Method for preparing a composition comprising functionalised silico/germano-metal particles and composition obtained

Abstract

A method for preparing a composition includes silico/germano-metal particles functionalized by at least one organic group, which involves:carrying out a hydrothermal treatment of a hydrogel precursor of the silico/germano-metal mineral particles, andpreparing a hydrogel including silico/germano-metal particles having at least one organic group by co-precipitation in an aqueous medium. A composition including functionalized silico/germano-metal mineral particles of which 1% to 75% of the silicon atoms and/or of the germanium atoms are covalently bonded to at least one organic group is also described.

Claims

1. A method for preparing a composition comprising silico/germano-metallic mineral particles functionalised by at least one organic group, said particles comprising at least one silicon (Si) atom and/or at least one germanium (Ge) atom and at least one atom of a metal (M) chosen from the group formed of alkali metals, alkaline earth metals and transition metals, said method comprising: carrying out a hydrothermal treatment under pressure of a hydrogel precursor of said silico/germano-metallic mineral particles, preparing a hydrogel precursor comprising silico/germano-metallic particles having said at least one organic group by carrying out a coprecipitation reaction in an aqueous medium between: at least one metal salt of said metal (M), at least one source of silicon and/or of germanium, and at least one compound chosen from water-soluble oxysilanes and oxygermanes of formula (I): ##STR00011## wherein: T is chosen from silicon and germanium, R1, R2 and R3 are identical or different and are chosen from a hydrogen and linear alkyl groups containing from 1 to 3 carbon atom(s), and A is chosen from: a methyl group, or a hydrocarbon group of formula Q-[CH.sub.2].sub.n, wherein Q is selected from the group consisting of H.sub.2N, a water-soluble cyclonic cationic group containing at least one heteroatom, a water-soluble aromatic cyclic cationic group containing at least one heteroatom, and a quaternary ammonium cation, and n is an integer from 3 to 11.

2. The method according to claim 1, wherein said hydrothermal treatment is carried out in the presence of at least one carboxylate salt of R8-COOM, wherein: M denotes a metal chosen from the group formed of Na and K, and R8 is chosen from H and alkyl groups containing fewer than 5 carbon atoms.

3. The method according to claim 1, wherein said hydrothermal treatment is carried out for a duration of from 1 second to 30 days.

4. The method according to claim 1, wherein said hydrothermal treatment is carried out at a pressure of from 0.5 MPa to 20 MPa.

5. The method according to claim 1, wherein said hydrothermal treatment of said hydrogel precursor is carried out at a temperature of from 150 C. to 300 C.

6. The method according to claim 1, wherein said hydrogel precursor is of formula:
((Si.sub.yGe.sub.1y).sub.x((Si.sub.zGe.sub.1z)-A).sub.1x) .sub.4M.sub.3O.sub.11, nH.sub.2O, wherein: Si denotes silicon, Ge denotes germanium, x is a real number of the interval [0.25; 1], y is a real number of the interval [0 ; 1], z is a real number of the interval [0 ; 1], M denotes the metal atom, and n relates to a number of molecule(s) of water associated with said hydrogel.

7. The method according to claim 1, wherein the group A is of formula (II): ##STR00012## wherein: R4, R5 and R6 are identical or different and are chosen from H and hydrocarbon groups containing at least one heteroatom.

8. The method according to claim 1, wherein the group A is chosen from: a methyl group, or a hydrocarbon group of formula Q-[CH.sub.2].sub.n, wherein: Q is a group selected from the group consisting of H.sub.2N, a water-soluble cyclic cationic group containing at least heteroatom, and a group of formula ##STR00013## wherein: R7 is chosen from linear and branched alkyls containing from 1 to 18 carbon atom(s), X.sup. is an anion wherein X is selected from the group consisting of chlorine, iodine and bromine, and n is an integer from 3 to 11.

9. The method according to claim 8, wherein there is carried out an at least partial exchange of the anion X.sup. by at least one anionic species selected from the group consisting of a chloride anion, an iodide anion, a bromide anion, a fluorosulfonate anion, a bis(fluorosulfonyl)amide anion, a bis(trifluoromethanesulfonyl)amide anion, a trifluoromethanesulfonate anion, a hexafluorophosphate anion, a tetrafluoroborate anion, an acetate anion, a nitrate anion NO.sub.3 .sup. and a nitrite anion NO.sub.2 .sup..

