Method for producing nanoparticles on the surface of a substrate and a part including such a substrate - Patents.com

Abstract

The present invention relates to a method for producing nanoparticles on a surface of a substrate, comprising the steps of: providing a substrate made of a material comprising at least one element from columns 4, 5, 13 and 14 of the periodic table and at least one noble or transition metal; and; a pulse duration between 1 fs and 100 ps, ​​0.01 J / cm. 2 from 100 J / cm 2 - irradiating a substrate with a laser at a fluence per pulse between 0.1 and 1.0, a wavelength between 100 nm and 5000 nm and a number of pulses per point between 1 and 1000, and - generating at least one nanoparticle on a surface of the substrate, the at least one nanoparticle comprising at least a noble metal or a transition metal and having a chemical composition different from that of the substrate. The invention also relates to a part comprising such nanoparticles.

Description

[Technical field]

[0001] The present invention relates to a surface functionalization method, i.e. a method for adding at least one property to a surface, giving it at least one new function, for example for increasing its chemical reactivity.

[0002] The invention more particularly relates to a method for surface functionalization by producing nanoparticles on the surface of a substrate made of a given material. [Background technology]

[0003] The production of nanoparticles (i.e. particles with a characteristic size of less than a few hundred nanometers) on the surface of a substrate made of a given material, called the base material, makes it possible to endow the material thus treated with new functions. This is due in particular to the fact that the specific surface area obtained is greater than that of the material before treatment, and that nanoparticles, due to their very small size, have a higher proportion of low-coordinated atoms (located at the edges or apexes of the nanoparticles), which makes them particularly reactive (a large number of active sites). Furthermore, by adding nanostructures to the surface of a material, its wettability properties are modified, and thus hydrophilic or very hydrophobic surfaces can be obtained in a controlled manner.

[0004] Such functionality may, for example, confer interesting advantages for antimicrobial (antibacterial or virucidal) surfaces.

[0005] Furthermore, by exposing, for example, Cu or Ag (elements known for their antimicrobial properties) on a surface in the form of nanoparticles, it is possible to increase the reactivity of the surface thus treated with respect to the degradation and destruction of microorganisms that come into contact with the surface. This makes it possible to reduce contamination in high-population environments induced by contact with contaminated objects (for example, reducing healthcare-associated infections in hospitals, medical settings). This treatment can be applied, for example, on parts that come into regular contact with hands, such as door handles or signs, handrails, bars, faucets, or ventilation or water purification systems.

[0006] By functionalizing the surface, it may also be possible to generate catalytic surfaces in the context of heterogeneous catalysis, with applications in environmental catalysis, industrial chemistry, and fine chemicals.

[0007] This is possible, for example, by producing nanoparticles on the surface of elements (noble or transition metals) that have known catalytic properties for the desired reaction.

[0008] The production of nanoparticles of noble metals (e.g. gold (Au), silver (Ag), copper (Cu), platinum (Pt) or palladium (Pd)) is also of interest in the field of plasmonics, with applications in molecular detection in biology, medicine and catalysis through devices using the surface plasmon resonance of these nanostructures.

[0009] The production of nanoparticles on the surface of a support material (herein referred to as the substrate) can be carried out by a variety of methods.

[0010] The most common is performed via an external supply of material that produces nanoparticles: deposition can be performed by immersion, by coating, by centrifugation, or by electrophoresis with a nanoparticle-loaded solution.

[0011] Alternatively, the nanoparticles may be generated in situ using a supplied material: this is the case for electrodeposition, vapor deposition, or vacuum evaporation, often followed by high temperature annealing.

[0012] A drawback of these various methods is the weak adhesion of the nanoparticles to the support: the particles are simply placed on the surface of the treated material and can therefore detach and be released into the environment during use of the part in question.

[0013] A further problem associated with the use of nanoparticles dispersed on a substrate is the tendency of the nanoparticles to grow, agglomerate, and "coke", i.e., the accumulation of carbon on the surface of the metal nanoparticles in a hydrocarbon environment, thereby resulting in lower chemical activity of the nanoparticles.

[0014] Furthermore, deposition by coating with nanoparticle-loaded solutions involves prior preparation and handling of the nanoparticles, thereby creating health risks for workers.

[0015] To circumvent these various weaknesses, the idea of ​​producing nanoparticles from support materials was conceived.

[0016] FIG. 1 shows such a principle very diagrammatically: instead of having nanoparticles deposited on a base material (on the surface of a substrate) as depicted in FIG. 1A, the nanoparticles are generated from the material of the substrate as depicted in FIG. 1B, thereby giving the nanoparticles a better anchorage on the surface of the substrate.

[0017] One relatively recently developed method in this regard, for example, is redox exsolution (also known as solid phase recrystallization) of nanoparticles.

