Surface elasticities of aqueous β-dodecyl-d-maltoside solutions: A capillary wave study

The surface rheology of the nonionic surfactant n-dodecyl-β-d-maltoside (β-C12G2) has been studied only recently over a broad concentration range. However, the frequency range was limited to ν < 100 Hz. On the basis of these data and of the Lucassen and van den Tempel theory (LvT theory), we calculated the complex dilational modulus ε¯ as a function of frequency as well as its high-frequency limit ɛ0. The validity of this approach was proven by a comparison of the data calculated for intermediate frequencies with those obtained in the study at hand by capillary wave measurements at frequencies between 100 and 400 Hz. The combination of the present results with those of the previous study provides us with a large number of surface rheological data for aqueous solutions of β-C12G2 covering a concentration range from 10−5 to 1.4 × 10−4 M and a frequency range from 0.005 to 400 Hz.