J. Coninck | Université de Mons (original) (raw)

Papers by J. Coninck

Research paper thumbnail of Early stages of dissolutive spreading

Scripta Materialia, 2010

ABSTRACT The initial instants of spreading in high-temperature dissolutive systems (Cu and Au on ... more ABSTRACT The initial instants of spreading in high-temperature dissolutive systems (Cu and Au on Ni) are recorded using high-speed video and a drop transfer set-up. The results suggest the existence of an initial regime where the advance of the triple junction is too fast compared with dissolution and spreading occurs on a flat unreacted surface. The analysis indicates that spreading is then controlled by the triple-line friction. The calculated friction coefficients are similar to those for non-reactive high-temperature systems.

Research paper thumbnail of Dynamics of the shock front propagation in a one-dimensional hard-core lattice gas

Research paper thumbnail of Nonreactive wetting kinetics of binary alloys: A molecular dynamics study

Acta Materialia, 2011

The dynamic wetting of Cu-Ag binary alloys of different concentrations on rigid Ni surfaces is co... more The dynamic wetting of Cu-Ag binary alloys of different concentrations on rigid Ni surfaces is considered via molecular dynamics. The statics of wetting are studied with regard to the alloy concentration. The dynamic data (speed v, dynamic contact angle h) are compared to the Molecular-Kinetic model by a fitting procedure. To validate the fittings, the microscopic features of the mechanism are studied. The main parameter of this model (the equilibrium jump frequency K 0) is calculated independently in the simulation. The two values, fitted and measured, are compatible, which extends the validity of the MKT theory for alloys. We also observe in our simulations Marangoni effects and Ag demixing in the formation of an adsorbed layer. Our results also seem to indicate that there is an optimum Cu-Ag binary alloy concentration for increasing the speed of wetting.

Research paper thumbnail of Stokes Formula and Density Perturbances for Driven Tracer Diffusion in an Adsorbed Monolayer

Physical Review Letters, 2000

We study the intrinsic friction of monolayers adsorbed on solid surfaces from a gas phase or vapo... more We study the intrinsic friction of monolayers adsorbed on solid surfaces from a gas phase or vapor. Within the framework of the Langmuir model of delocalized adsorption, we calculate the resistance offered by the mobile adsorbate's particles to some impure tracer molecule, whose diffusive random motion is biased by a constant external force. We find that for sufficiently small driving forces the force exerted on the tracer shows viscous-like behavior. We derive then the analog of the Stokes formula for two-dimensional adsorbates, calculate the corresponding friction coefficient and determine the stationary particle distribution in the monolayer as seen from the driven impurity.

Research paper thumbnail of Correlation between Superhydrophobicity and the Power Spectral Density of Randomly Rough Surfaces

Langmuir, 2010

We show experimentally and analytically that for single-valued, isotropic, homogeneous, randomly ... 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.

Research paper thumbnail of Spreading of Liquid Mixtures at the Microscopic Scale: A Molecular Dynamics Study of the Surface-Induced Segregation Process

Research paper thumbnail of Superhydrophobic Aluminum Surfaces by Deposition of Micelles of Fluorinated Block Copolymers

Langmuir, 2010

Superhydrophobic surfaces are generated by chemisorption on aluminum substrates of fluorinated bl... 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 cm(2).

Research paper thumbnail of Direct energy transfer in systems of polymerized acceptors

We study the direct incoherent energy transfer from an immobile excited donor molecule to accepto... more We study the direct incoherent energy transfer from an immobile excited donor molecule to acceptor molecules, which are all attached to polymer chains, randomly arranged in a viscous solvent. The decay forms are found explicitly, in terms of an optimal-fluctuation method, for arbitrary confomations of polymers.

