On the random Interface models of microemulsions as the foundation of hydrophilic-lipophilic difference - net average curvature (HLD-NAC) equation of state

in the NAC model. Furthermore, we show that the empirical HLD parameter corresponds to 〈H〉 normalized by the surfactant length, thereby enabling a direct prediction of the microemulsion composition at the emulsification failure from HLD. The resulting predictions show excellent agreement with experimental data. The possibility to evaluate the preferred mean and Gaussian curvature and compare it with the HLD equation of state opens the way to further in-depth analysis about the link between the film curvature and the parameters entering the HLD-NAC (viz. chemical structure of oil and surfactant, temperature and the ionic strength).