Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C24/00—Coating starting from inorganic powder
  • C23C24/02—Coating starting from inorganic powder by application of pressure only
  • C23C24/04—Impact or kinetic deposition of particles
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
  • C23C4/06—Metallic material
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
  • C23C4/06—Metallic material
  • C23C4/08—Metallic material containing only metal elements
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
  • C23C4/10—Oxides, borides, carbides, nitrides or silicides; Mixtures thereof
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
  • C23C4/134—Plasma spraying
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
  • C23C4/14—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying for coating elongate material
  • C23C4/16—Wires; Tubes

Definitions

• the present invention relates to a method of depositing and fixing nanoparticles on any support.
• nanoparticle describes an aggregate of small molecules, or an assembly of a few tens to a few thousand atoms, forming a particle whose dimensions are of the order of one nanometer. that is less than 1000 ⁇ m (l ⁇ ), preferably less than 100 nm. Because of their size, these particles possess particular physical, electrical, chemical and magnetic properties and give the supports on which they are applied new physical, electrical, chemical, magnetic and mechanical properties.
• Nanoparticles have a growing interest because of their involvement in the development of many devices used in very different fields, such as for example the detection of biological or chemical compounds, the detection of gas or chemical vapors, the elaboration fuel cells or hydrogen storage devices, the production of electronic or optical nanostructures, new chemical catalysts, bio-sensors, or so-called intelligent coatings, such as self-cleaning coatings or which have a particular biological activity, antibacterial for example.
• intelligent coatings such as self-cleaning coatings or which have a particular biological activity, antibacterial for example.
• the deposition of nanoparticles usually comprises a step of activation of the support, which, in the techniques described above, requires a pretreatment which is often complex and may take several hours or even days.
• all these techniques pose environmental problems for solution chemistry and electrochemistry, particularly because of the use of solvents and chemical pollutants, and problems of high energy consumption, as regards the vacuum techniques using a plasma.
• the document WO2007 / 122256 describes the deposition of nanoporous layers by spraying a colloidal solution in a jet of thermal plasma, a plasma whose neutral species, ionized species and electrons have the same temperature.
• the particles of the colloidal solution are at least partially melted in order to adhere to the substrate.
• the plasma jet described has a gas temperature of between 5000 ° K and 15000 ° K. A not insignificant thermal effect will therefore be noted on both the substrate and the soil particles.
• the present invention provides a method of depositing nanoparticles on a support which does not have the disadvantages of the state of the art.
• the present invention provides a rapid process, inexpensive and easy implementation.
• the present invention also proposes to minimize the thermal stresses both on the substrate and on the nanoparticles.
• the present invention also provides a deposition method which improves the homogeneity of the deposit, and, more particularly, the dispersion of the nanoparticles on the substrate.
• the present invention discloses a method using a colloidal solution (or suspension) of nanoparticles for the deposition of nanoparticles on a support, and using an atmospheric plasma for the deposition of nanoparticles on a support.
• the present invention relates to a method for depositing nanoparticles on a support comprising the following steps:
• nanoparticle an aggregate of small molecules, or an assembly of a few hundred to a few thousand atoms, forming a particle whose dimensions are of the order of one nanometer, generally less than 100 nm.
• colloidal solution means a homogeneous suspension of particles in which the solvent is a liquid and the solute a solid homogeneously disseminated in the form of very fine particles.
• Colloidal solutions can take various forms, liquid, gel or paste. Colloidal solutions are intermediate between suspensions, which are heterogeneous media comprising microscopic particles dispersed in a liquid, and true solutions, in which the solute or solutes are in the state of molecular division in the solvent. In liquid form, colloidal solutions are sometimes also called "soil”.
• the atmospheric plasma is an atmospheric non-thermal plasma.
• non-thermal plasma or “cold plasma” a partially or totally ionized gas which comprises electrons, ions (molecular or atomic), atoms or molecules, and radicals, outside the thermodynamic equilibrium, whose electron temperature (temperature of several thousands or tens of thousands of Kelvin) is significantly higher than that of ions and neutrons (temperature close to room temperature up to a few hundred Kelvin).
