Study On The Rheological Properties And Drag Reduction Of Cetyltrimethyl Ammonium Chloride Micelle Systems

In this paper, the micellization of cetyltrimethyl ammonium chloride (CTAC) and counterions, such as sodium salicylate(NaSal), trans-sodium cinnamate (trans-CANa, abbr.CA) and trans-Ortho-Chloro-sodium cinnamate (trans-Ortho-ClCANa, abbr.OCICA) was studied. The rheological properties and drag reducing behaviors of CTAC micelles were investigated. The main conclusions were made as follows.1) The viscoelastic micelle systems could be formed by CTAC and NaSal in certain conditions. Relative viscosity of CTAC/NaSal solutions appeared a peak value and the structure of viscoelastic micelle system was strongest when the molar ratio of CTAC to NaSal was about 0.6.The effect of temperature on the viscosity curves was significant. When the temperature reached 50℃, the viscoelasticity of micelle disappeared. Relative viscosity of CTAC/NaSal solutions would be greatly decreased by adding glycerol into CTAC/NaSal micelle solutions.2) The novel viscoelasitic micelle systems could be prepared by mixing CTAC with new counterions CA and OCICA respectively. These micelle systems possessed good properties of shear-thinning, viscoelasticity and thixotropy. The effects of CA and OCICA on the rheology of CTAC micelle solutions were discussed. The micelle structure made of CTAC and OCICA was stronger under the same condition compared with CTAC/CA micelle system. The non-linear co-rotational Jeffreys model was applied to describe the viscosity curves of the above micelle systems.The results showed that the calculated values were in good agreement with the experimental data.3) Both CTAC/CA and CTAC/OClCA viscoelastic micelle systems possessed good drag reducing behaviors and were proved to be novel drag reduction micelle systems. The results indicated that drag reduction rate for CTAC/CA micelle appeared a maximum value with the increase of Reynolds number. The critical Reynolds number (Recr) increases with the increase of CTAC concentration. When the molar ratio of CTAC to CA was 5mM/15mM, the maximum drag reduction rates were 72%in smooth pipe and 63%in rough pipe respectively. For the CTAC/OClCA micelle systems, when the molar ratios of CTAC to OCICA were 5mM/10mM and 5mM/15mM, the drag reduction rate could acheieve 85%in smooth pipe and 77%in rough pipe respectively. The Effect of counterions on the drag reduction was further illustrated.The studies in this paper can provide good basis for the future study of surfactant drag reduction.