Counterion-induced changes to the micellization of surfactin-C16 aqueous solution.
The effects of counterions on surfactin-C(16) micelle solution with its critical micelle concentration (cmc), microenvironment properties in micelles, micelle size distribution, and morphology were investigated by fluorescence, dynamic light-scattering, and freeze-fracture transmission electron microscopy measurements. Counterions enhanced the surface activity of surfactin-C(16) and reduced the cmc. With the micellization of surfactin-C(16), it adopted a beta-sheet conformation, and univalent concentrations reduced micelle micropolarity, increased micelle microviscosity, and tended to cause formation of small and spherical micelles, while divalent counterions had a special effect. With low concentration of divalent cations, they had strong interaction with surfactin-C(16) micelles and tended to form larger micelle aggregates.
Laboratory for Advanced Materials and Institute of Applied Chemistry, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, PR China.
Yi
Y
Li
Ai-Hua
AH
Zou
Ru-Qiang
RQ
Ye
Bo-Zhong
BZ
Mu
D000595:Amino Acid Sequence; D007477:Ions / Q000737:chemistry*; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D010456:Peptides, Cyclic / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D014867:Water / Q000737:chemistry*
D007477:Ions; D008823:Micelles; D010456:Peptides, Cyclic; C546617:surfactin C16; D014867:Water