References of "Jonas, Alain M"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailElectrospinning of a functional perfluorinated block copolymer as a powerful route for imparting superhydrophobicity and corrosion resistance to aluminum substrates
Grignard, Bruno ULg; Vaillant, Alexandre; de Coninck, Joel et al

in Langmuir (2011), 27(1), 335-342

Superhydrophobic aluminum surfaces with excellent corrosion resistance were successfully prepared by electrospinning of a novel fluorinated diblock copolymer solution. Micro- and nanostructuration of the ... [more ▼]

Superhydrophobic aluminum surfaces with excellent corrosion resistance were successfully prepared by electrospinning of a novel fluorinated diblock copolymer solution. Micro- and nanostructuration of the diblock copolymer coating was obtained by electrospinning which proved to be an easy and cheap electrospinning technology to fabricate superhydrophobic coating. The diblock copolymer is made of poly(heptadecafluorodecylacrylate-co-acrylic acid) (PFDA-co-AA) random copolymer as the first block and polyacrylonitrile (PAN) as the second one. The fluorinated block promotes hydrophobicity to the surface by reducing the surface tension, while its carboxylic acid functions anchor the polymer film onto the aluminum surface after annealing at 130 °C. The PAN block of this copolymer insures the stability of the structuration of the surface during annealing, thanks to the infusible character of PAN. It is also demonstrated that the so-formed superhydrophobic coating shows good adhesion to aluminum surfaces, resulting in excellent corrosion resistance. [less ▲]

Detailed reference viewed: 44 (2 ULg)
Full Text
Peer Reviewed
See detailCorrelation between superhydrophobicity and the power spectral density of randomly rough surfaces
Awada, Houssein; Grignard, Bruno ULg; Jérôme, Christine ULg et al

in Langmuir (2010), 26(23), 17798-17803

We show experimentally and analytically that for single-valued, isotropic, homogeneous, randomly rough surfaces consisting of bumps randomly protruding over a continuous background, superhydrophobicity is ... [more ▼]

We show experimentally and analytically that for single-valued, isotropic, homogeneous, randomly rough surfaces consisting of bumps randomly protruding over a continuous background, superhydrophobicity is related to the power spectral density of the surface height, which can be derived from microscopy measurements. More precisely, superhydrophobicity correlates with the third moment of the power spectral density, which is directly related to the notion of Wenzel roughness (i.e., the ratio between the real area of the surface and its projected area). In addition, we explain why randomly rough surfaces with identical root-mean-square roughness values may behave differently with respect to water repellence and why roughness components with wavelength larger than 10 μm are not likely to be of importance or, stated otherwise, why superhydrophobicity often requires a contribution from submicrometer-scale components such as nanoparticles. The analysis developed here also shows that the simple thermodynamic arguments relating superhydrophobicity to an increase in the sample area are valid for this type of surface, and we hope that it will help researchers to fabricate efficient superhydrophobic surfaces based on the rational design of their power spectral density. [less ▲]

Detailed reference viewed: 26 (3 ULg)
Full Text
Peer Reviewed
See detailSuperhydrophobic aluminum surfaces by deposition of micelles of fluorinated block copolymers
Desbief, Simon; Grignard, Bruno ULg; Detrembleur, Christophe ULg et al

in Langmuir (2010), 26(3), 2057-2067

Superhydrophobic surfaces are generated by chemisorption on aluminum substrates of fluorinated block copolymers synthesized by reversible addition−fragmentation chain transfer in supercritical carbon ... [more ▼]

Superhydrophobic surfaces are generated by chemisorption on aluminum substrates of fluorinated block copolymers synthesized by reversible addition−fragmentation chain transfer in supercritical carbon dioxide. In an appropriate solvent, those block copolymers can form micelles with a fluorinated corona, which are grafted on the aluminum substrate thanks to the presence of carboxylic acid groups in the corona. Water contact angle and drop impact analysis were used to characterize the wettability of the films at the macroscale, and atomic force microscopy measurements provided morphological information at the micro- and nanoscale. The simple solvent casting of the polymer solution on a hydroxylated aluminum surface results in a coating with multiscale roughness, which is fully superhydrophobic over areas up to 4 cm2. [less ▲]

