Anionic Surfactant Mixed System Of Interaction Between Surface Activity And Molecular Studies

The mixed surfactant system has attracted great attention in the field of surfactants, in that itis a fast, economic and effective method of improving specific performance of surfactants via thesynergistic effect, which arises from the mixed system through molecular interactions,complexation, electrostatic attraction or repulsion. In fact, the surfactant always exists in theform of a mixture of two or more surfactants such as surfactant formulations used in tertiary oilrecovery must be a mixture to achieve ultra low interfacial tension.In addition, the appropriateratio of surfactant formulations can optimize the performance of pesticide emulsifiers, shampooand detergent, Therefore, there has been very active research on the mixed surfactant system anda systematic theoretical system and experimental means have been established in last fewdecades. Although the ion complex system showed relatively large repulsion than ionic andnonionic system due to the repulsion between the same ionic charge, the anionc surfactant hasbeen widely used as emulsifier, solubilizer, wetting agent, live-efficient components synergistand so on. Moreover, due to many other advantageous factors such as a wide range of species,the mature production processes of anionc surfactant, and low prices, there are still a lot ofresearchers dedicated to the interaction between complex system of the anion-anion surfactants,which has practical significance for surfactant formulations.In this paper, we launched two aspects of the work：1、Surface active properties of theanionic surfactant mixed solution of Alpha-olefin sulfonate （AOS） / bis （2 - ethyl hexyl）（AOT）has been studied; The influence of different cations（Na⁺、NH₄⁺、K⁺）,anions（Cl^-、Br^-、I^-、NO₃^-）and the organic salt（NaSal、NaBen） on the interaction between AOS and AOT wasinvestigated by changing different ionic mediums.And the data was processed by the Rubinghtheoretical model and so on; The calcium soap dispersing power of the complex system wasMeasured by the Distributed index。The results show that the influence of different cations on thesystem is generally similar,but in the media of NH4Cl, the system showed obvious synergismwhenα_AOS= 0.84;The effect of anions for theβ^m of AOS/AOT follows the order：I^->Br^->Cl^->NO₃^-; The surface tension of mixed system shows a slight increase under theinfluence of the organic salts. In the media of NaSal, the two molecules in the mixed micellesshowed subtle mutual attraction only whenα_AOS= 0.84 and the mixed system shows a greater repulsion under the rest of the mole fractions; the datas of Dispersion index method show thatthe decentralization capacity of calcium soap（LSDP）of this mixed system is stronger than onlyone type of them and the calcium soap dispersing power has been increased with the increase ofthe mole fraction of AOS, and it achieves the lowest value whenα_AOS= 0.84.2、As practical and common anionic surfactants in the industry ,α-ene sulfonate （AOS） andbis （2 - ethyl hexyl） succinate sodium （AOT） are the Main objects of our study. the surface activeproperties of anionic / anionic complex system（AOS/AOT、AOS/SDS、AOS/NaOL、AOT/NaOL）by thesurface tension method in 0.1 mol/L sodium chloride solution were studied.The resultsshow that theof the mixed system AOS/SDS are negative at any different molar ratios of AOSand the surface active properties of AOS/SDS has been effectively improved; in the the mixedsystem of AOS/NaOL, it shows obvious mutual attraction with the lower mole fraction of AOS,and the value of the CMC, has been significantly reduced in the compound system; the attractiveinteraction between the compound system gradually reduce with the increases in thecomplexsystem of AOT/NaOL, and the CMC of the mixed system decreases at first and then increases,compared with the ideal mixing, the compound system shows positive deviation.