Pharmaceutical effluents are a serious environmental issue, which require to be treated by a suit... more Pharmaceutical effluents are a serious environmental issue, which require to be treated by a suitable technique; thus, the electrochemical process is actively considered as a viable method for the treatment.
Ce memoire presente les resultats concernant la mise en operation d'un reacteur pilote indust... more Ce memoire presente les resultats concernant la mise en operation d'un reacteur pilote industriel d'electrosynthese organique a ecoulement pulse (e3p). Deux reactions ont ete testees sur cette installation : l'oxydation indirecte du cyclohexanol en cyclohexanone, en milieu homogene, et l'oxydation indirecte du 1-pentanol en pentanoate de pentyle, en milieu diphasique liquide - liquide. Dans les deux cas, la reaction se fait par l'intermediaire d'une espece iodee qui sert a transferer des electrons entre le substrat organique et l'anode. Les influences des parametres operatoires, tels que l'amplitude et la frequence du mouvement pulsatoire impose a l'eclectrolyte, ainsi que de la densite de courant, sur les rendements chimique et faradique, sont etudiees.
Printed electronics is a branch of technology dedicated to create devices and gadgets which are a... more Printed electronics is a branch of technology dedicated to create devices and gadgets which are able to be portable, flexible, folded if necessary and in consequence very light. These devices will require energy sources with the same characteristics of the device (portable, light and able to be folded). For that reason we have worked on elastomeric conducting materials able to be used as capacitors in galvanic cells or rechargeable batteries 1. These elastomeric composites are the resulting blend from three polymers: SBS or SBR elastomers as matrix; An inherent conducting polymer nano-composite based on poly(3,4-ethylenedioxythiophene) synthetized over halloysite nanotubes or PEDOT:HT; And a extrinsic ionic conducting polymer based on acrylics dispersed with lithium salts in the proper solvent to obtain a kind of elastomeric acrylic. These components are not miscible between themselves, but they were blended in a mixing chamber to disperse the electrically conducting phases in the elastomeric matrix, so we obtain an elastomeric composite able to be processed by extrusion or rolling milling to obtain flexible films. The present job discusses about how these electrically conducting phases were obtained and characterized, but mainly about the distribution of these conducting phases inside the matrix, by employing a scanning electronic microscopy (SEM) and a DualBeam Versa 3D microscopy. An integrated methodology that enabled linking 3D spatial orientation and bulk structure, enables to estimate the volume fraction occupied by the elastomeric matric (SBS or SBR), figure 1. Moreover, we used this information to generate an idealized theoretical distribution of materials, figure 2, as an input, in a Hashin-Shtrikman model 2, to simulate the electrically conductive behavior of the elastomeric composite and compared it with electrical conductivity measures done using a Keithley electrometer at different voltages
A pilot plant electrolyser was built, which, in design, was similar to an industrial reactor used... more A pilot plant electrolyser was built, which, in design, was similar to an industrial reactor used for metal recovery from waste waters. Increased mass transport rates were achieved by applying a pulse to the reactor solution. The first reaction tested on this new cell was the indirect oxidation of cyclohexanol in aqueous solution by means of an iodinated intermediate species.
The synthesis and characterization of catalysts based on bimetallic materials, PtMo supported on... more The synthesis and characterization of catalysts based on bimetallic materials, PtMo supported on carbon for the anodic oxidation of methanol in direct methanol fuel cells is reported here. The catalysts were synthesized from the Pt carbonyl complex ([Pt3 (CO) 3 ( ...
