References of "Cloots, Rudi"
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See detailYBa2Cu3O7−x dispersion in iodine acetone for electrophoretic deposition: Surface charging mechanism in a halogenated organic media
Dusoulier, Laurent; Cloots, Rudi ULg; Vertruyen, Bénédicte ULg et al

in Journal of the European Ceramic Society (2011), 31

Electrophoretic deposition (EPD) performance strongly depends on the particles surface chemistry and the ability to manipulate surface–liquid interfaces. In this study an extensive investigation of YBCO ... [more ▼]

Electrophoretic deposition (EPD) performance strongly depends on the particles surface chemistry and the ability to manipulate surface–liquid interfaces. In this study an extensive investigation of YBCO suspension in dry acetone, acetone–water mixtures and acetone–iodine is reported. Chemical instability of YBCO particles determines their colloidal behaviour. Charging mechanism of particles has therefore had to be deeply investigated for complete dispersion understanding. In order to determine the conditions of the YBCO suspension stability, measurements of pH, conductivity, zeta-potential, settling tests, modelling of the particle networks and electrophoretic deposition were done. The influence of the water and iodine concentration, and their role as stabilizers was evaluated. Based on experimental results, pair particle potentials were calculated and then different charging mechanisms of YBCO surfaces in acetone were proposed. [less ▲]

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See detailSpray drying: An alternative synthesis method for polycationic oxide compounds
Rivas-Murias, B.; Fagnard, J.-F.; Vanderbemden, Philippe ULg et al

in Journal Of Physics And Chemistry Of Solids (2011), 72(3), 158-163

Synthesis of polycationic compounds by the spray-drying technique is an interesting alternative in the domain of aqueous precursor synthesis methods. Spray drying yields high quality samples with good ... [more ▼]

Synthesis of polycationic compounds by the spray-drying technique is an interesting alternative in the domain of aqueous precursor synthesis methods. Spray drying yields high quality samples with good reproducibility. The possibility of scaling up for production of large quantities with fast processing time is well established by the commercial availability of powders of various compositions. In this paper, we have discussed the advantages and limitations of this method and demonstrated its interest by synthesizing a few polycationic compounds selected for their attractive properties of thermoelectricity [Bi1.68Ca2Co1.69O8, La(0.95)A(0.05)CoO(3) (A = Ca, Sr, Ba)] or magnetoresistance [La(0.70)A(0.30)MnO(3) (A=Sr, Ba)]. We have confirmed the quality of these samples by reporting their structure, magnetic and transport properties. (C) 2010 Elsevier Ltd. All rights reserved. [less ▲]

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See detailPolymer micelles decorated by gadolinium complexes as MRI blood contrast agents: design, synthesis and properties
Grogna, Mathurin ULg; Cloots, Rudi ULg; Luxen, André ULg et al

in Polymer Chemistry (2010), 1

New micellar macrocontrast agents with improved contrast at high frequencies were designed by grafting a gadolinium based contrast agent onto functional stealth micelles formed by poly(ethylene oxide)-b ... [more ▼]

New micellar macrocontrast agents with improved contrast at high frequencies were designed by grafting a gadolinium based contrast agent onto functional stealth micelles formed by poly(ethylene oxide)-b-poly(ε-caprolactone) (PEO-b-PCL) in water. As evidenced by relaxometry measurements and the hemolytic CH50 test, the new contrast agents are of interest as MRI blood pool agents. [less ▲]

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See detailTiO2 thin films (1 µm) with ordered porosity used as high performance photoelectrode in DSSC
Dewalque, Jennifer ULg; Cloots, Rudi ULg; Dubreuil, Olivier et al

Poster (2010, July 06)

Mesoporous anatase thin films are very promising materials to act as electrode in dye-sensitized solar cells. Randomly oriented nanocrystalline TiO2 particles are usually used to prepare photoelectrodes ... [more ▼]

