To investigate the structural changes upon thermal treatment of resorcinol-formaldehyde-latex (RF... more To investigate the structural changes upon thermal treatment of resorcinol-formaldehyde-latex (RFL) interfacial layer in rubber-cord flexible composite, a multiscale approach has been employed. High-resolution AFM mapping showed a significant increase of the modulus of the RF phase from 1.2 GPa to 2.3 GPa and latex phase (L) from 0.3 GPa to 0.8 GPa after a thermal exposure at 100°C for 10 days. The increase of the RF and L phases elastic modulus was correlated with the increase of the oxygen content in RFL layer based on the measurements by SEM-EDX. Besides by combining finite element simulations and AFM modulus profiling, the presence of an interphase region (over 280 nm) between the RFL and the rubber regions was identified and was not deteriorated by the thermal treatment. Peel adhesion testing revealed that the increase of RF and L phases rigidity after thermal treatment was detrimental for the interfacial adhesion of the rubber composite.
Effect of surface low-wettability on bacterial colonization has become a prominent subject for th... more Effect of surface low-wettability on bacterial colonization has become a prominent subject for the development of antibacterial coatings. However, bacteria's fate on such surfaces immersed in liquid as well as causal factors are poorly understood. We address this question by using a range of coatings with increasing hydrophobicity, to superhydrophobic, obtained by an atmospheric plasma polymer method allowing series production. Chemistry, wettability and topography are thoroughly described, as well as bacterial colonization by in situ live imaging up to 24h culture time in different liquid media. In the extreme case of superhydrophobic coating, substrates are significantly less colonized in biomolecules-poor liquids and for shortterm culture only. Complex statistical analysis demonstrates that bacterial colonization on these low-wettable substrates is predominantly controlled by the culture conditions and only secondary by topographic coating's properties (variation in surface structuration with almost constant mean height). Wettability is less responsible for bacterial colonization reduction in these conditions, but allows the coatings to preserve colonization-prevention properties in nutritive media when topography is masked by fouling. Even after long-term culture in rich medium, many large places of the superhydrophobic coating are completely free of bacteria in relation to their capacity to preserve air trapping.
Laser assembly of a metal with a polymer is an innovative process for the development of hybrid l... more Laser assembly of a metal with a polymer is an innovative process for the development of hybrid lightweight structures. It was already demonstrated that surface treatment of aluminum prior to laser joining has a critical influence on joint strength of laser assembly with polyamide. In this work, further investigation of the influence of surface treatment prior to laser assembly is carried out. In particular, two kind of surface modification pretreatments of aluminum, laser ablation and plasma surface modification, in combination with plasma surface pretreatment of polyamide, were investigated. Surface properties of aluminum and polyamide after pretreatment are compared to their untreated state. More precisely, surface chemistry, surface energy and roughness characteristics are evaluated by X-ray photoelectron spectroscopy (XPS), sessile drop tests and 3D profilometry, respectively. Joint strength of laser assembly of treated aluminum and polyamide is reported. The more influential surface characteristics for the improvement of joint strength are determined, paving the way to significant advances in metal-polymer laser assembly technology.
The deposition of thin coatings by plasma processes operated at atmospheric pressure is a versati... more The deposition of thin coatings by plasma processes operated at atmospheric pressure is a versatile process for the deposition of functional coatings. However, there is a need to understand their mechanical properties as a function of plasma deposition process parameters since the durability of the coatings is strongly dependent on these properties. In this work, a new approach to obtaining plasma coatings with a controlled level of cross-linking was developed. The precursor molecule to plasma polymer coatings is hexanediol dimethacrylate (HdiMA), a di-functional methacrylate; the plasma deposition conditions were chosen to strongly decrease the precursor fragmentation, so that the plasma polymerization of this precursor leads to a cross-linked structure through the reaction of methacrylate bonds. Plasma coatings from HdiMA are deposited in different plasma conditions. The chemical structure of plasma polymers is investigated by means of infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The mechanical properties of the coatings are determined by nanoscratch and atomic force microscopy (AFM) force curves tests. Better mechanical properties are obtained for coatings deposited with a low concentration of aerosol in the plasma and a higher plasma power. This corresponds to coatings exhibiting the higher conversion rate.