[0018] The document GB 2566104 describes, for example, the substitution of catalytically active transition metals at the B site of perovskite crystals of the general formula ABO3 under oxidizing conditions (e.g. perovskite La xSr 1-3x / 2 A method is described in which nickel (Ni) in TiO3 (where La refers to lanthanum, Sr refers to strontium, Ti refers to titanium, and O refers to oxygen) is heated to high temperatures in a reducing atmosphere, which induces the release of metal nanoparticles (Ni in this example) from the volume and on the surface of the perovskite. The particles thus obtained have a strong interaction with the support to which they are rooted, which results from the growth of the particles from the support material. However, this method is limited to the substrate treatment of the above compositions and crystalline phases.

[0019] A laser irradiation method has also been proposed to generate nanoparticles from metal surfaces; in this case the nanoparticles have the same chemical composition as the irradiated substrate material: Ag nanoparticles formed on an Ag surface, Cu nanoparticles formed on a Cu surface. This is described, for example, in document CN2874686.

[0020] The following papers also describe various methods for producing nanoparticles on surfaces: - Hamad et al., Femtosecond Laser-Induced, Nanoparticle-Embedded Periodic Surface Structures on Crystalline Silicon for Reproducible and Multi-utility SERS Platforms, ACS Omega 3 (2018) pp. 18420-18432, - Neagu, D. et al., Nano-socketed nickel particles with enhanced coking resistance grown in situ by redox exsolution, Nat. Commun. 6 (2015) 8120, - Guay JM et al., Laser-induced plasmonic colors on metals, Nature communications 8 (2017) 16095, - Fan et al., J. Appl. Phys. 115, 124302 (2014) and J. Appl. Phys. 114, 083518 (2013), - Mohan et al., Applied Physics A; Materials Science & Processing, Springer, Berlin, DE, Vol. 86, No. 1, October 28, 2006, pp. 73 - 82.

Prior Art Documents

Patent Documents

[0021]

Patent Document 1

Patent Document 2

Non - Patent Documents

[0022]

Non - Patent Document 1

Non - Patent Document 2

Non - Patent Document 3

[0023] It is therefore an object of the present invention to form nanoparticles with good adhesion over time to the surface on which they are generated, in particular with respect to nanoparticles containing chemical elements with catalytic, antimicrobial and / or plasmonic properties of interest, i.e. for example noble or transition metals.

[0024] A further object is to provide a simple and industrializable functionalization method that is less demanding in terms of costs, processing conditions and processable parts (shape, chemical properties, heat resistance or chemical resistance).

[0025] A further object is to provide a method which makes it possible to avoid handling nanoparticles.

[0026] Another further object is to provide localized functionalization of the treated surface while being able to finely select the zone of the surface to be treated, possibly with micrometer resolution, and having little effect on the volume of the part. [Means for solving the problem]

[0027] To achieve at least partly the above cited objectives, according to a first aspect of the present invention there is provided a method for producing nanoparticles on a surface of a substrate, comprising the steps of: - providing a substrate having a free surface, the substrate comprising: at least one element from columns 4, 5, 13 and 14 of the Periodic Classification of the Elements, in particular Ti (titanium), Zr (zirconium), Hf (hafnium), Nb (niobium), Ta (tantalum), V (vanadium), Al (aluminium) or Si (silicon), preferably at least one element of Ti and / or Zr, at least one noble metal or one transition metal, in particular at least one noble metal or one transition metal from columns 8 to 11 of the Periodic Classification of the Elements, in particular Au (gold), Ag (silver), Pt (platinum), Pd (palladium), Cu (copper), Fe (iron), Co (cobalt), Ni (nickel), preferably at least one of Cu, Ag and / or Au, and - Pulse duration between 1fs and 100ps, 0.01J / cm 2 from 100 J / cm 2 irradiating at least a portion of the free surface of the substrate with a laser radiation source generating pulsed radiation having a pulse fluence between 0.1 and 0.5 nm, a wavelength between 100 nm and 5000 nm, and a number of pulses per treated point between 1 and 1000; - generating at least one nanoparticle on a free surface of the substrate from a material of the substrate, the at least one nanoparticle comprising at least a noble metal or a transition metal and having a chemical composition different from the chemical composition of the substrate; A method has been proposed, including:

[0028] Here, nanoparticles refer to particles with a characteristic size of less than a few hundred nanometers.

[0029] Therefore, the present invention proposes an alternative in situ nanoparticle generation solution to the known methods mentioned above, by segregating chemical elements of the substrate material.

[0030] This method uses highly localized heating (in location and depth) applied to the surface of a material, which induces the formation of nanoparticles on the surface being treated.

[0031] Indeed, so-called ultrashort laser irradiation induces localized heating of the surface to be treated: the laser-material interaction takes place over a typical depth of about 15 nanometers and the supplied energy is propagated in the form of heat and pressure waves over a typical depth of about 100 nanometers in the material of the substrate to be treated.

