Cohesive Energy Ratio CER Concept for Emulsifier Selection

Cohesive Energy Ratio (CER) Concept for Emulsifier Selection 

Beerbower and Hills [26] considered the dispersing tendency on oil and water interfaces of the surfactant or emulsifier in terms of the ratio of the cohesive energies of the mixtures of oil with the lipophilic portion of the surfactant and the water with the hydrophilic portion. They used the Winsor Rq concept, which is the ratio of the intermolecular attraction of oil molecules (O) and the lipophilic portion of surfactant (L), Clo, to that of water (W) and the hydrophilic portion (H), Chw, 

Several interaction parameters may be identified at the oil and water sides of the interface. One can identify at least nine interaction parameters, 

In the absence of emulsifier, there will be only three interaction parameters Coo, Cww, Cow- If Cow Cww, the emulsion breaks. 

The above interaction parameters may be related to the Hildebrand Solubility parameter 5 [27] (at the oil side of the interface) and the Hansen [28] non-polar, hydrogen bonding and polar contributions to S at the water side of the interface. The solubility parameter of any component is related to its heat of vaporization AH by Eq. (6.33), where Vm is the molar volume. 

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