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See detailHighly efficient organic/inorganic titania xerogels for photocatalysis applications
Bodson, Céline ULg; Bied, Catherine; Páez Martínez, Carlos ULg et al

Poster (2011)

TiO2 heterogeneous photocatalysis is an attractive technique for the complete destruction of undesirable contaminants either in aqueous or gaseous phase by using solar or artificial light illumination ... [more ▼]

TiO2 heterogeneous photocatalysis is an attractive technique for the complete destruction of undesirable contaminants either in aqueous or gaseous phase by using solar or artificial light illumination. The main drawback of TiO2 is that it can be activated only by UV light because of its large band gap (3.20 eV for anatase). Thus, it would be interesting to sensitize TiO2 to the whole visible region by doping with non-metal atoms such as phosphorus. Furthermore, it was found that the P-doped species could significantly increase the specific surface area of the materials, which consequently exhibit a higher content of surface hydroxyl groups. Upon band gap excitation of TiO2, the photoinduced electrons and positively charged holes can reduce and oxidize the species adsorbed on the TiO2 particles. The high degree of recombination between photogenerated electrons and holes is a major rate-limiting factor controlling the photocatalytic efficiency. Attempts to increase the titania efficiency have been made by doping P-doped TiO2 with metals, such as Ag. In the present study, a sol-gel method is developed to synthesize P-doped TiO2 and P/Ag-codoped xerogels by a cogelation method [1] based on the hydrolysis and the condensation of Ti(OC3H7)4 in the presence of a phosphoryled compound able to complex silver: NH2-(CH2)2-NH-(CH2)2-P(O)-(OC2H5)2, EDAP), in various alcohols. These xerogels are dried at 150°C under vacuum for 24 h, and calcined under air for 5 h at 350°C, 450°C, 550°C and 650°C. The resulting materials were characterized by ICP-AES, TG-DSC, TEM, XRD, nitrogen adsorption-desorption isotherms, FT-IR and diffuse reflectance measurements in the UV/Vis region. To measure the photoactivity of these new hybrid organic/inorganic titania xerogels, all these samples were tested for the degradation of p-nitrophenol under visible light. The titanium, phosphorus and silver contents in xerogels were confirmed by ICP-AES. As expected, theoretical and actual Ti/P molar ratio and Ag contents in xerogels are similar and then after washing with THF for 48 h. These results allow to conclude that EDAP and Ag are well incorporated within the TiO2 matrix: EDAP is anchored in the titania matrix by complexation and cogelation with TTIP [2], whereas silver, first incorporated by complexation through the ethylenediamine fragment of EDAP, is present in the xerogels in the form of nanoparticles. It was found that the phosphor-doped species could significantly increase the surface area of the materials. [2] It is noteworthy that the porosity of these materials is not affected by the addition of silver acetate during the synthesis, a very slight decrease of the specific surface area being observed in all cases. The organic/inorganic hybrid titania materials display very high photocatalytic efficiencies in the degradation of p-nitrophenol compared to pure titania. Deeper investigations concerning the structure of these materials should enable a better understanding of the photocatalytic mechanisms involved with these hybrids and will soon be reported. 1. S. Lambert, K. Y. Tran, G. Arrachart, F. Noville, C. Henrist, C. Bied, J. J. E. Moreau, M. Wong Chi Man, B. Heinrichs, Micropor. Mesopor. Mater. 2008, 115, 609. 2. C.J.Bodson1, S.D. Lambert1, C. Alié1, X. Cattoën2, J-P. Pirard1, C. Bied2, M.Wong Chi Man2, B. Heinrichs1 ,Micropor. Mesopor. Mater. 2010, 134,157 [less ▲]

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See detailHighly Efficient Separation of Actinide from Lanthanide by a Phenanthroline-Derived Bis-triazine Ligand
Lewis, Frank W.; Harwood, Laurence M.; Hudson, Michael J. et al

in Journal of the American Chemical Society (2011), 133

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See detailHighly efficient, long life, reusable and robust photosynthetic hybrid core-shell beads for the sustainable production of high value compounds
Desmet, Jonathan; Meunier, Christophe; Danloy, Emeric et al

in Journal of Colloid & Interface Science (2015), 448

An efficient one-step process to synthesize highly porous (Ca-alginate–SiO2–polycation) shell: (Na-alginate– SiO2) core hybrid beads for cell encapsulation, yielding a reusable long-life ... [more ▼]

