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Sergio Antonio Pellice - One of the best experts on this subject based on the ideXlab platform.

  • Epoxy-silica/Clay nanocomposite for silver-based antibacterial thin coatings: structure and ionic mobility
    Journal of Solid State Electrochemistry, 2020
    Co-Authors: Hugo Fernando Giraldo Mejía, Emilio Jiménez-piqué, Matias Hernan Valdes, Raul Ariel Procaccini, Sergio Antonio Pellice
    Abstract:

    A novel material was developed using sol-gel chemistry and an environmental-friendly grafting process of Clay Nanoparticles. In a previous work of our group, highly compact coatings had been generated using silicon alkoxides, as tetraethoxysilane (TEOS) and 3-glycidoxypropyl-trimethoxysilane (GPTMS), with the incorporation of silver ions and synthetic smectite-type Clay Nanoparticles, demonstrating antibacterial behaviour against Escherichia coli cultures. By controlling the loading, the exfoliation and the grafting processes of the Clay Nanoparticles, it was possible to control the migration kinetics of silver ions from the coating matrix to the surface. Morphological and structural studies, through SEM-FIB, revealed the effect of Clay Nanoparticles leading to the development of a homogeneous structure in 2-μm thickness coatings. Grazing incidence small angle X-ray scattering (GISAXS) experiments demonstrated that silver is distributed in a strongly anisotropic arrangement when Clay nanosheets are absent. The size of the silver particles developed on the surface is rather different from that of those developed in the bulk of the coating. Scattering patterns also revealed that the incorporation of Clay nanosheets promotes the development of less anisotropic structures. Electrochemical impedance spectroscopy (EIS) measurements confirmed the integrity of the material and the applicability of a physical model with normal distribution of resistive and capacitive elements.

  • Synthesis and characterization of silver-rich coatings loaded with functionalized Clay Nanoparticles
    Journal of Sol-Gel Science and Technology, 2018
    Co-Authors: Hugo Fernando Giraldo Mejía, Raul Ariel Procaccini, Sergio Antonio Pellice
    Abstract:

    A synthetic exfoliated nanoClay smectite type, Laponite® S482, was incorporated as a functionalized load in a silica hybrid matrix synthesized by the sol–gel route. The previous functionalization was carried out through a “grafting” reaction with (3-glycidoxypropyl)trimethoxysilane (GPTMS) assisted by ultrasonic dispersion. The precursor sols were synthesized by acid-catalyzed hydrolytic condensation between tetraethoxysilane (TEOS) and functionalized GPTMS, a silver ions source was added in order to obtain a coating material with controlled silver releasing properties. Coatings were obtained by “dip-coating” on different substrates. Structural characterization of the coatings was conducted by SAXS and SEM-EDS, the results revealed a complex silica matrix with intercalated nanoClays, an organic fraction and a homogeneous content of Ag+. The electrochemical characterization was realized by EIS tests on stainless steel coated substrates AISI 316L type; the results showed good barriers properties and a high integrity of the coatings loaded with nanoClay. The evolution of the release of Ag+ ions was studied by XRF, through exposing the coatings to a leaching process at steady state and determining the residual content of Ag within the coat at different immersion times. It was found that the addition of 1.5 wt. % of Clay, in respect to condensed silica, decreased the initial diffusion rate of Ag+ ions at near the half part, allowing its potential use in the development of antibacterial coatings with longer terms of life.

