Gianfranco Carotenuto - Academia.edu (original) (raw)
Papers by Gianfranco Carotenuto
Journal of Materials Chemistry, 2007
Polymer-embedded silver clusters have been prepared by thermal decomposition of silver dodecylmer... more Polymer-embedded silver clusters have been prepared by thermal decomposition of silver dodecylmercaptide previously dissolved in amorphous polystyrene. The morphology and structure of silver clusters have been determined by transmission electron microscopy (TEM) and large angle X-ray diffractometry (XRD), respectively. The mechanism involved in the thermolysis reaction was elucidated by different NMR techniques. The thermolysis produced thiol-derivatized silver clusters (i.e., silver clusters coated with a self-organized thiol monolayer, Ag x (SC 12 H 25 ) y ) and had the effect of increasing the branching degree of polystyrene due to enhanced cross-linking.
Polymer Engineering and Science, 2006
Homoleptic mercaptides of noble metals (i.e., Me(SR)x, where R is a linear alkyl group, i.e., CnH... more Homoleptic mercaptides of noble metals (i.e., Me(SR)x, where R is a linear alkyl group, i.e., CnH2n+1) dissolved in polymer undergo a thermal degradation process at moderately low temperatures (180–250°C), producing metal atoms that then give nanosized metal particles by clustering. As an example, the preparation of palladium, gold, and silver clusters dispersed in polystyrene has been described, but such chemical route is a very general approach and a variety of metal/polymer combinations can be equivalently obtained. POLYM. ENG. SCI. 46:1016–1021, 2006. © 2006 Society of Plastics Engineers.
Advanced Performance Materials, 1997
Theories and applications associated with sintering of ceramics and reducing of sintering tempera... more Theories and applications associated with sintering of ceramics and reducing of sintering temperature are reviewed. The whole sintering process is divided into three sub-processes as powder preparation, compaction and sintering, and each sub-process is discussed in terms of its possible contribution to the reducing of sintering temperature. New approach for practical optimization of sintering process is investigated. The application of above in the Low Temperature Co-fired Ceramics (LTCC) is discussed. Meanwhile, many successful applications in reducing the sintering temperatures are presented.
Journal of Materials Science, 2006
Polymer-embedding of nano-sized indium tin oxide (SnO·In2O3, ITO) produces electrically conductiv... more Polymer-embedding of nano-sized indium tin oxide (SnO·In2O3, ITO) produces electrically conductive materials transparent to the visible light at filling factors higher than the percolation threshold. ITO powders are commercially available in an aggregated form and a disaggregation technique was required. Here, aggregated ITO nanoparticles were transformed to colloidal suspension by high-speed stirring. This finely dispersed ceramic suspension was stabilized by addition of poly(vinyl pyrrolidone) and the obtained colloidal system was cast on an optical-grade substrate (PET) to produce electrically conductive-transparent nanocomposite films. Preliminary mechanical and electrical characterization of these films showed good conductivity and interfacial properties.
Journal of Applied Polymer Science, 1999
ABSTRACT
A unique guide to an essential area of nanoscience Interest in nano-sized metals has increased gr... more A unique guide to an essential area of nanoscience Interest in nano-sized metals has increased greatly due to their special characteristics and suitability for a number of advanced applications. As technology becomes more refined-including the ability to effectively manipulate and stabilize metals at the nanoscale-these materials present ever-more workable solutions to a growing range of problems. Metal-Polymer Nanocomposites provides the first guide solely devoted to the unique properties and applications of this essential area of nanoscience. It offers a truly multidisciplinary approach, making the text accessible to readers in physical, chemical, and materials science as well as areas such as engineering and topology. The thorough coverage includes: * The chemical and physical properties of nano-sized metals * Different approaches to the synthesis of metal-polymer nanocomposites (MPN) * Advanced characterization techniques and methods for study of MPN * Real-world applications, including color filters, polarizers, optical sensors, nonlinear optical devices, and more * An extensive list of references on the topics covered A unique, cutting-edge resource for a vital area of nanoscience development, Metal-Polymer Nanocomposites is an invaluable text for students and practitioners of materials science, engineering, polymer science, chemical engineering, electrical engineering, and optics.