During the last decade, synthesizing silver nanoparticles (Ag NPs) by Liquid Phase-Pulsed Laser A... more During the last decade, synthesizing silver nanoparticles (Ag NPs) by Liquid Phase-Pulsed Laser Ablation (LP-PLA) has attracted a lot of attention. Basically, this technique allows producing various metallic nanoparticles with controlled size, shape, composition or surroundings in several liquids (i.e.: water, ethanol, acetone, toluene,…). Recently, such processes have been studied in liquid organic monomer such as methyl methacrylate (MMA). However, the influence of the laser parameters on the materials synthesised in such reactive liquid and their features were not fully investigated so far. Here we investigate the LP-PLA of silver in two different but rather similar acrylate monomers: dodecylacrylate (DOCA) and 1H,1H,2H,2H perfluorodecylacrylate (PFDA). The influence of the fluence and the number of pulses on the production, size and morphology of the materials has been examined. First, a factorial design experiments have been achieved in order to determine the weight of the laser parameters in each precursor. This study shows two highly different behaviours in function of the monomer where the process took place. This has been explained by the plasma plume confinement and/or the "inter-pulses" self-absorption of the particles by the laser beam. The formation of graphite around the synthesized AgNPs has been highlighted by Raman spectroscopy at low number of pulses. Nevertheless, increasing the number of pulses could lead to three phenomenon depending on the fluence and the used monomer: degradation of the matrix, conservation of the matrix with changes in AgNPs size and distribution or sustainment of the matrix with any changes in the particles properties. So the surrounding, the size and stability could be triggered by adjusting these parameters. This paper does highlight that LP-PLA is a powerful technique to provide AgNPs in acrylate monomer with a good control of their features.
Rubbers or mostly polymers are exposed to different attacks from the surroundings during their us... more Rubbers or mostly polymers are exposed to different attacks from the surroundings during their uses. Two factors are known to be among the most important involved during aging: atmospheric oxygen and UV-visible radiation from the sun, leading to the phenomenon of photo-oxidation. Photo-ageing is governed by the light penetration and diffusion of oxygen, which involve the formation of an oxidative layer on the first microns at the surface of the material. The main objective of this thesis is to point out the relationship between the changes in the chemical structure due to the formation of the oxidative layer and the loss of mechanical properties during photo-aging of vulcanised rubber in the presence of fillers such as titanium dioxide and organic dye by means of a multi-techniques and multi-scale approach. To achieve this goal, we first simplified the vulcanized material and we focused only on the matrix and fillers. This first step allowed us to determine the influence of fillers ...
In this work, the use of Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) was explored a... more In this work, the use of Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) was explored as a technique for monitoring the interfacial retro Diels–Alder (retro DA) reaction occurring on well-controlled self-assembled monolayers (SAMs). A molecule containing a Diels–Alder (DA) adduct was grafted on to the monolayers, then the surface was heated at different temperatures to follow the reaction conversion. A TOF-SIMS analysis of the surface allowed the detection of a fragment from the molecule, which is released from the surface when retro DA reaction occurs. Hence, by monitoring the decay of this fragment’s peak integral, the reaction conversion could be determined in function of the time and for different temperatures. The viability of this method was then discussed in comparison with the results obtained by 1H NMR spectroscopy.
