applied as pickering emulsifiers

摘要

Clay mineral particles have longstanding applications in many semisolid formulations produced by the cosmetic and pharmaceutical industries, due to the good physical-chemical properties of the particles in dispersion. They are usually in the colloidal size range and can be easily intercalated/grafted with organic species, modulating the dispersion viscosity, with the added advantage of being eco-friendly. However, despite the longstanding application of clay minerals such as kaolinite and montmorillonite, the number of studies focused on understanding the behavior of such particles when dispersed in emulsions is scarce. Furthermore, studies of the application of synthetic layered double hydroxides and layered hydroxide salts are even rarer than those of clay minerals. Therefore, this short review presents the state of the art of the use of clay minerals and the former species in Pickering emulsions and provides perspectives for future research.