Jean-Yves Sanchez - Academia.edu (original) (raw)
Papers by Jean-Yves Sanchez
Energy Procedia, 2012
ABSTRACT Composite membranes based on Nafion blended with phosphatoantimonic acid (H3) exhibit hi... more ABSTRACT Composite membranes based on Nafion blended with phosphatoantimonic acid (H3) exhibit high conductivities associated to enhanced thermomechanical performances as compared to commercial Nafion 117 ®. The preliminary tests performed on MEAs based on these composites membranes allowed, for a given content in H3 i.e.10%, obtaining improved polarization curves as compared to the pristine membranes.
Electrochimica Acta, 2007
The paper deals with the use of extrusion to process PEMFC filled and unfilled membranes. Several... more The paper deals with the use of extrusion to process PEMFC filled and unfilled membranes. Several routes including the sulfonation of filled and unfilled extruded membranes and the extrusion of filled and unfilled ionomers are reported. Thanks to the use of selected water-soluble aid process plasticizers, acid and alkaline forms of sulfonated polyethersulfone were, for the first time, successfully extruded.
Reactive and Functional Polymers, 2008
A new class of poly(1,3,4-oxadiazole)s (PODs) with pendant phosphonic acid groups was synthesized... more A new class of poly(1,3,4-oxadiazole)s (PODs) with pendant phosphonic acid groups was synthesized via direct polycondensation of dicarboxylic acids and their dihydrazides using ionic liquid, namely 1-methyl-3-propylimidazoluium bromide ([mpim]Br), as a reaction medium, and triphenyl phosphite as a reaction activator. The polymers were obtained with inherent viscosities equal to 0.46-0.58 dL/g in two steps starting from polyhydrazides formation followed by thermal polycyclization under high vacuum. Polymers derived from 5-phosphonoisophtalic acid were soluble in traditional organic solvents, while application of 2-phosphonoterephthalic acid resulted in formation of insoluble gels. Such properties as thermal stability, glass transition temperatures, water uptake, molecular weights and proton conductivity of novel polymers were investigated in detail. A comparison between common poly(1,3,4-oxadiazole)s and their phosphorylated or phosphonated analogs having the same polymer backbone demonstrated that PODs with pendant phosphonic acid groups possess approximately the same thermal stability, but greater glass transition temperatures along with reduced solubility. Transparent flexible films cast from such novel polymers were characterized by high tensile properties, namely tensile strength of about 90-100 MPa and elongation up to 8%. The proton conductivity values measured at the temperature range from 20 to 90°C varied from 4 Â 10 À7 to 5 Â 10 À6 S/cm at 100% relative humidity.
The Journal of Physical Chemistry B, 2008
The structure and local organization of new proton conducting ionic liquids (PCILs) obtained by r... more The structure and local organization of new proton conducting ionic liquids (PCILs) obtained by reacting alkylamine with various acids were deciphered by complementary 1-and 2-D heteronuclear NMR experiments. One the one hand, PFG NMR yielded the self-diffusion coefficients of the PCIL components (and thus information on their possible concerted translational motions), while on the other hand, 13 C, 1 H, and 15 N, 1 H correlation and intermolecular Overhauser experiments gave insight into the nature of protonic species and ion-pairing behavior.
High Performance Polymers, 2008
Poly(phenylquinoxaline)s.(PPQs) are a family of aromatic condensation polymers known for their ou... more Poly(phenylquinoxaline)s.(PPQs) are a family of aromatic condensation polymers known for their outstanding thermal and chemical stability. The pendant phenyl groups and chains isomerism improve the solubility and processing characteristics of these polymers. PPQs have also been shown to possess excellent thermo-oxidative stability and thermohydrolytic stability. This stability makes these polymers candidates for development as proton exchange membranes (PEMs) to be
Films, useful for battery electrolyte, fuel cell membranes, supercondensers, electrochrome device... more Films, useful for battery electrolyte, fuel cell membranes, supercondensers, electrochrome devices, ion exchange membranes, and electrodialysis membranes, are manufd. by extruding prepolymers having arom. groups, functional groups, crosslinkable groups, and groups that can be modified with anionic groups, crosslinking the films thermally or photochem., and then grafting the anionic groups onto the films. A typical film was manufd. by polymg. 4,4'-dichlorodiphenyl sulfone with 4,4'-dihydroxybiphenyl, reacting the K salt of the resulting OH-terminated copolymer with 4-chloro-4'-(phenylethynyl)diphenyl sulfone, extruding the resulting modified polymer, thermally crosslinking, and sulfonating with trimethylsilyl chlorosulfonate
Journal of Power Sources, 2006
... One of the main requirements for these membranes is to avoid the well-known Hoffman degradati... more ... One of the main requirements for these membranes is to avoid the well-known Hoffman degradation of the quaternary ammoniums which occurs according to Scheme 2. ... Scheme 2.Hoffman degradation. View Within Article. ... Scheme 3. Impossibility of Hoffman degradation. ...