TOF-SIMS is well-known as a highly sensitive and depth-resolved technique for the profiling of so... more TOF-SIMS is well-known as a highly sensitive and depth-resolved technique for the profiling of soft matter, despite the use of “small” ions or clusters induces some damages and more critically fragmentation of the polymeric chains, leading to “sketchy” elemental rather than molecular analyses. New soft large cluster sources were developed to reduce damages into the multilayer structures, but cannot give any insights into the molecular composition of these thin films. On the contrary, MALDI-MS technique was specifically developed to allow large molecules such as proteins or polymers to be easily mass-analyzed as intact adducts. A derived MS method called Surface Layer (SL-MALDI) was recently developed by Wesdemiotis and coworkers to probe the very first nanometers of a polymeric thin film by MALDI-MS [1]. As a first step towards molecular depth profiling, we report here the combination of an ionic ablation step followed by a SL-MALDI analysis to evidence a molecular weight gradient i...
ABSTRACT Biocompatible plasma polymers are expected to be used in various applications in medicin... more ABSTRACT Biocompatible plasma polymers are expected to be used in various applications in medicine such as drug delivery with a controlled release. In this context we investigated the possibility to monitor the kinetic of hydrolytic degradation of plasma polymers by tailoring the chemistry of the precursor. A homemade precursor way synthesized by grafting acrylate function on both side of a polycaprolactone diol (PCL diol) to produce a PCL diacrylate characterized by IR, NMR and MS to confirm its chemical structure. Acrylates constitute a promising class of precursors to improve the retention of the integrity of the precursor by working in soft plasma conditions. The plasma polymerization of the so-synthesized precursor have been highlighted by means of a multi-technique analytical strategy and ensured the retention of hydrolyzable ester function of the precursor. Finally the thickness consumption during immersion in PBS were performed and found to be slower as compared to the degradation kinetic of a plasma polymerized methacrylic anhydride.
Photo-oxidation at l > 290 nm was performed on vulcanised styrene butadiene rubber (SBR) designed... more Photo-oxidation at l > 290 nm was performed on vulcanised styrene butadiene rubber (SBR) designed for flooring applications. The effect of the presence of coated titanium dioxide (TiO 2 ), used as a pigment, was evaluated. The chemical and nano-mechanical changes occurring at the surface during irradiation were studied by micro-FTIR spectroscopy and atomic force microscopy (AFM). Both techniques were used to obtain the oxidation profiles in the depth of the composites (in the absence and presence of TiO 2 ) to characterise the oxidative layer formation. The nano-mechanical and chemical profiles were superimposed for both composites (SBR and SBR/TiO 2 ) suggesting a correlation between both properties. Indeed, the increase of the DMT modulus determined by AFM reflects the crosslinking reactions which occur simultaneously with the formation of oxidised photo-products.
The use of reliable reference compounds was recently shown as a powerful and even mandatory strat... more The use of reliable reference compounds was recently shown as a powerful and even mandatory strategy for a thorough characterization of plasma-polymers. If (meth)acrylate precursors are particularly well-suited as precursors and readily polymerizable in wet chemistry, elaboration of standards remains nevertheless a topical issue since the wet chemistry processes such as radical polymerizations lead to structures with either a high degree of linearity or very specific chain ends which poorly mimic the notorious disorder found in plasma-polymers. The strategy proposed in this article as a way to overcome this analytical drawback consists in the production of reference (plasma-)polymers directly using an aerosol assisted plasma polymerization apparatus. First, a peculiar thick deposit found in a so-called "ante plasma zone" directly after the aerosol entrance and before the electrode, where no discharge is ignited but a huge amount of precursor is delivered was thoroughly analyzed using Size Exclusion Chromatography, Nuclear Magnetic Resonance and Mass Spectrometry. Exaggerating the phenomenon lead to the concept of discharge overfeeding to further decrease the energy per particle and produce oily deposits, described as intermediate polymeric materials between conventional polymers and traditional plasma-polymers, synthesized through a so-called plasma-assisted free radical polymerization.
