References of "Cloots, Rudi"
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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 detailAg-and SiO2-doped porous TiO2 with enhanced thermal stability
Braconnier, Benoît ULg; Páez Martínez, Carlos ULg; Lambert, Stéphanie ULg et al

in Microporous and Mesoporous Materials (2009), 122

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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 and 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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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 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 (2009)

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See detailEffects of Rice Straw on the Color and Microstructure of Bizen, a Traditional Japanese Stoneware, as a Function of Oxygen Partial Pressure
Kusano, Y.; Doi, A.; Fukuhara, M. et al

in Journal of the American Ceramic Society (2009), 92(8), 1840-1844

The effects of oxygen partial pressure during thermal treatment on the color and microstructure of Bizen, a traditional Japanese stoneware, were studied through model experiments using clay pellets ... [more ▼]

The effects of oxygen partial pressure during thermal treatment on the color and microstructure of Bizen, a traditional Japanese stoneware, were studied through model experiments using clay pellets covered lightly with rice straw as a coloring assistant. When heated in flowing nitrogen, the model pellet turned blackish owing to the formation of alpha-Fe particles coated with graphite. However, schreibersite (Fe3P), which is also blackish, was formed specifically on the pellet surface in direct contact with the straw. The rice straw seems to have generated a strongly reducing atmosphere, strong enough for the metallization to alpha-Fe, and also to have provided phosphorus through contact. When oxygen content in the surrounding gas atmosphere was raised to N-2/O-2=99/1, the pellet surface turned yellowish brown because the main coloring material was Fe3+-containing mullite. At oxygen contents of N-2/O-2=98/2 or more, the formation of hematite (alpha-Fe2O3) pushed the color to deep red. [less ▲]

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See detailRapid synthesis of submicron crystalline barium zirconate BaZrO3 by precipitation in aqueous basic solution below 100 degrees C
Boschini, Frédéric ULg; Rulmont, André ULg; Cloots, Rudi ULg et al

in Journal of the European Ceramic Society (2009), 29(8), 1457-1462

Pure crystalline BaZrO3 powders can be produced by precipitation in highly basic aqueous solution. The influence of several synthesis parameters is studied. At high OH- concentration ([NaOH] = 20 mol/l ... [more ▼]

Pure crystalline BaZrO3 powders can be produced by precipitation in highly basic aqueous solution. The influence of several synthesis parameters is studied. At high OH- concentration ([NaOH] = 20 mol/l), it is possible to obtain the well-crystallized stoichiometric perovskite phase at relatively low temperature (similar to 80 degrees C), after a short reaction time (15 min) and without requiring any precaution to avoid the presence of CO2. This synthesis method yields spherical particles, whose size can be controlled by changing the concentration of the Ba + Zr solution. No calcination treatment is necessary since the precipitate is crystalline. Suitable choice of the synthesis parameters ([NaOH] = 20 mol/l, [Ba + Zr] = 1 mol/l, reaction time= 15 min) yields a sub-micron precipitate with excellent densification behaviour. Corrosion tests in BaO-CuO melt show that similar to 98% dense BaZrO3 obtained by sintering at 1650 degrees C for 13 h could be used for crucibles in the synthesis of YBa2Cu3O7 superconducting single crystals. (C) 2008 Elsevier Ltd. All rights reserved. [less ▲]

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See detailStructural and electrochemical characterization of mesoporous thin films of Nb2xV2-2xO5 upon lithium intercalation
Krins, Natacha ULg; Lepot, Laurent; Cloots, Rudi ULg et al

in Solid State Ionics (2009), 180(11-13), 848-852

Nb2xV2 - 2xO5 (0 <= x <= 1) powders were prepared by a synthetic route based on the inorganic polymerization of alkoxy-choride precursors and characterized by a combination of X-ray diffraction V-51 and ... [more ▼]

Nb2xV2 - 2xO5 (0 <= x <= 1) powders were prepared by a synthetic route based on the inorganic polymerization of alkoxy-choride precursors and characterized by a combination of X-ray diffraction V-51 and Nb-93 NMR and Raman spectroscopy. Amorphous mesoporous thin films of similar compositions were successfully prepared by a modified Evaporation Induced Self Assembly method using polystyrene-b-polyethyleneoxide diblock copolymer as structuring agent. The electrochemical properties of the mesoporous films upon lithium insertion-deinsertion are investigated by cyclic voltammetry. This study highlights the advantages of such nanoarchitecture in terms of increased capacity to insert lithium. (C) 2009 Elsevier B.V. All rights reserved. [less ▲]

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See detailInteractions in YBa2Cu3O7-x aqueous suspensions
Dusoulier, Laurent; Cloots, Rudi ULg; Vertruyen, Bénédicte ULg et al

in Materials Chemistry & Physics (2009), 116(2-3), 368-375

Surface charging mechanism of YBa2Cu3O7-x (YBCO) particles in water has been investigated in order to understand their colloidal behaviour and stabilise concentrated suspensions. A broad study relating ... [more ▼]

Surface charging mechanism of YBa2Cu3O7-x (YBCO) particles in water has been investigated in order to understand their colloidal behaviour and stabilise concentrated suspensions. A broad study relating the suspension parameters (pH and zeta potential) vs. the conditions of the suspension performance (atmosphere and time) has been shown and discussed. The zeta potential values remain positive in all the pH range for the highest powder concentration studied (10 g l(-1)), evidencing a large influence of the solid content in the particle charge. The chemistry of YBa2Cu3O7-x in water has been studied through the chemical analysis of the supernatant by inductively coupled plasma (ICP), and the surface analysis of the particles by X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS). The presence of BaCO3, CuO, and the hydrolysed Ba species, such as Ba(OH)(2) and Ba(OH)(+), at the particles surface has been evaluated as a function of the powder concentration. Based on these analyses, the dependence of the colloidal behaviour of YBCO on the presence of Ba soluble species has been determined. A stabilisation mechanism for YBCO particles in aqueous suspension focus on the powders deleterious minimization was proposed. (C) 2009 Elsevier B.V. All rights reserved. [less ▲]