Detailed reference viewed: 46 (7 ULg)
Full Text
Peer Reviewed
See detailNanopatterned monolayers of an adsorbed chromophore
Frederich, Nadia; Duwez, Anne-Sophie ULg; Nysten, Bernard et al

in Nanotechnology (2008), 19

A simple lift-off process was developed to rapidly fabricate nanopatterned photofunctional surfaces. Dye molecules of a perylene derivative (PDID) were adsorbed irreversibly on clean silicon through the ... [more ▼]

A simple lift-off process was developed to rapidly fabricate nanopatterned photofunctional surfaces. Dye molecules of a perylene derivative (PDID) were adsorbed irreversibly on clean silicon through the holes of an electron-beam lithographied polymer mask. The subsequent removal of the mask in a proper solvent results in PDID nanosized regions of width as small as 30 nm for stripes and of diameter as small as 120 nm for dots. Numerical analyses of atomic force microscopy and laser-scanning confocal microscopy images show that the dye molecules are confined to the regions defined by the lithographic process, with the integrated fluorescence intensity being essentially proportional to the size of the nanofeatures. This demonstrates that a simple organic lift-off process compatible with clean-room technology, and not involving any chemical step, is able to produce photofunctional nanopatterned surfaces, even though the dye is not chemically bonded to the silicon surface. [less ▲]

Detailed reference viewed: 18 (4 ULg)
Full Text
Peer Reviewed
See detailAtomic force microscopy investigation of the morphology and the biological activity of protein-modified surfaces for bio- and immunosensors
Cecchet, Francesca; Duwez, Anne-Sophie ULg; Gabriel, Sabine ULg et al

in Analytical Chemistry (2007), 79(17), 6488-6495

With the purpose of developing biosensors, the reliable proof of the biological activity of two new sensor systems was obtained by atomic force microscopy (AFM) in both the imaging and the single-molecule ... [more ▼]

With the purpose of developing biosensors, the reliable proof of the biological activity of two new sensor systems was obtained by atomic force microscopy (AFM) in both the imaging and the single-molecule force spectroscopy modes. Antigens or antibodies of pharmacological interest were grafted onto self-assembled monolayers of thiols on gold, and AFM imaging demonstrated that the grafting process produced homogeneous submonolayers of isolated proteins. The analysis of the morphology of the surfaces at the different functionalization steps allowed evaluating the protein grafting density and showed that the recognition of complementary species present in the surrounding solution occurred. Single-molecule force spectroscopy experiments between the sensing surfaces and AFM probes, onto which the complementary species were grafted, enabled a direct and rapid test of the biological activity of the sensors by investigating the interaction occurring at the level of one single ligand-receptor bond. Ellipsometry and surface plasmon resonance allowed further characterization of the sensor surfaces and confirmed that the biological recognition took place. [less ▲]

Detailed reference viewed: 45 (14 ULg)
Full Text
Peer Reviewed
See detailOne-step polymer grafting from silicon nitride SPM probes: From isolated chains to brush regime
Gabriel, Sabine ULg; Jérôme, Christine ULg; Jérôme, Robert ULg et al

in Journal of the American Chemical Society (2007), 129(27), 8410

We show that a reactive polymer can be directly grafted from commercial Si3Nx SPM tips, without any intermediate layer. The conditions can be chosen to achieve either an isolated mushroom regime, with ... [more ▼]

We show that a reactive polymer can be directly grafted from commercial Si3Nx SPM tips, without any intermediate layer. The conditions can be chosen to achieve either an isolated mushroom regime, with only one or a few chains accessible at the tip apex, or a brush regime. [less ▲]