  • Epoxy-silica/Clay nanocomposite for silver-based antibacterial thin coatings: Synthesis and structural characterization
    Journal of colloid and interface science, 2017
    Co-Authors: Hugo Fernando Giraldo Mejía, Raul Ariel Procaccini, Lucia Yohai, Andrea Pedetta, Karina Herrera Seitz, Sergio Antonio Pellice
    Abstract:

    Development of new functional coatings in the field of health care, as antibacterial applications, deals with a straight control of the diffusive properties that rules the releasing of the active component. In this work, the development of a silver-rich nanocomposite thin coating, loaded with organically modified Clay Nanoparticles, is presented. The synthesis process included an environment-friendly silanization process of Clay Nanoparticles (Laponite® S482) with (3-glycidoxypropyl)trimethoxysilane (GPTMS) and the further hydrolytic condensation with tetraethoxysilane (TEOS). Silanization process and the obtained coatings were analysed by Fourier transformed infrared spectroscopy, UV-visible spectroscopy, X-ray diffraction, thermogravimetric curves and scanning electron microscopy. The silanization process of Clay Nanoparticles with the organically reactive alkyl alkoxysilane, allowed to stabilize and exfoliate the Clay nanosheets within a hybrid organic-inorganic sol-gel material. Ring opening of grafted epoxy groups carried to an increasing of the basal spacing, of intercalated Clay nanosheets, from 1.3 to 1.8nm. Moreover, incorporation of organically modified Clay nanosheets introduced a significant stabilization on the development of silver Nanoparticles inside the structure of the nanocomposite coating, retaining the silver inside the coating material and restricting the growing of silver Nanoparticles on the surface of the coating. Antibacterial behaviour, against E. coli cultures, performed through agar diffusion tests, provided promising results that allow assuming that the studied nanocomposite coating serves as a reservoir of ionic silver, permitting the antibacterial effect.

  • Hybrid sol-gel coatings containing Clay Nanoparticles for corrosion protection of mild steel
    Electrochimica Acta, 2016
    Co-Authors: Ianina Santana, Wido Schreiner, Andrés Pepe, Sergio Antonio Pellice, Silvia Ceré
    Abstract:

    The development of a new environment-friendly anticorrosive coating for mild steel substrate is afforded in this work. The combined use of cerium, as a self-healing agent, and Clay Nanoparticles, as improvers of the barrier properties, was considered to the development of new anticorrosive sol-gel coatings. Nanostructured hybrid films were synthesized by the sol–gel route from tetraethoxysilane (TEOS) and 3-glicidoxipropyl-trimetoxisilano (GPTMS) using laminar nanoClays (Laponite Na+0.7[Si8Mg5.5Li0.3H4O24]-0.7) to improve mechanical and barrier properties, and Ce(NO3)3•6H2O as a supplier of Ce(III) to provide an inhibiting effect in the event of coating failure. Carbon steel plates, AISI 1010, were used as substrates. Prior to the application of the coating, samples were treated with a phosphoric acid 2% v/v in order to improve coating adherence. In order to evaluate cerium effect, electrochemical behaviour of films containing Laponite and cerium salts (TGL-Ce) were compared with films containing only Laponite (TGL) by means of potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) measurements using a 0.35 wt% NaCl solution. Microstructural characterization and surface analysis of substrates and sol-gel coatings were performed by optical microscopy and by XPS techniques. The use of nanoClays allowed to achieve a significant improvement of the anticorrosive behaviour of the cerium doped coating at the same time that enhances the physical integrity of the coatings under immersion tests.

Per Jostein Hovde - One of the best experts on this subject based on the ideXlab platform.

  • durability reaction to fire properties and environmental impact of treated and untreated wooden claddings
    Wood Material Science and Engineering, 2013
    Co-Authors: Selamawit Mamo Fufa, Bjørn Petter Jelle, Per Jostein Hovde
    Abstract:

    Abstract This work summarizes the output of durability, reaction to fire properties, and environmental impact of wooden claddings subjected to treatments modified with TiO2 and Clay Nanoparticles. The objective was to investigate the effects of 1 wt% of TiO2 and Clay Nanoparticles in existing water-based and stain coatings and preservatives regarding the properties mentioned above. Water vapor resistance properties were used to assess the moisture transfer properties of the specimens by using the cup test. The reactions to fire properties of the specimens were analyzed using small-scale cone calorimeter test. Accelerated aging was used to study the weathering properties of specimens, where the performance of the specimens with aging was characterized using Fourier transform infrared (FTIR) analysis. The effect of increasing the percentage of Nanoparticles from 1 wt% to 3 wt% on the weathering properties of the specimens was further analyzed. Moreover, comparison between the overall environmental impact be...