Electrochimica Acta, 2006
New lithium conducting ionomers based on commercial polyethers were synthesized by chemical modif... more New lithium conducting ionomers based on commercial polyethers were synthesized by chemical modification in order to incorporate not only the anionic function on the polymer backbone but also polar aprotic and (or) protic groups improving both the salt dissociation and the anion-solvating ability of the multifunctional copolymers. The choice of environmentally friendly rather than perfluorinated anionic functions did not appear
High Performance Polymers, 2009
... free-volume) exhibited higher proton conductivity, particularly at low relative humidity [20,... more ... free-volume) exhibited higher proton conductivity, particularly at low relative humidity [20, 21], while reports from Guiver's group [22 ... in table 2. Thus, both fluorinated (6F) and unfluorinated polymers (BP) exhibited selectivity increases because of the ben-zonitrile incorporation. ...
Journal of Raman Spectroscopy, 2007
Organic solutions of lithium pentafluorobenzene sulfonate (C 6 F 5 SO 3 Li) with varying molaliti... more Organic solutions of lithium pentafluorobenzene sulfonate (C 6 F 5 SO 3 Li) with varying molalities in N,Ndimethyl formamide (DMF) and triethyleneglycol dimethylether (triglyme) were investigated by Raman spectroscopy. Spectral decomposition in the n s (SO 3 ) stretching region showed bands characteristic of free anions, ion pairs and various aggregates. The relative fraction of each species has been followed as a function of salt molality. In DMF, free anions dominate, while in triglyme ion pairs dominate, in accordance with the solvent dielectric constant.
The Journal of Physical Chemistry C, 2012
ABSTRACT The effect of the anion structure of proton-conducting ionic liquid dopants on the prope... more ABSTRACT The effect of the anion structure of proton-conducting ionic liquid dopants on the properties of a Nafion 117 membrane, neutralized by triethylammonium, is described. The synthesis and the properties of proton-conducting membranes, doped with triethylammonium methanesulfonate (TMS) or triethylammonium perfluorobutanesulfonate (TPFBu) ionic liquids are described. The properties of the doped membranes were investigated by thermogravimetric analysis, differential scanning calorimetry, and dynamic-mechanical analysis. The key findings are that the uptake of the ionic liquid is ca. 25 and 40 wt % for TMS and TPFBu, respectively, and these ionic liquid dopants extend the membranes thermal stability to 140 degrees C. Information concerning the structure and the interactions between the membrane components was obtained by Fourier transform infrared spectroscopy.
ECS Transactions, 2009
The paper deals with the synthesis and characterisation of proton conducting ionic liquids (PCIL)... more The paper deals with the synthesis and characterisation of proton conducting ionic liquids (PCIL) and their polymer electrolytes obtained by blending modified Nafion membranes with different concentrations of PCIL. We studied the impact of the acid nature on the PCILs ...
The Journal of Physical Chemistry C, 2013
Journal of Fluorine Chemistry, 2011
In this paper, we studied the durability of PEMFC MEAs after onsite operation in stationary condi... more In this paper, we studied the durability of PEMFC MEAs after onsite operation in stationary conditions. Harsh anode and cathode active layer degradation was monitored for Pt, C, F elements by chemical (EDS, XPS) and physical (SEM, TEM) techniques. At the cathode, Pt corrodes into Pt z+ species yielding severe redistribution within the MEA. Pt z+ dissolution and transport is favoured by activators/ligands (F or S-containing species resulting from the MEA polymers ageing, especially at the anode), which possibly act as counter ions. The presence of Pt z+ ions in the membrane favours chain-cutting and induces physical cross-links which modifies its thermo-mechanical, water uptake and conductivity properties. As a result, the risk of pinhole formation is greatly increased.