Mesoporous anatase thin films are very promising materials to act as electrode in dye-sensitized solar cells. Randomly oriented nanocrystalline TiO2 particles are usually used to prepare photoelectrodes with a thickness of 10-15 µm. Templated-assisted dip-coating techniques are used to obtain thin films with ordered porosity. The use of different templates influences the film porosity in terms of long-range order, percentage of porosity, pore size and pores connectivity. The photovoltaic performances of the samples have been evaluated. Such mesostructured films are compared in terms of photovoltaic performance with TiO2 nanoparticles films, generally used in DSSC. [less ▲]

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See detailRepeated thermal treatments applied to ordered TiO2 mesoporous thin film: Effect on the film crystallization and surface area
Henrist, Catherine ULg; Dubreuil, Olivier; Krins, Natacha ULg et al

Conference (2010, July 06)

Ordered, mesoporous films are prepared by template-assisted sol-gel techniques such as dip-coating from a precursors solution. However, monolayer films are only a few hundred nanometers thick and present ... [more ▼]

Ordered, mesoporous films are prepared by template-assisted sol-gel techniques such as dip-coating from a precursors solution. However, monolayer films are only a few hundred nanometers thick and present a limited surface area of active material resulting in poor photovoltaic performances. Therefore it is needed to increase the film thickness. A multilayer deposition process for anatase mesoporous film has been reported in the literature in 2005 by Zukalova and all. Unfortunately, later researches have shown a surface area limitation despite the increase of film thickness due to the repeated thermal treatments applied to the layers. In this study, we have investigated the microstructural evolution of a single mesoporous TiO2 layer submitted to repeated thermal treatments. The modifications are discussed in terms of film thickness, surface area, anatase crystals size and global crystallinity. Besides, we propose an alternative thermal treatment designed in an attempt to overcome the limitations induced by repeated calcinations. We have followed and compared the properties of mesoporous films submitted to both thermal treatments by X-ray diffraction (XRD), transmission electron microscopy (TEM) and environmental poroellipsometry (EEP). Those results show the importance of the tuning of thermal treatment when multilayers films are envisaged for DSSC applications. Indeed, this study quantifies the maximum perturbation encountered by the first layer during the preparation of a multilayer (up to 12) coating, which is submitted to a multistep calcination. Finally, the photovoltaic performances of assembled cells have been evaluated. [less ▲]

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See detailSynthesis of hybrid lamellar silica by liquid crystal templating and silanation
Toussaint, Gilles; Henrist, Catherine ULg; Vertruyen, Bénédicte ULg et al

in Advances in Science and Technology (2010), 68

This paper is focused on the preparation and characterization of different lamellar silica prepared by liquid crystal templating and silanisation. The initial template can be removed and replaced in the ... [more ▼]

This paper is focused on the preparation and characterization of different lamellar silica prepared by liquid crystal templating and silanisation. The initial template can be removed and replaced in the interlamellar spaces by different types of silane, being covalently grafted to the solid by reaction with the surface silanols. The lamellar stacking periodicity remains after this modification. The surfactant extraction can lead in significant grafting of isopropanol if the solid is simply refluxed in isopropanol, which have the effect of preserving the periodicity of the lamellar stacking. The surfactant extraction in an Soxhlet equipment avoid this reaction, with the effect of platelets organization collapsing. The lamellar silica studied exhibit great specific surface and combination of meso and microporosity, making them interesting materials for nanocomposite or catalysis applications. [less ▲]

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See detailVanadium oxide-based mesoporous films as positive electrode material in Li-ion batteries
Krins, Natacha ULg; Caes, Sébastien ULg; Arrebola, José-Carlos et al

Conference (2010)

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See detailStructural and magnetic properties of nanosized barium hexaferrite powders obtained by microemulsion technique
Koutzarova, Tantyana; Kolev, Svetoslav; Ausloos, Marcel ULg et al

in Diffusion and Defect Data--Solid State Data, Pt. B: Solid State Phenomena (2010), 159