Research paper thumbnail of Nonreactive spreading at high temperature: Molten metals and oxides on molybdenum

Physical Review E, 2007

The spontaneous spreading of small liquid metal (Cu, Ag, Au) and oxide drops on Mo substrates has... more The spontaneous spreading of small liquid metal (Cu, Ag, Au) and oxide drops on Mo substrates has been studied using a drop transfer setup combined with high-speed video. Under the experimental conditions used in this work, spreading occurs in the absence of interfacial reactions or ridging. The analysis of the spreading data indicates that dissipation at the triple junction (that can be described in terms of a triple-line friction) is playing a dominant role in the movement of the liquid front. This is due, in part, to the much stronger atomic interactions in high-temperature systems when compared to organic liquids. As a result of this analysis, a comprehensive view of spreading emerges in which the strength of the atomic interactions (solid-liquid, liquid-liquid) determines the relative roles of viscous impedance and dissipation at the triple junction in spreading kinetics.

Research paper thumbnail of Effect of photo-crosslinking on the performance of silica nanoparticle-filled epoxidized acrylic copolymer coatings

The effect of UV-crosslinking on the morphological, mechanical and barrier properties of a hybrid... more The effect of UV-crosslinking on the morphological, mechanical and barrier properties of a hybrid coating based on an epoxidized acrylic polymer filled with silica nanoparticles, incorporated in situ through the solgel method, was studied. A systematic comparison of coatings loaded with various amounts of silica nanoparticles subjected or not to UV-curing was reported. The morphological and mechanical properties were investigated by atomic force microscopy (AFM) and tribology tests, while the corrosion resistance of thin films applied on aluminum alloys was measured by electrochemical impedance spectroscopy (EIS). Our findings indicate that a synergic effect is brought about by the combination of silica nanoparticles and UV-curing, significantly enhancing the mechanical properties of the coating, although the corrosion protection was compromised. The resulting coating may be used in applications requiring high mechanical performance.

Research paper thumbnail of Gastric ATPase phosphorylation/dephosphorylation monitored by new FTIR-based BIA-ATR biosensors

Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. ... more Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. In this paper we present the specific application to a membrane embedded protein of a new sensor device, so-called BIA-ATR, based on Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. It consists in a functionalised ATR germanium crystal whose surface has been covalently modified to adsorb a biomembrane. Detection of the ligand-receptor interaction is achieved using FTIR spectroscopy. We report the specific detection of the phosphorylation/dephosphorylation of the H + /K + gastric ATPase. The H + , K +-ATPase is a particularly large protein entity. This glycosylated protein contains more than 1300 residues and is embedded in a lipid membrane. Yet we demonstrate that the BIA-ATR sensor is capable of monitoring the binding of a single phosphate on such a large protein entity. Furthermore, we also demonstrate the potential of the approach to monitor the kinetics of binding and dissociation of the ligand.

Research paper thumbnail of Gastric ATPase phosphorylation/dephosphorylation monitored by new FTIR-based BIA-ATR biosensors

Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. ... more Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. In this paper we present the specific application to a membrane embedded protein of a new sensor device, so-called BIA-ATR, based on Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. It consists in a functionalised ATR germanium crystal whose surface has been covalently modified to adsorb a biomembrane. Detection of the ligand-receptor interaction is achieved using FTIR spectroscopy. We report the specific detection of the phosphorylation/dephosphorylation of the H + /K + gastric ATPase. The H + , K +-ATPase is a particularly large protein entity. This glycosylated protein contains more than 1300 residues and is embedded in a lipid membrane. Yet we demonstrate that the BIA-ATR sensor is capable of monitoring the binding of a single phosphate on such a large protein entity. Furthermore, we also demonstrate the potential of the approach to monitor the kinetics of binding and dissociation of the ligand.

Research paper thumbnail of Surface modification of optical elements for the spectroscopic detection of molecules and organic components

Research paper thumbnail of Label-free detection of coagulation factor VIII in complex media

Research paper thumbnail of Device for multiple ATR analysis

Research paper thumbnail of Optical properties of NiCrOx thin films

physica status solidi (c), 2008

Research paper thumbnail of On the correlation structure of some random point processes on the line

Physica A: Statistical Mechanics and its Applications, 2008

The correlation structure of some remarkable point processes on the onedimensional real line is i... more The correlation structure of some remarkable point processes on the onedimensional real line is investigated. More specifically, focus is on translation invariant determinantal, permanental and/or renewal point processes. In some cases, anomalous (non-Poissonian) fluctuations for the number of points in a large window can be observed. This may be read from the total correlation function of the point process. We try to understand when and why this occurs and what are the anomalous behaviors to be expected.

