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See detailDesign of mesoporous carbon fibers from a poly(acrylonitrile) based block copolymer by a simple templating compression moulding process
Thomassin, Jean-Michel ULg; Debuigne, Antoine ULg; Jérôme, Christine ULg et al

in Polymer (2010), 51(14), 2965-2971

Mesoporous carbon fibers were prepared by controlled pyrolysis of poly(vinyl acetate)-b-poly(acrylonitrile) (PVAc-b-PAN) copolymer located inside a cylindrical nanoporous template. A melt-compression ... [more ▼]

Mesoporous carbon fibers were prepared by controlled pyrolysis of poly(vinyl acetate)-b-poly(acrylonitrile) (PVAc-b-PAN) copolymer located inside a cylindrical nanoporous template. A melt-compression method was developed to help the penetration of the infusible copolymer inside the template without the use of any solvent that ensures the formation of completely filled fibers instead of nanotubes. The influence of the composition of the PVAc-b-PAN copolymer and the heating rate during pyrolysis on the porous morphology of the fibers was studied by transmission electron microscopy (TEM). [less ▲]

Detailed reference viewed: 110 (7 ULg)
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See detailDesign of Microswitch Systems Avoiding Stiction due to Surface Contact
Wu, Ling ULg; Noels, Ludovic ULg; Rochus, Véronique et al

in Proulx, Tom (Ed.) MEMS and Nanotechnology, Volume 2 (2011)

Stiction which results from contact between surfaces is a major failure mode in micro electro-mechanical systems (MEMS). Increasing restoring forces using high spring constant allows avoiding stiction but ... [more ▼]

Stiction which results from contact between surfaces is a major failure mode in micro electro-mechanical systems (MEMS). Increasing restoring forces using high spring constant allows avoiding stiction but leads to an increase of the actuation voltage so that the switch’s efficiency is threatened. A statistical rough surfaces interaction model, based on Maugis’ and Kim’s formulations is applied to estimate the adhesive forces in MEMS switches. Based on the knowledge of these forces, the proper design range of the equivalent spring constant, which is the main factor of restoring force in MEMS switches, can be determined. The upper limit of equivalent spring constant depends mainly on the expected actuator voltage and on the geometric parameters, such as initial gap size and thickness of dielectric layer. The lower limit is assessed on the value of adhesive forces between the two contacting rough surfaces. It mainly depends on the adhesive work of contact surfaces and on the surfaces’ roughness. In order to study more complicated structures, this framework will be used in a multiscale model: resulting unloading micro adhesive contact-distance curves of two rough surfaces will be used as contact forces in a finite-element model. In this paper the extraction of these curves for the particular case of gold to gold micro-switches is pursued. [less ▲]

Detailed reference viewed: 92 (24 ULg)
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See detailDesign of Microswitch Systems Avoiding Stiction due to Surface Contact
Wu, Ling ULg; Noels, Ludovic ULg; Rochus, Véronique ULg et al

in SEM 2010 Annual Conference & Exposition on Experimental and Applied Mechanics (2010)

Stiction which results from contact between surfaces is a major failure mode in micro electro-mechanical systems (MEMS). Increasing restoring forces using high spring constant allows avoiding stiction but ... [more ▼]

Stiction which results from contact between surfaces is a major failure mode in micro electro-mechanical systems (MEMS). Increasing restoring forces using high spring constant allows avoiding stiction but leads to an increase of the actuation voltage so that the switch’s efficiency is threatened. A statistical rough surfaces interaction model, based on Maugis’ and Kim’s formulations is applied to estimate the adhesive forces in MEMS switches. Based on the knowledge of these forces, the proper design range of the equivalent spring constant, which is the main factor of restoring force in MEMS switches, can be determined. The upper limit of equivalent spring constant depends mainly on the expected actuator voltage and on the geometric parameters, such as initial gap size and ,thickness of dielectric layer. The lower limit is assessed on the value of adhesive forces between the two contacting rough surfaces. It mainly depends on the adhesive work of contact surfaces and on the surfaces’ roughness. In order to study more complicated structures, this framework will be used in a multiscale model: resulting unloading micro adhesive contact-distance curves of two rough surfaces will be used as contact forces in a finite-element model. In this paper the extraction of these curves for the particular case of gold to gold micro-switches is pursued. [less ▲]

