APPLICATION OF HYBRID ALUMINOSILICATES

Abstract

The use of hollow particles of hybrid aluminosilicates of imogolite or allophane type, characterized in that they have their external surface functionalized with AlOH units and their internal surface functionalized at least in part with SiR units, with R representing a nonhydrolyzable unit, preferably a hydrocarbon unit, as vehicle for one or more hydrophobic substances, in particular considered in the oil industry, the hydrophobic substances being chosen from any compound containing a linear or branched aliphatic chain having at least 4 carbon atoms, surfactants, biocides and methane clathrates inhibitors.

Claims

1-10. (canceled)

11. Method for obtaining a vehicle for one or more hydrophobic substances using hollow particles of hybrid aluminosilicates of imogolite or allophane type, wherein they have their external surface functionalized with AlOH units and their internal surface functionalized at least in part with SiR units, with R representing a nonhydrolyzable unit, said hydrophobic substances being chosen from any compound containing a linear or branched aliphatic chain comprising at least 4 carbon atoms, surfactants, biocides and methane clathrates inhibitors.

12. Method according to claim 11, wherein said hydrophobic substance is dedicated to being incorporated in a medium via said particle charged beforehand with said substance.

13. Method according to the claim 12, in which said substance is a compound of interest for enhanced oil or also hydrocarbon recovery techniques.

14. Method according to claim 11, wherein said substance is dedicated to being trapped and/or extracted by said uncharged aluminosilicate particle.

15. Method according to claim 14, wherein said substance is a methane clathrates inhibitor.

16. Method according to claim 14 for the extraction of undesirable fatty substances from bioreactor media.

17. Method according to claim 11, wherein said particles are of imogolite type with R representing a linear or branched C.sub.1-C.sub.12 alkyl or alkenyl group.

18. Method according to claim 11, wherein said particles are of imogolite type with R representing a methyl, ethyl, propyl, butyl or vinyl group.

19. Method according to claim 11, wherein said particles are of allophane type with R representing a methyl or vinyl group.

20. Method according to claim 11, wherein said particles are 100% hybrids.

21. Method according to claim 11, wherein R represents a hydrocarbon unit.

22. Method according to claim 11, wherein said vehicle for one or more hydrophobic substances is considered in the oil industry.

Description

EXAMPLE 1

[0070] Preparation of Particles of Aluminosilicates of Imogolite Type Having a Hybrid Core (C)

[0071] 30 ml of a solution of aluminosilicate, the aluminum/silicon molar ratio of which is set at 2 and the hydrolysis ratio (sodium hydroxide/aluminum molar ratio) of which is also set at 2, were prepared as follows:

[0072] An aqueous aluminum solution is prepared by dissolution of 0.487 g of aluminum perchlorate in pure water, in order to obtain a 0.1 mol.Math.l.sup.1 solution, and is then decanted into a 10 ml volumetric flask.

[0073] A solution of 50 ml of 0.1 mol.Math.l.sup.1 sodium hydroxide is prepared by dissolution of 0.2 g of sodium hydroxide and is then decanted into a 20 ml volumetric flask.

[0074] The aluminum perchlorate solution is decanted into a Teflon container containing a magnetic bar and is then stirred. Methyltriethoxysilane (99.6 l) is added to the solution. The sodium hydroxide solution is subsequently added at a flow rate of 4 ml.Math.min.sup.1 using a peristaltic pump. Once the addition is complete, the Teflon container is closed and left stirring at ambient temperature for a period of 20 h, and then placed in an oven at 85 C. for 5 days. The solution is subsequently washed and filtered several times in pure water using a 30 kDa membrane.

[0075] The hybrid imogolite nanotubes thus prepared were lyophilized in the solid form. A volatile white powder of very low density is obtained.

[0076] The yield of this synthesis is at least 50%.

