Methodologies for phase studies of amphiphilic compounds: recent developments

Isoplethal phase study methods, during which temperature is varied at constant composition, have seen little change during the last few years. However, isothermal methods (in which composition is varied at constant temperature) have undergone significant development. The deuterium-NMR variant of the classic isothermal analytic method has grown in importance. Also, more and better use has been made of qualitative isothermal swelling methods (‘penetration experiments’) to supplement other data. The quantitative Diffusive Interfacial Transport (DIT) method, first reported in 1987, has been much improved by replacing interferometry, as the basis for analysis, with the determination of water by NIR microspectroscopy. The resulting DIT-NIR method appears to be very general, and should see broad application in the future.