Interaction of the biosurfactant, surfactin with betaines in aqueous solution

Fang Liu, Jingwen Xiao, Vasil M. Garamus, László Almásy, Regine Willumeit, Bozhong Mu, Aihua Zou

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14 Citations (Scopus)


The interactions between the lipopeptide Surfactin and four betaines, N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SDDAB), N-tetradecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (STDAB), N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (SHDAB), and N-dodecyl-N,N-dimethyl-2-ammonio-acetate (C12BE) are studied by surface tension and small-angle neutron scattering (SANS). SDDAB, STDAB, and SHDAB have the same headgroup but different hydrophobic chains. C12BE has different headgroup but the same hydrophobic chain with SDDAB. According to the interfacial parameters calculated from surface tension, the synergism between Surfactin and betaine is relevant with the molecule structure of betaine and the mole ratio of them. For betaines, the optimum alkyl chain length (STDAB) and long enough separation between positive charge and negative charge in headgroup are responsible for highest synergetic interaction with Surfactin. The aggregates of individual Surfactin and the mixtures of Surfactin and sulfopropyl betaines are predicted to be spherical based on the packing parameter (pp) and the average packing parameter (Pav), which is in close qualitative agreement with SANS data analysis, while Surfactin/C 12BE forms ellipsoidal micelles due to the smaller headgroup of C12BE.

Original languageEnglish
Pages (from-to)10648-10657
Number of pages10
Issue number34
Publication statusPublished - Aug 27 2013

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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  • Cite this

    Liu, F., Xiao, J., Garamus, V. M., Almásy, L., Willumeit, R., Mu, B., & Zou, A. (2013). Interaction of the biosurfactant, surfactin with betaines in aqueous solution. Langmuir, 29(34), 10648-10657.