  • Effects of TiO2 and Clay Nanoparticles loading on weathering performance of coated wood
    Progress in Organic Coatings, 2013
    Co-Authors: Selamawit Mamo Fufa, Bjørn Petter Jelle, Per Jostein Hovde
    Abstract:

    The weathering performance of Norway spruce coated with acrylic water based paint mixed with TiO2 and Clay Nanoparticles were investigated. Uncoated specimens and specimens coated with unmodified paint were used as references. This work describes the effect of the Nanoparticles in general and compares the performance of 1 wt% and 3 wt% of Nanoparticles in particular on the weathering performance of the coated specimens. Accelerated ageing experiments were performed in an Atlas solar simulator to evaluate the ageing behaviour of the coated wood and characterized through colour measurements and Fourier transform infrared (FTIR) spectroscopy before, during and at the end of the exposure periods. In general, the addition of TiO2 and Clay Nanoparticles slightly slowed down the coated specimens degradation compared to specimens coated with unmodified paint.

  • Weathering performance of spruce coated with water based acrylic paint modified with TiO2 and Clay Nanoparticles
    Progress in Organic Coatings, 2013
    Co-Authors: Selamawit Mamo Fufa, Bjørn Petter Jelle, Per Jostein Hovde
    Abstract:

    Abstract This work examines the effect of wood specimens coated with water based acrylic coatings modified with TiO 2 and Clay Nanoparticles against weathering strain. The long-term durability of the specimens towards climate strain was studied within a relatively short time frame by accelerated climate ageing. The surface changes that occurred as a result of photodegradation of the specimens subjected to accelerated climate exposures were studied using colour measurements and Fourier transform infrared (FTIR) spectroscopy. The results revealed a significant decrease in the intensity of lignin bands attributed to degradation of the lignin component of the wood. However, the intensity of the lignin photodegradation was lower for coated specimens, with slightly lower degradation for the specimens coated with paints modified with TiO 2 and unmodified montmorillonite Clay Nanoparticles.

Hugo Fernando Giraldo Mejía - One of the best experts on this subject based on the ideXlab platform.

  • Epoxy-silica/Clay nanocomposite for silver-based antibacterial thin coatings: structure and ionic mobility
    Journal of Solid State Electrochemistry, 2020
    Co-Authors: Hugo Fernando Giraldo Mejía, Emilio Jiménez-piqué, Matias Hernan Valdes, Raul Ariel Procaccini, Sergio Antonio Pellice
    Abstract:

    A novel material was developed using sol-gel chemistry and an environmental-friendly grafting process of Clay Nanoparticles. In a previous work of our group, highly compact coatings had been generated using silicon alkoxides, as tetraethoxysilane (TEOS) and 3-glycidoxypropyl-trimethoxysilane (GPTMS), with the incorporation of silver ions and synthetic smectite-type Clay Nanoparticles, demonstrating antibacterial behaviour against Escherichia coli cultures. By controlling the loading, the exfoliation and the grafting processes of the Clay Nanoparticles, it was possible to control the migration kinetics of silver ions from the coating matrix to the surface. Morphological and structural studies, through SEM-FIB, revealed the effect of Clay Nanoparticles leading to the development of a homogeneous structure in 2-μm thickness coatings. Grazing incidence small angle X-ray scattering (GISAXS) experiments demonstrated that silver is distributed in a strongly anisotropic arrangement when Clay nanosheets are absent. The size of the silver particles developed on the surface is rather different from that of those developed in the bulk of the coating. Scattering patterns also revealed that the incorporation of Clay nanosheets promotes the development of less anisotropic structures. Electrochemical impedance spectroscopy (EIS) measurements confirmed the integrity of the material and the applicability of a physical model with normal distribution of resistive and capacitive elements.

