Mixed aggregation processes at the electrified Hg-electrolyte solution interface. The case of sodium dodecylsulphate-tween 80R, sodium dodecylsulphate-cetyltrimethylammonium bromide and Tween 80R-cetyltrimethylammonium bromide co-adsorption

Adsorption of the Neutral Macromonomeric Surfactant Tween-80 at the Mercury/Electrolyte Solution Interface as a Function of Electrode Potential and Time

“…The complex C vs E curve for all the concentrations (deformed cathodic peaks whose heights do not vary with concentration in a logarithmic manner, who have more than one minima, etc. ), together with the pronounced hysteresis upon the potential sweep reversal presented in ref , indicates that the adsorption of Tween-80 on the mercury electrode is accompanied by aggregation phenomena. The fact that the minimum of the capacitance curves, which corresponds to the thicker and denser arrangement of the adsorbed layer, varies with bulk surfactant concentration up to the cmc point can be explained by dependence of the adsorbate state on surface concentration.…”

“…Finally, such distorted peaks could be due to the partial convolution of two processes: one corresponding to the phase change and one to the adsorption/desorption of the surfactant. These pronounced capacitance peak deformations were observed for all the surfactants we studied. ,− Direct spectroscopic evidence of multilayer adsorption and phase changes via interfacial aggregates that extend in three dimensions has been recently reported for stearic acid adsorption on a gold single-crystal electrode …”

“…The adsorption of Tween-80 at the mercury electrode/electrolyte solution interface (a model charged interface) has been previously studied by means of differential capacitance measurements by Müller and Dörfler and by Sotiropoulos et al and Antoniou et al as a part of an extensive theoretical − and experimental 15,16,20-25 study of surfactant adsorption at the Hg electrode. The adsorption of organics at the polarized Hg electrode results in the replacement of water molecules and specifically adsorbed ions from the electrode double layer, hence causing significant changes in the corresponding capacitor .…”

“…The aim of the present work is to further investigate the nature of the various Tween-80 surface aggregates that were speculated to form at the Hg/electrolyte solution interface from near-steady C vs E curves, this time based on C vs t transients and long time, steady-state C vs E curves. The bulk cmc value and micelle aggregation number in solution were estimated from fluorescence and time-resolved fluorescence probing .…”

Electrochemical study of a cetylpyridinium bromide/glutathione mixed membrane electrochemically deposited at polycrystalline Ag electrodes

“…Owing to their physiological and chemical significance (e.g., the anticorrosion effect) the adsorption behavior of surfactants at the metal|solution interface has attracted much attention. Many methods, including electrochemical impedance spectroscopy, differential capacitive measurements, atomic force microscopy and STM, have been used to study the aggregation behavior of surfactants at metal|solution interfaces [10][11][12][13][14]. Surfactants adsorbed on the electrode surface change the characteristics of the metal|solution interface, making it easy for some organic compounds to adsorb at the electrode.…”