Adsorption properties of N-tetradecyl-N,N-dimethyl-N-(2,3-epoxy propyl) ammonium chloride with inorganic salts at air/water

A series of N-alkyl-N,N-dimethyl-N-(2,3-epoxy propyl) ammonium chloride (C_nEAC, n = 10, 12, 14, 16) with alkyl of decyl, dodecyl, tetradecyl, and hexadecyl were synthesized. The adsorption properties of C_nEAC under the different temperatures, concentrations, interfacial oscillation frequencies as well as the inorganic salts (NaCl and Na₂CO₃) at air/water interface were investigated by interfacial dilatational rheology. The dilatational properties of C_nEAC solutions including complex moduli, elastic moduli and viscosity moduli increased with oscillation frequency. The elastic moduli were higher than those of viscosity ones. With different hydrogen carbon length, the complex moduli of C_nEAC showed different changing role with their concentration and temperature. Inorganic salts compressed the oppositely charges on C_nEAC micelle surface and induced the decrease of both complex and viscosity moduli.