- Fluorescence Quenching in Double-Chained Surfactants. 1. Theory of Quenching in Micelles and Vesicles
-
The time-resolved fluorescence quenching technique is used to investigate the aggregation behavior of double-chained surfactants.With a new extension of this technique, surfactant solutions consisting of (1) only vesicles, (2) mixtures of vesicles and micelles, or (3) only micelles can be distinguished.When applied to solutions of didodecyldimethylammonium acetate, the microstructure is determined to be composed of mainly small micelles over a wide concentration range (0.001-0.1 M); the contribution of vesicles to the total surfactant inventory is quite small.In studies of double-chained surfactants, the technique is particularly valuable for following the transformation of liquid crystalline dispersions to micellar solutions upon heating or dilution.
- Miller, D. D.,Evans, D. F.
-
-
Read Online
- Supramolecular assistance between cyclodextrins and didecyldimethylammonium chloride against enveloped viruses: Toward eco-biocidal formulations
-
Nosocomial infections have emerged as important causes of morbidity and mortality in immunocompromised individuals. In this respect, biocides are widely used in hospitals leading to resistant microorganisms. We show here that cyclodextrins can remarkably boost the virucidal activity of di-n-decyldimethylammonium chloride. These oligosaccharides synergistically work with the biocide affording a noticeable reduction of the active virucide concentration between 40 and 85%. Partial replacement of a significant amount of the biocide by eco- and bio-compatible cyclodextrins whilst maintaining the same activity is of great interest as it allows the reduction of the toxicological drawbacks of classical biocide mixtures.
- Leclercq, Lo?c,Dewilde, Anny,Aubry, Jean-Marie,Nardello-Rataj, Véronique
-
p. 273 - 281
(2016/09/07)
-
- Acidic three-liquid-phase microemulsion systems based on balanced catalytic surfactant for epoxidation and sulfide oxidation under mild conditions
-
Didecyldimethylammonium tungstate has been designed as a balanced catalytic surfactant to form acidic three-liquid-phase microemulsion systems at room temperature in the presence of water, a non-chlorinated solvent and dimethyldioctylammonium salts (hydrogen sulfate and dihydrogen phosphate). The triphasic system is efficient for the oxidation of olefins, sulfides and thiophenes under mild conditions. Moreover, the recovery and reusability of the catalyst, the straightforward separation of products and catalysts in two distinct phases as well as the possible use of environmentally friendly solvents such as tert-butyl acetate, make this system particularly attractive for catalytic oxidation reactions involving hydrogen peroxide as the primary oxidant under acidic or neutral conditions.
- Fressancourt-Collinet, Marion,Hong, Bing,Leclercq, Loic,Alsters, Paul L.,Aubry, Jean-Marie,Nardello-Rataj, Veronique
-
supporting information
p. 409 - 420
(2013/05/22)
-
- Modeling of multiple equilibria in the self-aggregation of di- n -decyldimethylammonium chloride/octaethylene glycol monododecyl ether/cyclodextrin ternary systems
-
The surface tension equations of binary surfactant mixtures (di-n-decyldimethylammonium chloride and octaethylene glycol monododecyl ether) are established by combining the Szyszkowski equation of surfactant solutions, the ideal or nonideal mixing theory, and the phase separation model. For surfactant mixtures, the surface tension at the air-water interface is calculated using nonideal theory due to synergism between the two adsorbed surfactant types. The incorporation of cyclodextrin complexation model to the surface tension equations gives a robust model for the description of the surface tension isotherms of binary, ternary, and more complex systems involving numerous inclusion complexes. The surface tension data obtained experimentally shows excellent agreement with the theoretical model below and above the formation of micelles. The strong synergistic effect observed between the two surfactants is disrupted by the presence of CDs, leading to ideal behavior of ternary systems. Indeed, depending on the nature of the cyclodextrin (i.e., α, β, or γ), which allows a tuning of the cavity size, the binding constants with the surfactants are modified as well as the surface properties due to strong modification of equilibria involved in the ternary mixture.
- Leclercq, Loic,Lubart, Quentin,Aubry, Jean-Marie,Nardello-Rataj, Veronique
-
p. 6242 - 6252
(2013/07/27)
-
- METHODS OF EXCHANGING ANIONS OF TETRAALKYLAMMONIUM SALTS
-
Methods are provided for producing tetra-C1 -C20 alkyl or aryl-substituted Alkyl quaternary ammonium carbonates and bicarbonates. In methods of this invention, at least a tetra-C-1 -C20 alkyl or aryl-substituted alkyl quaternary ammonium bromide, a metal hydroxide, and a suitable solvent are combined, said metal hydroxide being present in a stoichiometric excess as to the quaternary ammonium bromide
- -
-
Page/Page column 6
(2009/04/25)
-
- METHOD FOR THE SYNTHESIS OF QUATERNARY AMMONIUM COMPOUNDS AND COMPOSITIONS THEREOF
-
A novel manufacturing process is described for producing quaternary ammonium compounds having a selected anion, which may be useful in wood preservative formulations. The process involves reacting a trialkylamine with an alkyl bromide to form a quaternary tetraalkylammonium bromide salt, converting the quaternary tetraalkylammonium bromide salt to a quaternary tetraalkylammonium hydroxide salt by using an ion exchange resin, and converting the quaternary tetraalkylammonium hydroxide salt to the quaternary tetraalkylammonium salt of the selected anion.
- -
-
Page/Page column 49-50; 51-52; 53-54
(2008/06/13)
-