Research paper thumbnail of Nonreactive Spreading at High-Temperature Revisited for Metal Systems via Molecular Dynamics

Langmuir, 2009

The spreading for Cu and Ag droplets on top of a rigid solid surface modeling Mo is herewith cons... more The spreading for Cu and Ag droplets on top of a rigid solid surface modeling Mo is herewith considered via molecular dynamics. The dynamics of the base radius and the contact angle are recorded and fitted using the molecular-kinetic theory. A method is described to determine for liquid metals at the microscopic level the parameters appearing in this theory. These microscopic parameters are calculated directly in the simulations and compared to the fitted values. The agreement between the fitted values and the calculated ones shows that the dissipation of energy within the drop is caused primarily by the friction of liquid atoms over the substrate. This validation supports the understanding of the mechanisms controlling the spreading of liquid metals which, up to now, were based on experimental data and fitting procedures.

Research paper thumbnail of The equilibrium shape of a two-dimensional crystal between parallel planes

Journal of Statistical Physics, 1994

By applying rather standard techniques for equilibrium crystal shapes (Wulff construction), we de... more By applying rather standard techniques for equilibrium crystal shapes (Wulff construction), we derive a construction for the equilibrium shape of a 2D crystal grown between two parallel plane substrates. The critical distance of the substrates at which this crystal splits into two parts is computed as a function of the wall free energy of the substrates. This may open new perspectives for the measurement of wall free energies.

Research paper thumbnail of Contact angle hysteresis in a solid-on-solid model

Journal of Statistical Physics, 1994

ABSTRACT

Research paper thumbnail of Early stages of dissolutive spreading

Scripta Materialia, 2010

ABSTRACT The initial instants of spreading in high-temperature dissolutive systems (Cu and Au on ... more ABSTRACT The initial instants of spreading in high-temperature dissolutive systems (Cu and Au on Ni) are recorded using high-speed video and a drop transfer set-up. The results suggest the existence of an initial regime where the advance of the triple junction is too fast compared with dissolution and spreading occurs on a flat unreacted surface. The analysis indicates that spreading is then controlled by the triple-line friction. The calculated friction coefficients are similar to those for non-reactive high-temperature systems.

Research paper thumbnail of Dynamics of the shock front propagation in a one-dimensional hard-core lattice gas

Research paper thumbnail of Nonreactive wetting kinetics of binary alloys: A molecular dynamics study

Acta Materialia, 2011

The dynamic wetting of Cu-Ag binary alloys of different concentrations on rigid Ni surfaces is co... more The dynamic wetting of Cu-Ag binary alloys of different concentrations on rigid Ni surfaces is considered via molecular dynamics. The statics of wetting are studied with regard to the alloy concentration. The dynamic data (speed v, dynamic contact angle h) are compared to the Molecular-Kinetic model by a fitting procedure. To validate the fittings, the microscopic features of the mechanism are studied. The main parameter of this model (the equilibrium jump frequency K 0) is calculated independently in the simulation. The two values, fitted and measured, are compatible, which extends the validity of the MKT theory for alloys. We also observe in our simulations Marangoni effects and Ag demixing in the formation of an adsorbed layer. Our results also seem to indicate that there is an optimum Cu-Ag binary alloy concentration for increasing the speed of wetting.