10. The method according to claim 2, wherein said hydrothermal treatment is carried out for a duration of from 1 second to 30 days.

Description

(1) FIGS. 1, 5 and 6 show RX diffractograms on each of which there is shown the relative intensity of the signal (number of counts per second) as a function of the interplanar spacing in angstroms.

(2) FIGS. 2 and 7 show proton NMR spectra of compositions obtained by a method according to the invention, carried out by means of a BRUKER Avance 400 spectrometer.

(3) FIGS. 3 and 8 show carbon NMR spectra of compositions obtained by a method according to the invention, carried out by means of a BRUKER Avance 400 spectrometer.

(4) FIGS. 4 and 9 show silicon NMR spectra of compositions obtained by a method according to the invention, carried out by means of a BRUKER Avance 400 spectrometer.

EXAMPLE 1

(5) A functionalised hydrogel is prepared:

(6) On the one hand, a solution of magnesium acetate is prepared by adding 16.97 g of magnesium acetate tetrahydrate (Mg(CH.sub.3COO).sub.2, 4H.sub.2O) to 52.74 ml of acetic acid CH.sub.3COOH at 1 mol/l.

(7) On the other hand, a solution of functionalised alkoxysilane and of sodium metasilicate is prepared:

(8) A solution of sodium metasilicate is first prepared by adding 17.86 g of sodium metasilicate pentahydrate to 150 ml of distilled water. The solution is heated gently to 40 C. in order to improve the dissolution.

(9) A solution of functionalised alkoxysilane is prepared by adding 6.796 g of 1-(trimethoxy-silyl-propyl)-3-butyl-imidazolium chloride to 50 ml of distilled water.

(10) 1-(Trimethoxy-silyl-propyl)-3-butyl-imidazolium chloride has the following chemical formula:

(11) ##STR00009##

(12) There is then added thereto, with magnetic stirring, a solution comprising 3.155 g of sodium iodide NaI in 10 ml of distilled water, so as to carry out an exchange between the chloride Cl.sup. and iodide I.sup. ions. The solution of functionalised alkoxysilane with sodium iodide NaI is stirred magnetically for 1 minute.

(13) The solution of functionalised alkoxysilane so prepared is then added in its entirety, with magnetic stirring, to the solution of sodium metasilicate previously prepared. Finally, the solution of magnesium acetate is added, with magnetic stirring, to the solution containing the functionalised alkoxysilane and the sodium metasilicate. A silico-metallic gel forms instantaneously. The silico-metallic gel is stirred for 5 minutes and then centrifuged for 5 minutes at 3500 revolutions/minute. It is then washed three times by addition of 100 ml of distilled water and centrifugation (5 minutes at 3500 revolutions/minute) so as to remove the salts formed during the precipitation.

(14) The silico-metallic gel that is recovered is then dried by lyophilisation at -50 C. under 0.064 mbar. After drying by lyophilisation, a white powder is recovered. 19.03 g of a composition comprising functionalised synthetic mineral particles are then recovered.

(15) A hydrothermal treatment of the hydrogel so prepared and obtained is then carried out at a temperature of 243 C. for 6 hours (which duration does not take into account the duration of rise in temperature). The hydrothermal treatment is carried out in the presence of a concentration of sodium acetate of 4 mol/l so as to accelerate the reaction of converting the hydrogel particles into hybrid organic-inorganic talcose particles.

(16) To that end, the hydrogel suspension obtained previously is placed directly into a closed titanium reactor. The titanium reactor is then arranged in a furnace at a temperature of 243 C. for 6 hours.

(17) After cooling to ambient temperature, the reactor is opened and the suspension obtained is centrifuged. After centrifugation there are recovered on the one hand a hybrid organic-inorganic talcose composition and on the other hand a supernatant solution comprising especially sodium acetate, which sodium acetate can then be recovered and optionally recycled.

(18) The hybrid talcose composition recovered is then subjected to two successive cycles of washing with demineralised water and centrifugation.

(19) Finally, the talcose composition recovered after centrifugation is dried in an oven at 60 C. for 12 hours.

(20) In the hybrid organic-inorganic talc particles of the composition so prepared, 20% of the silicon atoms carry a propyl-3-butyl-imidazolium group.