Hydrolysable polymers represent an extensive area of research such as drug delivery system, skin ... more Hydrolysable polymers represent an extensive area of research such as drug delivery system, skin patch, bone repair scaffolds or resorbable sutures. In this paper, we focused our attention on the elaboration of a hydrolyzable plasma-polymer produced by aerosol assisted atmospheric pressure plasma process. A DBD discharge was hence fed with a commercial methacrylic anhydride precursor -bearing an anhydride hydrolyzable function and two methacrylates groups aiming at producing a highly cross-linked deposit -to produce thin coatings of plasmapolymerized (pp) methacrylic anhydride. Infra-red spectroscopy and Nuclear Magnetic
A polymeric bilayer formed of two polystyrenes varying only by their molecular weight was success... more A polymeric bilayer formed of two polystyrenes varying only by their molecular weight was successfully described combining an ion beam etching and a MALDI-based analysis, to provide a molecular weight depth pro le. The use of a thickness measurement eventually allowed this pro le to be plotted as a function of the physical depth instead of the sputtering time or scan numbers classically used in XPS or TOF-SIMS analyses. As the depth resolution of both etching and analysis steps are below a few tens of nanometers, we expect this original o -line coupling to be of high potential for the analysis of molecular and molecular weight gradients (mimicked by a bilayer) with a broad range of applications, e.g. in the eld of the polymer light-emitting diodes (PLED).
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012
The deposition of polyelectrolyte multilayer films consists of the sequential adsorption of polyc... more The deposition of polyelectrolyte multilayer films consists of the sequential adsorption of polycationic and polyanionic species at solid-liquid interfaces. The adsorption process can be performed either by alternated dipping of the substrate to be coated in the polyelectrolyte containing solutions, by alternated spin coating of these solutions or by alternated spraying of them. Different coating technologies can lead to different properties of the obtained coatings even for the same combination of polycations and polyanions. The aim of this article is to show that by playing on the concentration of the supporting electrolyte, NaCl, the films obtained by alternated spraying and alternated dipping grow differently and display different properties, in terms of refractive index, surface morphology, wettability for water and surface composition.
To investigate the structural changes upon thermal treatment of resorcinol-formaldehyde-latex (RF... more To investigate the structural changes upon thermal treatment of resorcinol-formaldehyde-latex (RFL) interfacial layer in rubber-cord flexible composite, a multiscale approach has been employed. High-resolution AFM mapping showed a significant increase of the modulus of the RF phase from 1.2 GPa to 2.3 GPa and latex phase (L) from 0.3 GPa to 0.8 GPa after a thermal exposure at 100°C for 10 days. The increase of the RF and L phases elastic modulus was correlated with the increase of the oxygen content in RFL layer based on the measurements by SEM-EDX. Besides by combining finite element simulations and AFM modulus profiling, the presence of an interphase region (over 280 nm) between the RFL and the rubber regions was identified and was not deteriorated by the thermal treatment. Peel adhesion testing revealed that the increase of RF and L phases rigidity after thermal treatment was detrimental for the interfacial adhesion of the rubber composite.
Effect of surface low-wettability on bacterial colonization has become a prominent subject for th... more Effect of surface low-wettability on bacterial colonization has become a prominent subject for the development of antibacterial coatings. However, bacteria's fate on such surfaces immersed in liquid as well as causal factors are poorly understood. We address this question by using a range of coatings with increasing hydrophobicity, to superhydrophobic, obtained by an atmospheric plasma polymer method allowing series production. Chemistry, wettability and topography are thoroughly described, as well as bacterial colonization by in situ live imaging up to 24h culture time in different liquid media. In the extreme case of superhydrophobic coating, substrates are significantly less colonized in biomolecules-poor liquids and for shortterm culture only. Complex statistical analysis demonstrates that bacterial colonization on these low-wettable substrates is predominantly controlled by the culture conditions and only secondary by topographic coating's properties (variation in surface structuration with almost constant mean height). Wettability is less responsible for bacterial colonization reduction in these conditions, but allows the coatings to preserve colonization-prevention properties in nutritive media when topography is masked by fouling. Even after long-term culture in rich medium, many large places of the superhydrophobic coating are completely free of bacteria in relation to their capacity to preserve air trapping.
