Composite material constituted by a porous matrix and nanoparticles of metal or metal oxide

• US 20080176059A1
• Filed: 08/13/2007
• Published: 07/24/2008
• Est. Priority Date: 02/24/2005
• Status: Abandoned Application

• Current Assignee: Centre National De La Recherche Scientifique, Universite D'Orleans
• Original Assignee: Centre National De La Recherche Scientifique, Universite D'Orleans
• Inventors: Treguer-Delapierre, Mona, Benoit, Roland, Saboungi, Marie-Louise
• Application Number:
  US11/889,454
• Publication Number:
  US 20080176059A1
• Time in Patent Office: Days
• US Class Current: 428/315.5
• CPC Class Codes: B22F 1/054 Nanosized particles
• CPC Class Codes: B22F 2202/11 Use of irradiation
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/114 the porous products being formed by impregnation B22F3/1137, B22F3/26 take precedence
• CPC Class Codes: B22F 9/24 starting from liquid metal compounds, e.g. solutions
• CPC Class Codes: C04B 2235/3298 Bismuth oxides, bismuthates or oxide forming salts thereof, e.g. zinc bismuthate
• CPC Class Codes: C04B 2235/40 Metallic constituents or additives not added as binding phase
• CPC Class Codes: C04B 2235/408 Noble metals
• CPC Class Codes: C04B 2235/44 Metal salt constituents or additives chosen for the nature of the anions, e.g. hydrides or acetylacetonate
• CPC Class Codes: C04B 2235/652 Reduction treatment C04B2235/664 takes precedence
• CPC Class Codes: C04B 2235/667 Sintering using wave energy, e.g. microwave sintering
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/80 Phases present in the sintered or melt-cast ceramic products other than the main phase
• CPC Class Codes: C04B 35/10 based on aluminium oxide
• CPC Class Codes: C04B 35/14 based on silica
• CPC Class Codes: C04B 35/46 based on titanium oxides or titanates containing also zirconium or hafnium oxides, zirconates or hafnates C04B35/49
• CPC Class Codes: C04B 35/48 based on zirconium or hafnium oxides, zirconates, zircon or hafnates
• CPC Class Codes: C04B 35/64 Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: C04B 38/0054 the pores being microsized or nanosized
• CPC Class Codes: C04B 41/009 : characterised by the material treated
• CPC Class Codes: C04B 41/4535 : applied as a solution, emulsion, dispersion or suspension
• CPC Class Codes: C04B 41/4549 : Nanometer-sized particles
• CPC Class Codes: C04B 41/455 : the coating or impregnating process including a chemical conversion or reaction
• CPC Class Codes: C04B 41/51 : Metallising , e.g. infiltration of sintered ceramic preforms with molten metal covering materials with metals in general C23C; ceramic compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides, other than as macroscopic reinforcing agents C22C; infiltration of preforms containing free metal, e.g. cermets C22C
• CPC Class Codes: C04B 41/88 : Metals
• CPC Class Codes: C23C 18/143 : Radiation by light, e.g. photolysis or pyrolysis
• CPC Class Codes: Y10T 428/249978 : Voids specified as micro

Abstract

The invention relates to a composite material constituted by a microporous or mesoporous matrix and nanoparticles of metal or of metal oxide. The material being wherein the material of the matrix is either disordered, or ordered and optionally oriented, and wherein the nanoparticles are i) monodisperse in size when said matrix material is ordered and optionally oriented; ii) either monodisperse in size or of size identical to the size of the pores of the matrix material when said matrix material is disordered. The method of preparing the material consists in impregnating a microporous or mesoporous solid material with a solution of nanoparticle precursors, then in reducing the precursors within said material forming the matrix. Impregnation is performed under saturated vapor pressure and under reflux of the precursor solution, and reduction is performed radiolytically.

Claims

1. A method of preparing a composite material, the method consisting in impregnating a microporous or mesoporous solid material with a solution of one or more precursors of metallic nanoparticles or of metal oxide nanoparticles, then in reducing the precursors within said matrix-forming material, the method being wherein impregnation is performed under saturated vapor pressure and under reflux of the precursor solution, and wherein the reduction is performed radiolytically.