• Atmospheric plasma or “non-thermal atmospheric plasma” or “atmospheric cold plasma” means a partially or totally ionized gas which comprises electrons, ions (molecular or atomic), atoms or molecules , and radicals, out of thermodynamic equilibrium, whose electron temperature is significantly higher than that of ions and neutrals (the temperatures are similar to those described for a "cold plasma"), and whose pressure is between about 1 mbar and about 1200 mbar, preferably between about 800 and about 1200 mbar.
• the method comprises one or more of the following characteristics: the plasma comprises a plasmagenic gas and the macroscopic temperature of said plasma gas in said plasma can vary between about -20 0 C and about 600 0 C, preferably between -10 0 C and about 400 0 C and preferably between room temperature and about 400 0 C; the method further comprises a step of activating the surface of the support by subjecting said surface of said support to atmospheric plasma; the activation of the surface of the support and the nebulization of the colloidal solution are concomitant; activation of the surface of the support is preceded by a step of cleaning said surface of said support; the nebulization of the colloidal solution of nanoparticles is done in the discharge zone or in the post-discharge zone of the atmospheric plasma; the plasma is generated by an atmospheric plasma torch; the nebulization of the colloidal solution of nanoparticles is in a direction substantially parallel to the surface of the support;
• the nanoparticles are nanoparticles of a metal, of a metal oxide, of a metal alloy or of their mixture;
• the nanoparticles are nanoparticles of at least one transition metal, its corresponding oxide, a transition metal alloy or a mixture thereof; the nanoparticles are chosen from the group formed by magnesium (Mg), strontium (Sr), titanium (Ti), zirconium (Zr), lanthanum (La), vanadium (V), niobium (Nb) ), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), rhenium (Re), iron (Fe), ruthenium (Ru), osmium (Os), cobalt
• the nanoparticles are chosen from the group formed by titanium dioxide (titanium (TiO 2 )), copper oxide (CuO), ferrous oxide (FeO), ferric oxide (Fe 2 O 3), oxide iron (Fe3 ⁇ 4), iridium dioxide (IrO 2), zirconium dioxide (ZrO 2), aluminum oxide (Al2O3);
• the nanoparticles are chosen from the group formed by a gold / platinum (AuPt), platinum / ruthenium (PtRu), cadmium / sulfur (CdS) or lead / sulfur (PbS) alloy;
• the support is a solid support, a gel or a nano-structured material;
• the support is selected from the group consisting of a carbon support, carbon nanotubes, a metal, a metal alloy, a metal oxide, a zeolite, a semiconductor, a polymer, glass and / or ceramic;
• the support is silica, carbon, titanium, alumina or multi-walled carbon nanotubes;
• the atmospheric plasma is generated from a plasmagenic gas chosen from the group formed by argon, helium, nitrogen, hydrogen, oxygen, carbon dioxide, air or their mixed ;
• the colloidal solution comprises a surfactant.
• surfactant a compound modifying the surface tension between two surfaces.
• the surfactant compounds are amphiphilic molecules, that is to say that they have two parts of different polarity, one lipophilic and apolar, and the other, hydrophilic and polar. This type of molecule helps stabilize colloids.
• cationic surfactants anionic, amphoteric or nonionic.
• An example of such a surfactant is sodium citrate.
• the present invention also discloses the use of a colloidal solution of nanoparticles for depositing nanoparticles on a support using an atmospheric plasma.
• the use of the colloidal nanoparticle solution comprises one or more of the following characteristics: the colloidal solution is nebulized in the discharge or post-discharge zone of the atmospheric plasma; the atmospheric plasma is generated by an atmospheric plasma torch.
• the present invention also describes the use of an atmospheric plasma for the deposition of nanoparticles on a support, said nanoparticles being in the form of a colloidal solution of nanoparticles, and said colloidal solution being nebulized on the surface of said support in said atmospheric plasma.
• FIG. 1 represents the size distribution of the gold particles of a colloidal solution.