An efficient one-step process to synthesize highly porous (Ca-alginate–SiO2–polycation) shell: (Na-alginate– SiO2) core hybrid beads for cell encapsulation, yielding a reusable long-life photosynthetically active material for a sustainable manufacture of high-value metabolites is presented. Bead formation is based on crosslinking of an alginate biopolymer and mineralisation of silicic acid in combination with a coacervation process between a polycation and the silica sol, forming a semi-permeable external membrane. The excellent mechanical strength and durability of the monodispersed beads and the control of their porosity and textural properties is achieved by tailoring the silica and alginate loading, polycation concentration and incubation time during coacervation. This process has led to the formation of a remarkably robust hybrid material that confers exceptional protection to live cells against sheer stresses and contamination in a diverse range of applications. Dunaliella tertiolecta encapsulated within this hybrid core–shell system display high photosynthetic activity over a long duration (>1 year). This sustainable biotechnology could find use in high value chemical harvests and biofuel cells to photosynthetic solar cells (energy transformation, electricity production, water splitting technologies). Furthermore the material can be engineered into various forms from spheres to variable thickness films, broadening its potential applications. 2015 Elsevier Inc. All rights reserved. [less ▲]

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See detailHighly enantioselective synthesis of no-carrier-added 6-[18F]Fluoro-L-dopa by chiral phase-transfer alkylation
Lemaire, Christian ULg; Gillet, Steve; Guillouet, Stéphane et al

in European Journal of Organic Chemistry (2004), (13), 2899-2904

[F-18]Fluoro-L-dopa, an important radiopharmaceutical for positron emission tomography (PET), has been synthesized using a phase-transfer alkylation reaction. A chiral quaternary ammonium salt derived ... [more ▼]

[F-18]Fluoro-L-dopa, an important radiopharmaceutical for positron emission tomography (PET), has been synthesized using a phase-transfer alkylation reaction. A chiral quaternary ammonium salt derived from a Cinchona alkaloid served as phase-transfer catalyst for the enantioselective alkylation of a glycine derivative. The active methylene group of this Schiff-base substrate was deprotonated with cesium hydroxide and rapidly alkylated by the 2-[F-18]fluoro-4,5-dimethoxybenzyl halide (X = Br, I). The reaction proceeded with high yield (> 90%) at 0 degreesC or room temperature in various solvents such as toluene or dichloromethane. Preparation of the [F-18]alkylating agent on a solid support was developed. After labelling, the labeled [F-18]fluoroveratraldehyde was trapped on a (t)C18 cartridge and then converted on the cartridge into the corresponding benzyl halide derivatives by addition of aqueous sodium borohydride and gaseous hydrobromic or -iodic acid. Hydrolysis and purification by preparative HPLC made 6-[F-18]fluoro-L-dopa ready for human injection in a 25-30% decay-corrected radiochemical yield in a synthesis time of 100 min. The product was found to be chemically, radiochemically and enantiomerically pure (ee > 95%). (C) Wiley-VCH Verlag GmbH [less ▲]

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See detailHighly excited baryons in large N(c) QCD
Matagne, Nicolas; Stancu, Floarea ULg

in AIP Conference Proceedings (2005), 775

We use the $1/N_c$ expansion of QCD to analyse the spectrum of positive parity resonances with strangeness $S = 0, -1, -2$ and -3 in the 2--3 GeV mass region, supposed to belong to the $[\textbf{56},4 ... [more ▼]

We use the $1/N_c$ expansion of QCD to analyse the spectrum of positive parity resonances with strangeness $S = 0, -1, -2$ and -3 in the 2--3 GeV mass region, supposed to belong to the $[\textbf{56},4^+]$ multiplet. The mass operator is similar to that of $[\textbf{56},2^+]$, previously studied in the literature. The analysis of the latter is revisited. In the $[\textbf{56},4^+]$ multiplet we find that the spin-spin term brings the dominant contribution and that the spin-orbit term is entirely negligible in the hyperfine interaction, in agreement with constituent quark model results. More data are strongly desirable, especially in the strange sector in order to fully exploit the power of this approach. We discuss possibilities of extending the calculations to other excited baryons belonging to the N=2 or the N=4 band. [less ▲]