  • Synthesis and characterization of silver-rich coatings loaded with functionalized Clay Nanoparticles
    Journal of Sol-Gel Science and Technology, 2018
    Co-Authors: Hugo Fernando Giraldo Mejía, Raul Ariel Procaccini, Sergio Antonio Pellice
    Abstract:

    A synthetic exfoliated nanoClay smectite type, Laponite® S482, was incorporated as a functionalized load in a silica hybrid matrix synthesized by the sol–gel route. The previous functionalization was carried out through a “grafting” reaction with (3-glycidoxypropyl)trimethoxysilane (GPTMS) assisted by ultrasonic dispersion. The precursor sols were synthesized by acid-catalyzed hydrolytic condensation between tetraethoxysilane (TEOS) and functionalized GPTMS, a silver ions source was added in order to obtain a coating material with controlled silver releasing properties. Coatings were obtained by “dip-coating” on different substrates. Structural characterization of the coatings was conducted by SAXS and SEM-EDS, the results revealed a complex silica matrix with intercalated nanoClays, an organic fraction and a homogeneous content of Ag+. The electrochemical characterization was realized by EIS tests on stainless steel coated substrates AISI 316L type; the results showed good barriers properties and a high integrity of the coatings loaded with nanoClay. The evolution of the release of Ag+ ions was studied by XRF, through exposing the coatings to a leaching process at steady state and determining the residual content of Ag within the coat at different immersion times. It was found that the addition of 1.5 wt. % of Clay, in respect to condensed silica, decreased the initial diffusion rate of Ag+ ions at near the half part, allowing its potential use in the development of antibacterial coatings with longer terms of life.

  • Epoxy-silica/Clay nanocomposite for silver-based antibacterial thin coatings: Synthesis and structural characterization
    Journal of colloid and interface science, 2017
    Co-Authors: Hugo Fernando Giraldo Mejía, Raul Ariel Procaccini, Lucia Yohai, Andrea Pedetta, Karina Herrera Seitz, Sergio Antonio Pellice
    Abstract:

    Development of new functional coatings in the field of health care, as antibacterial applications, deals with a straight control of the diffusive properties that rules the releasing of the active component. In this work, the development of a silver-rich nanocomposite thin coating, loaded with organically modified Clay Nanoparticles, is presented. The synthesis process included an environment-friendly silanization process of Clay Nanoparticles (Laponite® S482) with (3-glycidoxypropyl)trimethoxysilane (GPTMS) and the further hydrolytic condensation with tetraethoxysilane (TEOS). Silanization process and the obtained coatings were analysed by Fourier transformed infrared spectroscopy, UV-visible spectroscopy, X-ray diffraction, thermogravimetric curves and scanning electron microscopy. The silanization process of Clay Nanoparticles with the organically reactive alkyl alkoxysilane, allowed to stabilize and exfoliate the Clay nanosheets within a hybrid organic-inorganic sol-gel material. Ring opening of grafted epoxy groups carried to an increasing of the basal spacing, of intercalated Clay nanosheets, from 1.3 to 1.8nm. Moreover, incorporation of organically modified Clay nanosheets introduced a significant stabilization on the development of silver Nanoparticles inside the structure of the nanocomposite coating, retaining the silver inside the coating material and restricting the growing of silver Nanoparticles on the surface of the coating. Antibacterial behaviour, against E. coli cultures, performed through agar diffusion tests, provided promising results that allow assuming that the studied nanocomposite coating serves as a reservoir of ionic silver, permitting the antibacterial effect.

Selamawit Mamo Fufa - One of the best experts on this subject based on the ideXlab platform.

