Fig. 2

Preparation and characterization of the Pickering emulsions stabilized by the CaCO₃ NPs. a Schematic illustration of the fabrication process of the CaCO₃ NP-based stabilized Pickering emulsion. b Visual appearance of creamed and homogenous emulsions (c = 1–4 % w/v and φ = 0.8). The right panel shows the gel-like emulsion prepared with the highest c (4 % w/v). c Micrographic images showing the microstructure of emulsions, as presented in b. Scale bars are 200 µm. d Confocal laser scanning microscope images of droplets stabilized by CaCO₃ NPs. The oil droplet dyed by Cur-6 showed green fluorescence, whereas the CaCO₃ NPs dyed by RB showed red fluorescence. The scale bar is 30 µm. e, f Mean droplet diameter (d₃₂) and DSD of CaCO₃ NPs stabilized emulsions as a function of c. The particle concentration refers to the particles or surfactant concentration in the continuous phase rather than the whole emulsion. Data are mean ± standard deviation in triplicate. Bars with different letters (a, b, and c) indicate statistically significant (p < 0.05) differences among samples