The semiconducting and non-toxic enzymatic polygallic acid (PGAL) produces water dispersible poly... more The semiconducting and non-toxic enzymatic polygallic acid (PGAL) produces water dispersible poly(3,4-ethylenedioxythiophene) (PEDOT-PGAL) and polyaniline (PANI-PGAL). The results indicate that PGAL is a template for the model polymers, and thereby, the complexes are processable by spray coating to produce flexible electrochromic devices (ECDs). The materials are characterized by infrared spectroscopy, thermogravimetric analysis, and conductivity measurements in pellet form. Additionally, potentiostatic and potentiodynamic techniques in combination with UV-spectroscopy assess the consecution of materials. The produced ECDs based on PEDOT-PGAL has a ΔT of up to 19% and a life span lower than 100 cycles. However, when the PEDOT-PGAL architecture is complementary with PANI-PGAL displays up to 1000 times with a ΔT of 15% and coloring efficiencies of 275 cm 2 /C. The color of this PGAL-based device changes from dark violet to light green which differs from the common complementary EDCs. Additionally, complementary ECD fabricated with PEDOT-PSS against PANI-PGAL enhances the coloring efficiency up to 517 cm 2 /C (ΔT=26%) and cycled 1000 times. 2
Journal of New Materials for Electrochemical Systems
The activities of a series of carbon-supported bimetallic catalysts, with different active phases... more The activities of a series of carbon-supported bimetallic catalysts, with different active phases loadings, were tested towards the oxygen reduction reaction (ORR). Pt was used in all materials and its loading was kept constant. Mo, W and Ru were used as promoting phases. Rotating Disk electrode experiments revealed that Pt-Ru displayed the best performance in oxygen reduction among the studied materials. The materials with the highest loadings of the second metal revealed the highest activities. X-Ray Diffraction studies (XRD) and Transmission Electron Microscopy (TEM) revealed the presence of homogeneously dispersed metallic ruthenium and different tungsten or molybdenum oxides in the corresponding catalysts. No evidence of alloying was found, and thus the catalytic performances appear to be related to the distribution and interaction of the active phases.
Poly(3,6-N-vinylcarbazole) (PVK) films were prepared by electrochemical oxidation of N-vinylcarba... more Poly(3,6-N-vinylcarbazole) (PVK) films were prepared by electrochemical oxidation of N-vinylcarbazole on a platinum electrode using acetonitrile as solvent and tetraethyl ammonium tetrafluoroborate as electrolyte. The electro-synthesis was carried out using electrical potential cycling in the presence of tetraethyl-ammonium phthalate. The presence of this salt in the electrolyte decreased the cross-linking of the electrodeposited polymer to give PVK bearing a more
Pharmaceutical effluents are a serious environmental issue, which require to be treated by a suit... more Pharmaceutical effluents are a serious environmental issue, which require to be treated by a suitable technique; thus, the electrochemical process is actively considered as a viable method for the treatment.
Ce memoire presente les resultats concernant la mise en operation d'un reacteur pilote indust... more Ce memoire presente les resultats concernant la mise en operation d'un reacteur pilote industriel d'electrosynthese organique a ecoulement pulse (e3p). Deux reactions ont ete testees sur cette installation : l'oxydation indirecte du cyclohexanol en cyclohexanone, en milieu homogene, et l'oxydation indirecte du 1-pentanol en pentanoate de pentyle, en milieu diphasique liquide - liquide. Dans les deux cas, la reaction se fait par l'intermediaire d'une espece iodee qui sert a transferer des electrons entre le substrat organique et l'anode. Les influences des parametres operatoires, tels que l'amplitude et la frequence du mouvement pulsatoire impose a l'eclectrolyte, ainsi que de la densite de courant, sur les rendements chimique et faradique, sont etudiees.