Journal of Fluorine Chemistry, 2012
Polymers, 2011
While Proton Exchange Membrane Fuel Cell (PEMFC) membranes are currently prepared by film casting... more While Proton Exchange Membrane Fuel Cell (PEMFC) membranes are currently prepared by film casting, this paper demonstrates the feasibility of extrusion, a solvent-free alternative process. Thanks to water-soluble process-aid plasticizers, duly selected, it was possible to extrude acidic and alkaline polysulfone ionomers. Additionally, the feasibility to extrude composites was demonstrated. The impact of the plasticizers on the melt viscosity was investigated. Following the extrusion, the plasticizers were fully removed in water. The extrusion was found to impact neither on the ionomer chains, nor on the performances of the membrane. This environmentally friendly process was successfully validated for a variety of high performance ionomers.
Electrochimica Acta, 2007
The salt PhSCF2CF2SO3Li appears promising for lithium-polymer batteries. Its poly(oxyethylene) co... more The salt PhSCF2CF2SO3Li appears promising for lithium-polymer batteries. Its poly(oxyethylene) complexes, although less conductive than lithium imide complexes, provided cationic transference numbers ranging between 0.45 and 0.5, enabling high cationic conductivities to be obtained. Thanks to its double substitution by aryl and perfluorinated moieties, the thioether function is stable enough to be used with positive electrodes, such as vanadium oxide
Abstr act. PEMFC Fuel Cell uses a polymer membrane as an electrolyte. It is used in all applicati... more Abstr act. PEMFC Fuel Cell uses a polymer membrane as an electrolyte. It is used in all applications with dynamic loads, especially in mobile applications but also as combined heat and power units in households. The development of the membranes ion-conductivity has much increased over the last 30 years. Today "Nafion"-based membranes achieve a power density up to 1 W/cm 2 active area. In the last 10 years the successful adoption of the PEMFC in different prototypes could be demonstrated. For a market-introduction a few "teething problem" like life-time and costs have to be solved.
Energy Procedia, 2012
ABSTRACT Composite membranes based on Nafion blended with phosphatoantimonic acid (H3) exhibit hi... more ABSTRACT Composite membranes based on Nafion blended with phosphatoantimonic acid (H3) exhibit high conductivities associated to enhanced thermomechanical performances as compared to commercial Nafion 117 ®. The preliminary tests performed on MEAs based on these composites membranes allowed, for a given content in H3 i.e.10%, obtaining improved polarization curves as compared to the pristine membranes.
Electrochimica Acta, 2007
The paper deals with the use of extrusion to process PEMFC filled and unfilled membranes. Several... more The paper deals with the use of extrusion to process PEMFC filled and unfilled membranes. Several routes including the sulfonation of filled and unfilled extruded membranes and the extrusion of filled and unfilled ionomers are reported. Thanks to the use of selected water-soluble aid process plasticizers, acid and alkaline forms of sulfonated polyethersulfone were, for the first time, successfully extruded.
Reactive and Functional Polymers, 2008
A new class of poly(1,3,4-oxadiazole)s (PODs) with pendant phosphonic acid groups was synthesized... more A new class of poly(1,3,4-oxadiazole)s (PODs) with pendant phosphonic acid groups was synthesized via direct polycondensation of dicarboxylic acids and their dihydrazides using ionic liquid, namely 1-methyl-3-propylimidazoluium bromide ([mpim]Br), as a reaction medium, and triphenyl phosphite as a reaction activator. The polymers were obtained with inherent viscosities equal to 0.46-0.58 dL/g in two steps starting from polyhydrazides formation followed by thermal polycyclization under high vacuum. Polymers derived from 5-phosphonoisophtalic acid were soluble in traditional organic solvents, while application of 2-phosphonoterephthalic acid resulted in formation of insoluble gels. Such properties as thermal stability, glass transition temperatures, water uptake, molecular weights and proton conductivity of novel polymers were investigated in detail. A comparison between common poly(1,3,4-oxadiazole)s and their phosphorylated or phosphonated analogs having the same polymer backbone demonstrated that PODs with pendant phosphonic acid groups possess approximately the same thermal stability, but greater glass transition temperatures along with reduced solubility. Transparent flexible films cast from such novel polymers were characterized by high tensile properties, namely tensile strength of about 90-100 MPa and elongation up to 8%. The proton conductivity values measured at the temperature range from 20 to 90°C varied from 4 Â 10 À7 to 5 Â 10 À6 S/cm at 100% relative humidity.
