Surface Activity Properties at Equilibrium of Novel Gemini Cationic Amphiphilic Compounds from Arginine, Bis(Args)

A systematic study of the surface active properties at equilibrium (in water and in the presence of 10 - 2 M NaCl) of a novel class of gemini cationic surfactants from arginine is described. They are N α, N ω -bis( N α -acylarginine) α,ω-alkylidenediamides or bis(Args). Parameters studied include cmc (critical micelle concentration), p C 20 (negative log of the surfactant molar concentration, C 20, required to reduce the surface tension of the solvent by 20 mN/m), γ cmc (the surface tension at the cmc), Γ max (the maximum surface excess concentration at the air/aqueous solution interface), A min (the minimum area per surfactant molecule at the air/aqueous solution interface), and the cmc/ C 20 ratio (which measures the tendency of the surfactant to adsorb at the interface relative to its micellization tendency). Data on the synthesis and chemical and spectral characteristics of surfactants are also reported.