Investigation of relationship between foam performance and surface dilatational rheology of sodium dodecyl sulfate/alcohol system

Key words:  small periodic oscillation method  foam performance  surface tension  dilational modulus  elastic modulus  surface viscosity

Abstract:

The relationship between foam performance(foamability and stability) of sodium dodecyl sulfate (SDS) and sodium dodecyl sulfate/long chain alcohol systems and surface parameters (surface tension and surface dilatational rheology) was investigated using small periodic oscillation method at room temperature by DSA100interfacial dilatational rheometer. The results show that foaming volume and drainage half-life of the systems firstly increase and then decrease with addition of laurylalcohol, myristyl alcohol, cetyl alcohol and stearyl alcohol. Surface tension of the systems firstly decreases and then increases, while dilational modulus, elastic modulus and surface viscosity of the systems firstly increase and then decrease. In addition, the foamability of the systems is determined by surface tension and surface viscoelasticity. Drainage half-life increases with the increase of the dilational modulus, elastic modulus and viscous modulus of the systems while it has a particularly obvious linear relationship with the elastic modulus.