Abstract
The dilational viscoelaticity properties of octyl-[ω-alkyloxy-tetraoxyethylene]yl-benzene sulfonates at the air/water interface were investigated by means of oscillating barriers method and their foam properties were measured by means of flowing method. The influences of dilational frequency and bulk concentration on surface dilational modulus and phase angle were expounded. The results show that the molecular interaction controls the nature of adsorption film during lower concentration range and the film behaves elastic in nature. During higher concentration range, the diffusion-exchange process controls the dynamic dilational properties and the surface film shows remarkable viscoelasticity. The foamability decreases with the alkyl chain increasing, while the trend of the foam stability is on the contrary.
Acknowledgments
This work was financially supported by the National Science & Technology Major Project (2008ZX05011) of China.