Development of poly (lactic acid) microspheres and their potential application in Pickering emulsions stabilization.

The aim of the present work was to study the feasibility of fabricating poly (lactic acid) (PLA) microspheres stabilized Pickering emulsions. For this purpose, the PLA microspheres were first prepared by oil-water emulsion solvent evaporation method. The effects of preparation conditions such as hydrophilic-lipophilic balance (HLB) value, emulsifier concentration, oil-water ratio and preparation temperature were evaluated by using optical microscopy. Besides, orthogonal experiments were designed to investigate the influence of preparation parameters on average diameter and uniformity, include stirring time, stirring speed, and PLA and polyvinyl alcohol (PVA) concentrations. Based on the analysis of orthogonal experimental results, an optimal level of parameters was defined for the fabrication of PLA microspheres. Furthermore, these microspheres were applied to the stabilization of Pickering emulsions, and the optimal Pickering emulsion with uniform microstructure was obtained through the adjustment of PLA microspheres concentrations. This study opens up a promising way for producing PLA microspheres stabilized Pickering emulsions.