Stable water-oil emulsions from the new insoluble surfactant sodium 5-(1-dodecylaminocarbonyl) picolinate.

The new compound sodium 5-(1-dodecylaminocarbonyl) picolinate (NaDPA) has been prepared and found to have the unusual surfactant property of forming stable water-oil (w/o) emulsions in the presence of water and a variety of organic liquids. A study of droplet size (diameters=0.1-1.0 mm) as a function of the amount of surfactant used shows that a near constant coverage of surfactant molecules exists at the water-oil interface and that the interface is made up of multiple layers. The structure of NaDPA, with its multiple hydrogen-bonding possibilities, probably contributes to the observed stability of the emulsions. The emulsions are made up of droplets that are stable for months and can be filled with dyes, buffers, and solutions of high ionic strength.