Abstract: Colloidal liquid aphrons(CLA) composed of polyoxyethylene 3 dodecyl ether(AEO-3)/n-decane/ sodium dodecyl sulphate(SDS)/water were subjected to a full rheological characterization. Steady-state flow and dynamic viscoelasticity were measured via a Haake RV-30 viscosimeter and a controlled stress rheometer Haake RS 300 with cone-plate geometry, respectively. The effects of the volume ratio of dispersed oil phase to the continuous phase(PVR), temperature and shear rate on the rheological behavior of CLA were also discussed. The results of the steady-state analysis indicate that both CLA and emulsions studied here were typical non-Newtonian liquids and exhibited strong shear thinning behavior. The flow curves of CLA were well described by the Hershel-Bulkley equation. Thixotropy was not observed in any of CLA and emulsions. The findings from the oscillatory viscoelastic analysis suggest that no linear viscoelasticity region existed in the entire range of stresses for low PVR(2—4), and at the PVR of 8, the systems display a viscoelastic behavior. The effect of temperature on the flow behavior and viscoelasticity of CLA and emulsions was not evident. The rheological properties of CLA are analogous to that of high internal phase ratio emulsions(HIPRE) through a comparison of the findings throughout this work and conclusions of HIPRE reported previously. This similarity further suggests that CLA and HIPRE display a similar microstructure.

Key words: Colloidal liquid aphrons(CLA), Flow model, Viscosity, Thixotropy, Viscoelasticity