Fig. 3. Mechanism of pH-responsive emulsions stabilized by NaCas. (a) Schematic illustration of the pH-responsive emulsion system stabilized by NaCas. (b) Cryo-SEM images of emulsions stabilized by NaCas: (b₁ and b₂) cryo-SEM image of emulsion droplets at pH 8.0; (b₃ and b₄) cryo-SEM image of emulsion droplets at pH 5.5. (c) CLSM image of NaCas-stabilized emulsions using dodecane as the oil phase at pH 8.0 and 5.0. (d) The change in interfacial tension with time using dodecane as the oil phase at different pH (d₁ and d₂). Droplet images of NaCas solutions at different pH values. A large number of flocs were present in the droplets at pH 4.8 (d₃).