This study investigates the influence of interlayer cations on the thermodynamics and sorption mechanisms of water in a reference Wyoming montmorillonite. The behaviour of the montmorillonite exchanged with monovalent cations (Li + , Na + , K + , Rb + , Cs + ) or divalent cations (Mg 2+ , Ca 2+ , Ba 2+ ) is compared. The analysis combines X-ray diffraction (XRD), water sorption isotherms at various temperatures and mid-infrared spectroscopy. Li + , Mg 2+ and Ca 2+ promote greater water uptake and swelling, whereas K + , Rb + and Cs + significantly limit these processes. The behaviour of Na + and Ba 2+ stands out, demonstrating intermediate water uptake and high swelling. Mid-infrared spectral analysis supports these observations. It is shown that a cation’s effect on water uptake and swelling correlates best with the product of its elementary charge and ionic radius rather than with other properties such as the electrostatic potential, solvation enthalpy or chemical hardness. However, differences in isotherm shapes, hysteresis between adsorption and desorption and the variation of isosteric heat with water content suggest the presence of two distinct sorption mechanisms: one involving Li + , Cs + , Mg 2+ , Ca 2+ and Ba 2+ , and another involving Na + , K + and Rb + . These findings indicate that isotherm shape and swelling alone do not directly reflect water uptake capacity. These findings thus outline that the chaotropic (structure-breaking) or kosmotropic (structure-making) nature of the cations, along with the complex interplay between cation hydration and TOT layer attraction, may explain the complex observed differences.

Hollow mesoporous organosilica (HMO) nanoparticles with a controlled core cavity and a mesoporous organosilica shell are elaborated , the synthesis steps are checked by IR spectroscopy, the HMO are then tested for endocytosis and biocompatibility.

The development of membranes for nanofiltration with ionic transport properties that combine ionic permeability and selectivity is essential for improving the performance of water desalination or blue energy generation systems [1]. Besides, lab-on-chips using one or a few nano-channels combining ionic and electronic transport could open up a whole field of fundamental explorations in bio-iono-electronics and its potential applications: single-molecule detection, artificial synapses/neurons, .... etc [2]. Within this general framework, our aim is to study the ion transport properties of a bioinspired artificial nano-channel consisting of a single-walled carbon nanotube (SWCNT) inside which a biological ion channel (BIC) is confined. The first phase of this project consists of verifying whether or not it is possible to confine such a channel in a SWCNT. The BIC being studied is gramicidin. It is a small, well-characterised protein having a helicoidal structure when inserted into the cytoplasmic membrane [3]. Its outer ring is particularly hydrophobic and hence should facilitate its insertion into a SWCNT. The SWCNTs used are purified EC-15 eDIPS whose average diameter, i.e. ~2.1-2.2 nm, is expected to be large enough to accommodate the protein in its helicoidal form. The results presented here show that gramicidin strongly interacts with SWCNTs and gets inserted. This outcome is obtained using a range of technics: XRD, Raman, XPS, TEM and Water Sorption Isotherms. Particular emphasis will be made on the use of Water Sorption Isotherms as a powerful tool for characterising confinement in SWCNT.

L’écoconception est une démarche qui consiste à développer un produit ou système en minimisant ses impacts environnementaux sur l’ensemble de son cycle de vie à service rendu équivalent. Elle nécessite l’utilisation d’outils d’analyse de cycle de vie permettant de quantifier les impacts environnementaux par une approche multicritère à partir d’un inventaire des flux entrants et sortants du produit ou système. Ainsi, le but est de traduire les consommations et les rejets recensés lors de l'inventaire en impacts environnementaux. La présentation introduira le principe de la démarche d’écoconception, le calcul des impacts environnementaux d’un produit et les limites de l’approche.

Cette intervention introduit l’écoconception ses enjeux et ses limites. Elle permet de comprendre les grands principes de l’ACV des produits et des systèmes, la méthode multicritère et prospective permettant de calculer des impacts environnementaux.