[0032] The effect of this treatment is to decompose material from the surface of the substrate (on a scale of about 100 nanometers) and to cause at least one constituent metal element of the initial material of the substrate to diffuse towards the surface of the substrate to form metal nanoparticles.

[0033] By virtue of such a method, the nanoparticles are composed of some of the chemical elements of the material to be treated, but have a different chemical composition from this material (chemical segregation effect).

[0034] These nanoparticles have a different chemical composition than that of the substrate material and therefore can expose elements on the surface of the substrate material that have different reactivity properties than those of the substrate material, which are generally more advantageous in a given context.

[0035] For example, to impart at least one antimicrobial property to a surface, one possibility is to produce copper (Cu) nanoparticles, since Cu is an element that has advantageous catalytic and antimicrobial properties (the same is true for silver (Ag)).

[0036] Thus, for example, if the base material is an alloy containing at least zirconium (Zr) and copper (Cu), the treatment according to the invention induces the chemical segregation of Cu in the form of nanoparticles on the surface of the ZrCu alloy, and thus the chemical reactivity of the material so treated is increased (due to the development of a larger surface area facing the external environment due to the addition of nanoparticles, as well as the greater reactivity of the nanoparticles compared to the reactivity of the base material), resulting in a chemically active surface, i.e. capable of promoting or enabling chemical reactions required, for example, for antimicrobial functionality.

[0037] These applications are not limiting and the method can be used in other areas where surface functionalization with nanostructures, especially nanoparticles, may be required.

[0038] Therefore, this method has several advantages over other methods for obtaining nanoparticles, as listed below. - the particles so produced from the substrate have good mechanical fixation on their surface; This method makes it possible to avoid implementing hot wet methods or vacuum treatments, so that the method according to the invention can be applied without specific constraints on the working environment and with simple items of equipment: - the method can be used to functionalize a wide range of materials, and the materials do not need to be in a particular crystalline form; - There are reduced health risks associated with the supply of nanoparticles.

[0039] Furthermore, since the heating is then localized on the surface of the material, it is possible to treat not only solid parts of the material, but also coatings of said material deposited on another type of substrate. Thus, plastic, metal, ceramic or composite parts can be functionalized if they are coated with a layer that can be functionalized by the above means.

[0040] For example, a laser has a pulse duration of, say, 1 femtosecond (1 fs = 10-15 seconds) to 100 picoseconds (1ps=10 -12 The laser emits a very short pulse of light with a duration of about 10 fs (fs) or 20 ps (ps).

[0041] For example, the surface is irradiated by laser pulses, e.g. focused directly on the surface, repeated at a repetition frequency between 1 kHz and 25 GHz, in particular between 1 kHz and 20 GHz, such as between 1 kHz and 100 MHz, e.g. between 1 kHz and 500 kHz.

[0042] For example, a laser beam typically has a diameter of about 50 μm.

[0043] For example, the number of pulses required to treat a surface point (depending on the size of the laser beam) may be between 1 and 1000.

[0044] For example, the pulse fluence (energy received per unit of surface area) for generating nanoparticles is below the threshold fluence for the material in question (the fluence at which the material is ablated), i.e., for example, a fraction of a J / cm 2 This fluence depends on the material to be treated and other laser irradiation parameters.

[0045] For example, the laser treatment can be carried out in air or in an inert environment.

[0046] To treat large surface areas, the size of which is much larger than the size of the laser beam, it is possible to use a scanner to scan the beam over the part, or to use a rotation stage, in particular a motorized rotation stage, to move the part facing the beam.

[0047] In other words, the method may comprise, for example, a step of scanning a laser over the free surface of the substrate using a scanner, and / or a step of moving the free surface of the substrate relative to the laser using a rotation stage, in particular a motorized rotation stage.

[0048] In an example implementation, the laser source used is configured to generate a pulsed laser beam, for example an ultrashort (femtosecond or picosecond) one.

[0049] Furthermore, ultrashort laser processing does not require a solid or liquid to come into contact with the surface of the part, which makes it possible to process parts of any shape, even complex ones.

[0050] The part to be treated, i.e. prior to the above treatment, comprises at least one substrate on a surface, i.e. a substrate having a free surface.

[0051] The substrate to be treated comprises, at least on the surface, a material in a solid state.

[0052] The material comprises, for example, at least one element from columns 4, 5, 13 or 14 of the Periodic Classification of the Elements, in particular at least one element of Ti, Zr, Hf (hafnium), Nb (niobium), Ta (tantalum), V (vanadium), Al (aluminium) or Si (silicon), preferably at least one element of Ti and / or Zr, and at least one noble metal or one transition metal, in particular at least one noble metal or one transition metal from columns 8 to 11 of the Periodic Classification of the Elements, in particular at least one of Au, Ag, Pt, Pd, Cu, Fe, Co, Ni, preferably at least one of Cu, Ag and / or Au.