Research paper thumbnail of Stokes Formula and Density Perturbances for Driven Tracer Diffusion in an Adsorbed Monolayer

Physical Review Letters, 2000

We study the intrinsic friction of monolayers adsorbed on solid surfaces from a gas phase or vapo... more We study the intrinsic friction of monolayers adsorbed on solid surfaces from a gas phase or vapor. Within the framework of the Langmuir model of delocalized adsorption, we calculate the resistance offered by the mobile adsorbate's particles to some impure tracer molecule, whose diffusive random motion is biased by a constant external force. We find that for sufficiently small driving forces the force exerted on the tracer shows viscous-like behavior. We derive then the analog of the Stokes formula for two-dimensional adsorbates, calculate the corresponding friction coefficient and determine the stationary particle distribution in the monolayer as seen from the driven impurity.

Research paper thumbnail of Correlation between Superhydrophobicity and the Power Spectral Density of Randomly Rough Surfaces

Langmuir, 2010

We show experimentally and analytically that for single-valued, isotropic, homogeneous, randomly ... 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.

Research paper thumbnail of Spreading of Liquid Mixtures at the Microscopic Scale: A Molecular Dynamics Study of the Surface-Induced Segregation Process

Research paper thumbnail of Superhydrophobic Aluminum Surfaces by Deposition of Micelles of Fluorinated Block Copolymers

Langmuir, 2010

Superhydrophobic surfaces are generated by chemisorption on aluminum substrates of fluorinated bl... 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 cm(2).

Research paper thumbnail of Direct energy transfer in systems of polymerized acceptors

We study the direct incoherent energy transfer from an immobile excited donor molecule to accepto... more We study the direct incoherent energy transfer from an immobile excited donor molecule to acceptor molecules, which are all attached to polymer chains, randomly arranged in a viscous solvent. The decay forms are found explicitly, in terms of an optimal-fluctuation method, for arbitrary confomations of polymers.

Research paper thumbnail of Nonreactive spreading at high temperature: Molten metals and oxides on molybdenum

Physical Review E, 2007

The spontaneous spreading of small liquid metal (Cu, Ag, Au) and oxide drops on Mo substrates has... more The spontaneous spreading of small liquid metal (Cu, Ag, Au) and oxide drops on Mo substrates has been studied using a drop transfer setup combined with high-speed video. Under the experimental conditions used in this work, spreading occurs in the absence of interfacial reactions or ridging. The analysis of the spreading data indicates that dissipation at the triple junction (that can be described in terms of a triple-line friction) is playing a dominant role in the movement of the liquid front. This is due, in part, to the much stronger atomic interactions in high-temperature systems when compared to organic liquids. As a result of this analysis, a comprehensive view of spreading emerges in which the strength of the atomic interactions (solid-liquid, liquid-liquid) determines the relative roles of viscous impedance and dissipation at the triple junction in spreading kinetics.

Research paper thumbnail of Effect of photo-crosslinking on the performance of silica nanoparticle-filled epoxidized acrylic copolymer coatings

The effect of UV-crosslinking on the morphological, mechanical and barrier properties of a hybrid... more The effect of UV-crosslinking on the morphological, mechanical and barrier properties of a hybrid coating based on an epoxidized acrylic polymer filled with silica nanoparticles, incorporated in situ through the solgel method, was studied. A systematic comparison of coatings loaded with various amounts of silica nanoparticles subjected or not to UV-curing was reported. The morphological and mechanical properties were investigated by atomic force microscopy (AFM) and tribology tests, while the corrosion resistance of thin films applied on aluminum alloys was measured by electrochemical impedance spectroscopy (EIS). Our findings indicate that a synergic effect is brought about by the combination of silica nanoparticles and UV-curing, significantly enhancing the mechanical properties of the coating, although the corrosion protection was compromised. The resulting coating may be used in applications requiring high mechanical performance.