Laser assembly of a metal with a polymer is an innovative process for the development of hybrid l... more Laser assembly of a metal with a polymer is an innovative process for the development of hybrid lightweight structures. It was already demonstrated that surface treatment of aluminum prior to laser joining has a critical influence on joint strength of laser assembly with polyamide. In this work, further investigation of the influence of surface treatment prior to laser assembly is carried out. In particular, two kind of surface modification pretreatments of aluminum, laser ablation and plasma surface modification, in combination with plasma surface pretreatment of polyamide, were investigated. Surface properties of aluminum and polyamide after pretreatment are compared to their untreated state. More precisely, surface chemistry, surface energy and roughness characteristics are evaluated by X-ray photoelectron spectroscopy (XPS), sessile drop tests and 3D profilometry, respectively. Joint strength of laser assembly of treated aluminum and polyamide is reported. The more influential surface characteristics for the improvement of joint strength are determined, paving the way to significant advances in metal-polymer laser assembly technology.
The deposition of thin coatings by plasma processes operated at atmospheric pressure is a versati... more The deposition of thin coatings by plasma processes operated at atmospheric pressure is a versatile process for the deposition of functional coatings. However, there is a need to understand their mechanical properties as a function of plasma deposition process parameters since the durability of the coatings is strongly dependent on these properties. In this work, a new approach to obtaining plasma coatings with a controlled level of cross-linking was developed. The precursor molecule to plasma polymer coatings is hexanediol dimethacrylate (HdiMA), a di-functional methacrylate; the plasma deposition conditions were chosen to strongly decrease the precursor fragmentation, so that the plasma polymerization of this precursor leads to a cross-linked structure through the reaction of methacrylate bonds. Plasma coatings from HdiMA are deposited in different plasma conditions. The chemical structure of plasma polymers is investigated by means of infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The mechanical properties of the coatings are determined by nanoscratch and atomic force microscopy (AFM) force curves tests. Better mechanical properties are obtained for coatings deposited with a low concentration of aerosol in the plasma and a higher plasma power. This corresponds to coatings exhibiting the higher conversion rate.
During the last decade, synthesizing silver nanoparticles (Ag NPs) by Liquid Phase-Pulsed Laser A... more During the last decade, synthesizing silver nanoparticles (Ag NPs) by Liquid Phase-Pulsed Laser Ablation (LP-PLA) has attracted a lot of attention. Basically, this technique allows producing various metallic nanoparticles with controlled size, shape, composition or surroundings in several liquids (i.e.: water, ethanol, acetone, toluene,…). Recently, such processes have been studied in liquid organic monomer such as methyl methacrylate (MMA). However, the influence of the laser parameters on the materials synthesised in such reactive liquid and their features were not fully investigated so far. Here we investigate the LP-PLA of silver in two different but rather similar acrylate monomers: dodecylacrylate (DOCA) and 1H,1H,2H,2H perfluorodecylacrylate (PFDA). The influence of the fluence and the number of pulses on the production, size and morphology of the materials has been examined. First, a factorial design experiments have been achieved in order to determine the weight of the laser parameters in each precursor. This study shows two highly different behaviours in function of the monomer where the process took place. This has been explained by the plasma plume confinement and/or the "inter-pulses" self-absorption of the particles by the laser beam. The formation of graphite around the synthesized AgNPs has been highlighted by Raman spectroscopy at low number of pulses. Nevertheless, increasing the number of pulses could lead to three phenomenon depending on the fluence and the used monomer: degradation of the matrix, conservation of the matrix with changes in AgNPs size and distribution or sustainment of the matrix with any changes in the particles properties. So the surrounding, the size and stability could be triggered by adjusting these parameters. This paper does highlight that LP-PLA is a powerful technique to provide AgNPs in acrylate monomer with a good control of their features.