[0053] During the implementation of the method, these elements diffuse onto the surface to form at least one nanoparticle, which further has advantageous catalytic and / or antimicrobial and / or plasmonic properties.

[0054] At least one element from columns 4, 5, 13, and 14 is thermodynamically less noble than the precious or transition metals and has low abundance or is absent in the nanoparticles formed after irradiation, which may nevertheless form an oxide layer of about 100 nanometers on the surface of the treated material.

[0055] In example implementations, the substrate material prior to processing is crystalline.

[0056] The substrate may for example have a thickness of at least 50 nm, or 100 nm, such as between 50 nm and 5 μm, such as between 100 nm and 5 μm, for example between 500 nm and 5 μm.

[0057] In an example implementation, the roughness of the substrate to be treated must be low enough on the scale of the laser beam, e.g., the height variations of the substrate's surface on the scale of the laser spot must be included in the depth of field of the laser.

[0058] The part to be treated may be entirely of the same material as the substrate (in other words, its entire volume may be formed only from the substrate) or may comprise a support made of a first material covered on its surface with a coating consisting of the substrate, having the above-mentioned characteristics.

[0059] Thus, plastic, metal, ceramic or composite materials can be functionalized if they are coated with a layer that can be functionalized by the above means.

[0060] According to another aspect, the invention also relates to a process for the preparation of a ferroelectric material comprising at least one element from the 4th, 5th, 13th or 14th column of the Periodic Classification of the Elements, in particular at least one element of Ti (titanium), Zr (zirconium), Hf (hafnium), Nb (niobium), Ta (tantalum), V (vanadium), Al (aluminium) or Si (silicon), preferably at least one element of Ti and / or Zr, and at least one noble metal or one transition metal, in particular at least one noble metal or one transition metal from columns 8 to 11 of the Periodic Classification of the Elements, in particular The present invention relates to a component comprising at least one substrate made of a material having a chemical composition comprising Au (gold), Ag (silver), Pt (platinum), Pd (palladium), Cu (copper), Fe (iron), Co (cobalt), Ni (nickel), preferably at least one of Cu, Ag, and / or Au, the substrate having a surface, at least a portion of which has a nanostructure comprising at least one nanoparticle, the at least one nanoparticle comprising at least a precious metal or a transition metal, and having a chemical composition different from the chemical composition of the substrate.

[0061] Such a part is obtained, for example, by a method including at least some of the characteristics described above.

[0062] Thus, for example, at least one nanoparticle includes a chemical element that has advantageous catalytic, antimicrobial, plasmonic, and / or hydrophobic properties.

[0063] The nanoparticles so formed have a low rate of loss, for example under mechanical stress or by immersion in a liquid, optionally with the application of ultrasound.

[0064] Such losses can be observed by SEM microscopy (e.g., by top view as shown in FIG. 3B) before and after stress; for example, a loss rate of nanoparticles would be evident if the nanoparticles were not sufficiently anchored to the surface as they could be thanks to the method according to the present invention.

[0065] A layer of an oxide of at least one element from columns 4, 5, 13, and 14 is optionally formed on the surface of the substrate, for example beneath the nanoparticles.

[0066] For example, the substrate has a thickness (measured to the apex of the nanostructures) of at least 50 nm, or at least 500 nm, for example between 50 nm and 5 μm.

[0067] For example, the part is solid and is formed only by the substrate.

[0068] In example embodiments, the thickness of the substrate is between 100 nm and 5 μm depending on the type of part, the type and surface condition of the optional support to be coated with the substrate, and the desired functionality (wear resistance, corrosion, design, etc.).

[0069] For example, the nanoparticles so obtained have a characteristic size, eg average diameter, between 1 nm and 200 nm.

[0070] For example, the at least one nanoparticle comprising at least one precious or transition metal comprises one of Au, Ag, Pt, Pd, Cu, Fe, Co, or Ni, preferably Cu, Ag, and / or Au.

[0071] For example, the nanoparticles are crystallized.

[0072] According to an advantageous option, the nanostructure further comprises periodic relief.

[0073] Such periodic relief is also known as LIPPS ("Laser Induced Periodic Surface Structures").

[0074] For example, the periodic relief is repeated periodically on the surface, for example according to a spatial periodicity typically between 200 nm and 1000 nm, depending on the material of the substrate being treated and the irradiation parameters used.

[0075] According to an embodiment, at least one nanoparticle is formed on a ridge (or apex) of such undulation.