(21) The X-ray diffractogram of the hybrid talc composition so obtained is shown in FIG. 1. The X-ray diffractogram of this talcose composition has diffraction peaks corresponding to the diffraction peaks of a functionalised phyllosilicate, and in particular the following characteristic diffraction peaks: a plane (001) situated at a distance of 13.461 (I=100); a plane (020) situated at a distance of 4.542 (I=86); a plane (003) situated at a distance of 3.358 (I=62); a plane (060) situated at a distance of 1.526 (I=47).

(22) The proton NMR spectrum (FIG. 2) of the hybrid mineral particles makes it possible to identify the presence of the Hs of the Mg(OH) groups of the talc lamellae (chemical shifts between 0 and 1 ppm), of the CH.sub.2Si groups (chemical shifts between 0.5 ppm and 1 ppm), the Hs of the imidazolium ring (chemical shifts between 6 ppm and 9 ppm), the Hs of the SiOH and/or CH.sub.2C groups (chemical shifts between 1 and 3 ppm) and the Hs of the immediately adjacent CH.sub.2s of the imidazolium group and/or of water (chemical shifts between 3 and 5 ppm).

(23) The carbon NMR spectrum (FIG. 3) of the hybrid mineral particles makes it possible to identify the presence of an imidazolium group (chemical shifts between 115 ppm and 140 ppm) as well as the presence of a butyl group and of methylene groups (chemical shifts between 0 ppm and 60 ppm, including the methylene of the CH.sub.2-Si bond between 9 ppm and 10 ppm).

(24) The silicon NMR spectrum (FIG. 4) of the hybrid mineral particles makes it possible to identify the presence of SiOSi groups (chemical shifts between 80 ppm and -100 ppm).

EXAMPLE 2

(25) A functionalised hydrogel corresponding to that prepared in Example 1 is prepared.

(26) A hydrothermal treatment of the hydrogel so prepared and obtained is then carried out at a temperature of 243 C. for 6 hours (which duration does not take into account the duration of rise in temperature).

(27) To that end, the hydrogel suspension obtained previously is placed directly into a closed titanium reactor. The titanium reactor is then arranged in a furnace at a temperature of 243 C. for 6 hours.

(28) After cooling to ambient temperature, the reactor is opened and the suspension obtained is centrifuged. After centrifugation there is recovered a hybrid organic-inorganic talcose composition.

(29) The hybrid talcose composition recovered is then subjected to two successive cycles of washing with demineralised water and centrifugation.

(30) Finally, the talcose composition recovered after centrifugation is dried in an oven at 60 C. for 12 hours.

(31) The X-ray diffractogram of the talc composition so obtained is shown in FIG. 5. The X-ray diffractogram of this talcose composition has diffraction peaks corresponding to the diffraction peaks of a functionalised phyllosilicate, and in particular the following characteristic diffraction peaks: a plane (001) situated at a distance of 13.298 (I=96); a plane (020) situated at a distance of 4.558 (I=100); a plane (003) situated at a distance of 3.485 (I=79); a plane (060) situated at a distance of 1.523 (I=49).

(32) In the hybrid organic-inorganic talc particles of the composition so prepared, 20% of the silicon atoms carry a propyl-3-butyl-imidazolium group.

EXAMPLE 3

(33) A functionalised hydrogel is prepared:

(34) On the one hand, a solution of magnesium acetate is prepared by adding 30.24 g of magnesium acetate tetrahydrate (Mg(CH.sub.3COO).sub.2, 4H.sub.2O) to 94.00 ml of acetic acid CH.sub.3COOH at 1 mol/l.

(35) On the other hand, a solution of functionalised alkoxysilane and of sodium metasilicate is prepared:

(36) A solution of sodium metasilicate is first prepared by adding 31.83 g of sodium metasilicate pentahydrate to 200 ml of distilled water. The solution is heated gently to 40 C. in order to improve the dissolution.

(37) A solution of functionalised alkoxysilane is prepared by adding 10.534 g of 1-(trimethoxy-silyl-propyl)-3-methyl-imidazolium chloride to 50 ml of distilled water.

