Self‐assembly of surfactin‐like polymer in solution by the dissipative particle dynamics method.

Surfactin is a kind of special and efficient cyclic lipopeptide biosurfactant, which is composed of a seven‐peptide ring and a fatty acid tail chain and is widely used in the fields of medicine, environmental remediation and heavy oil transportation. This special ring structure also makes surfactin have great application potential in biomedicine and surface catalysis. In this work, the self‐assembly behavior of surfactin‐like polymer in selective solvents was studied by dissipative particle dynamics. By changing the interaction parameters, the size of the hydrophilic ring, the length of the hydrophobic tail chain and the concentration, a series of structures such as vesicles, disk‐like micelles, worm‐like micelles, sphere‐like micelles and ring‐like micelles were obtained from the establishment of the phase diagram. We explored the dynamic formation paths of vesicles and ring‐like micelles and discovered morphological changes during their aggregation. The mechanism of sphere‐like micelle formation at lower concentration was also studied, explained by the packing of molecules of effective conical shape. The structural properties of the vesicles were also intensively studied. Based on the special ring structure of surfactin‐like polymers, we explored the difference in their self‐assembly behavior from those of linear block copolymers and giant surfactant‐like polymers. A detailed study on the self‐assembly of surfactin‐like polymer can deepen the understanding of ordered aggregates of cyclic surfactants in selective solvents and can drive important implications for their practical application. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]