Laurent Gaillon

Bio: Laurent Gaillon is an academic researcher from University of Paris. The author has contributed to research in topics: Ionic liquid & Cyclic voltammetry. The author has an hindex of 17, co-authored 37 publications receiving 1043 citations. Previous affiliations of Laurent Gaillon include Pierre-and-Marie-Curie University & Chimie ParisTech.

Volumetric Study of Binary Solvent Mixtures Constituted by Amphiphilic Ionic Liquids at Room Temperature (1-Alkyl-3-Methylimidazolium Bromide) and Water

Abstract: At room temperature, the 1-decyl-3-methylimidazolium bromide (DMImBr) is a long alkyl chain imidazolium ionic liquid miscible with water and forming a gel zone between 5 and 40% w/w H2O. We measured the density of the liquid mixtures of water and DMImBr. We determined the apparent molar volume of the molten salt for dilute solutions. For the concentrated solutions the partial molar volume of each component was evaluated by a perturbation method. These results are shown to be substantially different from those obtained with a short chain bromide ionic liquid, 1-butyl-3-methylimidazolium bromide (BMImBr). The amphiphilic ionic liquid (DMImBr) has been shown to form micelles and its critical micelle concentration (cmc) has been determined. Below the cmc, the Debye–Huckel limiting law for 1:1 electrolytes describes very accurately the behavior of low concentrations of the DMImBr salt in water. Above the cmc, the partial molar volume of the micellized monomer was approximately equal to the molar volume of the pure fused salt. The partial molar volume of water in these mixtures was similar to that of pure water. The concentrated solutions behave like mixtures of interpenetrated phases.

Counterion Effects in Aqueous Solutions of Cationic Surfactants: Electromotive Force Measurements and Thermodynamic Model.

Abstract: EMF measurements have been performed to study the influence of counterions in aqueous solutions of ionic surfactants in which the amphiphile is ann-alkyltrimethylammonium cation. General rules of variation were observed for the activities of the amphiphilic ion and the counterion, as a function of the global concentration of the surfactant salt. This study also allows us to have access to the degree of counterion binding β over a wide range of counterions (bromide, chloride, fluoride, hydroxide, nitrate, acetate, benzoate). A systematic correlation between the concentrations of an amphiphilic cation and a counterion in solution has been established when the micellization process occurs. This correlation is also verified when a background electrolyte with a common anion is added to the surfactant solution. The mathematical relation translating the real link between concentrations of both ions of the micellar salt, deduced from this correlation, emphasizes the existence of a condition of micellization, in the form of a micellization product. A new thermodynamic model based on the electrochemical equilibrium of a dispersed phase (pseudo-phase) is developed, and we justify the existence of this condition of micellization or micellization product. Furthermore, this model is shown to be well adapted for the description of the whole phenomena observed in micellar solutions.

Life with 6000 Genes

Abstract: The genome of the yeast Saccharomyces cerevisiae has been completely sequenced through a worldwide collaboration. The sequence of 12,068 kilobases defines 5885 potential protein-encoding genes, approximately 140 genes specifying ribosomal RNA, 40 genes for small nuclear RNA molecules, and 275 transfer RNA genes. In addition, the complete sequence provides information about the higher order organization of yeast's 16 chromosomes and allows some insight into their evolutionary history. The genome shows a considerable amount of apparent genetic redundancy, and one of the major problems to be tackled during the next stage of the yeast genome project is to elucidate the biological functions of all of these genes.

Electrochemical reactivity in room-temperature ionic liquids.

Abstract: A review. Physicochem. properties of ionic liqs. are discussed. Chem. and electrochem. reactivity in ionic liqs. is described including electrode reactions, electrode reaction kinetics, electrosynthesis, etc.

Synthesis, characterization and applications of layered double hydroxides containing organic guests

Abstract: The use of layered inorganic solids as host materials for the creation of inorganic–organic host-guest supramolecular structures is of increasing interest. In this review we outline the preparation, characterization and uses of layered double hydroxides (LDHs) containing organic guests. LDHs consist of stacks of positively charged mixed metal hydroxide layers that require the presence of interlayer anions to maintain overall charge neutrality. A range of organic guests may be incorporated, including aliphatic and aromatic carboxylates, sulfonates and phosphonates as well as porphyrin and phthalocyanine derivatives. Potential applications of organo-LDHs in the areas of catalysis, sorption, photochemistry and electrochemistry are outlined. Overall, it is demonstrated that with LDHs it is possible to create, in a systematic manner, novel inorganic–organic supramolecular structures.