Detailed reference viewed: 171 (43 ULg)
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Peer Reviewed
See detailDesign of Movable Weirs and Storm Surge Barriers
Rigo, Philippe ULg; Abdelnour, R.; Bulckaen, D. et al

in PIANC 2006, 31ème Congrès de l’PIANC (Article 031) (2006, May)

Detailed reference viewed: 91 (3 ULg)
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See detailDesign of movables Weirs and Storm Surge Barriers
Rigo, Philippe ULg; Abdelnour, R.; Bulckaen, D. et al

Book published by PIANC - INCOM (2006)

State of of in the dsign of movable weirs and storm surge barriers

Detailed reference viewed: 399 (26 ULg)
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See detailDesign of Muong Chuoi, Kinh-Lo and Thu-Bo Barriers (report Jan 2011)
Rigo, Philippe ULg

Report (2011)

Consulting activities for the water level control for flood protection of HCMC area Design of Muong Chuoi, Kinh-Lo and Thu-Bo Barriers ICMB-9, HCMC, Vietnam

Detailed reference viewed: 73 (1 ULg)
See detailDesign of nanoobjects endowed with specific properties
Willet, Nicolas ULg; Qiu, Hongjin; Rieger, Jutta ULg et al

Conference (2004, March)

Detailed reference viewed: 7 (3 ULg)
See detailDesign of new multifunctional nanocarriers for protein delivery
Parilti, Rahmet ULg; Jérôme, Christine ULg; Howdle, Steven M. et al

Conference (2015, May 18)

Polymeric nanoparticles have been extensively investigated for their biomedical applications especially as drug carriers. However, efficient encapsulation and delivery of therapeutic proteins in targeted ... [more ▼]

Polymeric nanoparticles have been extensively investigated for their biomedical applications especially as drug carriers. However, efficient encapsulation and delivery of therapeutic proteins in targeted manner still present challenges. This project aims to develop a novel one-pot strategy to obtain nanoparticles able to carry proteins in their core, as well as bearing targeting and/or imaging agents on their surface. In addition to this objective, polymerizations are carried out in supercritical carbon dioxide (scCO2), which confers environmentally benign features to the process. Dispersion polymerizations of hydrophilic monomer 2-hydroxyethyl methacrylate (HEMA) in are carried out in scCO2 in the presence of an initiator, cross-linker and CO2-philic photoclevable stabilizer. Upon exposure to UV light, the o-nitrobenzyl junctions present at the surface of the particles are cleaved, thus providing water dispersible hydrogels. Spherical monodisperse nanoparticles were successfully synthesized in scCO2 with two different conditions. Milder reaction conditions were achieved by using 2,2'-Azobis(4-methoxy-2,4-dimethyl valeronitrile (V70) as an initiator which opens up the platform for one-pot protein encapsulation in scCO2. [less ▲]

Detailed reference viewed: 86 (5 ULg)
Peer Reviewed
See detailDesign of new potential hypoglycemic drugs
Masereel, B.; De Tullio, Pascal ULg; Dogne, J.-M. et al

in Journal de Pharmacie de Belgique (1998), 53

Detailed reference viewed: 4 (0 ULg)
Peer Reviewed
See detailDesign of new potential hypoglycemic drugs
Masereel, B.; De Tullio, Pascal ULg; Dogne, J. M. et al

Poster (1997, May)

Detailed reference viewed: 8 (0 ULg)
See detailDesign of new stealthy and pH-sensitive polymer micelles for potential solid tumor targeting
Van Butsele, Kathy

Doctoral thesis (2008)

Detailed reference viewed: 64 (30 ULg)
See detailDesign of novel copolymers by cobalt-mediated radical polymerization of N-vinyl amides
Debuigne, Antoine ULg

Conference (2012, September 21)

Detailed reference viewed: 18 (5 ULg)
See detailDesign of novel polyphosphoesters (co)polymers for improving a drug delivery system based on calcium carbonate particles
Ergül, Zeynep ULg; Boury, Frank; Debuigne, Antoine ULg et al

Poster (2013, October)

Biomedical applications, especially drug delivery systems, often require biodegradable and biocompatible materials that permit safe retention as well as controlled delivery of a drug. CaCO3 particles are ... [more ▼]

