the zwitterionic surfactant n-dodecyl-N,N-dimethylamino
The technique of specular neutron reflection has been used to acetate (C 12 Betaine). Solutions of both pure single surfacstudy the structure and composition of single and mixed surfactant tants and mixtures of various bulk compositions were studlayers adsorbed from aqueous solution onto self-assembled monoied. The results are compared with those of a similar experilayers of octadecyl trichlorosilane on silicon oxide. The surfactants ment at the air/solution interface and with interfacial tension used were the anionic sodium n-dodecyl sulfate and the zwittermeasurements performed on the same surfactant systems ionic n-dodecyl-N,N-dimethylamino acetate and all measureusing the drop volume method (4) and a hydrophobic oil ments were made at the critical micelle concentration of the sys-(glycerol trioleate).
tem. Molecular areas for the single surfactants were found to be similar to those measured at the air/solution interface and to those SDS and C 12 Betaine are commonly used, and in commermeasured at the glycerol trioleate/solution interface. The structure cial formulations each will be a mixture of different chain and composition of the mixed surfactant layers are also similar to lengths. Although here we use the pure single compounds those obtained at the air/solution interface. The two surfactants to form the binary mixtures, the study of such mixtures mix at the solid/liquid interface in a highly nonideal and specific has obvious industrial significance. In addition, these two manner. แญง 1997 Academic Press surfactants may be expected to form mixed micelles and