The conversion of glycerol in supercritical water (SCW) was studied at 510 -550°C and a pressure of 350 bars using both a bed of inert and non-porous ZrO 2 particles (hydrothermal experiments), and a bed of 1 % Ru/ZrO 2 catalyst particles. Experiments were conducted with a glycerol concentration of 5 wt% in a continuous isothermal fixed-bed reactor at a residence time between 2 and 10 s. Hydrothermolysis of glycerol formed water-soluble products such as acetaldehyde, acetic acid, hydroxyacetone and acrolein, and also gases like H 2 , CO and CO 2 .The catalyst enhanced the formation of acetic acid, inhibited the formation of acrolein, and promoted the gasification of the glycerol decomposition products. Hydrogen and carbon oxides were the main gases produced in the catalytic experiments, with only minor amounts of methane and ethylene. Complete glycerol conversion was achieved at a residence time of 8.5 s at 510 °C, and at around 5 s at 550 °C with a 1 wt% Ru/ZrO 2 catalyst. The catalyst was not active enough to achieve complete gasification, since high yields of primary products like acetic acid and acetaldehyde were still present. Carbon balances were between 80 and 60 % in the catalytic experiments, decreasing continuously as the residence time was increased. This was attributed partially to the formation of methanol and acetaldehyde, which were not recovered and analyzed efficiently in our set-up, but also to the formation of carbon deposits. Carbon deposition was not observed on the catalyst particles but on the surface of the inert zirconia particles, especially at high residence time. This was related to the higher concentration of acetic acid and other acidic species in the catalytic experiments, which may polymerize to form tar-like carbon precursors. Because of carbon deposition, hydrogen yields were significantly lower than expected; for instance at 550 ºC the hydrogen yield potential was only 50 % of the stoichiometric value.

This article reports the phase behavior determination of a system forming reverse liquid crystals, and the formation of novel disperse systems in the two-phase region. The studied system is formed by water, cyclohexane, and Pluronic L-121, an amphiphilic block copolymer considered of special interest due to its aggregation and structural properties. This system forms reverse cubic (I 2 ) and reverse hexagonal (H 2 ) phases at high polymer concentrations. These reverse phases are of particular interest, since in the two-phase region, stable high internal phase reverse emulsions can be formed. The characterization of Published in: Langmuir, February 2, 2011, Volume 27, Number 6, Pages 2286-2298 the I 2 and H 2 phases and of the derived gel emulsions was performed with small-angle X-ray scattering (SAXS) and rheometry, and the influence of temperature and water content was studied. The H 2 phase experimented a thermal transition to an I 2 phase when temperature was increased, which presented an Fd3m structure. All samples showed a strong shear thinning behavior from low shear rates. The elastic modulus (G') in the I 2 phase was around one order of magnitude higher than in the H 2 phase. G' was predominantly higher than the viscous modulus (G''). In the gel emulsions, G' was nearly frequencyindependent, indicating their gel type nature. Contrarily to water-in-oil (W/O) normal emulsions, in W/I 2 and W/H 2 gel emulsions, G', the complex viscosity (|*|) and the yield stress ( 0 ) decreased with increasing water content, since the highly viscous microstructure of the continuous phase was responsible for the high viscosity and elastic behavior of the emulsions, instead of the volume fraction of dispersed phase and droplet size. A rheological analysis, in which the cooperative flow theory, the soft glass rheology model and the slip plane model were analyzed and compared, was performed to obtain one single model that could describe the non-Maxwellian behavior of both reverse phases and highly-concentrated emulsions and to characterize their microstructure with the rheological properties.

A simple and effective route has been developed for the synthesis of bimodal (3.6 and 9.4 nm) mesoporous silica materials that have two ordered interconnected pore networks.Mesostructures have been prepared through the self assembly mechanism by using a mixture of polyoxyethylene fluoroalkyl ether and triblock copolymer as building block. The investigation of the R F 8 (EO) 9 /P123/water phase diagram evidences that in the considered surfactant range of concentrations, the system is micellar (L 1 ). DLS measurements indicate that this micellar phase is composed of two types of micelles, the size of the first one at around 7.6 nm corresponds unambiguously to the pure fluorinated micelles. The second type of micelles at higher diameter consists of fluorinated micelles which have accommodated a weak fraction of P123 molecules. Thus, in this study the bimodal mesoporous silica are really templated by two kinds of micelles.

Herein, we report the formation of organized mesoporous silica materials prepared from a novel nonionic gemini surfactant, myristoyl-end-capped Jeffamine, synthesized from a polyoxyalkyleneamine (ED900). The behavior of the modified Jeffamine in water was first investigated. A direct micellar phase (L(1)) and a hexagonal (H(1)) liquid crystal were found. The structure of the micelles was investigated from the SAXS and the analysis by generalized indirect Fourier transformation, which show that the particles are globular of core-shell type. The myristoyl chains, located at the ends of the amphiphile molecule, are assembled to form the core of the micelles and, as a consequence, the molecules are folded over on themselves. Mesoporous materials were then synthesized from the self-assembly mechanism. The recovered materials were characterized by SAXS measurements, nitrogen adsorption-desorption analysis, and transmission and scanning electron microscopy. The results clearly evidence that by modifying the synthesis parameters, such as the surfactant/silica precursor molar ratio and the hydrothermal conditions, one can control the size and the nanostructuring of the resulting material. It was observed that, the lower the temperature of the hydrothermal treatment, the better the mesopore ordering.