Complex voltammetric and fractal study of adsorbed layer’s structure of pure Triton-X-100 and in mixture with o- or p-nitrophenol

Abstract

Adsorption of well-known surfactant Triton-X-100 (T-X-100) and mixed systems comprising T-X-100 with o-or p-nitrophenols, at the mercury/electrolyte solution interface vs. T-X-100 bulk concentration has been studied. Diversified approach comprising capacitive current measurements, desorption peak height analysis, fractal analysis,

The simple electrochemical method for detection of 3d molecular reorientation in adsorbed layers of organic substances

“…Such transformations are related to the anisotropic, namely rod-like shape of the molecule [5]. Hence, it may be expected that such molecules would not follow simple adsorption behavior predicted by the theory presented.…”

“…1(a)), and to a highly anisotropic (rod-like) molecule, Triton-X-100 (T-X-100), which has been shown to undergo reorientation during the adsorption process [5]. The experiments were conducted for diffusion controlled adsorption and in the case of adsorption from stirred solution.…”

“…However, detection is not easy in electrochemical measurements. Recently, it has been shown that these processes can be detected by the corresponding changes of the fractal dimension, D, of the adsorbed layer [5,6]. Moreover, the fractal dimension is also sensitive to the changes in hydrodynamic conditions and influences the basic material properties [7,8].…”

“…The structure of the adsorbed layer changes during the film formation. These changes may include formation of ordered and/or fractal structures and comprise different transformational phases such as 2d nematization [5] and 3d reorientation as second order phase transitions [5,6]. However, detection is not easy in electrochemical measurements.…”

A theory of square-wave voltammetry of surface-active, electroinactive compounds

“…The measurement of ac current as a function of electrode potential is called tensammetry [5]. It is used for the determination of adsorption parameters [2,6], the influence of SAS molecular structure on the SAS surface activity [3,7], the structure of adsorbed layer [8][9][10][11][12], the reorientation of molecules in the adsorbed layer [13][14][15] and the concentration of SAS in natural waters [16,17].…”