The Determination of the Effective HLB of Nonionic Surfactants by a Phenol Titration I: Relation to Cloud Point

The qualitative similarities in two various methods of the HLB (Hydrophile-Lipophile Balance) determination based on the cloud point and so called phenol index measurements are demonstrated. The effects of polyoxyethylene chain length, surfactant concentration and the presence of additives on the cloud point and phenol index values have been compared. The results are interpreted as the change of the effective HLB of polyoxyethylene nonionic surfactants.