• FIG. 2 represents an image obtained by transmission electron microscopy (TEM) of a colloidal solution of the gold particles.
• Figure 3 schematically shows an atmospheric plasma torch.
• FIG. 4 represents X-ray photoelectron spectroscopy (XPS) spectra of the HOPG graphite surface after plasma gold nanoparticle deposition according to the process of the present invention, (a) spectrum. global, (b) deconvolved spectrum of the Au 4f level, (c) deconvolved spectrum of the Is level, (d) deconvolved spectrum of the C Is level.
• XPS X-ray photoelectron spectroscopy
• FIG. 5 represents atomic force microscopy (AFM) images of a HOPG graphite sample a) before, and b) after deposition of gold nanoparticles according to the method of the present invention.
• FIG. 6 represents high-resolution electron microscopy images of secondary electrons (FEG-SEM) of a HOPG graphite sample a) before, b) and c) after deposition of gold nanoparticles according to the method of FIG. the present invention, (a) magnification x 2000, (b) magnification x 25000, (c) magnification x 80000.
• EDS Energy dispersive analysis
• FIG. 7 represents the comparison of the experimental XPS spectrum of the Au 4f level presented in FIG. 4 (b) and of the modeled spectrum using a Volmer-Weber type growth model.
• FIG. 8 represents an X-ray photoelectron spectroscopy spectrum (XPS) of the HOPG graphite surface after deposition of gold nanoparticles without the use of a plasma (comparative).
• FIG. 9 represents a high-resolution electron microscopy image of the secondary electrons (FEG-SEM) of a HOPG graphite sample after the deposition of gold nanoparticles without the use of a plasma (comparative).
• FIG. 8 represents an X-ray photoelectron spectroscopy spectrum (XPS) of the HOPG graphite surface after deposition of gold nanoparticles without the use of a plasma (comparative).
• FIG. 9 represents a high-resolution electron microscopy image of the secondary electrons (FEG-SEM) of a HOPG graphite sample after
• FIG. 10 represents an image (magnification x 100000) obtained by high resolution electron microscopy of the secondary electrons (FEG-SEM) of a steel sample after deposition of gold nanoparticles according to the method of the present invention.
• FIG. 11 represents an image (magnification ⁇ 3000) obtained by high-resolution electron microscopy of the secondary electrons (FEG-SEM) of a glass sample after deposition of gold nanoparticles according to the process of the present invention.
• FIG. 12 represents an image (magnification ⁇ 50000) obtained by high-resolution electron microscopy of the secondary electrons (FEG-SEM) of a sample of PVC polymer after deposition of gold nanoparticles according to the process of the present invention. .
• FIG. 13 represents an image (magnification x 10000) obtained by high-resolution electron microscopy of secondary electrons (FEG-SEM) of a sample of HDPE polymer after deposition of gold nanoparticles according to the method of the present invention. .
• FIG. 14 represents an image (magnification ⁇ 10000) obtained by high resolution electron microscopy of the secondary electrons.
• FIG. 15 represents an image obtained by transmission electron microscopy (TEM) of a sample of carbon nanotubes before (a) and after deposition of gold nanoparticles according to the process of the present invention (b).
• TEM transmission electron microscopy
• FIG. 16 represents an X-ray photoelectron spectroscopy (XPS) spectrum of the surface of the carbon nanotubes after deposition of gold nanoparticles according to the process of the present invention.
• XPS X-ray photoelectron spectroscopy
• FIG. 17 represents an image obtained by transmission electron microscopy (TEM) of a sample of carbon nanotubes after deposit of platinum nanoparticles according to the process of the present invention.
• TEM transmission electron microscopy
• FIG. 18 represents an X-ray photoelectron spectroscopy (XPS) spectrum of the surface of the carbon nanotubes after deposition of platinum nanoparticles according to the process of the present invention.
• XPS X-ray photoelectron spectroscopy
• FIG. 19 represents an image
• FIG. 20 represents an X-ray photoelectron spectroscopy (XPS) spectrum of the HOPG graphite surface after deposition of rhodium nanoparticles according to the method of the present invention.