Printed electronics is a branch of technology dedicated to create devices and gadgets which are a... more Printed electronics is a branch of technology dedicated to create devices and gadgets which are able to be portable, flexible, folded if necessary and in consequence very light. These devices will require energy sources with the same characteristics of the device (portable, light and able to be folded). For that reason we have worked on elastomeric conducting materials able to be used as capacitors in galvanic cells or rechargeable batteries 1. These elastomeric composites are the resulting blend from three polymers: SBS or SBR elastomers as matrix; An inherent conducting polymer nano-composite based on poly(3,4-ethylenedioxythiophene) synthetized over halloysite nanotubes or PEDOT:HT; And a extrinsic ionic conducting polymer based on acrylics dispersed with lithium salts in the proper solvent to obtain a kind of elastomeric acrylic. These components are not miscible between themselves, but they were blended in a mixing chamber to disperse the electrically conducting phases in the elastomeric matrix, so we obtain an elastomeric composite able to be processed by extrusion or rolling milling to obtain flexible films. The present job discusses about how these electrically conducting phases were obtained and characterized, but mainly about the distribution of these conducting phases inside the matrix, by employing a scanning electronic microscopy (SEM) and a DualBeam Versa 3D microscopy. An integrated methodology that enabled linking 3D spatial orientation and bulk structure, enables to estimate the volume fraction occupied by the elastomeric matric (SBS or SBR), figure 1. Moreover, we used this information to generate an idealized theoretical distribution of materials, figure 2, as an input, in a Hashin-Shtrikman model 2, to simulate the electrically conductive behavior of the elastomeric composite and compared it with electrical conductivity measures done using a Keithley electrometer at different voltages
A pilot plant electrolyser was built, which, in design, was similar to an industrial reactor used... more A pilot plant electrolyser was built, which, in design, was similar to an industrial reactor used for metal recovery from waste waters. Increased mass transport rates were achieved by applying a pulse to the reactor solution. The first reaction tested on this new cell was the indirect oxidation of cyclohexanol in aqueous solution by means of an iodinated intermediate species.
The synthesis and characterization of catalysts based on bimetallic materials, PtMo supported on... more The synthesis and characterization of catalysts based on bimetallic materials, PtMo supported on carbon for the anodic oxidation of methanol in direct methanol fuel cells is reported here. The catalysts were synthesized from the Pt carbonyl complex ([Pt3 (CO) 3 ( ...
The semiconducting and non-toxic enzymatic polygallic acid (PGAL) produces water dispersible poly... more The semiconducting and non-toxic enzymatic polygallic acid (PGAL) produces water dispersible poly(3,4-ethylenedioxythiophene) (PEDOT-PGAL) and polyaniline (PANI-PGAL). The results indicate that PGAL is a template for the model polymers, and thereby, the complexes are processable by spray coating to produce flexible electrochromic devices (ECDs). The materials are characterized by infrared spectroscopy, thermogravimetric analysis, and conductivity measurements in pellet form. Additionally, potentiostatic and potentiodynamic techniques in combination with UV-spectroscopy assess the consecution of materials. The produced ECDs based on PEDOT-PGAL has a ΔT of up to 19% and a life span lower than 100 cycles. However, when the PEDOT-PGAL architecture is complementary with PANI-PGAL displays up to 1000 times with a ΔT of 15% and coloring efficiencies of 275 cm 2 /C. The color of this PGAL-based device changes from dark violet to light green which differs from the common complementary EDCs. Additionally, complementary ECD fabricated with PEDOT-PSS against PANI-PGAL enhances the coloring efficiency up to 517 cm 2 /C (ΔT=26%) and cycled 1000 times. 2
Journal of New Materials for Electrochemical Systems
The activities of a series of carbon-supported bimetallic catalysts, with different active phases... more The activities of a series of carbon-supported bimetallic catalysts, with different active phases loadings, were tested towards the oxygen reduction reaction (ORR). Pt was used in all materials and its loading was kept constant. Mo, W and Ru were used as promoting phases. Rotating Disk electrode experiments revealed that Pt-Ru displayed the best performance in oxygen reduction among the studied materials. The materials with the highest loadings of the second metal revealed the highest activities. X-Ray Diffraction studies (XRD) and Transmission Electron Microscopy (TEM) revealed the presence of homogeneously dispersed metallic ruthenium and different tungsten or molybdenum oxides in the corresponding catalysts. No evidence of alloying was found, and thus the catalytic performances appear to be related to the distribution and interaction of the active phases.
Poly(3,6-N-vinylcarbazole) (PVK) films were prepared by electrochemical oxidation of N-vinylcarba... more Poly(3,6-N-vinylcarbazole) (PVK) films were prepared by electrochemical oxidation of N-vinylcarbazole on a platinum electrode using acetonitrile as solvent and tetraethyl ammonium tetrafluoroborate as electrolyte. The electro-synthesis was carried out using electrical potential cycling in the presence of tetraethyl-ammonium phthalate. The presence of this salt in the electrolyte decreased the cross-linking of the electrodeposited polymer to give PVK bearing a more
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