The title spectra were measured at various concentrations of SDS. IER spectra demonstrated that conformational order of alkyl chains of SDS and MA and surface composition at the air/water interface was clarified. Conformational order was found to improve on increasing SDS concentration up to [SDS]=3 mM. MA showed essentially no change. The ratio of MA to SDS composition at the interface is exceeded that in bulk solution and decreased at greater SDS.