Applied Surface Science, 2005
Gold nanoparticles have been prepared by alcoholic reduction of Au(III) ions in presence of a pol... more Gold nanoparticles have been prepared by alcoholic reduction of Au(III) ions in presence of a polymeric stabilizer (poly(Nvinyl pyrrolidone), PVP). On-line UV-vis spectroscopic characterization and transmission electron microscopy (TEM) analysis are presented. Optical spectroscopy data show that the temporal evolution of absorption spectra and the absorbance peak properties are correlated to the off-line size measurements obtained at chemical reaction end by TEM micrographs. The Au cluster size behaves linearly with time above a threshold temperature (70 8C), according to a deposition-controlled growth mechanism. # 2005 Published by Elsevier B.V.
Journal of Materials Chemistry, 2003
... Gianfranco Carotenuto*a, Brunetto Martoranab, Piero Perlob and Luigi Nicolaisa. a Institute o... more ... Gianfranco Carotenuto*a, Brunetto Martoranab, Piero Perlob and Luigi Nicolaisa. a Institute of Composite and Biomedical Materials. ... 5, KE Gonsalves, G. Carlson, X. Chen, J. Kumar, F. Aranda, R. Perez and M. Jose-Yacaman, J. Mater. Sci. ...
Applied Composite Materials, 1994
Metal Matrix Composites (MMC's) reinforced with continuous fibers were generally fabricated by a ... more Metal Matrix Composites (MMC's) reinforced with continuous fibers were generally fabricated by a foil-sandwich technique or by liquid metal infiltration. Liquid metal infiltration may be used to cast final shapes in molds containing fiber preforms. It is also used to make composite wire from which may be fabricated panels and shapes by hot-press diffusion bonding or pultrusion. The major drawback of this method is that the molten matrix must wet the fiber for successful infiltration to occur, requiring special fiber surface treatments or matrix additives, and that, molten metals generally dissolve or degrade the fibers, necessitating a barrier coating on the fibers. All these problems can be solved using carbon fibers coated with metallic layers, e.g. nickel. This work analyses an easy method to produce modified carbon fibers by electroplating and the process of its recristallization. The topography of the growth front of the deposit has been studied. At temperatures higher than about 300° C an annealing under vacuum is required, because of the high reactivity of metal coating, nevertheless the heat treatment of metal deposit produces always an embrittled material.
Applied Organometallic Chemistry, 2001
Dispersions of very small metal particles in polymeric matrixes are scientifically and technologi... more Dispersions of very small metal particles in polymeric matrixes are scientifically and technologically important. Here, poly(N-vinylpyrrolidone) (PVP) filled with nanometric silver particles characterized by a narrow size distribution and a controlled average dimension has been obtained using a modification of the polyol process. In particular, the nanocomposite material was prepared by reduction of silver nitrate in ethylene glycol in the presence of ultrasound and PVP as a protective agent. The final particle size was controlled by removing the silver–PVP system from the reactive mixture by addition of acetone. The UV–visible spectrum of the material shows a very strong plasmon resonance band centred at 410 nm. The band position depends on the particle size and, consequently, the control of the particle growth process allows one to modulate the nanocomposite absorption wavelength. Such an important characteristic offers the possibility to use Ag–PVP nanocomposites to produce UV-absorbers and colour filters for advanced optical devices. Copyright © 2001 John Wiley & Sons, Ltd.
