SURFACE-ACTIVITY OF SEMIFLUORINATED ALKANES - F(CF2)M(CH2)NH

The surface tensions of dilute dodecane solutions of several semifluorinated alkanes have been measured at room temperature. Decrements of up to 4 mN/m have been observed. While other workers have obtained evidence of micelle formation by these compounds in other solvents, constancy of surface tension with increasing concentration, denoting micellization, has not been observed in the present work. This may result from the onset of gel formation, which occurs at very low concentrations in these systems. It has also been found that some of these compounds form fairly stable monolayers when spread at the air-water interface, and Langmuir-Blodgett multilayer deposition has been demonstrated.