  • durability reaction to fire properties and environmental impact of treated and untreated wooden claddings
    Wood Material Science and Engineering, 2013
    Co-Authors: Selamawit Mamo Fufa, Bjørn Petter Jelle, Per Jostein Hovde
    Abstract:

    Abstract This work summarizes the output of durability, reaction to fire properties, and environmental impact of wooden claddings subjected to treatments modified with TiO2 and Clay Nanoparticles. The objective was to investigate the effects of 1 wt% of TiO2 and Clay Nanoparticles in existing water-based and stain coatings and preservatives regarding the properties mentioned above. Water vapor resistance properties were used to assess the moisture transfer properties of the specimens by using the cup test. The reactions to fire properties of the specimens were analyzed using small-scale cone calorimeter test. Accelerated aging was used to study the weathering properties of specimens, where the performance of the specimens with aging was characterized using Fourier transform infrared (FTIR) analysis. The effect of increasing the percentage of Nanoparticles from 1 wt% to 3 wt% on the weathering properties of the specimens was further analyzed. Moreover, comparison between the overall environmental impact be...

  • Effects of TiO2 and Clay Nanoparticles loading on weathering performance of coated wood
    Progress in Organic Coatings, 2013
    Co-Authors: Selamawit Mamo Fufa, Bjørn Petter Jelle, Per Jostein Hovde
    Abstract:

    The weathering performance of Norway spruce coated with acrylic water based paint mixed with TiO2 and Clay Nanoparticles were investigated. Uncoated specimens and specimens coated with unmodified paint were used as references. This work describes the effect of the Nanoparticles in general and compares the performance of 1 wt% and 3 wt% of Nanoparticles in particular on the weathering performance of the coated specimens. Accelerated ageing experiments were performed in an Atlas solar simulator to evaluate the ageing behaviour of the coated wood and characterized through colour measurements and Fourier transform infrared (FTIR) spectroscopy before, during and at the end of the exposure periods. In general, the addition of TiO2 and Clay Nanoparticles slightly slowed down the coated specimens degradation compared to specimens coated with unmodified paint.

  • Weathering performance of spruce coated with water based acrylic paint modified with TiO2 and Clay Nanoparticles
    Progress in Organic Coatings, 2013
    Co-Authors: Selamawit Mamo Fufa, Bjørn Petter Jelle, Per Jostein Hovde
    Abstract:

    Abstract This work examines the effect of wood specimens coated with water based acrylic coatings modified with TiO 2 and Clay Nanoparticles against weathering strain. The long-term durability of the specimens towards climate strain was studied within a relatively short time frame by accelerated climate ageing. The surface changes that occurred as a result of photodegradation of the specimens subjected to accelerated climate exposures were studied using colour measurements and Fourier transform infrared (FTIR) spectroscopy. The results revealed a significant decrease in the intensity of lignin bands attributed to degradation of the lignin component of the wood. However, the intensity of the lignin photodegradation was lower for coated specimens, with slightly lower degradation for the specimens coated with paints modified with TiO 2 and unmodified montmorillonite Clay Nanoparticles.

Raul Ariel Procaccini - One of the best experts on this subject based on the ideXlab platform.

  • Epoxy-silica/Clay nanocomposite for silver-based antibacterial thin coatings: structure and ionic mobility
    Journal of Solid State Electrochemistry, 2020
    Co-Authors: Hugo Fernando Giraldo Mejía, Emilio Jiménez-piqué, Matias Hernan Valdes, Raul Ariel Procaccini, Sergio Antonio Pellice
    Abstract:

    A novel material was developed using sol-gel chemistry and an environmental-friendly grafting process of Clay Nanoparticles. In a previous work of our group, highly compact coatings had been generated using silicon alkoxides, as tetraethoxysilane (TEOS) and 3-glycidoxypropyl-trimethoxysilane (GPTMS), with the incorporation of silver ions and synthetic smectite-type Clay Nanoparticles, demonstrating antibacterial behaviour against Escherichia coli cultures. By controlling the loading, the exfoliation and the grafting processes of the Clay Nanoparticles, it was possible to control the migration kinetics of silver ions from the coating matrix to the surface. Morphological and structural studies, through SEM-FIB, revealed the effect of Clay Nanoparticles leading to the development of a homogeneous structure in 2-μm thickness coatings. Grazing incidence small angle X-ray scattering (GISAXS) experiments demonstrated that silver is distributed in a strongly anisotropic arrangement when Clay nanosheets are absent. The size of the silver particles developed on the surface is rather different from that of those developed in the bulk of the coating. Scattering patterns also revealed that the incorporation of Clay nanosheets promotes the development of less anisotropic structures. Electrochemical impedance spectroscopy (EIS) measurements confirmed the integrity of the material and the applicability of a physical model with normal distribution of resistive and capacitive elements.

