The objective of this work is to study the effect of interlayer cations on the mechanism of adsorption-desorption of water in the case of a montmorillonite exchanged by alkali metals. This is done through thermodynamic measurements, i.e. isotherms of adsorption and desorption of water. The raw material is subjected to purification treatment by using the sedimentation followed by cationic exchange. IR and XRD analysis of the dry state confirm that the treatment used for obtaining homoionic clays does not deteriorate their structure. The value of the interlayer distance d001obtained from XRD depends directly on the cation radius. IR spectra recorded on our montmorillonite reveals that the area ratio νOH/νSiO peaks which corresponds to the amount of adsorbed water under room atmosphere follows the sequence: K >Rb> Cs > Li > Na In accordance the evolution observed for the desorption enthalpies. The adsorption and desorption isotherms show that the nature of the compensating cation considerably changes the adsorbed / desorbed amount for a given water relative pressure. Thus, the total amount of water adsorbed at P/P0 = 0.5 follows the same sequence.

The response of micrometric pseudo-single crystals of β-H2NiO2, deposited on an Au substrate and submitted to high rate charge/discharge cycling under controlled current conditions, is studied by in situ μ-Raman spectroscopy. The intensities of the Raman background and of the hydroxyl stretching band are used to probe in time the single-particle surface and bulk oxidation states respectively. Results, obtained in the absence of electrical binders and chemical dopants, substantiate previous electrochemical investigations suggesting that the occurrence of the nickel electrode activation process is related to the formation of a thin surface limiting layer hindering the active material capacity to store and deliver energy. The feasibility of in situ μ-Raman spectroscopy on nickel hydroxide single particles submitted to electrochemical operation is demonstrated for the first time.

Three ensembles designed to investigate condensed matter in complex environments have been developed recently on the AILES beamline at SOLEIL. They have been exploited for studies aiming at understanding the properties of water molecules and their network in various confining systems, namely:- a hydration and temperature-controlled cell for the study of water confined in nanoporous Vycor,- a high pressure set-up allowing the study of the evolution of water molecules network trapped in Faujasite through the pressure-induced amorphisation of the matrix material,- a temperature resolved electrochemical cell used to record FIR difference spectra of metalloproteins interacting with water molecules.By combining the high infrared flux and collimation of the AILES beamline with these optimized sample environments, it is possible to measure the infrared and THz spectra for minute quantities of samples in precise physical conditions.

Hydroxyapatites were prepared in the presence of different amounts of phosphonoformic acid (PFA) via the hydrothermal method. The obtained powders were characterized through chemical analysis, XRD, IR, 31P MAS-NMR, TEM, and TG-TDA. The XRD showed that the PFA did not affect the apatite composition. Indeed, only a reduction of the crystallite size was noted. After grafting of PFA, the IR spectroscopy revealed the appearance of new bands belonging to HPO42− and carboxylate groups of the apatite and organic moiety, respectively. Moreover, the 31P MAS-NMR spectra exhibited a peak with a low intensity assigned to the terminal phosphonate group of the organic moiety in addition to that of the apatite. Based on these results, a reaction mechanism involving the surface hydroxyl groups (triple bond; length of mdashCasingle bondOH) of the apatite and the carboxyl group of the acid was proposed.

Confined H$_2$O molecules act as local probes for depressurization phenomena during the pressure induced amorphisation of faujasite NaX at which the OH stretching frequency first decreases and then increases almost to its room pressure value upon further compression. Pair distribution function (PDF) analysis provides evidence that amorphisation corresponds to a collapse of the structure around hydrated sodium cations with strong distortion of the secondary building units (double six-membered rings, sodalite cages). Both the use of guest molecules as local probes in far- and mid-infrared spectroscopy, where we correlate intermolecular water H bonding vibrations and internal mode behaviour under confinement, and PDF analysis could be of great use to study the mechanical behaviour of other hydrated materials.

We report an experimental study on the confinement of oligothiophene derivatives into single-walled carbon nanotubes over a large range of diameter (from 0.68 to 1.93 nm). We evidence by means of Raman spectroscopy and transmission electron microscopy that the supramolecular organizations of the confined oligothiophenes depend on the nanocontainer size. The Raman Radial Breathing Mode frequency is shown to be monitored by both the number of confined molecules into a nanotube section and the competition between oligothiophene/oligothiophene and oligothiophene/tube wall interactions. We finally propose simple Raman criteria to characterize oligothiophene supramolecular organization at the nanoscale.

During the past years, considerable interest has been focused on materials that exhibit potential applications as luminescent solar concentrators (LSCs). Indeed, the incorporation of trivalent lanthanide ion (Ln3+) complexes in organic-inorganic coatings enables the down-shifting of the UV radiationinto light that can be efficiently trapped inside the substrate and guided to the edges by total internal reflection where it can be efficiently collected by a solar cell [2]. In this communication, we will present two new precursors based on ethane tetracarboxamide and ethane dicarboxamide fragments P4 (Figure 1 (a)) and P2 (Figure 1 (b)), and their conversion into luminescent hybrid materials by the sol-gel process in the presence of Eu3+ salts (EuCl36H2O) and ligand 2-thienoyltrifluoracetone (tta) (Eu3+/tta molar ratio of 1:2). The organic-inorganic hybrid materials (P4(Eu3+/tta) and P2(Eu3+/tta)) were processed as free standing films by solvent casting. They display maximum emission quantum yield () values of 0.22 and 0.48, respectively, under excitation at 320 nm. In addition, P4(Eu3+/tta) was processed by spin-coating on glass substrates, yielding films (P4-F(Eu3+/tta) with controlled thickness of 75 nm. Under UV irradiation the films display a bright red emission ascribed to the intra-4f6 Eu3+ transitions, as illustrated in Figure 1(c) and a remarkable  value of 0.60 under excitation at 345 nm.