Research paper thumbnail of Gastric ATPase phosphorylation/dephosphorylation monitored by new FTIR-based BIA-ATR biosensors

Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. ... more Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. In this paper we present the specific application to a membrane embedded protein of a new sensor device, so-called BIA-ATR, based on Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. It consists in a functionalised ATR germanium crystal whose surface has been covalently modified to adsorb a biomembrane. Detection of the ligand-receptor interaction is achieved using FTIR spectroscopy. We report the specific detection of the phosphorylation/dephosphorylation of the H + /K + gastric ATPase. The H + , K +-ATPase is a particularly large protein entity. This glycosylated protein contains more than 1300 residues and is embedded in a lipid membrane. Yet we demonstrate that the BIA-ATR sensor is capable of monitoring the binding of a single phosphate on such a large protein entity. Furthermore, we also demonstrate the potential of the approach to monitor the kinetics of binding and dissociation of the ligand.

Research paper thumbnail of Gastric ATPase phosphorylation/dephosphorylation monitored by new FTIR-based BIA-ATR biosensors

Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. ... more Biosensors are composite devices suitable for the investigation of receptor-ligand interactions. In this paper we present the specific application to a membrane embedded protein of a new sensor device, so-called BIA-ATR, based on Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. It consists in a functionalised ATR germanium crystal whose surface has been covalently modified to adsorb a biomembrane. Detection of the ligand-receptor interaction is achieved using FTIR spectroscopy. We report the specific detection of the phosphorylation/dephosphorylation of the H + /K + gastric ATPase. The H + , K +-ATPase is a particularly large protein entity. This glycosylated protein contains more than 1300 residues and is embedded in a lipid membrane. Yet we demonstrate that the BIA-ATR sensor is capable of monitoring the binding of a single phosphate on such a large protein entity. Furthermore, we also demonstrate the potential of the approach to monitor the kinetics of binding and dissociation of the ligand.

Research paper thumbnail of Surface modification of optical elements for the spectroscopic detection of molecules and organic components

Research paper thumbnail of Label-free detection of coagulation factor VIII in complex media

Research paper thumbnail of Device for multiple ATR analysis

Research paper thumbnail of Optical properties of NiCrOx thin films

physica status solidi (c), 2008

Research paper thumbnail of On the correlation structure of some random point processes on the line

Physica A: Statistical Mechanics and its Applications, 2008

The correlation structure of some remarkable point processes on the onedimensional real line is i... more The correlation structure of some remarkable point processes on the onedimensional real line is investigated. More specifically, focus is on translation invariant determinantal, permanental and/or renewal point processes. In some cases, anomalous (non-Poissonian) fluctuations for the number of points in a large window can be observed. This may be read from the total correlation function of the point process. We try to understand when and why this occurs and what are the anomalous behaviors to be expected.

Research paper thumbnail of Nonreactive Spreading at High-Temperature Revisited for Metal Systems via Molecular Dynamics

Langmuir, 2009

The spreading for Cu and Ag droplets on top of a rigid solid surface modeling Mo is herewith cons... more The spreading for Cu and Ag droplets on top of a rigid solid surface modeling Mo is herewith considered via molecular dynamics. The dynamics of the base radius and the contact angle are recorded and fitted using the molecular-kinetic theory. A method is described to determine for liquid metals at the microscopic level the parameters appearing in this theory. These microscopic parameters are calculated directly in the simulations and compared to the fitted values. The agreement between the fitted values and the calculated ones shows that the dissipation of energy within the drop is caused primarily by the friction of liquid atoms over the substrate. This validation supports the understanding of the mechanisms controlling the spreading of liquid metals which, up to now, were based on experimental data and fitting procedures.

Research paper thumbnail of The equilibrium shape of a two-dimensional crystal between parallel planes

Journal of Statistical Physics, 1994

By applying rather standard techniques for equilibrium crystal shapes (Wulff construction), we de... more By applying rather standard techniques for equilibrium crystal shapes (Wulff construction), we derive a construction for the equilibrium shape of a 2D crystal grown between two parallel plane substrates. The critical distance of the substrates at which this crystal splits into two parts is computed as a function of the wall free energy of the substrates. This may open new perspectives for the measurement of wall free energies.

Research paper thumbnail of Contact angle hysteresis in a solid-on-solid model

Journal of Statistical Physics, 1994

ABSTRACT