Polymer International, 2004
A method for the controlled synthesis of alkanethiol-derivatized gold clusters to be used as fill... more A method for the controlled synthesis of alkanethiol-derivatized gold clusters to be used as fillers for polymeric nanocomposites has been developed. Gold clusters embedded in poly(N-vinyl pyrrolidone) (PVP) were obtained by reduction of AuCl4− with ethylene glycol in the presence of PVP as a stabilizer. The gold/PVP system was separated from the reactive mixture by flocculation with acetone, and this material was treated with a dodecanethiol/ethanol solution to produce thiol-derivatized gold clusters. Then, the clusters were dispersed in polystyrene/chloroform solutions and highly transparent purple-colored nanocomposite films were obtained by solution casting. This preparative scheme allows one to obtain high-purity nanocomposites, with complete control over the filler percentage and size. Copyright © 2004 Society of Chemical Industry
Journal of Materials Science-materials in Medicine, 1999
In the dentistry field, synthetic hydroxyapatite can be conveniently used as semiabsorbable allop... more In the dentistry field, synthetic hydroxyapatite can be conveniently used as semiabsorbable alloplastic material to solve a number of clinical problems. The hydroxyapatite structure influences bone ingrowth as well as its resorption. In particular, pore size must exceed 100 μm to allow new bone ingrowth. Because of its brittleness, highly porous hydroxyapatite is difficult to handle without causing damage, and, therefore, its mechanical performance has to be improved placing the material on a dense hydroxyapatite substrate. Dense/porous hydroxyapatite laminates can be obtained by slip casting technology. The method starts with the preparation of a ceramic powder–binder–solvent system. This slurry produces, after solvent evaporation, a soft green tape, that is successively baked at 300 °C to remove all organic component, and finally sintered at high temperature (1200 °C). The material porosity cannot be significantly modified by changes in the slurry composition and sintering temperature; therefore, the macroporous hydroxyapatite layer must be obtained using a porous hydroxyapatite powder. The powder is prepared by grinding of green tape pieces and the resulting coarse material is successively baked at 300 °C. Such material is mixed with a polymer solution and cast on a green tape substrate. Layer fractures are not observed in both film bulks and interface, because during sintering the consolidation of two layers happens simultaneously. In the resulting material, the first layer consisted of macroporous hydroxyapatite with high osteoconductive properties, and the second layer was a dense hydroxyapatite substrate able to improve the laminate mechanical properties. © 1999 Kluwer Academic Publishers
Clinical Oral Implants Research, 1999
Sensors and Actuators B-chemical, 2006
ABSTRACT
Journal of Materials Science-materials in Medicine, 1999
A new generation of electrocardiogram (ECG) electrodes have been fabricated and superficially mod... more A new generation of electrocardiogram (ECG) electrodes have been fabricated and superficially modified by a special controlled precorrosion process. The electrodes have been characterized by scanning electron microscopy (SEM), resistance–capacitance measurements (RCM) and simulated defibrillation recovery (SDR). The resulting surface of the Sn alloys was rough, and, consequently, a large active surface area was available. As a result, a higher electrocardiogram electrode performance, including low alternating current (a.c.) impedance, excellent time stability and improved SDR, was achieved. Such new design can surely find important future applications in clinical diagnosis. © 1999 Kluwer Academic Publishers
Journal of Nanoparticle Research, 2009
An effective method of preparation of bismuth nanopowders by thermal decomposition of bismuth dod... more An effective method of preparation of bismuth nanopowders by thermal decomposition of bismuth dodecyl-mercaptide Bi(SC12H25)3 and preliminary results on their thermoelectric properties are reported. The thermolysis process leads to Bi nanoparticles due to the efficient capping agent effect of the dodecyl-disulfide by-product, which strongly bonds the surface of the Bi clusters, preventing their aggregation and significantly reducing their growth rate. The structure and morphology of the thermolysis products were investigated by differential scanning calorimetry, thermogravimetry, X-ray diffractometry, 1H nuclear magnetic resonance spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. It has been shown that the prepared Bi nanopowder consists of spherical shape nanoparticles, with the average diameter depending on the thermolysis temperature. The first results on the thermoelectric characterization of the prepared Bi nanopowders reveal a peculiar behavior characterized by a semimetal–semiconductor transition, and a significant increase in the Seebeck coefficient when compared to bulk Bi in the case of the lowest grain size (170 nm).