Rubbers or mostly polymers are exposed to different attacks from the surroundings during their us... more Rubbers or mostly polymers are exposed to different attacks from the surroundings during their uses. Two factors are known to be among the most important involved during aging: atmospheric oxygen and UV-visible radiation from the sun, leading to the phenomenon of photo-oxidation. Photo-ageing is governed by the light penetration and diffusion of oxygen, which involve the formation of an oxidative layer on the first microns at the surface of the material. The main objective of this thesis is to point out the relationship between the changes in the chemical structure due to the formation of the oxidative layer and the loss of mechanical properties during photo-aging of vulcanised rubber in the presence of fillers such as titanium dioxide and organic dye by means of a multi-techniques and multi-scale approach. To achieve this goal, we first simplified the vulcanized material and we focused only on the matrix and fillers. This first step allowed us to determine the influence of fillers ...
In this work, the use of Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) was explored a... more In this work, the use of Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) was explored as a technique for monitoring the interfacial retro Diels–Alder (retro DA) reaction occurring on well-controlled self-assembled monolayers (SAMs). A molecule containing a Diels–Alder (DA) adduct was grafted on to the monolayers, then the surface was heated at different temperatures to follow the reaction conversion. A TOF-SIMS analysis of the surface allowed the detection of a fragment from the molecule, which is released from the surface when retro DA reaction occurs. Hence, by monitoring the decay of this fragment’s peak integral, the reaction conversion could be determined in function of the time and for different temperatures. The viability of this method was then discussed in comparison with the results obtained by 1H NMR spectroscopy.
TOF-SIMS is well-known as a highly sensitive and depth-resolved technique for the profiling of so... more TOF-SIMS is well-known as a highly sensitive and depth-resolved technique for the profiling of soft matter, despite the use of “small” ions or clusters induces some damages and more critically fragmentation of the polymeric chains, leading to “sketchy” elemental rather than molecular analyses. New soft large cluster sources were developed to reduce damages into the multilayer structures, but cannot give any insights into the molecular composition of these thin films. On the contrary, MALDI-MS technique was specifically developed to allow large molecules such as proteins or polymers to be easily mass-analyzed as intact adducts. A derived MS method called Surface Layer (SL-MALDI) was recently developed by Wesdemiotis and coworkers to probe the very first nanometers of a polymeric thin film by MALDI-MS [1]. As a first step towards molecular depth profiling, we report here the combination of an ionic ablation step followed by a SL-MALDI analysis to evidence a molecular weight gradient i...
ABSTRACT Biocompatible plasma polymers are expected to be used in various applications in medicin... more ABSTRACT Biocompatible plasma polymers are expected to be used in various applications in medicine such as drug delivery with a controlled release. In this context we investigated the possibility to monitor the kinetic of hydrolytic degradation of plasma polymers by tailoring the chemistry of the precursor. A homemade precursor way synthesized by grafting acrylate function on both side of a polycaprolactone diol (PCL diol) to produce a PCL diacrylate characterized by IR, NMR and MS to confirm its chemical structure. Acrylates constitute a promising class of precursors to improve the retention of the integrity of the precursor by working in soft plasma conditions. The plasma polymerization of the so-synthesized precursor have been highlighted by means of a multi-technique analytical strategy and ensured the retention of hydrolyzable ester function of the precursor. Finally the thickness consumption during immersion in PBS were performed and found to be slower as compared to the degradation kinetic of a plasma polymerized methacrylic anhydride.
