[article]
| Titre : |
HLB - Sense or nonsense ? |
| Type de document : |
texte imprimé |
| Auteurs : |
Joachim Venzmer, Auteur |
| Année de publication : |
2020 |
| Article en page(s) : |
p. 22-26 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Emulsifiants
Emulsions
Equilibre hydrophile-lipophile
Ethoxylate d'alcool
|
| Index. décimale : |
541.34 Solutions |
| Résumé : |
The Hydrophilic/Lipophilic Balance (HLB) concept as introduced by Griffin in 1949 means assigning a single number between 0 and 20 to fatty alcohol ethoxylates in order to describe their hydrophilicity/lipophilicity and assuming that this number is useful to predict the applicability as emulsifier. This approach has severe limitations as it ignores crucial parameters such as temperature, presence of the oil phase, pH, salt, or processing during emulsion manufacturing. However, despite these deficiencies, HLB values are still given today by the surfactant manufacturers in their brochures and product documentations. The only meaningful purpose of the HLB value is that it provides (especially in case it has been determined experimentally) a rough guesstimate of the water solubility or dispersability of an emulsifier. All other properties, often a consequence of the molecular architecture especially of polymeric emulsifiers, cannot be predicted by a single HLB value. This paper critically discusses the limitations of the HLB concept in order to avoid misconceptions, especially when dealing with non-fatty-alcohol-ethoxylate amphiphiles. |
| Note de contenu : |
- History - Griffin and Davies
- Alternative methods to generate HLB values
- Benefits of the HLB concept - Examples of success
- Limitations of the HLB concept - Examples of failure
- Table 1 : HLB values, water solubility and potential uses of surfactants
- Table 2 : Comparison of emulsifier efficiency ÿ in an oil/water system with emulsifiers of same calculated HLB, but different molecular architecture (C18PO6EO6 vs. C18EO6PO6). ÿ is defined as the minimal mass fraction of surfactant ÿ = msurfactant / (moil + mwater + msurfactant) which is necessary to form a one-phase microemulsion
- Fig. 1 : Contact angle of a 0.1% aqueous solutions of castor oil ethoxylate and a fatty alcohol ethoxylate having the same HLB value of 10 (according to Griffin) on Parafilm (DataPhysics OCA50, 25°C, 50% rel. humidity, droplet volume 3.7 µL; average of at least 8 droplets)
- Fig. 2 : Cloud points of two alcohol ethoxylates of identical calculated HLB |
| En ligne : |
https://drive.google.com/file/d/1yb8AN69xrkiTCvcyTRmHfoNnCPel72Kt/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34596 |
in SOFW JOURNAL > Vol. 146, N° 10 (10/2020) . - p. 22-26
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HLB - Sense or nonsense ? in SOFW JOURNAL, Vol. 146, N° 10 (10/2020)