The Journal of Physical Chemistry B, 2008
The structure and local organization of new proton conducting ionic liquids (PCILs) obtained by r... more The structure and local organization of new proton conducting ionic liquids (PCILs) obtained by reacting alkylamine with various acids were deciphered by complementary 1-and 2-D heteronuclear NMR experiments. One the one hand, PFG NMR yielded the self-diffusion coefficients of the PCIL components (and thus information on their possible concerted translational motions), while on the other hand, 13 C, 1 H, and 15 N, 1 H correlation and intermolecular Overhauser experiments gave insight into the nature of protonic species and ion-pairing behavior.
High Performance Polymers, 2008
Poly(phenylquinoxaline)s.(PPQs) are a family of aromatic condensation polymers known for their ou... more Poly(phenylquinoxaline)s.(PPQs) are a family of aromatic condensation polymers known for their outstanding thermal and chemical stability. The pendant phenyl groups and chains isomerism improve the solubility and processing characteristics of these polymers. PPQs have also been shown to possess excellent thermo-oxidative stability and thermohydrolytic stability. This stability makes these polymers candidates for development as proton exchange membranes (PEMs) to be
Films, useful for battery electrolyte, fuel cell membranes, supercondensers, electrochrome device... more Films, useful for battery electrolyte, fuel cell membranes, supercondensers, electrochrome devices, ion exchange membranes, and electrodialysis membranes, are manufd. by extruding prepolymers having arom. groups, functional groups, crosslinkable groups, and groups that can be modified with anionic groups, crosslinking the films thermally or photochem., and then grafting the anionic groups onto the films. A typical film was manufd. by polymg. 4,4'-dichlorodiphenyl sulfone with 4,4'-dihydroxybiphenyl, reacting the K salt of the resulting OH-terminated copolymer with 4-chloro-4'-(phenylethynyl)diphenyl sulfone, extruding the resulting modified polymer, thermally crosslinking, and sulfonating with trimethylsilyl chlorosulfonate
Journal of Power Sources, 2006
... One of the main requirements for these membranes is to avoid the well-known Hoffman degradati... more ... One of the main requirements for these membranes is to avoid the well-known Hoffman degradation of the quaternary ammoniums which occurs according to Scheme 2. ... Scheme 2.Hoffman degradation. View Within Article. ... Scheme 3. Impossibility of Hoffman degradation. ...
Electrochimica Acta, 2006
New lithium conducting ionomers based on commercial polyethers were synthesized by chemical modif... more New lithium conducting ionomers based on commercial polyethers were synthesized by chemical modification in order to incorporate not only the anionic function on the polymer backbone but also polar aprotic and (or) protic groups improving both the salt dissociation and the anion-solvating ability of the multifunctional copolymers. The choice of environmentally friendly rather than perfluorinated anionic functions did not appear
High Performance Polymers, 2009
... free-volume) exhibited higher proton conductivity, particularly at low relative humidity [20,... more ... free-volume) exhibited higher proton conductivity, particularly at low relative humidity [20, 21], while reports from Guiver's group [22 ... in table 2. Thus, both fluorinated (6F) and unfluorinated polymers (BP) exhibited selectivity increases because of the ben-zonitrile incorporation. ...
Journal of Raman Spectroscopy, 2007
Organic solutions of lithium pentafluorobenzene sulfonate (C 6 F 5 SO 3 Li) with varying molaliti... more Organic solutions of lithium pentafluorobenzene sulfonate (C 6 F 5 SO 3 Li) with varying molalities in N,Ndimethyl formamide (DMF) and triethyleneglycol dimethylether (triglyme) were investigated by Raman spectroscopy. Spectral decomposition in the n s (SO 3 ) stretching region showed bands characteristic of free anions, ion pairs and various aggregates. The relative fraction of each species has been followed as a function of salt molality. In DMF, free anions dominate, while in triglyme ion pairs dominate, in accordance with the solvent dielectric constant.