[0076] With reference to the attached drawings, the invention will be clearly understood by way of examples of embodiments, and its advantages will become more apparent on reading the following detailed description, given by way of indication and in no way limiting. [Brief description of the drawings]

[0077] [Figure 1] FIG. 1A shows a schematic representation of the difference in fixation of nanoparticles on a substrate depending on whether the nanoparticles were obtained by a deposition method (FIG. 1A) or by production from a support material (FIG. 1B). [Diagram 2] FIG. 1 shows a schematic representation of a part obtained by a method according to an implementation of the present invention, the part comprising any support (metal, ceramic, composite, or plastic) coated with a substrate on the surface of which nanoparticles are generated. [Diagram 3] 1 is a SEM (scanning electron microscope) photograph of a nanostructured surface obtained by a method according to a first example of implementation of the present invention. [Figure 4] FIG. 4 illustrates the chemical segregation effect obtained with a method according to a first example of implementation of the invention as shown in FIG. 3. [Diagram 5] FIG. 13 shows in more detail the top of a ridge showing Cu nanoparticles on a thin layer of ZrO2. [Figure 6] FIG. 11 shows a surface obtained by implementing a method according to a third example of implementation of the present invention. [Figure 7] FIG. 11 shows a surface obtained by implementing a method according to a fourth example of implementation of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0078] The method according to an implementation of the present invention makes it possible to functionalize materials by generating nanostructures, in particular nanoparticles, on their surface.

[0079] FIG. 1 shows the fundamental difference between nanoparticles 2 that are added to the surface of a substrate 1 as in the prior art method (shown in FIG. 1A) and nanoparticles 12 that are generated from a substrate 11 as in the method according to an implementation of the present invention (shown in FIG. 1B).

[0080] From the scenario of FIG. 1B, it is clear that the nanoparticles 12 are later better anchored to the surface of the substrate 11.

[0081] To carry out the method according to an embodiment of the present invention, a part 10 to be treated is provided which comprises at least one substrate 11 on whose surface the method is to be applied.

[0082] 2 shows a schematic representation of such a part 10, which includes at its surface a substrate 11. The figure illustrates that such a part 10 to be treated may also include an optional support 13 (e.g., metal, ceramic, composite, or plastic) that is subsequently coated with the substrate 11.

[0083] Thus, the part to be treated may be a bulk solid having the same composition throughout its volume, or may be comprised of a first support material 13 having a surface covered with a coating (i.e., substrate 11) having the characteristics described herein.

[0084] Thus, plastic, metal, ceramic or composite support materials can be functionalized.

[0085] In this example, the substrate 11 comprises a metal alloy AB formed from elements A and B.

[0086] Under the effect of localized heating induced by laser processing in accordance with an example implementation of the method, element A of the material of the substrate 11 diffuses onto the surface of the substrate 11 and nanoparticles 12 are formed mainly based on element A.

[0087] In particular, the elements forming nanoparticles 12 are elements known for their tendency to form nanoparticles, and when the surface of a substrate containing such elements is irradiated, for example, by a femtosecond (or picosecond) laser, it is common for nanoparticles of the same elements to be observed on the surface (e.g., Ag nanoparticles on an irradiated Ag surface).

[0088] These nanoparticles 12 are therefore composed of some of the chemical elements of the treated material of the substrate, but have a different chemical composition than the substrate (chemical segregation effect).

[0089] Such nanoparticles 12 are then substantially immobilized on a substrate 11, as depicted in FIG. 1A.

[0090] According to the implementation considered here, the method used to generate these nanoparticles 12 is the irradiation of the surface of the substrate 11 material with an ultrashort (femtosecond or picosecond) laser beam.

[0091] Ultrashort lasers are, for example, 1 fs (=10 -15 It emits very short pulses of light with durations between 100 ps and 100 ps.

[0092] The wavelength of the laser is for example here between 100 nm and 5000 nm, or for example between 400 nm and 1030 nm.

[0093] The surface is now illuminated by laser pulses repeated at frequencies between 1 kHz and 25 GHz.

[0094] The number of pulses used to treat a surface point (corresponding to a laser beam size of about 50 μm) is here between 1 and 1000.

[0095] The pulse fluence (energy received per unit of surface area) for generating nanostructures and especially nanoparticles is preferably below the threshold fluence of the material in question (the fluence at which the material is ablated), e.g., a fraction of a J / cm2 This fluence depends on the material to be treated and other femtosecond laser irradiation parameters (as well as picosecond lasers).

[0096] The laser treatment may be carried out in air or in an inert atmosphere.

[0097] These ultrashort laser irradiations induce localized heating of the surface to be treated: the laser-material interaction occurs over a typical depth of about 15 nanometers and the supplied energy is propagated in the form of heat and pressure waves over a typical depth of about 100 nanometers in the material to be treated.

[0098] The effect of this treatment is to decompose material from the surface (on the scale of about 100 nanometers) and one or more elements forming the initial material diffuse towards the surface to form nanoparticles.