Detailed reference viewed: 64 (13 ULg)
Full Text
Peer Reviewed
See detailFirst insights into electrografted polymers by AFM-based force spectroscopy
Cuenot, Stéphane; Gabriel, Sabine ULg; Jérôme, Robert ULg et al

in Macromolecules (2006), 39(24), 8428-8433

The very first characterization of the structural properties of polymer films obtained by electrografting is reported. AFM-based force spectroscopy was used to investigate poly-N-succinimidyl acrylate ... [more ▼]

The very first characterization of the structural properties of polymer films obtained by electrografting is reported. AFM-based force spectroscopy was used to investigate poly-N-succinimidyl acrylate (PNSA) layers electrografted directly from a silicon substrate. Quantitative analysis of compression profiles obtained in a good solvent and single molecule bridging interaction, in light of the Alexander-de Gennes model, gave access to the grafting density and degree of polymerization. A high swelling capacity has been evidenced. This report is the first evidence that polymers obtained by cathodic electrografting are in fact brush systems, and consequently the first evidence that a polymer brush can be obtained from a direct "grafting from" method, without any intermediate layer. [less ▲]

Detailed reference viewed: 39 (13 ULg)
Full Text
Peer Reviewed
See detailElectrografting of Poly(ethylene glycol) Acrylate : A One-Step Strategy for the Synthesis of Protein-Repellent Surfaces
Gabriel, Sabine ULg; Dubruel, Peter; Schacht, Etienne et al

in Angewandte Chemie (International ed. in English) (2005), 44(34), 5505-5509

Electrografting of acrylate end-capped poly(ethylene glycol) (PEG) is an important technique for the one-step coating of electroconductive substrates by an adherent hydrophilic coating (see figure). This ... [more ▼]

Electrografting of acrylate end-capped poly(ethylene glycol) (PEG) is an important technique for the one-step coating of electroconductive substrates by an adherent hydrophilic coating (see figure). This technique is very efficient for the production of new protein-repellent surfaces. [less ▲]

Detailed reference viewed: 43 (3 ULg)
See detailElectrografting of poly(ethylene glycol) acrylate: a novel one-step strategy for protein repellent surfaces
Gabriel, Sabine ULg; Dubruel, P.; Schacht, Etienne et al

Conference (2005, June 01)

Detailed reference viewed: 14 (4 ULg)
Full Text
Peer Reviewed
See detailNanoporous Thin Films from Self-Assembled Metallo-supramolecular Block Copolymers
Fustin, Charles-André; Lohmeijer, Bas G.G.; Duwez, Anne-Sophie ULg et al

in Advanced Materials (2005), 17

Detailed reference viewed: 8 (1 ULg)
Full Text
Peer Reviewed
See detailElectrodeposition of mixed adherent thin films of poly(ethyl acrylate) and polyacrylonitrile onto nickel
Baute, Noëlle; Geskin, Victor M; Lazzaroni, Roberto et al

in e-Polymers (2004), (63), 1-20

Adherent thin polymer films have been prepared by sequential electrodeposition of ethyl acrylate (EA) and acrylonitrile (AN) onto nickel. Their composition has been studied by IR spectroscopy and time of ... [more ▼]

Adherent thin polymer films have been prepared by sequential electrodeposition of ethyl acrylate (EA) and acrylonitrile (AN) onto nickel. Their composition has been studied by IR spectroscopy and time of flight-secondary ion mass spectrometry. Morphology and thickness have been analyzed by atomic force microscopy and ellipsometry, respectively, and compared to single component films of PEA and PAN. No microphase separation was detected in the mixed PEA/PAN films. These show a granular morphology comparable to that of PAN films. The grains contain the two constitutive polymers, as confirmed by the selective thermal degradation of PEA. [less ▲]