Photo-oxidation at l > 290 nm was performed on vulcanised styrene butadiene rubber (SBR) designed... more Photo-oxidation at l > 290 nm was performed on vulcanised styrene butadiene rubber (SBR) designed for flooring applications. The effect of the presence of coated titanium dioxide (TiO 2 ), used as a pigment, was evaluated. The chemical and nano-mechanical changes occurring at the surface during irradiation were studied by micro-FTIR spectroscopy and atomic force microscopy (AFM). Both techniques were used to obtain the oxidation profiles in the depth of the composites (in the absence and presence of TiO 2 ) to characterise the oxidative layer formation. The nano-mechanical and chemical profiles were superimposed for both composites (SBR and SBR/TiO 2 ) suggesting a correlation between both properties. Indeed, the increase of the DMT modulus determined by AFM reflects the crosslinking reactions which occur simultaneously with the formation of oxidised photo-products.
The use of reliable reference compounds was recently shown as a powerful and even mandatory strat... more The use of reliable reference compounds was recently shown as a powerful and even mandatory strategy for a thorough characterization of plasma-polymers. If (meth)acrylate precursors are particularly well-suited as precursors and readily polymerizable in wet chemistry, elaboration of standards remains nevertheless a topical issue since the wet chemistry processes such as radical polymerizations lead to structures with either a high degree of linearity or very specific chain ends which poorly mimic the notorious disorder found in plasma-polymers. The strategy proposed in this article as a way to overcome this analytical drawback consists in the production of reference (plasma-)polymers directly using an aerosol assisted plasma polymerization apparatus. First, a peculiar thick deposit found in a so-called "ante plasma zone" directly after the aerosol entrance and before the electrode, where no discharge is ignited but a huge amount of precursor is delivered was thoroughly analyzed using Size Exclusion Chromatography, Nuclear Magnetic Resonance and Mass Spectrometry. Exaggerating the phenomenon lead to the concept of discharge overfeeding to further decrease the energy per particle and produce oily deposits, described as intermediate polymeric materials between conventional polymers and traditional plasma-polymers, synthesized through a so-called plasma-assisted free radical polymerization.
Hydrolysable polymers represent an extensive area of research such as drug delivery system, skin ... more Hydrolysable polymers represent an extensive area of research such as drug delivery system, skin patch, bone repair scaffolds or resorbable sutures. In this paper, we focused our attention on the elaboration of a hydrolyzable plasma-polymer produced by aerosol assisted atmospheric pressure plasma process. A DBD discharge was hence fed with a commercial methacrylic anhydride precursor -bearing an anhydride hydrolyzable function and two methacrylates groups aiming at producing a highly cross-linked deposit -to produce thin coatings of plasmapolymerized (pp) methacrylic anhydride. Infra-red spectroscopy and Nuclear Magnetic
A polymeric bilayer formed of two polystyrenes varying only by their molecular weight was success... more A polymeric bilayer formed of two polystyrenes varying only by their molecular weight was successfully described combining an ion beam etching and a MALDI-based analysis, to provide a molecular weight depth pro le. The use of a thickness measurement eventually allowed this pro le to be plotted as a function of the physical depth instead of the sputtering time or scan numbers classically used in XPS or TOF-SIMS analyses. As the depth resolution of both etching and analysis steps are below a few tens of nanometers, we expect this original o -line coupling to be of high potential for the analysis of molecular and molecular weight gradients (mimicked by a bilayer) with a broad range of applications, e.g. in the eld of the polymer light-emitting diodes (PLED).
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2012
The deposition of polyelectrolyte multilayer films consists of the sequential adsorption of polyc... more The deposition of polyelectrolyte multilayer films consists of the sequential adsorption of polycationic and polyanionic species at solid-liquid interfaces. The adsorption process can be performed either by alternated dipping of the substrate to be coated in the polyelectrolyte containing solutions, by alternated spin coating of these solutions or by alternated spraying of them. Different coating technologies can lead to different properties of the obtained coatings even for the same combination of polycations and polyanions. The aim of this article is to show that by playing on the concentration of the supporting electrolyte, NaCl, the films obtained by alternated spraying and alternated dipping grow differently and display different properties, in terms of refractive index, surface morphology, wettability for water and surface composition.
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Papers by Grégory Mertz