• XPS X-ray photoelectron spectroscopy
• FIG. 21 represents an image (magnification x 100000) of secondary electron electron microscopy (FEG-SEM) of a steel sample after the deposition of platinum nanoparticles according to the process of the present invention.
• FEG-SEM secondary electron electron microscopy
• FIG. 22 represents an image (magnification x 100000) of secondary electron electron microscopy (FEG-SEM) of a PVC sample after the deposition of rhodium nanoparticles according to the process of the present invention.
• FEG-SEM secondary electron electron microscopy
• FIG. 23 represents an image (magnification x 100000) of secondary electron electron microscopy (FEG-SEM) of a sample of HDPE after the deposition of rhodium nanoparticles according to the method of the present invention.
• FEG-SEM secondary electron electron microscopy
• the nanoparticle deposition method according to the invention involves a colloidal solution or suspension of nanoparticles which is deposited on any support with the aid of an atmospheric plasma, said atmospheric plasma being able to be generated by any device adequate use of an atmospheric plasma.
• This method has many advantages. For example, it allows a so-called “clean” deposit, that is to say without the use of solvents called “pollutant”.
• the deposition of nanoparticles according to the invention uses only a low energy consumption.
• the deposition of nanoparticles is rapid because the activation of the support and the nebulization of the nanoparticles, and possibly also the prior cleaning of the support, are carried out in the atmospheric plasma, or in the flow of the atmospheric plasma, in a single step or one continuous process.
• the method according to the invention allows a strong adhesion of the nanoparticles to the support.
• This technique makes it possible to control the properties of the interface and to adjust the deposition of the nanoparticles on the support.
• this method does not require expensive installations and is easily implemented industrially.
• the colloidal solution of nanoparticles can be prepared by any technique and / or any suitable means.
• the support, on which the colloidal solution of nanoparticles is deposited is any suitable material that can be covered with nanoparticles, any material whatever its nature and / or its shape.
• he it is a solid support, a gel or a nano-structured material.
• the plasma is any suitable atmospheric plasma. It is a plasma generated at a pressure of between about 1 mbar and about 1200 mbar, preferably between 800 and 1200 mbar. Preferably, it is an atmospheric plasma whose macroscopic temperature of the gas can vary for example between room temperature and about 400 ° C. Preferably, the plasma is generated by an atmospheric plasma torch.
• An atmospheric plasma does not use vacuum, which can be inexpensive and easy maintenance.
• the atmospheric plasma makes it possible to clean and activate the surface of the support, either by functionalizing it, for example by creating oxygen, nitrogen, sulfur, and / or hydrogenated groups, or by creating surface defects, for example gaps, steps, and / or stings.
• These surface groups can for example comprise very reactive radicals and having a short life.
• the nanoparticles themselves can be activated by plasma, either directly by radical formation from the water of hydration, or by reactions with a surfactant attached to the surface of the nanoparticle.
• the activation of the support and the nebulization of the colloidal solution are concomitant, namely in the plasma, or in the plasma flow, generated by a device use of an atmospheric plasma.
• the nebulization of the colloidal solution occurs at the same time, or immediately after, the activation of the support by the atmospheric plasma.
• the nebulization of the colloidal solution can be done either in the discharge zone or in the post-discharge zone of the atmospheric plasma.
• the nebulization of the colloidal solution is in the post-discharge area of the plasma because, in some cases, this may have additional advantages. This may not contaminate the device generating the plasma. This may make it possible to facilitate the treatment of polymeric supports, to avoid the degradation of the support to be coated, and also, for example, not to cause melting, oxidation, degradation and / or aggregation of the nanoparticles.
• the nebulization of the colloidal solution is any nebulization and can be done in any direction (orientation) relative to the surface of the support.
• the nebulization is in a direction substantially parallel to the support, but it can also be done for example at an angle of about 45 °, or for example at an angle of about 75 ° relative to the surface of the support treat.