Journal of Materials Chemistry, 2003
ABSTRACT
Journal of Materials Science Letters, 2001
In the last few years, nanocomposites have become the major part of new materials synthesis all o... more In the last few years, nanocomposites have become the major part of new materials synthesis all over the world for applications ranging from mechanics and tribology to optics, magnetism and electronics . In the polymer-based nanocomposite field, the unique properties of the nanoparticle surface atoms are used to modify synthetic polymers. Thus, tuning the size and the structure of nanoparticles makes it possible to obtain optical plastics dyed by the plasmon absorption band, extremely low or high refractive index materials, nonlinear optical materials, photoluminescent plastics, etc.
Applied Composite Materials, 1996
Optically transparent nanocomposites are of special interest since they have great potential in o... more Optically transparent nanocomposites are of special interest since they have great potential in optical applications. The synthesis of poly(methacrylic methylester)/monodispersed Cu2(OH)2CO3 particles, a new nanocomposite material with a refractive index similar to glass, is here described. The system can be easily deposited on glass plates by spin-coating technology, yielding homogeneous, low-defect thin films of high transparency, that can be used as color filters for liquid crystal displays. Differential scanning calorimetry (DSC), dynamic light scattering (DLS), scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive spectroscopy (EDS) have been used to characterize the composite material.
Applied Composite Materials, 1996
It is possible to optimize the performance of the inorganic-organic composites dispersing the ino... more It is possible to optimize the performance of the inorganic-organic composites dispersing the inorganic component in the organic matrix on a nanomiter length scale. If dry the inorganic phase cannot be intimately dispersed during the incorporation in the matrix. When the particle surface is organically modified, and the incorporation is made starting from a liquid dispersion (particles in polymer solution), the resulting composites exhibit an excellent homogeneity. Here, monolithic [poly(methyl methacrylate)/monodisperse silica particles] nanocomposites have been prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), micro-hardness, and differential scanning calorimetry (DSC).
Journal of Materials Chemistry, 2007
Polymer-embedded silver clusters have been prepared by thermal decomposition of silver dodecylmer... more Polymer-embedded silver clusters have been prepared by thermal decomposition of silver dodecylmercaptide previously dissolved in amorphous polystyrene. The morphology and structure of silver clusters have been determined by transmission electron microscopy (TEM) and large angle X-ray diffractometry (XRD), respectively. The mechanism involved in the thermolysis reaction was elucidated by different NMR techniques. The thermolysis produced thiol-derivatized silver clusters (i.e., silver clusters coated with a self-organized thiol monolayer, Ag x (SC 12 H 25 ) y ) and had the effect of increasing the branching degree of polystyrene due to enhanced cross-linking.
Polymer Engineering and Science, 2006
Homoleptic mercaptides of noble metals (i.e., Me(SR)x, where R is a linear alkyl group, i.e., CnH... more Homoleptic mercaptides of noble metals (i.e., Me(SR)x, where R is a linear alkyl group, i.e., CnH2n+1) dissolved in polymer undergo a thermal degradation process at moderately low temperatures (180–250°C), producing metal atoms that then give nanosized metal particles by clustering. As an example, the preparation of palladium, gold, and silver clusters dispersed in polystyrene has been described, but such chemical route is a very general approach and a variety of metal/polymer combinations can be equivalently obtained. POLYM. ENG. SCI. 46:1016–1021, 2006. © 2006 Society of Plastics Engineers.
Advanced Performance Materials, 1997
Theories and applications associated with sintering of ceramics and reducing of sintering tempera... more Theories and applications associated with sintering of ceramics and reducing of sintering temperature are reviewed. The whole sintering process is divided into three sub-processes as powder preparation, compaction and sintering, and each sub-process is discussed in terms of its possible contribution to the reducing of sintering temperature. New approach for practical optimization of sintering process is investigated. The application of above in the Low Temperature Co-fired Ceramics (LTCC) is discussed. Meanwhile, many successful applications in reducing the sintering temperatures are presented.