[0099] To treat large surface areas, the size of which is much larger than the size of the laser beam, it is possible, for example, to use a scanner to scan the beam over the part, or to use a rotating stage to move the part facing the beam.

[0100] The substrate material to be treated is preferably in a solid state and is formed from at least metallic elements.

[0101] In particular, the material comprises at least one noble metal or one transition metal, for example from columns 8 to 11 of the periodic classification (e.g. Au, Ag, Pt, Pd, Cu, Fe, Co, Ni), preferably Cu, Ag and / or Au. These elements then rise to the surface to form nanoparticles. These elements have advantageous catalytic and / or antimicrobial and / or plasmonic properties.

[0102] It also optionally contains at least one element (e.g., metal or nonmetal) from columns 4, 5, 13 and 14 of the periodic classification (in particular selected from Ti, Zr, Hf, Nb, Ta, V, Al, Si), preferably Ti and / or Zr. These elements are less thermodynamically noble than the previously cited elements and are less frequently found in the nanoparticles formed after irradiation. On the other hand, they may optionally form an oxide layer on the surface of the treated material, possibly up to about 100 nanometers thick.

[0103] The processed material is optionally crystalline.

[0104] The surface of the material to be treated preferably has a sufficiently low roughness on the scale of the laser beam (feature size of about 10 μm). EXAMPLES

[0105] Example 1: Amorphous Zr 0.5 Cu 0.5 (Part processing, including coating deposition) According to a first example of implementation, the method includes: 0.5 Cu 0.5 Applied to the part containing the coating.

[0106] In this example, a stainless steel metal part is provided, which later forms the support.

[0107] To functionalize the surface of the component, the method now comprises the preliminary step of depositing a coating containing the elements described below.

[0108] A layer of a 50 / 50 atomic percent ZrCu alloy is applied onto the substrate by vacuum deposition.

[0109] To do this, the support is, for example, cleaned (degreased, rinsed and blown) and then clamped to a substrate holder and placed in a vacuum deposition machine.

[0110] The machine was degassed and heated with the support in place, and the deposition was continued for 10 -7 ~10 -5 It is possible to achieve pressures of the order of mbar. The support is stripped to remove any oxide layers on the surface. A solid target of the desired composition (here 50 / 50 ZrCu) is then sputtered by magnetron cathode sputtering on the opposite side of the part to be treated (here the support). In that way, a coating of about 2 μm of amorphous 50 / 50 ZrCu alloy is obtained on the surface of the stainless steel support. The same alloy can also be obtained by sputtering two metal targets (co-sputtering method).

[0111] The coating then forms a substrate that undergoes method steps according to implementations of the present invention to produce nanoparticles.

[0112] A femtosecond laser treatment (having a wavelength of about 800 nm) is then applied to at least one targeted area of ​​the surface of the substrate, such area being, for example, centimeter-sized.

[0113] Duration 50fs and fluence 0.1J / cm 2 are applied per irradiation point at a frequency of 1 kHz. The area to be treated is scanned by the beam, for example using a motorized rotation stage.

[0114] FIG. 3 shows an SEM image of the surface of a substrate 11, a part 11a of which has been treated with a method according to the first example implementation of the invention described above.

[0115] In FIG. 3A, the irradiated portion 11a has a width of about 30 μm and at either end (top and bottom in FIG. 3A) the surface has not been subjected to the method according to the invention.

[0116] FIG. 3B shows a detail of FIG. 3A.

[0117] The figure shows that irradiation of the surface of the substrate produced nanostructures comprising periodic relief 22 (LIPPS - Laser Induced Periodic Surface Structures) and nanoparticles 12 .

[0118] The spatial periodicity of the reliefs 22 is generally between 200 nm and 1000 nm, according to the material to be treated and the irradiation parameters of the laser used.

[0119] Here, the undulations 22 have an average height (measured from the bottom of the valley to the adjacent ridge) of about 300 nm and a lateral feature size (thickness) of about 500 nm.

[0120] Here, the nanoparticles 12 are more particularly present on the undulations 22 , in particular on the ridges of the undulations 22 .

[0121] The nanoparticles may, for example, have a characteristic size (eg, average diameter) between 10 nm and 200 nm, and may, for example, be crystallized, where they have a characteristic size of about 50 nm.

[0122] 4 and 5 show cross sections of the substrate of FIG.

[0123] In FIG. 4, FIG. 4A shows a TEM (Transmission Electron Microscopy) image, FIG. 4B shows an EDS (Energy Dispersive Spectroscopy) mapping, and images 4C, 4D, and 4E show the presence of Cu, Zr, and O, respectively.

[0124] Figure 5 shows in more detail the top of the undulations 22. Figure 5A shows a TEM image of the top of the undulations 22, Figure 5B shows an EDS mapping of Figure 5A, and images 5C, 5D, and 5E provide chemical mapping of Cu, Zr, and O, respectively.