• EXAMPLE 1 Gold nanoparticles were deposited on highly oriented pyrolytic graphite (HOPG), a support which has chemical properties similar to those of multiwall carbon nanotubes (MWCNTs).
• HOPG highly oriented pyrolytic graphite
• MWCNTs multiwall carbon nanotubes
• Highly oriented pyrolytic graphite (HOPG) is commercially available (MikroMasch
• this graphite With a ZYB quality, this graphite, with a size of 10 mm x 10 mm x 1 mm, has an angle called "mosaic spread angle" of 0.8 ° ⁇ 0.2 ° and a size of "lateral grain” greater than 1 mm. Few layers of The surface of the graphite is previously detached with adhesive tape, before the graphite sample is immersed in an ethanol solution for 5 minutes, under ultrasonication. The colloidal suspension is prepared for example by the method of thermal reduction of citrate as described in the article by Turkevich et al. J. Faraday Discuss. Chem. Soc.
• This method of thermal reduction of the citrate makes it possible to obtain a stable dispersion of gold particles, whose gold concentration is 134 mM, and whose particles have an average diameter of approximately 10 nm and approximately 10% of polydispersity (Figure 1).
• the diffuser of the plasma torch comprises two perforated aluminum electrodes 33 mm in diameter and separated by a gap of 1.6 mm wide.
• the diffuser is placed inside an airtight chamber, under argon atmosphere at room temperature.
• the upper electrode 1 of the plasma source is connected to a radio frequency generator, for example 13.56 MHz, while the lower electrode 2 is grounded.
• the plasma torch operates at 80 W and the plasma 3 is formed by feeding the torch upstream of the electrodes with argon 4 at a rate of 30 L / min.
• the space between the sample of graphite HOPG resting on a sample holder 7 and the lower electrode 2 is 6 ⁇ 1 mm. This space is under atmospheric pressure.
• the graphite support Before the deposition of the nanoparticles, the graphite support is subjected to the plasma stream of the plasma torch, for example about 2 minutes, which allows to clean and activate the support.
• 3 to 5 ml of colloidal suspension is nebulized in the post-discharge area of the plasma torch and in a direction 6 substantially parallel to the sample ( Figure 3).
• the colloidal suspension is injected for about 5 minutes, by periodic pulsations of about one second, spaced about 15 seconds apart.
• the samples are then washed in ethanol solution under ultrasonication for about 5 minutes.
• X-ray photoelectron spectroscopy (XPS) analysis of the surface of the HOPG graphite coated with nanoparticles was carried out on a ThermoVG Microlab 350 apparatus, with an analytical chamber at a pressure of 10 -9 mbar and a radiation source.
• X Al Ka (h ⁇ 1486.6 eV) operating at 300 W.
• the spectra were measured with a recording angle of 90 ° and were recorded with a passing energy in the analyzer of 100 eV and a beam size of X-rays of 2 mm x 5 mm.
• the determination of the chemical state was made, with a passing energy in the analyzer of 20 eV.
• FIG. 4 a shows the presence of carbon at a percentage of 77.8%, oxygen at a percentage of 14, 9%, potassium at a percentage of 3.2% and gold at a percentage of 1.0%. Traces of silica were also detected; these are impurities incorporated in the HOPG graphite samples.
• the graphite samples are previously deposited on a copper strip of a sample holder before being introduced into the analysis chamber under a pressure of about 10 ⁇ 8 mbar.
• Figure 6a in the initial state, several steps are observable at a magnification of 20000 times.
• Figure 6 b) many clusters, represented by bright spots, and having a homogeneous distribution, are present on the surface of the graphite after the deposition of nanoparticles according to the method of the invention.
• a larger magnification (80000 times, Figure 6c) it is easy to see isolated aggregates and nanoparticles with a diameter of about 10 nm.
• the growth mode is of the Volmer-Weber type (3D structure in islands) Table 1:
• the height of the gold islands (h) varies between 9.2 and 10.6 nm, values substantially identical to the average diameter of the nanoparticles of the colloidal suspension ( Figure 1).
