Adsorption of Dimethyldodecylamine Oxide and Its Mixtures with Triton X-100 at the Hydrophilic Silica/Water Interface Studied Using Total Internal Reflection Raman Spectroscopy

Abstract

Adsorption of dimethyldodecylamine oxide (DDAO) and its mixtures with Triton X-100 (TX-100) at the hydrophilic silica/water interface has been studied using total internal reflection (TIR) Raman spectroscopy and target factor analysis (TFA). The use of a linear vibrational spectroscopic technique helps obtain information on molecular behavior, adsorbed amount, and conformational order of surfactant molecules at the interface. The results obtained from polarized Raman measurements of pure DDAO show insignificant changes in the orientation and conformational order of surface molecules as a function of DDAO bulk concentrations. The adsorption isotherm of pure DDAO shows a change in the structure of the adsorbed layer at concentrations close to the critical micelle concentration (cmc). TFA reveals that, for a low concentration of DDAO (0.30 mM in this study), adsorption of both DDAO and TX-100 in the mixed surfactants was enhanced at low TX-100 concentrations. The synergistic effect is dominant at low concentrations of TX-100, with enhanced adsorption of both surfactants. Although competitive adsorption is effective at high concentrations of TX-100, the presence of a small amount of DDAO at the interface still enhances TX-100 adsorption. When DDAO concentrations are increased to 1.00 mM, TX-100 replaces DDAO molecules on the surface when TX-100 concentration is increased.

Segregation of Amine Oxide Surfactants in PVA Films

“…Although neutron reflectivity is not capable of resolving the nature of the structures at the interface of these films spun onto a silicon substrate due to the similar SLD of the silicon oxide and the PVA containing this volume fraction of deuterated surfactant, there has been substantial evidence for the formation of structures on solution-substrate interfaces. When reflectivity data for a PVA/DDAO film was fitted with a 4-layer model, to include an additional surfactant-rich layer adjacent to the substrate, the thickness of the interfacial layer was found to be 13 ± 10 Å, which could correspond to a number of different structures, which have been probed theoretically and experimentally. − The significant uncertainty in this value is a result of the difficulty in resolving the interfacial surfactant from the SiO x (25 ± 15 Å). It was previously reported that treating structured surfactant films as a bilayer generally results in a good fit to reflectivity data .…”

A review of artificial intelligence methods combined with Raman spectroscopy to identify the composition of substances

“…In substance analysis, the adsorption of dimethyldodecylamine oxide (DDAO) and its mixtures with Triton X‐100 (TX‐100) at the hydrophilic silica/water interface has been studied using total internal reflection (TIR) Raman spectroscopy and target factor analysis (TFA). [ 64 ] When studying the influence of pressure and environment on the Raman spectra of methane, carbon monoxide, carbon dioxide, and hydrogen, a method was proposed to predict the positions of these molecule peaks. [ 65 ] In recent years, Raman spectroscopy has been proven to qualitatively and quantitatively analyze xylene isomers and their mixtures.…”

Multicolor Chemical Imaging by Sum Frequency Generation Imaging Microscopy of Monolayers on Metal Surfaces

“…Chemometrics and analytical techniques, such as partial least-squares, principal component analysis, multivariate analysis, and factor analysis, have been utilized in spectral and image analysis in many spectroscopic techniques. − Factor analysis (FA) is a statistical method that uses mathematical procedures to investigate whether some observed variables are linearly related to some smaller number of unobservable factors. The application of FA in chemistry has been pioneered by Malinowski in the 1980s .…”