Review: Implementing the hydrophilic–lipophilic deviation model when formulating detergents and other surfactant‐related applications

Abstract

AbstractWhen designing surfactant formulations using ionic and nonionic surfactants, the hydrophile lipophile balance (HLB) is a generalized surfactant characterization parameter that has shown to be useful when designing surfactant formulations, in the case of both ionic and nonionic surfactants (Davies' and Griffin's methods). Microemulsion phase behavior studies have been extensively used to optimize surfactant formulations, but these studies can cover a very wide phase space and can often encounter troublesome non‐equilibrium issues such as coacervation. Detailed phase behavior studies can be time‐consuming and difficult to apply beyond the specific surfactant‐oil system studied. The hydrophilic–lipophilic deviation (HLD) provides a method to help expedite surfactant formulation research by reducing the number of phase behavior studies required to optimize a given formulation. Detergency experiments have indicated that there is an optimal range of HLD for a given fabric surface. This appears to apply to other applications, as well, for example, surfactant formulations used in enhanced oil recovery have been optimized using the HLD method. These studies found that the HLD can reflect total oil recovery, even if the surfactants were derived from different alcohol feedstocks (e.g., HLD of 0 would describe optimum conditions regardless the type of surfactant). Also with additional parameterization, the HLD method can also be applied to non‐ideal surfactant mixtures, specifically ionic/nonionic blends. Overall, the HLD framework has shown to be an effective screening tool for a wide range of surfactant‐related applications when appropriate experiments, assumptions, and understanding of surfactant and oil interactions are used to generate the HLD parameters.