• a gold coverage percentage of about 10% is in agreement with the recovery rate determined by atomic force microscopy and scanning electron microscopy.
• the analysis of the Au 4f spectral curve by the QUASES software shows a good correlation between experimental and theoretical data.
• a deposit of gold nanoparticles on HOPG according to the method of Example 1 is carried out, with the exception of the step of nanoparticle deposition that is carried out without the use of an atmospheric plasma ( Figures 8 and 9). After the deposition of the nanoparticles and before analysis, the samples obtained are washed with ethanol for about 5 minutes with ultrasound.
• Example 4 the method used is that described in Example 1, only the supports (substrates) used and the nature of the colloidal solutions are different.
• Example 4 the method used is that described in Example 1, only the supports (substrates) used and the nature of the colloidal solutions are different.
• Gold nanoparticles were deposited on a steel support according to the method described in Example 1, with ultrasonic cleaning. Note in Figure 10 the presence of nanoparticles.
• Example 5
• Gold nanoparticles were deposited on a glass support according to the method described in Example 1. It can be seen from Figure 11 the presence of nanoparticles after ultrasonic cleaning.
• Gold nanoparticles were deposited on a PVC support according to the method described in Example 1, with ultrasonic cleaning.
• the microscopy image of FIG. 12 was obtained after covering the sample with a metal layer. Note in Figure 12 the presence of nanoparticles.
• Gold nanoparticles were deposited on an HDPE support (FIG. 13) according to the method described in example 1, with ultrasonic cleaning.
• the microscopy image of FIG. 13 was obtained after covering the sample with a metal layer. Note in Figure 13 the presence of nanoparticles.
• Gold nanoparticles were deposited on a carbon nanotube support according to the method described in Example 1, with ultrasonic cleaning. Note in Figure 15 the presence of spherical nanoparticles of about 10 nm after ultrasonic cleaning. This presence of gold is confirmed by the XPS spectrum in FIG. 16.
• colloidal solutions of platinum and rhodium provided by GA Somorjai provided by GA Somorjai (Department of Chemistry, University of California, Berkeley (USA) ) were used (RM Rioux, H. Song, JD Hoefelmeyer, Yang P. and GA Somorjai, J. Phys Chem B 2005, 109, 2192-2202, Yuan Wang, Jiawen Ren, Kai Deng, Lin Gui, and Youqi Tang, Chem Materials 2000, 12, 1622-1627.).
• Platinum nanoparticles were deposited on a carbon nanotube support according to the method described in US Pat. Example 1. It is noted in Figure 17 the presence of spherical nanoparticles of about 10 nm. This presence of platinum is confirmed by the XPS spectrum in FIG. 18.
• Example 10 Rhodium nanoparticles were deposited on a HOPG carbon support according to the process described in Example 1. It is noted in FIG. presence of spherical nanoparticles of around 10 nm after ultrasonic cleaning. This presence of rhodium is confirmed by the XPS spectrum in Figure 20.
• Rhodium nanoparticles were deposited on a PVC support according to the method described in Example 1, with ultrasonic cleaning.
• the microscopy image of FIG. 22 was obtained after covering the sample with a metal layer. Note in Figure 22 the presence of nanoparticles.
• the microscopy image of FIG. 23 was obtained after covering 1 sample with a metal layer. Note in Figure 23 the presence of nanoparticles.

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• 2008
  • 2008-08-14 CA CA2696081A patent/CA2696081A1/en not_active Abandoned
  • 2008-08-14 US US12/673,437 patent/US20120003397A1/en not_active Abandoned
  • 2008-08-14 CN CN200880111576A patent/CN101821421A/zh active Pending
  • 2008-08-14 JP JP2010520582A patent/JP2010535624A/ja active Pending
  • 2008-08-14 EP EP08787216.4A patent/EP2179071B1/de not_active Not-in-force
  • 2008-08-14 WO PCT/EP2008/060676 patent/WO2009021988A1/fr active Application Filing
  • 2008-08-14 KR KR1020107005411A patent/KR20100072184A/ko not_active Application Discontinuation

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