The Rheological Properties Of Wormlike Micelle Solution Formed By Imidazoles Ionic Liquid/SDS And Their Alkane Responsiveness

Wormlike micelle has high viscoelasticity,which has a certain prospect application in the process of oil recovery and fracturing.In under the influence of external conditions,worm-like micelles will be constantly breaking and restructuring of dynamic balance,leading to the macroscopic viscoelastic change,thus exploring the responsiveness of different length of carbon chain alkanes has practical guiding significance for practical applications.Due to its designable structure of ionic liquid,it can been adjusted the chain length of hydrophobic chain to build orderly aggregates of different types of molecules,and thus achieve the purpose of regulating macro viscoelastic.Therefore,this paper chooses a series of imidazoles ionic liquids with different alkyl side chain:1-butyl chloride?hexyl,octyl,dodecyl?-3-methyl imidazole and the commonly used anionic surfactant sodium dodecyl sulfate?SDS?to prepare worm-like micelles solution,then studied the rheological properties of those worm-like micelles.The microstructure and formation mechanism of the micellar micelles were studied by means of low temperature transmission electron microscopy?cryo-TEM?,isothermal titration calorimetry?ITC?,DLS and NMR.The experimental results show that the the main driver of forming worm-like micelles are electrostatic interaction and hydrophobic effect.By changing the alkyl side chain length of imidazoles ionic liquids,it can significantly influence the ability of imidazoles ionic liquid system with SDS to form wormlike solution.The alkyl side chains of 1-butyl-3-methyl imidazole were short,and their interaction with SDS was weak,and they could not form wormlike micelles.Compared to other ionic liquid,the 1-octyl-3-methyl imidazole cholide has moderatly electrostatic interactions,hydrophobic effect with SDS,so it can form worm-like micelles solution with largest viscoelastic property.Increasing 1-octyl-3-methyl imidazole chloride concentrations,the zero shear viscosity??₀?decreases firstly increased,then decreased,this is due to the transition from linear worm-like micelles to branching wormlike micelle.ITC and H-NMR resluts show that the ionic liquid/SDS system is driving the worm-like micelle formation is the electrostatic interactions between the two kinds of surfactants and the hydrophobic ionic liquids.In order to study the response of wormlike micelle solution to alkanes,a typical worm-like micelles system?1-octyl-3-methyl imidazole chloride/SDS system?is selected,different length of carbon chain of alkanes?n-hexane,octane,positive decane?is introduced into the system.The results showed that different types of micelles with different microstructures were found to produce different responses.In the case of branched wormlike micellar system,the introduction of alkanes can reverse the transation from linear worm-like micelle to branched wormlike micelle,and the viscosity and viscoelasticity are significantly increased.In the linear worm-like micelle system,alkanes were introduced,and as the content of alkane increased,the viscosity gradually decreased until the micellar micelle was destroyed.