Together with Prof. Edgar Acosta and Prof. Steven Abbott, VLCI promotes HLD for a wide range of applications.
Surfactants are widely used in the Formulation Industry, and selecting the right surfactant for a specific system can be very time-consuming. The HLD-NAC (Hydrophilic Lipophilic Difference – Net Average Curvature) theory has been developed by world-known experts to make surfactant selection easier for formulators. Contrary to HLB (Hydrophilic Lipophilic Balance) theory, the HLD-NAC approach is widely applicable to both anionic and non-ionic surfactants. It allows profound predictions to be made about the type of emulsion (o/w, w/o, micro-emulsion) and the suitability and efficiency of a surfactant for defined formulations. Phenomena such as phase inversion temperature can also be understood via HLD-NAC.
The predictions are based on the HLD equation:
HLD = f(S) – k.EACN – α.ΔT + Cc + f(A)
At its heart are two numbers: the Cc (Characteristic curvature) of the surfactant and the EACN (Equivalent Alkane Carbon Number) of the oil. Surfactant behaviour is also dependent on the salinity (S), the temperature (T), the co-solvent/co-surfactant influence (A) and constants related to the surfactant (k and α).
VLCI offers a practical method to determine HLD parameters via standard scan techniques, which systematically vary oil, surfactant and salt concentrations. High Throughput workflows are ideally suited to conduct these scans efficiently and reliably. Visual assessments are compiled in order to build ternary diagrams and/or fish diagrams, for combinations of oils and surfactants.
VLCI offers HLD expertise combined with High Throughput capabilities to deliver fast, practical and accurate results.