  • Synthesis and characterization of silver-rich coatings loaded with functionalized Clay Nanoparticles
    Journal of Sol-Gel Science and Technology, 2018
    Co-Authors: Hugo Fernando Giraldo Mejía, Raul Ariel Procaccini, Sergio Antonio Pellice
    Abstract:

    A synthetic exfoliated nanoClay smectite type, Laponite® S482, was incorporated as a functionalized load in a silica hybrid matrix synthesized by the sol–gel route. The previous functionalization was carried out through a “grafting” reaction with (3-glycidoxypropyl)trimethoxysilane (GPTMS) assisted by ultrasonic dispersion. The precursor sols were synthesized by acid-catalyzed hydrolytic condensation between tetraethoxysilane (TEOS) and functionalized GPTMS, a silver ions source was added in order to obtain a coating material with controlled silver releasing properties. Coatings were obtained by “dip-coating” on different substrates. Structural characterization of the coatings was conducted by SAXS and SEM-EDS, the results revealed a complex silica matrix with intercalated nanoClays, an organic fraction and a homogeneous content of Ag+. The electrochemical characterization was realized by EIS tests on stainless steel coated substrates AISI 316L type; the results showed good barriers properties and a high integrity of the coatings loaded with nanoClay. The evolution of the release of Ag+ ions was studied by XRF, through exposing the coatings to a leaching process at steady state and determining the residual content of Ag within the coat at different immersion times. It was found that the addition of 1.5 wt. % of Clay, in respect to condensed silica, decreased the initial diffusion rate of Ag+ ions at near the half part, allowing its potential use in the development of antibacterial coatings with longer terms of life.

  • Epoxy-silica/Clay nanocomposite for silver-based antibacterial thin coatings: Synthesis and structural characterization
    Journal of colloid and interface science, 2017
    Co-Authors: Hugo Fernando Giraldo Mejía, Raul Ariel Procaccini, Lucia Yohai, Andrea Pedetta, Karina Herrera Seitz, Sergio Antonio Pellice
    Abstract:

    Development of new functional coatings in the field of health care, as antibacterial applications, deals with a straight control of the diffusive properties that rules the releasing of the active component. In this work, the development of a silver-rich nanocomposite thin coating, loaded with organically modified Clay Nanoparticles, is presented. The synthesis process included an environment-friendly silanization process of Clay Nanoparticles (Laponite® S482) with (3-glycidoxypropyl)trimethoxysilane (GPTMS) and the further hydrolytic condensation with tetraethoxysilane (TEOS). Silanization process and the obtained coatings were analysed by Fourier transformed infrared spectroscopy, UV-visible spectroscopy, X-ray diffraction, thermogravimetric curves and scanning electron microscopy. The silanization process of Clay Nanoparticles with the organically reactive alkyl alkoxysilane, allowed to stabilize and exfoliate the Clay nanosheets within a hybrid organic-inorganic sol-gel material. Ring opening of grafted epoxy groups carried to an increasing of the basal spacing, of intercalated Clay nanosheets, from 1.3 to 1.8nm. Moreover, incorporation of organically modified Clay nanosheets introduced a significant stabilization on the development of silver Nanoparticles inside the structure of the nanocomposite coating, retaining the silver inside the coating material and restricting the growing of silver Nanoparticles on the surface of the coating. Antibacterial behaviour, against E. coli cultures, performed through agar diffusion tests, provided promising results that allow assuming that the studied nanocomposite coating serves as a reservoir of ionic silver, permitting the antibacterial effect.