Journal of Materials Science, 2006
Polymer-embedding of nano-sized indium tin oxide (SnO·In2O3, ITO) produces electrically conductiv... more Polymer-embedding of nano-sized indium tin oxide (SnO·In2O3, ITO) produces electrically conductive materials transparent to the visible light at filling factors higher than the percolation threshold. ITO powders are commercially available in an aggregated form and a disaggregation technique was required. Here, aggregated ITO nanoparticles were transformed to colloidal suspension by high-speed stirring. This finely dispersed ceramic suspension was stabilized by addition of poly(vinyl pyrrolidone) and the obtained colloidal system was cast on an optical-grade substrate (PET) to produce electrically conductive-transparent nanocomposite films. Preliminary mechanical and electrical characterization of these films showed good conductivity and interfacial properties.
Journal of Applied Polymer Science, 1999
ABSTRACT
A unique guide to an essential area of nanoscience Interest in nano-sized metals has increased gr... more A unique guide to an essential area of nanoscience Interest in nano-sized metals has increased greatly due to their special characteristics and suitability for a number of advanced applications. As technology becomes more refined-including the ability to effectively manipulate and stabilize metals at the nanoscale-these materials present ever-more workable solutions to a growing range of problems. Metal-Polymer Nanocomposites provides the first guide solely devoted to the unique properties and applications of this essential area of nanoscience. It offers a truly multidisciplinary approach, making the text accessible to readers in physical, chemical, and materials science as well as areas such as engineering and topology. The thorough coverage includes: * The chemical and physical properties of nano-sized metals * Different approaches to the synthesis of metal-polymer nanocomposites (MPN) * Advanced characterization techniques and methods for study of MPN * Real-world applications, including color filters, polarizers, optical sensors, nonlinear optical devices, and more * An extensive list of references on the topics covered A unique, cutting-edge resource for a vital area of nanoscience development, Metal-Polymer Nanocomposites is an invaluable text for students and practitioners of materials science, engineering, polymer science, chemical engineering, electrical engineering, and optics.
Applied Surface Science, 2005
Gold nanoparticles have been prepared by alcoholic reduction of Au(III) ions in presence of a pol... more Gold nanoparticles have been prepared by alcoholic reduction of Au(III) ions in presence of a polymeric stabilizer (poly(Nvinyl pyrrolidone), PVP). On-line UV-vis spectroscopic characterization and transmission electron microscopy (TEM) analysis are presented. Optical spectroscopy data show that the temporal evolution of absorption spectra and the absorbance peak properties are correlated to the off-line size measurements obtained at chemical reaction end by TEM micrographs. The Au cluster size behaves linearly with time above a threshold temperature (70 8C), according to a deposition-controlled growth mechanism. # 2005 Published by Elsevier B.V.
Journal of Materials Chemistry, 2003
... Gianfranco Carotenuto*a, Brunetto Martoranab, Piero Perlob and Luigi Nicolaisa. a Institute o... more ... Gianfranco Carotenuto*a, Brunetto Martoranab, Piero Perlob and Luigi Nicolaisa. a Institute of Composite and Biomedical Materials. ... 5, KE Gonsalves, G. Carlson, X. Chen, J. Kumar, F. Aranda, R. Perez and M. Jose-Yacaman, J. Mater. Sci. ...