EXAMPLE 2

[0077] Preparation of Particles of Aluminosilicates of Allophane Type Having a Hybrid Core (E)

[0078] 32.46 g of Al(ClO.sub.4).sub.3.9H.sub.2O are added to 700 ml of DI water in a container made of polypropylene or of stainless steel. The medium is left stirring for hour, 4.53 g of MeSi(OMe).sub.3 are subsequently added. The homogeneous reaction medium is kept stirred at ambient temperature.

[0079] A fresh sodium hydroxide solution (5.33 g of NaOH in 1333 ml of DI water) is subsequently added to a dropping funnel. Addition is carried out at the rate of 250 ml per minute. The reaction medium is clear after hour. The reaction medium is stirred at ambient temperature for 12 hours before being heated at 90 C. for 5 days in a container made it polypropylene or of stainless steel. After cooling to ambient temperature, the reaction medium is washed (diafiltered) and concentrated by ultrafiltration through a 10 kD membrane.

[0080] The yield at (OH).sub.3Al.sub.2O.sub.3SiMe with respect to the aluminum introduced is 76%.

EXAMPLE 3

[0081] Test of Extraction of Hydrophobic Compounds

[0082] 0.2 g of crystals of polyaromatic compounds (pyrene and 9-phenylanthracene) is dispersed in 30 ml of an aqueous solution of NaCl (20 g/l) and CaCl.sub.2 (2 g/l). It should be noted that pyrene (m.p.: 150 C.) and 9-phenylanthracene 153 C.) are very sparingly soluble in water.

[0083] 10 ml of a 10% by weight solution of allophone or imogolite tested are added. The reaction medium is left stirring for 5 hours. The reaction medium is subsequently centrifuged in polypropylene tubes equipped with a PVDF membrane with a cutoff threshold of 0.1 m for the allophones and of 0.25 m for the imogolites, in order to take into account the aspect ratio. After the centrifugation/filtration stage, the reaction medium is clear and virtually colorless. It is subsequently dialyzed against 5 liters of DI water in a Zellu Trans Roth tube made of cellulose (MWCO: 4000-6000) for 2 days. Finally, the reaction medium is evaporated to dryness and the residue is dried in an oven at 140 C. for 5 hours. The powder recovered is weighed and stored in argon.

[0084] All the experiments were carried out 3 times on samples originating from the same hatch, except for G and H, whose experiments were carried out only once on one and the same batch.

[0085] For the sample E, 2 batches E and E were prepared and were each tested 3 times.

[0086] For H, the nanogibbsite sample, the centrifugation/filtration is carried out on 0.250 m filters.

[0087] The extraction results are given in table 1 below.

TABLE-US-00001 TABLE I Reference weight/10 g Organic weight Extraction Sample theoretical extracted yield Fluorescence A 7.5 g <mg Yes B 8.5 g <mg Yes C 8 g 0.12 g 0.6 Yes D 7.5 g 0.11 g 0.55 Yes E 9.2 g 0.16 g 0.8 Yes E 8.9 g 0.15 g 0.75 Yes F 8.5 g 0.05 g 0.25 Yes G 8.3 g 0.03 g 0.15 Yes H 9 g <mg Yes

[0088] Obviously, the 100% hybrid allophones and/or imogolites (C, D, E and E) have proved to be the most effective since they make it possible to obtain an extraction yield of 60%, 55%, 80% and 75% respectively.

[0089] The 50% hybrid allophones also adsorb the organic compounds hut at a reduced scale.

EXAMPLE 4

[0090] Resistance to Adsorption

[0091] The protocol of example 3 was repeated for the batches D and E while carrying out a dialysis against 5 liters of an EtOH/water (80/20 by volume) mixture before redoing another dialysis in DI water.

[0092] The results are compiled in table II below.

TABLE-US-00002 TABLE II Reference weight/10 g Organic weight Extraction Sample theoretical extracted yield Fluorescence D 7.4 g 0.10 g 0.5 Yes E 8.9 g 0.17 g 0.85* Yes *The increase observed in the extraction yield for the hybrid allophanes might originate from the secondary adsorption of alcohol.

[0093] The dialysis in an alcoholic medium does not appear to affect the extraction yield of the hybrid allophones and/or imogolites. in the application: