Isabelle Beurroies

Aix-Marseille Université | AMU · Département de chimie

Silica aerogels are known to be materials with exceptional characteristics, such as ultra-low density, high surface area, high porosity, high adsorption, and low-thermal conductivity. In addition, these unique properties are mainly related to their specific processing. Depending on the aerogel synthesis procedure, the aerogels texture can be tailor...

Perfluorierte Verbindungen finden breite Anwendung, haben aber schädliche Folgen für die Umwelt und Gesundheit. Es gibt daher einen Bedarf an der selektiven Zurückgewinnung aus Prozess‐ und Oberflächenwasser. In ihrer Zuschrift (DOI: 10.1002/ange.202002953) zeigen D. E. De Vos et al., dass ein mikroporöser Zeolith‐Beta in seiner reinen Silicaform h...

Perfluorinated compounds have found wide applications but have adverse effects on health and environment. There is a need to selectively recover them from process and surface waters. In their Communication (DOI: 10.1002/anie.202002953), D. E. De Vos et al. show that a microporous zeolite Beta, in its all‐silica form, shows outstanding capacity and...

Perfluorinated alkylated substances (PFASs) are widely used in industrial and commercial applications, leading to a widespread occurrence of these persistent and harmful contaminants in our environment. Removal of these compounds from surface and waste waters is being mandated by European and U.S. governments. Currently, there are no treatment tech...

Perfluorinated alkylated substances (PFASs) are widely used in industrial and commercial applications, leading to a widespread occurrence of these persistent and harmful contaminants in our environment. Removal of these compounds from surface and waste waters is being mandated by European and U.S. governments. Currently, there are no treatment tech...

Two novel compounds {[Cu(bpy)2]3H2W12O40}·3H2O (1) and {{[Cu(OH2)(bpy)][Cu(bpy)]2W6O21}·4H2O}n (2) were isolated under hydrothermal conditions. 1 is an α-metatungstate Keggin unit decorated by three "{Cu(bpy)2}2+" fragments. 2 is a thermodynamically stable 1D-polymer built-up from an unusual hexatungstate moiety decorated by three Cu-complexes. Com...

The CO2 adsorption uptake and enthalpies with MIL-96(Al) were assessed in the presence of up to 40% relative humidity using via both experiment and simulation. Interestingly at 10% relative humidity, the water equilibrated in the pores of this MOF profers a significant increase in affinity for CO2 at 0.2 bar, which is associated with a limited decr...

Different approaches can be considered to use nanoporous materials for mechanical energy storage. First the most well known is founded on the use of hydrophobic porous solids in which water is forced to enter into the pores by mechanical pressure. To study this mechanical to surface energy transformation a specific device has been settled relying o...

Ion-imprinted polymers (IIPs) for nickel were synthesized by inverse suspension copolymerization of vinylbenzyl iminodiacetic acid (VbIDA) with ethyleneglycol dimethacrylate (EDMA) in the presence of nickel(II) ions with various porogen solvents to study their impact on the IIPs properties. They were prepared with mixtures of acetonitrile and dimet...

Adsorption of an acidic polyaromatic asphaltene model compound (C5PeC11) and indigenous C6 asphaltenes onto the liquid-solid surface is studied. The model compound C5PeC11 exhibits a similar type of adsorption with a plateau adsorbed amount as C6-asphaltenes onto three surfaces (silica, calcite and stainless steel). The model compound BisAC11, with...

HIGHLIGHTS Synchrotron Soleil 2015

A thermodynamic study of the structural large-pore (LP) to narrow pore (NP) transition in various Metal Organic Frameworks (MOFs) is presented. First, the pressure induced transition at a constant temperature is investigated using a Tian-Calvet microcalorimeter set-up equipped with a high pressure cell. This device permits simultaneous measurements...

This paper presents an extensive set of measurements from complementary surface analysis techniques performed for characterizing deuterium retention in carbon fiber composite Sepcarb®NB31 subsequently to a deuterium beam exposition: adsorption isotherm measurements and Hg porosimetry to characterize the porous network, coupled deuterium beam exposu...

The aluminum Fumarate MOF A520 is revealed as a promising material for mechanical energy-related applications with performances in terms of work and heat energies which surpass that of any porous solids reported so far. Complementary experimental and computational tools are deployed to finely characterize and understand the pressure-induced structu...

By combining experimental adsorption isotherms, microcalorimetric data, infrared spectroscopy and quantum chemical calculations the adsorption behaviour of the CPO-27/MOF-74 series (Ni, Co, Mg, Cu, Zn) in the desulfurization of fuels is evaluated. The results show a clear influence of the metal ion on the adsorption capacity and affinity for S-hete...

In any process, the heat exchanged is an essential property required in its development. Whilst the work related to structural transitions of some flexible metal-organic frameworks (MOFs) has been quantified and linked with potential applications such as molecular springs or shock absorbers, the heat related to such transitions has never been direc...

In any process, the heat exchanged is an essential property required in its development. Whilst the work related to structural transitions of some flexible metal–organic frameworks (MOFs) has been quantified and linked with potential applications such as molecular springs or shock absorbers, the heat related to such transitions has never been direc...

Several composite membranes have been prepared from cellulose triacetate (CTA) and activated carbon (AC) by solvent casting, varying temperature from 35 to 55°C and relative humidity (RH): 10–70%. Some conditions promoted AC particle agglomeration which is evidenced by SEM and IFME® program. In those membranes, where homogeneity is attained, a deep...

An extension to the MARTINI coarse-grained model is presented to describe the adsorption of organic molecules on graphite surfaces. The model allows the study of the dynamics of the preferential adsorption of long-chain organic molecules from solvent and the formation of ordered structures on the surface through self-assembly on the microsecond tim...

Metal Organic Frameworks (MOFs) are porous materials made of inorganic clusters coordinated by organic linkers. These materials are mainly used as adsorbents for either gas or liquid separation. Some of them show spectacular changes of structure that may be evidenced by mechanical stress. We developed an experimental device which was placed in a mi...

The influence of the metal ion in the mesoporous metal trimesate MIL-100(Al3+, Cr3+, Fe3+, V3+) on the adsorptive removal of N/S-heterocyclic molecules from fuels has been investigated by combining isotherms for adsorption from a model fuel solution with microcalorimetric and IR spectroscopic characterizations. The results show a clear influence of...

This work reports on the adsorptive separation of mono- and disubstituted alkylaromatics with various alkyl groups in the microporous metal-organic frameworks MIL-47 (VIVO{O2C–C6H4–CO2}) and MIL-53 (AlIII(OH){O2C–C6H4–CO2}). The mechanisms underlying the adsorption selectivity are investigated via determination of the adsorption enthalpies at low o...

Ion-imprinted polymer beads are prepared for the first time by inverse suspension polymerization in mineral oil using nickel(II) as the template ion. As water is not used as the continuous phase, this new route of synthesis avoids the risk that the ion template leaves the suspension for the aqueous phase. The leaching of nickel from the resin beads...

Porous poly(styrene-co-divinylbenzene) resins functionalized with catechol were prepared in two different ways. Catechol was either grafted on commercial Amberlite® XAD-4 resin via a reduced imine and diazo bridges or incorporated by direct copolymerization of divinylbenzene with dimethoxystyrene followed by deprotection of the methoxy groups. The...

Para-disubstituted alkylaromatics such as p-xylene are preferentially adsorbed from an isomer mixture on three isostructural metal-organic frameworks: MIL-125(Ti) ([Ti(8)O(8)(OH)(4)(BDC)(6)]), MIL-125(Ti)-NH(2) ([Ti(8)O(8)(OH)(4)(BDC-NH(2))(6)]), and CAU-1(Al)-NH(2) ([Al(8)(OH)(4)(OCH(3))(8)(BDC-NH(2))(6)]) (BDC = 1,4-benzenedicarboxylate). Their u...

Bring in the cleaner! Metal-organic frameworks (MOFs) are able to separate nitrogen and sulfur contaminants from fuel, which may lead to the production of cleaner fuels (see picture; ppmw=parts per million by weight). The separation ability is shown to originate from the Lewis acidity of the metal sites in the MOFs.

Self-organized block copolymers can be effectively utilized as nanostructured precursors to functionalized ordered mesoporous polymeric materials. Novel nanoporous polystyrene frameworks with carboxylic acid (COOH)-coated pore walls were obtained from the selective degradation of the polyester block in polystyrene-block-poly(d,l-lactide) (PS-b-PLA)...

We present a unified thermodynamic description of the breathing transitions between large pore (lp) and narrow pore (np) phases of MIL-53 (Cr) observed during the adsorption of guest molecules and the mechanical compression in the process of mercury porosimetry. By revisiting recent experimental data on mercury intrusion and in situ XRD during CO(2...

Performance under pressure: Hysteresis of intrusion-extrusion of mercury observed in MIL-53(Cr) particles is interpreted as the transition from large-pore to narrow-pore forms of this metal-organic framework (MOF) material, provoked by the isostatic pressure created by mercury around the porous particles. The observed behavior may be qualitatively...

Semi-interpenetrating polymer network (semi-IPN) and IPN systems based on poly(D,L-lactide) and a functional vinylic polymer can be effectively used as nanostructured precursors to novel functionalized (meso)porous networks. Indeed, the extraction of uncross-linked oligoesters from semi-IPNs as well as the quantitative hydrolysis of the polyester s...

Poly(vinylcatechol-co-divinylbenzene) resins have been prepared by suspension copolymerization of 3,4-dimethoxystyrene (DMS) with divinylbenzene (DVB) using toluene as the porogen and followed by deprotection of the catechol functions. The ratio of DMS versus DVB was modified and led to a maximum catechol content (determined by elemental analysis)...

Novel carboxy (COOH)-functionalized mesoporous polystyrene membranes were prepared from polystyrene-block-poly(D,L-lactide) (PS-b-PLA) diblock copolymers through the selective degradation of the PLA block. The combination of atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) techniques enabled the synthesis of nanostr...

Pore-size distribution studies were carried out employing nitrogen adsorption, mercury porosimetry and thermoporometry techniques on two titania gels prepared from titanous chloride and ammonia using oxygen gas as the oxidizing agent. These gels were also characterized by scanning electron microscopy and X-ray diffraction. After heat-treatment at 3...

A set of chromatographic materials for bioseparation were characterised by various methods. Both commercial materials and new supports presenting various levels of rigidity were analysed. The methods included size-exclusion and capillary phenomena based techniques. Both batch exclusion and inverse size-exclusion chromatography were used. Gas adsorp...

In order to identify the key steps and the driving force for the hydration process of swelling clays, the water adsorption isotherms and enthalpies were measured on monoionic montmorillonite samples saturated with alkali or calcium ions, and on bi-ionic samples saturated with a sodium-calcium mixture. The specific surface area evolution along the h...

Over the past decades, self-organized block copolymers have received great attention and they have been seriously considered for nanotechnological application. The use of these copolymers as nanostructured precursors with controlled architectures is a promising approach for achieving functionalized mesoporous membranes. Novel carboxy (COOH)-functio...

Thermoporometry, a calorimetric technique, has been applied on solid montmorillonite samples at variable relative humidity (RH) and brings novel information on the swelling mechanism of Na-montmorillonite. Some mesopores are already filled with water in conditions where the interlamellar space is only occupied by one layer of water molecules. It wa...

We present a study of novel clay-polymer nanocomposite materials using a combination of both atomistic simulation and experiment. We show how computational simulation can bring new insight to our understanding of the structure and dynamics of these materials. Experiments of the intercalation of low molecular weight amine functionalized (poly propyl...

A new experimental procedure based on the isothermal desorption of vapour is proposed to extend the domain of characterisation of porous solids and powders by capillary condensation until the macropore range. The set-up is based on the use of a Tian-Calvet type microcalorimeter that insures a full control of temperature gradients around the sample...

The water uptake, transport and mechanical properties of organic–inorganic hybrid materials based on sulfonated and silylated, cross-linked polyetheretherketone (called SOSi-PEEK/N, where N is the molar percentage of silylated monomeric units) for application in fuel cells are reported. The mechanical properties are superior to those of S-PEEK, due...

The experimental density dependence of gas (argon and nitrogen) permeability of partially densified silica aerogels in the Knudsen regime is quantitatively accounted for by a computer model. The model simulates both the structure of the sintered material and the random ballistic motion of a point particle inside its voids. The same model is also ab...

Pseudomorphism is a term introduced by mineralogist to describe phase transformation that does not change the shape of a material. Pseudomorphic process, assisted by surfactants, for mesoporous pre-shaped silica particles allows to narrow the mesopore size distribution, to increase the surface area and the pore volume without changing the initial s...

The influence of a non-ionic surfactant on the adsorption behaviour of alkylphenols onto bentonite was studied via measurements of their adsorption isotherms in the absence and presence of various concentrations of the surfactant. Irrespective of the presence of the surfactant, the alkylphenols were always adsorbed by the same mechanism. However, o...

The formation of mesoscopically ordered silica/surfactant composites under alkaline synthesis conditions has been studied by time-resolved in situ small-angle X-ray diffraction with synchrotron radiation. Alkyltrimethylammoniumbromide surfactants, C(n)()TAB, of different chain lengths (n = 14, 16, and 18) as well as mixtures thereof were used as st...

The thermal and structural stability of sulfonated cross-linked PEEK (polyether ether ketone) and its silicon-containing class II hybrid derivatives were characterized by combination of mass spectrometry, infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. Thermodynamic properties of the hybr...

The development of proton exchange membranes as electrolytes for polymer electrolyte fuel cells operating at intermediate temperatures has been achieved combining two approaches: the preparation of a cross-linked polymer and the formation of covalent organic/inorganic hybrids. A covalently cross-linked sulfonated polyetheretherketone with elevated...

The solubilization of pentachlorophenol (PCP) in cationic surfactant micelles and in surfactant–silica mesostructures is studied. The micelle–water distribution coefficient is derived from both theoretical models and experiments. The sorption isotherm in the mesostructure is determined by the solution depletion method and compared to that of phenol...

A general, efficient and experimentally simple method for the synthesis of covalently crosslinked class II hybrid polymers based on PolyEtherEtherKetone (PEEK) with a high degree of sulfonation (DS = 0.8) was performed. The synthetic strategy foreseen two steps: the first one, direct sulfonation, led to the introduction of sulfonic acid groups and...

The influence of aluminium and titanium dopants on the structure and properties of MCM-41 silica has been evaluated and compared with previously published results. The acidity and basicity of the surface states (adsorption sites) were of special interest. The total acidity was studied by using temperature-programmed ammonia desorption (NH3-TPD). Ad...

The wetting state of a solid/fluids system depends on the relative value of the surface tensions acting at the different interfaces. Whereas the free energy of a given solid/fluid interface is not directly measurable, the internal energy part can be relatively easily determined in the case of powders by microcalorimetry. In this paper, the various...

A methodology based on thermoporometry is proposed to evidence the hysteresis phenomenon observed between melting and solidification of a confined fluid. This method allows plotting hysteresis loops comparable to those observed for gas adsorption–desorption. It is applied to solids with various pore structure, size or connectivity. The hysteresis l...

The partitioning of four organic compounds, phenol, 3-chlorophenol, 3,5-dichlorophenol and paratoluidine, between water and either bulk cationic surfactant micelles and surfactant aggregates confined in porous silica is studied. The partition coefficients between the two types of surfactant phase and water are determined from both theoretical model...

Gas adsorption at 77 K is probably the most widely used method to characterize mesoporous adsorbents via capillary condensation. Mercury intrusion is also commonly used for the characterization of such materials with the possibility to extend the pore width distribution measurement to the macropore range. More recently water intrusion was proposed...

The influence of nonionic surfactants on the adsorption behaviour of phenol onto kaolinite and montmorillonite is studied by determining its adsorption isotherm separately or in the presence of various concentrations of the nonionic surfactants. An enhancement of the adsorption of phenol is observed. Phenol alone can be adsorbed both by kaolinite a...

The influence of a nonionic surfactant on the adsorption behaviour of alkylphenols onto kaolinite is studied by determining their adsorption isotherms separately or in the presence of various concentrations of the nonionic surfactant. When alone, alkylphenols are adsorbed with a mechanism close to that of surfactants. If the nonionic surfactant TX1...

Silica gels (classical aerogels and composite aerogels) have been prepared by classical gelation and addition of silica soot in the gelifying solution before gelation. Due to the aggregation mechanisms, these structures are characterized by a fractal organization. The fractal network previously described in the literature (1–100 nm) which results f...

A comparison of different methods to characterise the porosity of Egyptian mortars presented. The results obtained using adsorption manometry, mercury porosimetry and thermoporometry are complementary and overlap in certain regions of pore size.

The interaction of a powder with vapours or their wettability by liquids are involved in many industrial processes and then needs to be studied by simple and reproducible methods. Two microcalorimetric methods, one for the simultaneous measurement of adsorption isotherm and enthalpy and the other for the determination of wetting or immersion energy...

During the synthesis of micelle-templated silica an intermediate inorganic/organic mesostructure is obtained with an hexagonal arrangement of channels filled by surfactant molecules. The ability of such a mesostructure to solubilize organic molecules from an aqueous solution was investigated. To that end, silica/cationic surfactant mesostructures w...

Under isostatic pressure aerogels display an irreversible shrinkage caused by plastic deformation. As a consequence of this plastic shrinkage it is possible to densify, and thus to modify the elastic properties of aerogels. We show that the elasticity of the material is strongly influenced by structural transformation, and we observe a weakenin...

The effect of the structure and surface properties of support material on metallocene (zirconocene chloride) adsorption and catalyst activity in ethene polymerization was studied. Commercial Grace silica, mesoporous silicate, MCM-41, and aluminium-modified MCM-41 were used as supports. The highest amount of zirconocene dichloride was adsorbed on Al...

The density and the structure (fractal and non-fractal) of aerogels are modified either by the adjustment of the gelifying concentration, by a precise control of the viscous flow sintering process or by an isostatic pressure deformation. These aerogels have porosities ranging from 98% to 0%. The mechanical properties of the different aerogels (elas...

Texture change induced by an isostatic compression of low density aerogels exhibiting fractal geometry has been investigated. Fractal features are analyzed from small angle X-ray scattering experiments. It was found that at the onset of densification a decrease in the correlation length occurs while the fractal dimension increases a little. Isostat...

We report on a low-frequency Raman scattering study of base-catalyzed silica aerogels (BCSA) and partially densified BCSA prepared by heat treatment (HT), hydrostatic pressure (HP) and uniaxial pressure (UP). Low-frequency Raman susceptibility scales with frequency, χ(ω)∼ω−φ, within a large range of frequencies whose extent decreases with densifica...

The density and the structure (fractal and non-fractal) of aerogels are modified either by the adjustment of the gelifying concentration, by a precise control of the viscous flow sintering process or by an isostatic pressure deformation. These aerogels have porosities ranging from 98% to 0%. The mechanical properties of the different aerogels (elas...

When gently stressed, aerogels show an elastic response. However it was found that under isostatic pressure aerogels display an irreversible shrinkage which may be attributed to plastic behaviour. As a consequence of this plastic shrinkage it is possible to densify and modify the elastic properties of aerogels at room temperature. The structural ev...

Gas flows through partially densified aerogels were measured for samples of various densities (0.4–1.2 g cm−3). Measurements were done at various pressure drops with argon and nitrogen. The gas flow in these partially densified aerogels is always molecular at the pressures and temperature examined. The permeability and conductivity of two sets of s...