%0 Journal Article
%T Self-Assembly of the Bio-Surfactant Aescin in Solution: A Small-Angle X-ray Scattering and Fluorescence Study
%A Carina Dargel
%A Isabell Kemker
%A Norbert Sewald
%A Ramsia Geisler
%A Thomas Hellweg
%A Yvonne Hannappel
%J -
%D 2019
%R https://doi.org/10.3390/colloids3020047
%X Abstract This work investigates the temperature-dependent micelle formation as well as the micellar structure of the saponin aescin. The critical micelle concentration ( c m c ) of aescin is determined from the concentration-dependent autofluorescence (AF) of aescin. Values between c m c aescin , AF (10 ¡ã C) = 0.38 ¡À 0.09 mM and c m c aescin , AF (50 ¡ã C) = 0.32 ¡À 0.13 mM were obtained. The significance of this method is verified by tensiometry measurements. The value determined from this method is within the experimental error identical with values obtained from autofluorescence ( c m c aescin , T ( WP ) (23 ¡ã C) = 0.33 ¡À 0.02 mM). The structure of the aescin micelles was investigated by small-angle X-ray scattering (SAXS) at 10 and 40 ¡ã C. At low temperature, the aescin micelles are rod-like, whereas at high temperature the structure is ellipsoidal. The radii of gyration were determined to ¡Ö31 £¿ (rods) and ¡Ö21 £¿ (ellipsoid). The rod-like shape of the aescin micelles at low temperature was confirmed by transmission electron microscopy (TEM). All investigations were performed at a constant pH of 7.4, because the acidic aescin has the ability to lower the pH value in aqueous solution. View Full-Tex
%K saponin
%K aescin
%K critical micelle concentration (cmc)
%K autofluorescence
%K small-angle X-ray scattering (SAXS)
%K transmission electron microscopy (TEM)
%K micelle structure
%U https://www.mdpi.com/2504-5377/3/2/47