Applied Composite Materials, 1994
Metal Matrix Composites (MMC's) reinforced with continuous fibers were generally fabricated by a ... more Metal Matrix Composites (MMC's) reinforced with continuous fibers were generally fabricated by a foil-sandwich technique or by liquid metal infiltration. Liquid metal infiltration may be used to cast final shapes in molds containing fiber preforms. It is also used to make composite wire from which may be fabricated panels and shapes by hot-press diffusion bonding or pultrusion. The major drawback of this method is that the molten matrix must wet the fiber for successful infiltration to occur, requiring special fiber surface treatments or matrix additives, and that, molten metals generally dissolve or degrade the fibers, necessitating a barrier coating on the fibers. All these problems can be solved using carbon fibers coated with metallic layers, e.g. nickel. This work analyses an easy method to produce modified carbon fibers by electroplating and the process of its recristallization. The topography of the growth front of the deposit has been studied. At temperatures higher than about 300° C an annealing under vacuum is required, because of the high reactivity of metal coating, nevertheless the heat treatment of metal deposit produces always an embrittled material.
Applied Organometallic Chemistry, 2001
Dispersions of very small metal particles in polymeric matrixes are scientifically and technologi... more Dispersions of very small metal particles in polymeric matrixes are scientifically and technologically important. Here, poly(N-vinylpyrrolidone) (PVP) filled with nanometric silver particles characterized by a narrow size distribution and a controlled average dimension has been obtained using a modification of the polyol process. In particular, the nanocomposite material was prepared by reduction of silver nitrate in ethylene glycol in the presence of ultrasound and PVP as a protective agent. The final particle size was controlled by removing the silver–PVP system from the reactive mixture by addition of acetone. The UV–visible spectrum of the material shows a very strong plasmon resonance band centred at 410 nm. The band position depends on the particle size and, consequently, the control of the particle growth process allows one to modulate the nanocomposite absorption wavelength. Such an important characteristic offers the possibility to use Ag–PVP nanocomposites to produce UV-absorbers and colour filters for advanced optical devices. Copyright © 2001 John Wiley & Sons, Ltd.
Polymer International, 2004
A method for the controlled synthesis of alkanethiol-derivatized gold clusters to be used as fill... more A method for the controlled synthesis of alkanethiol-derivatized gold clusters to be used as fillers for polymeric nanocomposites has been developed. Gold clusters embedded in poly(N-vinyl pyrrolidone) (PVP) were obtained by reduction of AuCl4− with ethylene glycol in the presence of PVP as a stabilizer. The gold/PVP system was separated from the reactive mixture by flocculation with acetone, and this material was treated with a dodecanethiol/ethanol solution to produce thiol-derivatized gold clusters. Then, the clusters were dispersed in polystyrene/chloroform solutions and highly transparent purple-colored nanocomposite films were obtained by solution casting. This preparative scheme allows one to obtain high-purity nanocomposites, with complete control over the filler percentage and size. Copyright © 2004 Society of Chemical Industry
Journal of Materials Science-materials in Medicine, 1999
In the dentistry field, synthetic hydroxyapatite can be conveniently used as semiabsorbable allop... more In the dentistry field, synthetic hydroxyapatite can be conveniently used as semiabsorbable alloplastic material to solve a number of clinical problems. The hydroxyapatite structure influences bone ingrowth as well as its resorption. In particular, pore size must exceed 100 μm to allow new bone ingrowth. Because of its brittleness, highly porous hydroxyapatite is difficult to handle without causing damage, and, therefore, its mechanical performance has to be improved placing the material on a dense hydroxyapatite substrate. Dense/porous hydroxyapatite laminates can be obtained by slip casting technology. The method starts with the preparation of a ceramic powder–binder–solvent system. This slurry produces, after solvent evaporation, a soft green tape, that is successively baked at 300 °C to remove all organic component, and finally sintered at high temperature (1200 °C). The material porosity cannot be significantly modified by changes in the slurry composition and sintering temperature; therefore, the macroporous hydroxyapatite layer must be obtained using a porous hydroxyapatite powder. The powder is prepared by grinding of green tape pieces and the resulting coarse material is successively baked at 300 °C. Such material is mixed with a polymer solution and cast on a green tape substrate. Layer fractures are not observed in both film bulks and interface, because during sintering the consolidation of two layers happens simultaneously. In the resulting material, the first layer consisted of macroporous hydroxyapatite with high osteoconductive properties, and the second layer was a dense hydroxyapatite substrate able to improve the laminate mechanical properties. © 1999 Kluwer Academic Publishers
