A novel additive of multi-walled carbon nanotubes (MWNTs) dispersed with cationic surfactants or mixed cationic/anionic surfactants was used for MEEKC separation of eight phenolic compounds, four glycosides, and one phenanthraquinone. In this context, several parameters affecting MEEKC separation were studied, including the dispersion agents of MWNTs, MWNTs content, oil type, SDS concentration,...

Surfactants are characterized by the essential features that we saw in sodium oleate. A surfactant molecule has a hydrophilic (water-loving) head and a long hydrophobic (water-hating or oil-loving) tail. For this reason, we often describe surfactants is being amphiphilic molecules they love everything. Surfactants can be categorized according to the charge present in the hydrophilic portion of ...

Imidazolium-based ionic surfactants with hydrocarbon tails of different sizes were simulated with lipid bilayers at different salt concentrations. Starting with the random position of ionic surfactants outside the bilayer, surfactants with long tails mostly insert into the bilayer, while those with short tails show the insertion of fewer surfactant molecules, indicating the effect of the tail l...

The reformation of secondary structure for unfolded, disulfide reduced hen egg white lysozyme (HEWL) upon interaction with surfactants was studied using CD, fluorescence and IR (infrared) techniques. Equilibrium CD studies showed that reduced HEWL when mixed with negatively charged surfactants, such as SDS (sodium dodecyl sulfate), gradually regains average helical structure to a level equivale...

In this study, the solubilization of two organic dyes, Sudan I (1-Phenylazo-2-naphtol) and Quinizarin (1,4-Dihydroxyanthraquinone), was studied in the presence of different types of surfactants (2 polymerics, 2 nonionics, 2 anionic, and one cationic) using UV-Vis spectroscopy. The effects of temperature, pH and addition of different electrolytes (NaCl, Na2CO3, NaI, NaOH, NaSCN) on dye solubiliz...

The effect of uncharged surfactant additives on the oppositely charged polyion/ionic surfactant complexation is usually described as a direct equilibrium association between the polyelectrolyte molecules and free mixed micelles analogous to the polyion/colloidal particle interactions. This approach predicts that the binding of the ionic surfactant to the polyelectrolyte molecules can be complet...

Highly organized mesoporous silica monoliths were reproducibly prepared by nanocasting mixtures of fluorinated nonionic surfactants and micelles of two hydrocarbon block copolymers. It is the special feature of this fluorocarbon/hydrocarbon template mixture that they form not mixed micelles but individual micelles instead. By careful analysis of the pore architectures by gas sorption measuremen...

Surfactants, or surface active agents, are used in many pharmaceutical, industrial, and environmental applications. Selection of the appropriate surfactant or mixture of surfactants for any given application is driven by the need to control bulk solution micellization and solubilization characteristics. The goal of this thesis has been to develop computer simulations and molecular-thermodynamic...