2. A method according to claim 1, wherein the precursor solution also contains an oxidizing radical interceptor agent.

3. A method according to claim 2, wherein the concentration ratio of “

interceptor agent”

/“

precursor metallic salt”

is not less than the value of about 10³ to 10⁴.

4. A method according to claim 2, wherein the concentration ratio of “

interceptor agent”

/“

precursor metallic salt”

is less than or equal to a value of about 10<sup>−

2</sup> to 10<sup>−

1</sup>.

5. A method according to claim 1, wherein the microporous or mesoporous material is selected from:

silica, alumina, zeolites, metallic oxides such as zirconia, titanium oxide, and polymers that present mesoporosity.

6. A method according to claim 1, wherein the distribution of pores at nanometer scale in the microporous or mesoporous material is disordered.

7. A method according to claim 1, wherein the distribution of pores at nanometer scale in the microporous or mesoporous material is ordered and optionally oriented.

8. A method according to claim 1, wherein the nanoparticle precursor(s) is/are selected from compounds of:

Bi, Au, Ag, Ti, Mg, Al, Be, Mn, Zn, Cr, Cd, Co, Ni, Mo, Sn, and Pb.

9. A method according to claim 8, wherein the nanoparticle precursor compound is an inorganic salt, an organic salt, or an organometallic compound.

10. A method according to claim 9, wherein the inorganic salt is a sulfate or a perchlorate.

11. A method according to claim 9, wherein the organic salt is a formate or a neodecanoate.

12. A method according to claim 11, wherein the precursor is a bismuth neodecanoate.

13. A method according to claim 9, wherein the precursor compound is an organometallic compound selected from diphenyl magnesium, diphenyl beryllium, triisobutyl aluminum, biscyclopentadienyl chromium, biscyclopentadienyl titanium, biscyclopentadienyl manganese, tetracarbonyl cobalt, tetracarbonyl nickel, hexacarbonyl molybdenum, dipropyl cadmium, tetraallyl zinc, and tetrapropyl lead.

14. A method according to claim 2, wherein the oxidizing radical interceptor is a primary alcohol, a secondary alcohol, or an alkaline metal formate.

15. A method according to claim 1, wherein the radiolytic reduction is performed using a gamma ray source, an X-ray source, or a source of accelerated electrons.

16. A composite material constituted by a matrix constituted by a microporous solid material having pores with a mean size less than one nanometer or by a mesoporous solid material having pores with a mean size in the range 1 nm to 100 nm, and by nanoparticles of metal or of metal oxide, the material being wherein the material of the matrix is either disordered, or ordered, and optionally oriented, and wherein:

the nanoparticles are monodisperse in size and represent 50% to 67% of the total pore volume of the matrix material, when said matrix material is ordered and optionally oriented; and

the nanoparticles are either monodisperse in size, or are of size identical to the size of the pores of the matrix material, and they represent at least 50% of the initial volume of the pores of the matrix material when said matrix material is disordered.

17. Composite material according to claim 16, wherein the solid matrix is constituted by a material selected from silica, alumina, zeolites, metallic oxides, and polymers that present mesoporosity.

18. A composite material according to claim 16, wherein the nanoparticles are constituted by a metal selected from:

Bi, Au, Ag, Ti, Mg, Al, Be, Mn, Zn, Cr, Cd, Co, Ni, Mo, Sn, and Pb, or by an oxide of one of said metals.

19. A composite material according to claim 16, wherein the matrix material is mesoporous and the nanoparticles are constituted by bismuth.

20. A composite material according to claim 16, wherein the microporosity of the matrix is of the ordered and oriented type, being in the form of cylindrical channels, and the nanoparticles are in contact with one another, the residual porosity corresponding to the empty spaces between the nanoparticles being 33%.

21. The use of a composite material according to claim 19, as a thermoelectric material.

22. A low temperature generator including a material according to claim 19 as its active material.

23. A voltage generator including a material according to claim 19 as its active material.

24. The use of a composite material according to claim 19, as a magnetoresistive material presenting large magnetoresistance.

25. A magnetic sensor, including as active material a material according to claim 19.