Dissipative particle dynamics simulation on the association between polymer and surfactant: Effects of surfactant and polymer feature

The effect of hydrophobic and hydrophilic feature of surfactant (SAA) and polymer on their association is investigated by Dissipative Particle Dynamics (DPD) simulation method. The system comprises of five surfactants and two sections of interaction parameters. Our simulation results show that the polymer chain becomes more stretched and lower compactness with the hydrophilic chain length of surfactant increase and the hydrophobic chain decrease. For the same surfactant, when polymer attracts with surfactant tail, the polymer chain is more curved comparing with that attracting with surfactant head. The presence of polymer also results in the conformation of surfactants in formed complexes more stretched and the compactness of surfactant micelle depressed. However, if the surfactants have stronger hydrophilicity, the compactness of surfactant micelle is higher than that in the absence of polymer. Comparing two sections of interaction parameters, when the polymer interacts with surfactant tail, the conformation of surfactant chain is more stretched. Specially, the capacity of resisting shear for the two complex structures is influenced by the feature of surfactant and polymer chain. The complex is difficult to be destroyed if the polymer chain locates in the interior of micelle and a solubilized structure is formed.

Density distribution of polymer bead P, shown as a two dimensional cross section for the aggregate with different surfactants at the surfactant mole fraction 0.004. (a) attraction between polymer and surfactant tail, (b) attraction between polymer and surfactant head. With the color changing from red to blue in the scale, the density of bead P increases.Figure optionsDownload as PowerPoint slideHighlights
► DPD is used to research the association between polymer and surfactant.
► The effect of surfactant and polymer features on the association was studied.
► The capacity of resisting shear for different complex was investigated.