A Surface Rheological Study of Polyoxyethylene Alkyl Ether Carboxylic Salts and the Stability of Corresponding Foam

Abstract

The dynamic dilational viscoelastic properties of polyoxyethylene alkyl ether carboxylic salts at the air-water interface were investigated by drop shape analysis method and their foam stability were measured by Bikerman Method. The influences of time, dilational frequency, and bulk concentration on surface dilational modulus and phase angle were expounded. The results show that the surfactant with the longest straight-chain shows the highest dilational modulus, which in agreement with the best foam stability. However, the foam stability of branched-alkyl chain surfactant cannot be explained in terms of film elasticity alone.

Keywords:

• Foam stability
• phase angle
• polyoxyethylene alkyl ether carboxylic salts
• surface dilational modulus