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See detailImprovement of the thermoelectric properties of [Bi1.68Ca2O4-delta](RS)[CoO2](1.69) cobaltite by chimie douce methods
Muguerra, Hervé; Rivas-Murias, Beatriz; Traianidis, Maria et al

in Journal of Solid State Chemistry (2010), 183(6), 1252-1257

[Bi1 68Ca2O4 delta](RS)[CoO2](1 69) has been obtained by different chimie douce methods and uniaxially or isostatically pressed The influence of these parameters on the thermoelectric properties has been ... [more ▼]

[Bi1 68Ca2O4 delta](RS)[CoO2](1 69) has been obtained by different chimie douce methods and uniaxially or isostatically pressed The influence of these parameters on the thermoelectric properties has been investigated. Contrary to the Seebeck coefficient, which remains unchanged, the electrical conductivity is greatly modified In particular, spray-drying synthesis followed by uniaxial pressing results in an electrical conductivity two times larger than in the case of conventional solid state synthesis. Our results suggest that a narrow particle size distribution is beneficial to the thermoelectric properties of the layered compounds. The spray-drying technique seems to be promising to Improve the electrical conductivity of layered materials. Moreover, this method presents other advantages (homogeneous samples and less energetic processing) which could be interesting to the future manufacturing of thermoelectric devices (C) 2010 Elsevier Inc. All rights reserved [less ▲]

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See detailImage analysis of pearlite spheroidization based on the morphological characterization of cementite particles
Nutal, Nicolas; Gommes, Cédric ULg; Blacher, Silvia ULg et al

in Image Analysis and Stereology (2010), 29

Pearlite spheroidization is a metallurgical process in steels by which cementite lamellaer decompose into spheroids, a process accompanied by a decrease of the Vickers hardness of the samples. In thi ... [more ▼]

Pearlite spheroidization is a metallurgical process in steels by which cementite lamellaer decompose into spheroids, a process accompanied by a decrease of the Vickers hardness of the samples. In thi study, different methods are compared for measuring cementite particles length and width from scanning electron micrographs. Based on a test-image, a so-called ribbon-like method is proposed for measuring particles length and width, and for discriminating lamellae from spheroids. Differently heat-treated samples are prepared and characterized. The results of analysis are used to rationalize the evolution of the microstructure of the samples. Compared to teh calssical DeHoff shape factor, it is shown that new insight into the spheroidization process is gained by analysing the lamellar length and widh distributions. [less ▲]

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See detailEnhancement of the power factor of [Bi1.68Ca2O4](RS)[CoO2](1.69) - Ag composites prepared by the spray-drying method
Rivas-Murias, B.; Muguerra, Hervé ULg; Traianidis, M. et al

in Solid State Sciences (2010), 12(8), 1490-1495

[Bi1.68Ca2O4](RS)[CoO2](1.69) (BCCO) sample and Ag-BCCO composites (with 10, 20 or 30 wt% Ag) have been prepared by the spray-drying technique and uniaxially/isostatically packed. Scanning electron ... [more ▼]

[Bi1.68Ca2O4](RS)[CoO2](1.69) (BCCO) sample and Ag-BCCO composites (with 10, 20 or 30 wt% Ag) have been prepared by the spray-drying technique and uniaxially/isostatically packed. Scanning electron microscopy reveals that the Ag particles are well distributed in the BCCO cobaltite matrix at low Ag contents. The Ag particles have an important effect on densification and grain orientation of the samples, with a direct impact on their electrical conductivity. The electrical conductivity is higher for the uniaxial samples and increases with the Ag content up to 20% in weight, while the Seebeck coefficient is hardly affected. These features induce an improvement of the power factor, reaching a maximum value of 2.2 mu W K-2 cm(-1) at similar to 1050 K for the uniaxial sample with 20 wt% Ag. Our results suggest that the spray-drying technique is a promising method to obtain composites with a well-dispersed secondary phase. (C) 2010 Elsevier Masson SAS. All rights reserved. [less ▲]