Detailed reference viewed: 59 (1 ULg)
Full Text
Peer Reviewed
See detailProbing thermoplastic matrix-carbon fiber interphases. 1. Preferential segregation of low molar mass chains to the interface
Carlier, V.; Sclavons, M.; Jonas, Alain M et al

in Macromolecules (2001), 34(11), 3725-3729

The molecular mobility of polystyrene (PS) chains near the surface of carbon fibers was investigated. The glass transition temperature of very thin coatings deposited on carbon fibers was measured by ... [more ▼]

The molecular mobility of polystyrene (PS) chains near the surface of carbon fibers was investigated. The glass transition temperature of very thin coatings deposited on carbon fibers was measured by supported DMTA in order to probe the properties of the thermoplastic interphase. Depending on the fiber impregnation method from the melt or from solution, Tg changed in an opposite way for the thinnest coatings, decreasing with coating thickness in the case of impregnation in the melt and increasing when a polymer solution was used. This observation is explained by degradation of PS in the melt and subsequent preferential segregation of low molar mass chains to the interface. This conclusion is supported by the study of the Tg of coatings made from a bimodal molar mass distribution. [less ▲]

Detailed reference viewed: 24 (0 ULg)
Full Text
Peer Reviewed
See detailSynthesis and bulk characterization of new P(CB-b-S) diblock copolymers
Stone, V. W.; Jonas, Alain M; Legras, Roger et al

in Journal of Polymer Science. Part A, Polymer Chemistry (1999), 37(2), 233-244

Strongly asymmetric chlorinated polybutadiene-b-polystyrene, [P((CB)x-b-(PS)y)] diblock copolymers with increasing x/(x + y) ratios (up to 5.2 mol %) have been synthesized by the selective chlorination of ... [more ▼]

Strongly asymmetric chlorinated polybutadiene-b-polystyrene, [P((CB)x-b-(PS)y)] diblock copolymers with increasing x/(x + y) ratios (up to 5.2 mol %) have been synthesized by the selective chlorination of the polybutadiene (PB) block in solution. Chlorination has been performed in anhydrous dichloromethane added with an antioxidant [2,2-methylenebis-(6-tert-butyl-4-methyl-phenol)], at -50°C, under a continuous Ar flow and in the dark. Under the optimized experimental conditions, the PB chlorination is not complete, but the PS block is left unmodified. Even in the presence of a large chlorine excess (Cl2/butene unit molar ratio of 2.5), the experimental degree of chlorination of homo PB does not exceed 85%. The chlorinated copolymers have been characterized by 1H-NMR, IR spectroscopy, size-exclusion chromatography, and elemental analysis. The chlorinated copolymers have also been studied by DSC and SAXS after annealing at 150°C. Although at this temperature the parent homopolymers are immiscible, no microphase separation has been observed for the block copolymers. [less ▲]

Detailed reference viewed: 35 (2 ULg)
Full Text
Peer Reviewed
See detailCharacterization of polyacrylonitrile films grafted onto nickel by ellipsometry, atomic force microscopy and X-ray reflectivity
Calberg, Cédric ULg; Mertens, Marc; Jérôme, Robert ULg et al

in Thin Solid Films (1997), 310(1-2), 148-155

The thickness and roughness of polyacrylonitrile films electrografted on a nickel surface have been measured by ellipsometry, atomic force microscopy and X-ray reflectivity. From combined ellipsometry and ... [more ▼]

The thickness and roughness of polyacrylonitrile films electrografted on a nickel surface have been measured by ellipsometry, atomic force microscopy and X-ray reflectivity. From combined ellipsometry and X-ray reflectivity measurements, accurate values for the refractive indices of polyacrylonitrile and nickel have been derived at a 6328-Åwavelength. Dependence of the film thickness on the monomer concentration has been quantified for the first time. Furthermore, the thickness of the polyacrylonitrile (PAN) film is related to the nature of the solvent, depending on whether it is a good solvent for PAN (dimethylformamide; DMF) or not (acetonitrile; ACN). [less ▲]

Detailed reference viewed: 31 (1 ULg)