Surfactants are molecules that contain groups that are water-loving (hydrophilic) and oil-loving (lipophilic). The central question in formulations is often which of the two portions dominate the behavior of the surfactant. For many years that question was answered in terms of the surfactant structure only. However, the modern view is that the hydrophilic-lipophilic nature of the surfactant is the result of surfactant structure and formulation conditions (nature of the oil, temperature, aqueous phase composition) as captured by a semi-empirical equation called the hydrophilic-lipophilic difference (HLD). The HLD is a dimensionless number that indicate the approach to the point where the surfactant inverts its solubility from being water-soluble (negative HLD) to oil-soluble (positive HLD). The HLD alone is a good indicator of how the formulation could behave but it does not produce any formulation property that can be used to predict product performance. The net-average curvature (NAC) are a set of equations that take the value of HLD to predict the properties of the formulation, such as oil (and/or water) solubilization capacity, interfacial tension, phase diagrams, contact angle and others. Surfactant Formulation Engineering using HLD and NAC will not only introduce the reader to HLD-NAC but also to the practical use of these concepts in numerous applications ranging from application in the petroleum industry, to environmental remediation, to food, cosmetic and pharmaceutical applications, and even nanotechnology. The last part of the book will look at the molecular origins of the empirical terms in HLD via the Integrated Free Energy Model (IFEM).
Table of Contents
Section I: Hydrophilic-lipophilic difference (HLD) fundamentals1. The HLD-NAC in a nutshell: an introduction to the principles and uses of HLD-NAC
2. History and evolution of the HLD
3. Surfactant mixtures and the measurement of characteristic curvature (Cc)
4. Oil mixtures and the measurement of equivalent alkane carbon number (EACN)
5. Effect of electrolytes, polymers, co-solvents and additives
Section II: Hydrophilic-lipophilic difference (HLD) applications
6. Use of HLD in Surfactant-Enhanced Oil Recovery and Aquifer Remediation
7. Use of HLD for corrosion inhibitors and flow assurance chemicals
8. Use of HLD in Detergent formulations
9. Use of HLD in Fragrance formulation
10. High-throughput HLD phase scans for surfactant characterization and formulation
11. HLD-guided surfactant design for enhanced oil recovery applications
12. High-throughput HLD-guided formulation design for latex and agrochemical formulations
13. HLD-guided surfactant structure-performance relationship in cold detergency applications
14. HLD-guided design of self-emulsifying drug delivery applications
15. HLD-guided design of vegetable oil extraction technology
Section III: Net-Average Curvature (NAC) fundamentals
16. History and evolution of NAC
17. Prediction of phase diagrams for surfactant-oil-water (SOW) and surfactant-water (SW) systems
18. Prediction of interfacial tension, rigidity, emulsion formation and stability
19. Prediction of oil-water-solid wettability
Section IV: Applications of the net-average curvature
20. HLD-NAC in practical applications
21. HLD-NAC in reservoir simulation
22. HLD-NAC alternatives in reservoir simulation
23. HLD-NAC design of hard surface cleaning systems
24. HLD-NAC design of microemulsion-templated nanoparticles
25. HLD-NAC design of microemulsion-templated nanostructured polymers
26. HLD-NAC guided design of extended surfactants for enhanced oil recovery operations
Section V: The Integrated Free Energy Model (IFEM)
27. Derivation and predictive capabilities of the Integrated Free Energy model
28. Applications of IFEM in detergent formulation development
