Co-surfactant properties of ketones

Abstract A series of ternary systems water/sodium dodecylsulfate (SDS)/ketone for different ketones ranging from propanone to 2-octanone are studied in some detail as well as the quaternary system water/SDS/2-pentanone/n-dodecane. Phase diagrams, electric conductivities and one small angle neutron scattering spectrum of these systems are given and compared to corresponding results of systems containing aldehydes instead of ketones. From this comparison it follows a remarkable analogy between the systems containing a linear aliphatic aldehyde with n-carbon atoms and those containing 2-ketones withn+1 carbon atoms. It is concluded that the recently suggested co-surfactant behaviour of aldehydes can also be discussed for ketones. As far as the electrical conductivity is concerned this analogy is also shown for water/AOT/aldehyde and water/AOT/ketone systems.