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See detailNovel Stealthy Gd(III)-DOTA/polymer Conjugates for Magnetic Resonance Imaging (MRI)
Grogna, Mathurin ULg; Bémelmans, Stéphanie ULg; Vanasschen, Christian ULg et al

Conference (2009, May 14)

Magnetic resonance imaging (MRI) is a routine diagnostic tool in modern clinical medicine. MRI has many advantages as a diagnostic imaging modality. It is noninvasive, delivers no radiation, and has ... [more ▼]

Magnetic resonance imaging (MRI) is a routine diagnostic tool in modern clinical medicine. MRI has many advantages as a diagnostic imaging modality. It is noninvasive, delivers no radiation, and has excellent (submillimeter) spatial resolution. Some Gadolinium(III) complexes are commonly used to enhance the contrast between adjacent tissues when the resolution/sensitivity of MRI is too low. Because free Gd3+ is very toxic in doses required for MRI, Gd(III) is chelated by poly(amino-carboxylate) such as diethylenetriamine pentaacetic acid (DTPA) or 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). Although DTPA/Gd3+ and DOTA/Gd3+ are water soluble, they have a very short circulation lifetime in blood, a low molecular weight and a short rotational time that make the contrast poor. To enhance the contrast, the Gd3+/complex doses have to be increased. In order to increase the sensitivity of the technique, while not increasing the concentration of the contrast agent, we were investigating different strategies to improve (i) the circulation lifetime in blood, (ii) the relaxation rate of Gd(III) (and consequently, the contrasting efficiency) and (iii) the targeting of the contrast agent. This presentation aims at reporting how a multifunctional (co)polymer can be designed and exploited for improving the contrasting ability and bioavailability of gadolinium-based complexes. [less ▲]

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See detailHybrid lamellar silica: Combined template extraction and hydrophilic silanation
Toussaint, Gilles ULg; Brisbois, Magali ULg; Grandjean, Jean ULg et al

in Journal of Colloid & Interface Science (2009), 329(1), 120-126

The surface modification of lamellar silica prepared by liquid crystal templating has been investigated. Two hydrophilic surface modifier agents, 2-glycidoxypropyltrimethoxysilane and 2-[methoxy ... [more ▼]

The surface modification of lamellar silica prepared by liquid crystal templating has been investigated. Two hydrophilic surface modifier agents, 2-glycidoxypropyltrimethoxysilane and 2-[methoxy(polyethyleneoxy)propyl)] trimethoxysilane, have been tested. Characterizations of the modified silica include thermal analysis, C-13 and Si-29 solid state NMR, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The different characterizations confirmed the preservation of the lamellar morphology and the Successful surface modification with both silanes along with the template elimination. The results also indicate that the structure and length of the silanes influence the final lamellar organization as well as the grafting yields and mechanisms. (C) 2008 Elsevier Inc. All rights reserved. [less ▲]

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See detailControl of the porosity of anatase thin films prepared by EISA: Influence of thickness and heat treatment
Henrist, Catherine ULg; Dewalque, Jennifer ULg; Mathis, François ULg et al

in Microporous & Mesoporous Materials (2009), 117

Mesoporous anatase thin films were prepared by the evaporation-induced self-assembly process. This paper reports a study of the influence of several physical parameters on the long-range ordering of the ... [more ▼]

Mesoporous anatase thin films were prepared by the evaporation-induced self-assembly process. This paper reports a study of the influence of several physical parameters on the long-range ordering of the mesopores. A preliminary study was done to set the best humidity conditions during dip-coating and ageing of the films. The withdrawal speed, already known to modify the thickness of the deposited film, was shown to exert a strong influence on the percentage of porosity. This was studied by step profilometry combined with Rutherford backscattered spectrometry (RBS). In parallel, small angle X-ray scattering (SAXS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and RBS were used to tune the precise thermal treatment applied to the so-obtained films, in order to preserve the porous mesostructure and promote the nanocrystallization of anatase TiO2. [less ▲]

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