Biomedical applications, especially drug delivery systems, often require biodegradable and biocompatible materials that permit safe retention as well as controlled delivery of a drug. CaCO3 particles are safe and biodegradable drug carriers that have excellent properties such as low density, high specific surface areas and porosity for drugs microencapsulation. The encapsulation of a model protein within CaCO3 particles has been successfully investigated by Boury and coworkers but the release profiles still need to be improved. In this project, we would like to slow down the kinetics of protein release. One strategy consists in loading the CaCO3 particles with degradable micelles containing the protein/drug in their core. In this perspective, we have developed a novel class of degradable polyphosphoesters (PPE) (co)polymers able to self-assemble into micelles. Note that the degradation products of PPEs, like phosphates, associated with calcium from the inorganic carrier could favor some reconstruction processes like bone regeneration. Pendant carboxylic acid functions were introduced along the backbone of the copolymers in order to increase their affinity for calcium and facilitate their incorporation in the CaCO3 particles. First, an alkynyl-functionalized phospholane monomer, i.e. butynyl phosphate (BYP), was prepared by condensation of 2-chloro-2-oxo-1,3,2-dioxaphospholane and 3-butyn-1-ol (43 % yield), according to a reported procedure. Then, a series of well-defined (Ɖ < 1.2) alkyne-containing PBYP (co)polymers were synthesized by ring opening polymerization using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and thiourea (TU) as catalysts[5] (see scheme below). The structures of the PPE (co)polymers were characterized by 1H NMR, 31P NMR and size exclusion chromatography (SEC). Next, carboxylic acid functions were introduced along the PPE backbone by click-type thiol-yne addition of mercaptopropionic acid onto the pendant alkynes. The degradability of the PPEs was investigated at different pH. In the future, the self-assembly behavior of the PPE-based copolymers will be studied as well as their drug loading capacity and ability to accumulate within the CaCO3 particles. In addition, the acid-bearing PPE-based copolymers will be tested as templating agents for the synthesis of CaCO3 particles. [less ▲]

Detailed reference viewed: 71 (5 ULg)
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See detailDesign of perfluorinated macroligand for the implementation of atom transfer radical polymerization in supercritical carbon dioxide
Grignard, Bruno ULg; Jérôme, Christine ULg; Calberg, Cédric ULg et al

Conference (2008, November 28)

Due to an increasing need for polymers with well-defined architecture (diblock-, graft-, star-shaped copolymers), molecular weight and/or functional end-groups, the use of controlled radical ... [more ▼]

Due to an increasing need for polymers with well-defined architecture (diblock-, graft-, star-shaped copolymers), molecular weight and/or functional end-groups, the use of controlled radical polymerization (CRP) in scCO2 has started to gain attention. Among all the controlled processes, Atom Transfer Radical Polymerization has emerged as a robust tool for the preparation of polymers with well-defined molecular weight, architecture and chain-end functionality. The goal of the research relies on the development of ATRP of vinyl monomers in scCO2. Perfluorinated polymethacrylate, i.e. poly2,2,2-trifluoroethyl methacrylate (PFMA), was successfully prepared by homogenous ATRP using a polymeric ligand in order to complex the copper catalyst. CO2-soluble poly(2,2,2-trifluoroethylmethacrylate) was also prepared in supercritical CO2 by supported ATRP using a “pseudo-homogeneous” catalyst consisting of copper (I) ligated by macroligand immobilized onto an inorganic support, that results in polymers with well defined molecular weight and low polydispersity. The first efficient dispersion ATRP of methyl methacrylate (MMA) in scCO2 using a fluorinated polymeric ligand that had a dual role, i.e., the complexation of the copper salt and the stabilization of PMMA growing particles was also reported and the concept of dispersion ATRP was extended to the dispersion ATRP of styrene, to the synthesis of diblock copolymers beads using PMMA beads as macroinitiators, leading to (co)polymers with predictable molecular weight and narrow polydispersity. Finally, because both ATRP and alkyne-azide Huisgen’s 1,3-dipolar cycloaddition relies on the use of a Cu(I) catalyst, synthesis of pyrene end-functionalized polymers by simultaneous dispersion ATRP and click reaction was also investigated in supercritical carbon dioxide, leading to the formation of PMMA of well defined characteristics that was collected as fluorescent micropheres. [less ▲]

Detailed reference viewed: 68 (7 ULg)