A Janus emulsions stabilized only by natural cellulose particles under the dual driving force of temperature and density

Janus emulsions have particularly drawn researchers' attention due to their asymmetrical morphology and anisotropic characteristics. However, except for Janus emulsions with liquid-liquid structures, other types of Janus emulsions have not been studied yet. Inspired by the occasional discovery that the water film on the foam surface freezes and transforms into a hard solid interface film below freezing point, a Janus emulsion was developed by using the phase change characteristics of solid paraffin wax. In this study, decane or perfluorooctane was used as the oil phase (O), solid paraffin wax as the solid interfacial film (S), and solutions of sodium dodecyl sulfate (SDS) or natural cellulose particles as the water phase (W). By controlling temperature and microgravity, hemispherical (O + S)/W and (S + O)/W type Janus phase change emulsions were successfully prepared. The experimental results show that paraffin wax content, oil phase density and polarity have significant effects on the stability and microstructure of emulsions. By calculating and fitting the solid-liquid interface ratio of Janus emulsions, the quantitative relationship between solid-liquid interface ratio, surfactant concentration and oil phase composition was obtained. This provides a theoretical basis and experimental basis for interface solid-state encapsulation and regulation.