It has been recently shown that solutions of surfactants in organic solvents in the presence of a small amount of water can be transformed into gels displaying a very high viscosity (of the order of 10 000 P). Both gelatine and lecithin 'microemulsion gels' have been described and the former have been partly characterized by physical chemical methods. Their structure is still under investigation. In the case of lecithin gels, scattering and rheological techniques are certainly the most efficient for characterizing the macromolecular characteristic of the gel structure. However, they are intrinsically incapable of describing the molecular details. For these reasons, a detailed NMR study of the lecithin gels has been undertaken, which includes both pulse low resolution proton NMR (measurements of T1 and T2) as well as high resolution NMR measurements, 31P (line width, relaxation times and NOE), 1H, and 13C. In this paper present line width data performed on 1H, 31P, and 13C NMR resonances for a family of lecithin gels from isooctane, the line width is the most immediate criterium for molecular mobility.
Microemulsion Organogels from Lecithin: A NMR Study of Molecular Mobility based on line widths
D Capitani;
1991
Abstract
It has been recently shown that solutions of surfactants in organic solvents in the presence of a small amount of water can be transformed into gels displaying a very high viscosity (of the order of 10 000 P). Both gelatine and lecithin 'microemulsion gels' have been described and the former have been partly characterized by physical chemical methods. Their structure is still under investigation. In the case of lecithin gels, scattering and rheological techniques are certainly the most efficient for characterizing the macromolecular characteristic of the gel structure. However, they are intrinsically incapable of describing the molecular details. For these reasons, a detailed NMR study of the lecithin gels has been undertaken, which includes both pulse low resolution proton NMR (measurements of T1 and T2) as well as high resolution NMR measurements, 31P (line width, relaxation times and NOE), 1H, and 13C. In this paper present line width data performed on 1H, 31P, and 13C NMR resonances for a family of lecithin gels from isooctane, the line width is the most immediate criterium for molecular mobility.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