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See detailHighly excited negative parity baryons in the 1/Nc expansion.
Matagne, Nicolas ULg; Stancu, Floarea ULg

in Physical Review. D : Particles and Fields (2012), D85

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See detailHighly excited states of baryons in large Nc QCD
Matagne, Nicolas; Stancu, Floarea ULg

in Bled Workshops in Physics (2012, November), 13(1), 47-53

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See detailHighly functional branched and dendri-graft aliphatic polyesters through ring opening polymerization
Trollsas, Michaël; Hedrick, James L.; Mecerreyes, David et al

in Macromolecules (1998), 31(9), 2756-2763

Highly branched poly(ε-caprolactones) with novel and well-defined molecular architectures have been synthesized by the use of new multifunctional initiators. The ring-opening polymerization methods used ... [more ▼]

Highly branched poly(ε-caprolactones) with novel and well-defined molecular architectures have been synthesized by the use of new multifunctional initiators. The ring-opening polymerization methods used to prepare these new structures allowed accurate control of molecular weight and narrow molecular weight distributions. In addition, the synthesis of even more complex molecular architectures was possible by the use of 1,4,9-trioxaspiro[4.6]-9-undecanone as a comonomer with ε-caprolactone. After copolymerization, complete deacetalization of the polyester chains into the corresponding ketone groups followed by quantitative reduction formed polymers with hydroxyl pendant groups. With this synthetic strategy, significant additional functionality was introduced. In addition, the pendant hydroxyl groups along the chains can serve as macroinitiators for the further initiation of ε-caprolactone to prepare dendri-graft molecular architectures. The new polymers were characterized by 1H NMR, 13C NMR, and size exclusion chromatography (SEC). 13C NMR spectra clearly showed that the hydroxyl groups of the initiators were fully substituted to give polymers with two, four, and six arms. [less ▲]

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See detailHighly Luminescent Aqueous Ag2S Quantum Dots as New Generation Quantum Dots
Yağcı Acar, Havva Funda; Hocaoğlu, I.; Demir, F. et al

in Proceediing of the meeting (2015, March 09)

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See detailHighly non-classical symmetric states of an N-qubit system
Baguette, Dorian ULg; Martin, John ULg

Poster (2013, September 02)

In this work, we consider two measures of non-classicality for pure symmetric N-qubit states : Wehrl entropy (S) and Wehrl participation ratio (R). Measures of non-classicality help to the understanding ... [more ▼]

In this work, we consider two measures of non-classicality for pure symmetric N-qubit states : Wehrl entropy (S) and Wehrl participation ratio (R). Measures of non-classicality help to the understanding of the mechanisms responsible for the transition from quantum to classical physics and are usefull in the context of information processing and quantum-enhanced measurements. [less ▲]

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See detailHighly non-classical symmetric states of an N-qubit system
Baguette, Dorian ULg; Martin, John ULg

Poster (2013, March 19)

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See detailHighly ordered mesoporous CMI-n materials and hierarchically structured meso-macroporous compositions
Su, B.-L.; Léonard, Alexandre ULg; Yuan, Z.-Y.

in Comptes Rendus Chimie (2005), 8(3-4), 713-726

The present review outlines the research work realized during last the 10 years in our laboratory in the field of the conception of new nanostructured porous materials, from mesoporous silicas and metal ... [more ▼]

The present review outlines the research work realized during last the 10 years in our laboratory in the field of the conception of new nanostructured porous materials, from mesoporous silicas and metal oxides to hierarchical meso-macroporous compounds with various compositions (single and binary metal oxides and aluminosilicates, aluminophosphates and silicoaluminophosphates). An accent was especially made on the evolution in the development of new synthesis strategies for the introduction of a hierarchy in one solid body with and without surfactant molecules. © 2005 Académie des sciences. Published by Elsevier SAS. All rights reserved. [less ▲]

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See detailHighly pathogenic avian influenza H5N1 virus in cats and other carnivores
Thiry, Etienne ULg; Zicola, Angélique ULg; Addie, D. et al

in Veterinary Microbiology (2007), 122(1-2), 25-31

The Asian lineage highly pathogenic avian influenza (HPAI) H5N1 virus is a known pathogen of birds. Only recently, the virus has been reported to cause sporadic fatal disease in carnivores, and its ... [more ▼]

