INVESTIGATIONS OF A SERIES OF NONIONIC SURFACTANTS OF SUGAR-LIPID HYBRIDS BY LIGHT-SCATTERING AND ELECTRON-MICROSCOPY

Sugar-lipid hybrids of the type CnCm were prepared by coupling an alkane chain (Cn) with a maltooligosaccharide (Gm) over an amide linkage. Coupling was performed with maltobionolactone (G2) and n-alkylamine chains Cn with n=8,10,12,14,16, i.e. variation of the hydrophobic part of the molecule, and with hexadecylamine (C16) and different maltooligosaccharides (Gm, m=2,3,4,6). The solution properties of the various products were studied by means of static and dynamic light scattering (LS) and by electron-microscopy (EM). The results may be summarized as follows: If the alkane chain is shorter than n=14, small spherical micelles with a radius of about 3 nm are observed. In time these micelles aggregate further to form increasingly larger spherical clusters which eventually precipitate. Long rod-like micelles form when n ≥ 14. Contour length and chain stiffness were determined by applying theories of semiflexible chains. A qualitative confirmation of the light scattering results, i.e., micelle size and shape, was obtained from electron microscopy. © 1990 Steinkopff.