[0125] From these figures 4 and 5 it is clear that the relief is essentially formed from the base material (ZrCu layer), while the upper part of the relief comprises a layer of ZrO2 of about 100 nanometers. Finally, pure crystallized Cu nanoparticles are present on the relief, partially anchored in this ZrO2 layer.

[0126] Figure 5 shows the top of the relief in more detail and more clearly shows the Cu nanoparticles (e.g., Fig. 5C) on the thin layer of ZrO2 (the presence of O is more evident in Fig. 5E). Furthermore, Fig. 5b shows that the thin layer of ZrO2 has a thickness of about 130 nm, while the Cu nanoparticles form a layer about 60 nm thick.

[0127] Thus, the above method makes it possible to produce Cu nanoparticles on the surface of metal parts, additionally protected by a thin layer of ZrO2. Thus, catalytic, antimicrobial, plasmonic and hydrophobic functions (due to the nanostructure) can be added to the treated parts, with potential applications linked to these functions.

[0128] Example 2: Effect of atomic ratio and number of elements present in the material The effectiveness of the method according to the implementation of the present invention is also evident in the case of other amorphous substrates based on Zr and Cu, for example binary alloy Zr x Cu 1-x (wherein x is between 0.35 and 0.65), ternary alloy Zr x Cu 1-x-y Ta y (The same range of values ​​for x and y is less than 0.15), or Zr 52.5 Al 10 Cu 27 Ni8Ti 2.5 For more complex alloys such as

[0129] To form the substrate, these materials can be produced in the form of thin layers, for example by magnetron cathode sputtering, either on a solid target or on several solid targets of the desired composition. In the second scenario (co-sputtering of several targets), the power applied on the different targets is adjusted to obtain the desired composition for the layer thus produced. Thus, the alloy Zr x Cu 1-x-y Ta yTo produce x, y, y+1, three sputtering targets of Zr, Cu, and Ta, respectively, can be used, with the power ratio between these targets adjusted according to the desired ratio of x and y.

[0130] The laser irradiation parameters are adjusted depending on the composition of the alloy to obtain nanostructuring (nanoparticles and, optionally, undulations) and chemical segregation effects.

[0131] In these different scenarios, after the laser irradiation treatment, the formation of Cu nanoparticles on the surface of the alloy is observed, the size and number of which depends on the proportion of Cu in the substrate alloy.

[0132] Alloys that have a strong tendency to remain amorphous, e.g., Zr 52.5 Al 10 Cu 27 Ni8Ti 2.5 or Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 Complex alloys of the composition can be obtained in the amorphous state and in bulk solid form (of limited dimensions).

[0133] Laser irradiation can be performed directly on the bulk solid using the same protocols as above, with similar results as for a layer of the same or identical material.

[0134] Ultrashort laser irradiation, which induces a localized heating effect on the surface of the treated material, the chemistry of which is seen below (supports of different chemistry, or homogeneous materials), does not affect the treatment and its effects.

[0135] Example 3: Effect of the alloying element chemistry of the substrate and the irradiation environment Substrates of other binary alloys with compositions as above can be functionalized.

[0136] Therefore, Ti 0.5 Cu 0.5 Irradiation of the substrate produced Cu nanoparticles, Zr0.66 Ag 0.33 Irradiation of the substrate resulted in the formation of Ag nanoparticles and Zr 0.5 Au 0.5 Irradiation of the substrate results in the production of Au nanoparticles.

[0137] Depending on the substrate material and the laser treatment environment, the generated nanoparticles may be located either above and fixed to the oxide formed by the passivating elements of the alloy, or below (or within) a thin layer of this oxide.

[0138] Thus, the first scenario is, for example, Zr 0.5 Cu 0.5 Obtained by laser treatment in air of the alloy, the generated Cu nanoparticles are on the surface and are fixed in a layer of ZrO2. Oxygen then results in the passivation of the material after re-ventilation. This is because the Ti 0.5 Cu 0.5 This also applies to laser treatment of the alloy in an inert environment, where the Cu nanoparticles are anchored in a layer of TiO2.

[0139] The second scenario is, for example, Ti 0.5 Cu 0.5 In the case of laser treatment of the alloy in air, Cu nanoparticles are obtained, which are located underneath a very thin layer of TiO2.

[0140] This is shown, for example, by FIG.

[0141] In this figure, FIG. 6A shows a Ti on a Si support. 0.5 Cu 0.5 FIG. 6B shows a TEM image of a cross-section of the substrate, and FIG. 6B shows an EDS mapping of a detail of FIG. 6A, with images 6C, 6D, 6E, and 6F showing the presence of Cu, Ti, TiCu, and O, respectively.

[0142] The EDS mapping in FIG. 6B shows a series of Cu nanoparticles beneath a thin layer of TiO2.