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See detailMullite coatings on ceramic substrates: Stabilisation of Al2O3-SiO2 suspensions for spray drying of composite granules suitable for reactive plasma spraying
Schrijnemakers, Audrey ULg; Andre, Sophie; Lumay, Geoffroy ULg et al

in Journal of the European Ceramic Society (2009), 29(11), 2169-2175

The present work deals with the preparation of stable alumina + silica suspensions with high solid loading for the production of spray-dried composite powders. These composite powders are to be used for ... [more ▼]

The present work deals with the preparation of stable alumina + silica suspensions with high solid loading for the production of spray-dried composite powders. These composite powders are to be used for reactive plasma spraying whereby the formation of mullite and the coating on a ceramic substrate are achieved in a single step process. Electrostatic stabilisation of alumina and silica suspensions has been studied as a function of pH. Silica suspensions are most stable at basic pH whereas alumina suspensions are stable at acidic pH. The addition of ammonium polymethacrylate (APMA) makes it possible to stabilise alumina and prepare a stable 50 wt% alumina + silica suspension at pH 10. The optimum amounts of dispersant and binder have been determined by zeta potential, viscosity and sedimentation measurements. Spray drying of the suspension yields composite powders whose morphology, size distribution and flowability have been characterized before realizing reactive plasma spraying tests. (C) 2009 Elsevier Ltd. All fights reserved. [less ▲]

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See detailTiO2 mesoporous thin films acting as photoelectrode in dye-sensitized solar cells
Dewalque, Jennifer ULg; Cloots, Rudi ULg; Henrist, Catherine ULg

Conference (2008, December 03)

This study aims at developing thin films of nanocrystalline, mesostructured titanium dioxide in order to build low cost and efficient photovoltaic devices. The synthesis is based on the Evaporation ... [more ▼]

This study aims at developing thin films of nanocrystalline, mesostructured titanium dioxide in order to build low cost and efficient photovoltaic devices. The synthesis is based on the Evaporation Induced-Self Assembly method using titanium isopropoxide as inorganic source, block copolymers as structuring and porogeneous agents and ethanol as solvent. The films were obtained by dip-coating various substrates in the solution. The influence of different experimental parameters, such as dip-coating and ageing relative humidity, withdrawal speed, surfactant:Ti ratio, substrate, was studied. The post-deposition thermal treatment had to be accurately adjusted in order to maximise the crystallisation of the inorganic network while avoiding the collapse of the porous mesostructure. The final structure obtained is discussed in the light of the XRD results combined with TEM analysis. Moreover the cell performance is limited by the film thickness which is mainly responsible of the small amount of absorbed light. Therefore a multilayer deposition process was studied and the as-obtained mesostructure was characterized by TEM, RBS and environmental ellipsometry. [less ▲]

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See detailElaboration of Magnetic Nanodots by Nanosphere Lithography : a Computerized Method for Order Quantification
Colson, Pierre ULg; Cloots, Rudi ULg; Henrist, Catherine ULg

Conference (2008, December 01)

Nanosphere lithography (NSL) is an ideal inexpensive fabrication tool for producing regular, nearly homogenous arrays of nanoparticules with different sizes. There are many different methods for the ... [more ▼]

Nanosphere lithography (NSL) is an ideal inexpensive fabrication tool for producing regular, nearly homogenous arrays of nanoparticules with different sizes. There are many different methods for the fabrication of the latex monolayer based on electrophoresis, the controlled evaporation of a solvent from the suspension containing latex particles, spincoating etc… We focused our work on this last method. The main problem with formation of 2D latex monolayers is that there are always a high number of different structural defects such as: point defects (vacancies), line defects (dislocations) and also many disordered areas. The influence of the different spincoating parameters on the amount of defects was determined by image analysis of SEM micrographies from the different samples. FePt and Co films were deposited onto quartz substrates through the polystryrene monolayers by magnetron sputtering. The nanopsheres were removed by sonication in toluene. Post-deposition annealing treatment was performed under reductive atmosphere for the FePt nanodots in order to transform the as-deposited chemically disoredered face-centered cubic (fcc) structure into the chemically ordered face-centered tetragonal (fct) phase (L10-phase). DRX , SEM and MFM analysis were performed on the different samples. [less ▲]

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See detailMesoporous TiO2 thin films for photovoltaic applications
Dewalque, Jennifer ULg; Cloots, Rudi ULg; Mathis, François ULg et al

Poster (2008, September 08)

Thin films of nanocrystalline, mesostructured titanium dioxide are very promising materials to build low cost and efficient photovoltaic devices. TiO2 present a high chemical stability and electronic ... [more ▼]

Thin films of nanocrystalline, mesostructured titanium dioxide are very promising materials to build low cost and efficient photovoltaic devices. TiO2 present a high chemical stability and electronic properties such as photoinduced electronic transfer properties associated with the anatase phase. For many applications, highly porous nanostructured thin films with accessible pores are preferable to dense ones. Indeed, high accessible porosity leads to high surface area increasing the electron transfer area. [less ▲]

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