Molecular Dynamics Simulation Of Sodium Odd-alkylbenzene Sulfonates

The article mainly makes an introduction about using Molecular dynamics simulation to research the accumulation of surfactant in different viscosity, and so on, this place should be expand:1) The micelle shapes of thirteen alkyl toluene sulfonate sodium in different density oil/water system were simulated by molecular dynamics. The results found that above the critical micelle concentration, with the concentration increasing ,various aggregation were formed spontaneity in turn, these aggregation were sphericity micelle, claviform micelle, samdwich micelle and reversed micelle structure. Through corresponding the diffused coefficient numerical value and the intuitived simulated results, we found that the self-assembled situation surfactant solution was indicated by diffused coefficient.2) Molecular dynamics simulated method was used to research the dynamics characteristic of anion surfactants in this paper, which were putted in water/octane, water/toluene and water/ the commix oil phase of octane and toluene. Simulated results lay out the formation of oil and water interface when the system was balanced. Making density section charts was order to illuminate the abducted action of surfactant, and the action came into being in different oil phase. At the same time, simulation computed interfacial tension,root mean square,contact area and so on, they were formed in oil and water interface by salt alkylbenzene sulphonate.3) The interaction of nine alkyl aryl sulfonates in the vacuum and solution was simulated used by a molecular dynamics method. The solvation free energy which have nine structure was calculated from free energy perturbation (FEP), and the result indicate: as the aromatic ring shift from the edge to the middle of the long alkyl chain, the formation ability of micelle and the micelle stability is decreased. With the aromation ring carbon number increasing of the long alkyl chain and with the number of aromation ring of the short alkyl chain the micelle stability is increasing, it so as to the aromation ring carbon number increasing of the short alkyl chain. Through disassembling free energy and analyzing radial function of the twain atom, the result of hydrophobe offect synthesis effect was micelle drived force.The reciprocity of series polarity of surfactant and the hydrogen bond of water was analysed, which based on the graph definition of the hydrogen bond. We found that the number of hydrogen bond could strenghen or weaken the current of molecule deviating micelle, and then effected the stability of micelle. At the same time, the existent cycle of hydrogen bond in water molecule could be calculated.