The Asian lineage highly pathogenic avian influenza (HPAI) H5N1 virus is a known pathogen of birds. Only recently, the virus has been reported to cause sporadic fatal disease in carnivores, and its zoonotic potential has been dominating the popular media. Attention to felids was drawn by two outbreaks with high mortality in tigers, leopards and other exotic felids in Thailand. Subsequently, domestic cats were found naturally infected and experimentally susceptible to H5N1 virus. A high susceptibility of the dog to H3N8 equine influenza A virus had been reported earlier, and recently also HPAI H5N1 virus has been identified as a canine pathogen. The ferret, hamster and mouse are suitable as experimental animals; importantly, these species are also kept as pets. Experimental intratracheal and oral infection of cats with an HPAI H5N1 virus isolate from a human case resulted in lethal disease; furthermore, cats have been infected by the feeding of infected chickens. Spread of the infection from experimentally infected to in-contact cats has been reported. The epidemiological role of the cat and other pet animal species in transmitting HPAI H5N1 virus to humans needs continuous consideration and attention. (c) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailHighly regular polyampholytic structures adsorbed directly from solution
Mahltig, Boris; Müller-Buschbaum, P.; Wolkenhauer, M. et al

in Journal of Colloid and Interface Science (2001), 242(1), 36-43

This article concerns the adsorption of the diblock polyampholyte poly(methacrylic acid)-block-poly((dimethylamino)ethyl methary-late) (PMAA-b-PDMAEMA) from aqueous solution on silicon substrates. The ... [more ▼]

This article concerns the adsorption of the diblock polyampholyte poly(methacrylic acid)-block-poly((dimethylamino)ethyl methary-late) (PMAA-b-PDMAEMA) from aqueous solution on silicon substrates. The investigated polyampholyte is characterized by a small molecular weight around 15,000 g/mol and a big positively charged PDMAEMA block. The adsorbed amount determined by ellipsom-etry was str ongly influenced by the pH of the adsorption solution. Using dynamic light scattering polyampholytic structures with diameters around 50 nm were found in aqueous solution. The hy-drodynamic diameter was hardly affected by changing the pH of the polymer solution. Analogous regular structures were also found by scanning force microscopy (SFM) and grazing incidence, small angle X-ray scattering (GISAXS) at the silicon surface after the adsorption process. While SFM provides a topographical image of a small part of the adsorbed polyampholytic layer; GISAXS was used to get a statistical description of the lateral surface structures. The adsorbed structures were highly regular and their sizes were nearly pH independent over a lar ge pH region. Only directly at the isoelectric point of the polyampholyte larger adsorbed structures were observed. Compared with earlier investigated PMAA-b-PDMAEMA systems we are now able to prepare highly regular polyampholytic structures at silicon surfaces. There are two kinds of interactions for the adsorbed micelles. First, the charged block of the chains is directly attracted to the substrate via electrostatic interactions, while the uncharged part of the chains is only hydrophobically attracted via the hydrophobic core of the adsorbed micelle. [less ▲]

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See detailA highly reliable integrated PDMS interconnector with a long cast flange for microfluidic systems
Chang, Honglong; Zhang, F.; Ding, J. et al

in Microsystem Technologies (2012), 18(6), 723--730

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See detailHighly sensitive immunodetection of DNA on sections with exogenous terminal deoxynucleotidyl transferase and non-isotopic nucleotide analogues.
Thiry, Marc ULg

in Journal of Histochemistry and Cytochemistry : Official Journal of the Histochemistry Society (1992), 40(3), 411-9

A new method is described for locating DNA on ultra-thin sections. Sections of aldehyde-fixed, plastic-embedded cells were incubated in a medium containing terminal deoxynucleotidyl transferase (TdT) and ... [more ▼]

A new method is described for locating DNA on ultra-thin sections. Sections of aldehyde-fixed, plastic-embedded cells were incubated in a medium containing terminal deoxynucleotidyl transferase (TdT) and various non-isotopic nucleotide analogues. The labeled nucleotides bound to the surface of ultra-thin sections were then visualized by an indirect immunogold labeling technique. The resulting labeling pattern was strongly dependent on the divalent cation used in the TdT medium. The method revealed with great precision the specific DNA-containing structures within Ehrlich tumor cells, even where DNA was present in very low amounts. The method is compatible with all usual fixation and embedding procedures and can be combined with cytochemical methods. The in situ TdT method provides a very useful tool for pinpointing the precise location of DNA within biological material at the ultrastructural level. [less ▲]

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