Ellipsometry and Infrared Reflection Absorption Spectroscopy of Adsorbed Layers of Soluble Surfactants at the Air–Water Interface

Modeling of Equilibrium Adsorption and Surface Tension of Cationic Gemini Surfactants

“…From conductivity studies (Cl − ), these surfactants are known to be strong electrolytes, which further supports the above assumption (7). Direct probing of the adsorbed surface monolayers of LAM and C 6 (LA) 2 using the techniques of ellipsometry and infrared reflection absorption spectroscopy (IRRAS) provides experimental adsorption density data (8)(9)(10). The maximum surface densities max and implied surface areas per molecules obtained from all the above methods are summarized in Table 1.…”

“…[1] with the finite differences method, with a value for¯ consistent with the solution to Eq. [9] for a given set of parameters. A model will be considered successful if δγ is the same as or lower than the estimated error in the tension measurements, taken to be within 2 mN m −1 .…”

“…Independent surface density data obtained using ellipsometry (data from algorithm B with m = 4 × 10 −6 mol m −2 (8,9)) and IRRAS (data from an isotropic monolayer model (10)) are shown in Fig. 4.…”

“…The direct adsorption density data of Walsh et al (9), obtained by ellipsometry and IRRAS, are reevaluated here within the context of the equilibrium tension models. Although surface densities inferred from these optical techniques may be model dependent and may not be as reliable as surface densities obtained from techniques such as neutron reflection, the reported data of Walsh et al appear to be consistent and are suitable for our purposes here.…”

Adsorption and Direct Probing of Fibrinogen and Sodium Myristate at the Air/Water Interface

“…For comparison, this procedure is repeated for the three different λ's. Method 2 is used for very thin films, with d 1 λ, and where values of δ are not significantly different from zero (±0.05) (49,50). Then, only δ is measurable and related to n 1 and d 1 .…”