The Journal of Physical Chemistry C, 2012
ABSTRACT The effect of the anion structure of proton-conducting ionic liquid dopants on the prope... more ABSTRACT The effect of the anion structure of proton-conducting ionic liquid dopants on the properties of a Nafion 117 membrane, neutralized by triethylammonium, is described. The synthesis and the properties of proton-conducting membranes, doped with triethylammonium methanesulfonate (TMS) or triethylammonium perfluorobutanesulfonate (TPFBu) ionic liquids are described. The properties of the doped membranes were investigated by thermogravimetric analysis, differential scanning calorimetry, and dynamic-mechanical analysis. The key findings are that the uptake of the ionic liquid is ca. 25 and 40 wt % for TMS and TPFBu, respectively, and these ionic liquid dopants extend the membranes thermal stability to 140 degrees C. Information concerning the structure and the interactions between the membrane components was obtained by Fourier transform infrared spectroscopy.
ECS Transactions, 2009
The paper deals with the synthesis and characterisation of proton conducting ionic liquids (PCIL)... more The paper deals with the synthesis and characterisation of proton conducting ionic liquids (PCIL) and their polymer electrolytes obtained by blending modified Nafion membranes with different concentrations of PCIL. We studied the impact of the acid nature on the PCILs ...
The Journal of Physical Chemistry C, 2013
Journal of Fluorine Chemistry, 2011
In this paper, we studied the durability of PEMFC MEAs after onsite operation in stationary condi... more In this paper, we studied the durability of PEMFC MEAs after onsite operation in stationary conditions. Harsh anode and cathode active layer degradation was monitored for Pt, C, F elements by chemical (EDS, XPS) and physical (SEM, TEM) techniques. At the cathode, Pt corrodes into Pt z+ species yielding severe redistribution within the MEA. Pt z+ dissolution and transport is favoured by activators/ligands (F or S-containing species resulting from the MEA polymers ageing, especially at the anode), which possibly act as counter ions. The presence of Pt z+ ions in the membrane favours chain-cutting and induces physical cross-links which modifies its thermo-mechanical, water uptake and conductivity properties. As a result, the risk of pinhole formation is greatly increased.
Journal of Fluorine Chemistry, 2012
Polymers, 2011
While Proton Exchange Membrane Fuel Cell (PEMFC) membranes are currently prepared by film casting... more While Proton Exchange Membrane Fuel Cell (PEMFC) membranes are currently prepared by film casting, this paper demonstrates the feasibility of extrusion, a solvent-free alternative process. Thanks to water-soluble process-aid plasticizers, duly selected, it was possible to extrude acidic and alkaline polysulfone ionomers. Additionally, the feasibility to extrude composites was demonstrated. The impact of the plasticizers on the melt viscosity was investigated. Following the extrusion, the plasticizers were fully removed in water. The extrusion was found to impact neither on the ionomer chains, nor on the performances of the membrane. This environmentally friendly process was successfully validated for a variety of high performance ionomers.
Electrochimica Acta, 2007
The salt PhSCF2CF2SO3Li appears promising for lithium-polymer batteries. Its poly(oxyethylene) co... more The salt PhSCF2CF2SO3Li appears promising for lithium-polymer batteries. Its poly(oxyethylene) complexes, although less conductive than lithium imide complexes, provided cationic transference numbers ranging between 0.45 and 0.5, enabling high cationic conductivities to be obtained. Thanks to its double substitution by aryl and perfluorinated moieties, the thioether function is stable enough to be used with positive electrodes, such as vanadium oxide
Abstr act. PEMFC Fuel Cell uses a polymer membrane as an electrolyte. It is used in all applicati... more Abstr act. PEMFC Fuel Cell uses a polymer membrane as an electrolyte. It is used in all applications with dynamic loads, especially in mobile applications but also as combined heat and power units in households. The development of the membranes ion-conductivity has much increased over the last 30 years. Today "Nafion"-based membranes achieve a power density up to 1 W/cm 2 active area. In the last 10 years the successful adoption of the PEMFC in different prototypes could be demonstrated. For a market-introduction a few "teething problem" like life-time and costs have to be solved.