Study On The Preparation And Viscoelasticity Of Wormlike Micelles

Under suitable conditions,it is possible to form worm-like micelles with excellent viscoelasticity,which has been widely used in oilfield fracturing fluid.At present,most reports on worm-like micelles focus on explore the influence of external factors such as temperature,pH and CO₂ on the viscoelastic properties of the micelles,but lack of systematic study on the formulation used to prepare worm-like micelles.In this paper,we choose alkyl trimethyl ammonium bromide with different carbon chain lengths as the main agents,mixing with NaSal or NaOA to prepare worm-like micelles.The steady rheology and dynamic viscoelasticity of the micelles were tested by rheometer,and the morphology of the micelles was observed by FF-TEM.Through these means,we studied the formulation of worm-like micelles,such as the types of additives and the length of the main agent carbon chain on the viscoelasticity of the micelles was investigated.Through experimental analysis,it can be concluded as follows:?1?STAB,CTAB and TTAB cationic surfactants could form worm-like micelles with different viscoelastic properties at different molar ratios with NaSal or Na OA.?2?In the six worm-like micelles systems,when the main agent is STAB and NaOA is selected as the additive,the longest worm-like micelles and the longest network structure can be formed.As the mass concentration of STAB was 5.8%and the molar ratio was 2.6:1,the maximum value of solution?₀ was 20047 mPa·s,G₀ of 14089,and?_R of 1.61.?3?While STAB,CTAB and TTAB were used G₀ as the main agent to prepare worm-like micelles,NaOA as additive would get greater?₀?G₀ and?_R,the worm-like micelles formed in the solution were longer and the degree is more widespread than NaSal as adjuvant.It shows that when preparing worm-like micelles with quaternary ammonium surfactants,adding NaOA counterions can form better viscoelastic worm-like micelles than adding NaSal.?4?When worm-like micelles were prepared with STAB,CTAB,and TTAB solutions in the same counterion,?₀?G₀ and?_R of the worm-like miceller solution formed by STAB could reach the maximum values,followed by CTAB and the minimal is TTAB.When worm-like micelles were prepared by quaternary ammonium salt surfactants,with longer alkyl chains,better viscoelastic worm-like micelle was achieved.