[0143] These figures are based on Ti0.5 Cu 0.5 It is shown that after laser treatment of the alloy in air, the Cu nanoparticles are located in or beneath a thin layer of TiO2 formed on the surface of the substrate.

[0144] Example 4: Effect of Crystallinity of Treated Materials The treated substrate was prepared as described above. x Cu 1-x , Zr x Cu 1-x-y Ta y , Zr 52.5 Al 10 Cu 27 Ni8Ti 2.5 , Ti 0.5 Cu 0.5 Unlike the amorphous alloys described above, it does not have to be amorphous.

[0145] Zr with X-ray diffraction crystalline phase signatures before laser treatment 0.66 Ag 0.33 and Zr 0.5 Au 0.5 The substrates can have the same surface nanoparticle generation and chemical segregation effects after laser irradiation.

[0146] This is shown, for example, by FIG.

[0147] In this figure, FIG. 7A shows a Zr 0.66 Ag 0.33 FIG. 7B shows a TEM image of a cross-section of the substrate, and FIG. 7B shows an EDS mapping of a detail of FIG. 7A, with images 7C, 7D, 7E, and 7F showing the presence of Ag, Zr, ZrAg, and O, respectively.

[0148] The EDS mapping in Figure 7B shows the Zr alloy 0.66 Ag 0.33 After laser treatment in air, Ag nanoparticles were formed in the nanocrystalline alloy Zr 0.66 Ag 0.33 It is shown that a layer of ZrO2 is formed on the surface of the [Explanation of symbols]

[0149] 1 Base material 2. Nanoparticles 10 parts 11 Base material 11a Irradiated part 12 Nanoparticles 13 Support 22 undulations

Claims

1. 1. A method for producing nanoparticles on a surface of a substrate, comprising: Providing a substrate having a free surface, the substrate comprising: at least one element from columns 4, 5, 13, and 14 of the Periodic Classification of Elements; at least one noble metal or one transition metal; and Pulse duration between 1 fs and 100 ps, ​​0.01 J / cm ２ to 100 J / cm ２ irradiating at least a portion of the free surface of the substrate with a laser radiation source generating pulsed radiation having a pulse fluence between 0.05 and 0.5, a wavelength between 100 nm and 5000 nm, and a number of pulses per treated point between 1 and 1000; generating at least one nanoparticle on a free surface of the substrate from a material of the substrate, the at least one nanoparticle comprising at least a noble metal or a transition metal and having a chemical composition different from the chemical composition of the substrate; A method comprising:

2. The method of claim 1 , wherein the laser emits pulses with durations between 1 fs and 100 ps.

3. 10. The method of claim 1, wherein the surface is irradiated with laser pulses repeated at a repetition rate between 1 kHz and 25 GHz.

4. 4. The method of claim 1, comprising scanning a laser over the free surface of the substrate using a scanner and / or moving the free surface of the substrate relative to the laser using a rotation stage.

5. at least, an element from the 4th, 5th, 13th, or 14th column of the Periodic Classification of Elements; one noble metal or one transition metal; at least one substrate made of a material having a chemical composition comprising a substrate having a surface, at least a portion of which has a nanostructure including at least one nanoparticle, the at least one nanoparticle including at least a noble metal or a transition metal and having a chemical composition different from the chemical composition of the substrate; parts.

6. 6. The component of claim 5, wherein the at least one element from column 4, 5, 13, or 14 of the Periodic Classification of Elements is selected from the group consisting of Ti (titanium), Zr (zirconium), Hf (hafnium), Nb (niobium), Ta (tantalum), V (vanadium), Al (aluminum), or Si (silicon).

7. Component according to claim 5, characterized in that the at least one noble or transition metal from columns 8 to 11 of the periodic classification of the elements is selected from the group consisting of Au (gold), Ag (silver), Pt (platinum), Pd (palladium), Cu (copper), Fe (iron), Co (cobalt), Ni (nickel).

8. The component of claim 5 , wherein the at least one nanoparticle has a characteristic size between 1 nm and 200 nm.

9. 6. The component of claim 5, wherein the at least one nanoparticle comprising at least one noble or transition metal comprises one of Au, Ag, Pt, Pd, Cu, Fe, Co, or Ni.

10. 6. The component according to claim 5, wherein at least one nanoparticle is crystallized.

11. The component of claim 5 , wherein the nanostructure further comprises periodic undulations.

12. Component according to claim 5, characterized in that the periodic relief is repeated periodically on the surface according to a spatial periodicity between 200 nm and 1000 nm.

13. 12. The component of claim 11, wherein at least one nanoparticle is formed on a ridge of one of the undulations.

14. Component according to claim 5, characterized in that only a portion of the surface of the substrate has the nanostructure.

15. 15. A component according to any one of claims 5 to 14, characterized in that at least one element from columns 4, 5, 13 and 14 forms an oxide layer on the surface of the treated material.

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