(38) 1-(Trimethoxy-silyl-propyl)-3-methyl-imidazolium chloride has the following structural chemical formula:

(39) ##STR00010##

(40) There is then added thereto, with magnetic stirring, a solution comprising 5.62 g of sodium iodide NaI in 10 ml of distilled water, so as to carry out an exchange between the chloride Cl.sup. and iodide I.sup. ions. The solution of functionalised alkoxysilane with sodium iodide NaI is stirred magnetically for 1 minute.

(41) The solution of functionalised alkoxysilane so prepared is then added in its entirety, with magnetic stirring, to the solution of sodium metasilicate previously prepared.

(42) Finally, the solution of magnesium acetate is added, with magnetic stirring, to the solution containing the functionalised alkoxysilane and the sodium metasilicate. A silico-metallic gel forms instantaneously. The silico-metallic gel is stirred for 5 minutes and then centrifuged for 5 minutes at 3500 revolutions/minute. It is then washed three times by addition of 100 ml of distilled water and centrifugation (5 minutes at 3500 revolutions/minute) so as to remove the salts formed during the precipitation.

(43) The silico-metallic gel that is recovered is then dried by lyophilisation at -50 C. under 0.064 mbar. After drying by lyophilisation, a white powder is recovered. 16.60 g of a composition comprising functionalised synthetic particles are then recovered.

(44) A hydrothermal treatment of the hydrogel so prepared and obtained is then carried out at a temperature of 243 C. for 6 hours (which duration does not take into account the duration of rise in temperature). The hydrothermal treatment is carried out in the presence of a concentration of sodium acetate of 4 mol/l so as to accelerate the reaction of converting the hydrogel particles into hybrid organic-inorganic talcose particles.

(45) To that end, the hydrogel suspension obtained previously is placed directly into a closed titanium reactor. The titanium reactor is then arranged in a furnace at a temperature of 243 C. for 6 hours.

(46) After cooling to ambient temperature, the reactor is opened and the suspension obtained is centrifuged. After centrifugation there are recovered on the one hand a hybrid organic-inorganic talcose composition and on the other hand a supernatant solution comprising especially sodium acetate, which sodium acetate can then be recovered and optionally recycled.

(47) The hybrid talcose composition recovered is then subjected to two successive cycles of washing with demineralised water and centrifugation.

(48) Finally, the talcose composition recovered after centrifugation is dried in an oven at 60 C. for 12 hours.

(49) In the hybrid organic-inorganic talc particles of the composition so prepared, 20% of the silicon atoms carry a propyl-3-methyl-imidazolium group.

(50) The X-ray diffractogram of the hybrid talc composition so obtained is shown in FIG. 6. The X-ray diffractogram of this talcose composition has diffraction peaks corresponding to the diffraction peaks of talc, and in particular the following characteristic diffraction peaks: a plane (001) situated at a distance of 13.118 (I=99); a plane (020) situated at a distance of 4.476 (I=100); a plane (003) situated at a distance of 3.252 (I=65); a plane (060) situated at a distance of 1.516 (I=50).

(51) The proton NMR spectrum (FIG. 7) of the hybrid mineral particles makes it possible to identify the presence of the Hs of the Mg(OH) groups of the talc lamellae (chemical shifts between 0 and 1 ppm), of the CH.sub.2Si groups (chemical shifts between 0.5 ppm and 1 ppm), the Hs of the imidazolium ring (chemical shifts between 6 ppm and 9 ppm), the Hs of the SiOH and/or CH.sub.2C groups (chemical shifts between 1 and 3 ppm) and the Hs of the immediately adjacent CH.sub.2s of the imidazolium group and/or of water (chemical shifts between 3 and 5 ppm).

(52) The carbon NMR spectrum (FIG. 8) of the hybrid mineral particles makes it possible to identify the presence of an imidazolium group (chemical shifts between 115 ppm and 140 ppm) as well as the presence of a methyl group and of methylene groups (chemical shifts between 0 ppm and 60 ppm, including the methylene of the CH.sub.2Si bond between 9 ppm and 10 ppm).

(53) The silicon NMR spectrum (FIG. 9) of the hybrid mineral particles makes it possible to identify the presence of SiOSi groups (chemical shifts between 80 ppm and 100 ppm).

(54) The invention can be the subject of many other applications and of different variants with respect to the embodiments and examples described above. In particular, the functionalised mineral particles of a composition according to the invention can be used as a supported ionic liquid (SIL), for example in the field of catalysis.