Hydrophile-lipophile balance emulsion droplet size

When an 0/W emulsion is prepared using a nonlonlc surfactant of the ethoxylate type and is heated, then at a critical temperature (the PIT), the emulsion inverts to a W/0 emulsion. At the PIT the hydrophilic and lipophilic components of the surfactant are exactly balanced and the PIT is sometimes referred to as the HLB temperature. At the PIT the droplet size reaches a minimum emd the interfacial tension also reaches a minimum. However, the small droplets are unstable and they coalesce very rapidly. 

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