What are the two steps in emulsification?

• A. Lowering interfacial tension (initial formation of emulsion) and formation of protective wedge film (stability of emulsion)
• B. Mixing oil and water without emulsifier
• C. Increasing viscosity only
• D. Evaporation of solvent

Answer: (A)

Emulsification relies on two coordinated actions. First, lowering the interfacial tension between oil and water reduces the energy barrier so droplets can form during mixing. This step makes it possible to break the phases into small droplets. Second, forming a protective interfacial film around those droplets stabilizes them, preventing coalescence. This film, built by emulsifiers and related polymers, creates a barrier that keeps droplets separate and maintains emulsion stability.

Without lowering interfacial tension, droplets won’t form easily; without the protective film, those droplets would merge back together and the emulsion would collapse. Simply mixing without an emulsifier, increasing viscosity alone, or evaporating solvent doesn’t achieve both formation and stabilization of droplets.