Clinical Oral Implants Research, 1999
Sensors and Actuators B-chemical, 2006
ABSTRACT
Journal of Materials Science-materials in Medicine, 1999
A new generation of electrocardiogram (ECG) electrodes have been fabricated and superficially mod... more A new generation of electrocardiogram (ECG) electrodes have been fabricated and superficially modified by a special controlled precorrosion process. The electrodes have been characterized by scanning electron microscopy (SEM), resistance–capacitance measurements (RCM) and simulated defibrillation recovery (SDR). The resulting surface of the Sn alloys was rough, and, consequently, a large active surface area was available. As a result, a higher electrocardiogram electrode performance, including low alternating current (a.c.) impedance, excellent time stability and improved SDR, was achieved. Such new design can surely find important future applications in clinical diagnosis. © 1999 Kluwer Academic Publishers
Journal of Nanoparticle Research, 2009
An effective method of preparation of bismuth nanopowders by thermal decomposition of bismuth dod... more An effective method of preparation of bismuth nanopowders by thermal decomposition of bismuth dodecyl-mercaptide Bi(SC12H25)3 and preliminary results on their thermoelectric properties are reported. The thermolysis process leads to Bi nanoparticles due to the efficient capping agent effect of the dodecyl-disulfide by-product, which strongly bonds the surface of the Bi clusters, preventing their aggregation and significantly reducing their growth rate. The structure and morphology of the thermolysis products were investigated by differential scanning calorimetry, thermogravimetry, X-ray diffractometry, 1H nuclear magnetic resonance spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. It has been shown that the prepared Bi nanopowder consists of spherical shape nanoparticles, with the average diameter depending on the thermolysis temperature. The first results on the thermoelectric characterization of the prepared Bi nanopowders reveal a peculiar behavior characterized by a semimetal–semiconductor transition, and a significant increase in the Seebeck coefficient when compared to bulk Bi in the case of the lowest grain size (170 nm).
Journal of Materials Chemistry, 2003
ABSTRACT
Journal of Materials Science Letters, 2001
In the last few years, nanocomposites have become the major part of new materials synthesis all o... more In the last few years, nanocomposites have become the major part of new materials synthesis all over the world for applications ranging from mechanics and tribology to optics, magnetism and electronics . In the polymer-based nanocomposite field, the unique properties of the nanoparticle surface atoms are used to modify synthetic polymers. Thus, tuning the size and the structure of nanoparticles makes it possible to obtain optical plastics dyed by the plasmon absorption band, extremely low or high refractive index materials, nonlinear optical materials, photoluminescent plastics, etc.
Applied Composite Materials, 1996
Optically transparent nanocomposites are of special interest since they have great potential in o... more Optically transparent nanocomposites are of special interest since they have great potential in optical applications. The synthesis of poly(methacrylic methylester)/monodispersed Cu2(OH)2CO3 particles, a new nanocomposite material with a refractive index similar to glass, is here described. The system can be easily deposited on glass plates by spin-coating technology, yielding homogeneous, low-defect thin films of high transparency, that can be used as color filters for liquid crystal displays. Differential scanning calorimetry (DSC), dynamic light scattering (DLS), scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive spectroscopy (EDS) have been used to characterize the composite material.
Applied Composite Materials, 1996
It is possible to optimize the performance of the inorganic-organic composites dispersing the ino... more It is possible to optimize the performance of the inorganic-organic composites dispersing the inorganic component in the organic matrix on a nanomiter length scale. If dry the inorganic phase cannot be intimately dispersed during the incorporation in the matrix. When the particle surface is organically modified, and the incorporation is made starting from a liquid dispersion (particles in polymer solution), the resulting composites exhibit an excellent homogeneity. Here, monolithic [poly(methyl methacrylate)/monodisperse silica particles] nanocomposites have been prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), micro-hardness, and differential scanning calorimetry (DSC).