MULTI-FUNCTIONAL HYBRID MATERIAL BASED ON SEPIOLITE FOR ENVIRONMENTAL RECOVERY AND BIO-REMEDIATION

Abstract

A multifunctional hybrid material based on sepiolite for environmental recovery and bio-remediation is described. In particular, the invention describes the design and development of suitably functionalized hybrid nanomaterials starting from sepiolite and the subsequent study of the absorbent and degrading properties in relation to aromatic hydrocarbons, by activating hydrocarbon-clastic bacteria. These nanomaterials have been prepared in order to remove hydrocarbon pollutants (e.g. oil) in natural matrices (marine environment), with potential applications in the field of environmental remediation.

Claims

1. A functionalized hybrid material comprising a sepiolite functionalized with at least an alkoxysilane crosslinking agent, wherein said at least an alkoxysilane crosslinking agent comprises an epoxy trialkoxysilane.

2. The functionalized hybrid material of claim 1, wherein said at least an alkoxysilane crosslinking agent and said sepiolite are in a weight ratio of 1:5 to 5:1.

3. The functionalized hybrid material of claim 2, wherein said at least an alkoxysilane crosslinking agent and said sepiolite are in a weight ratio of 1:2 to 2:1.

4. The functionalized hybrid material of claim 3, wherein said epoxy trialkoxysilane is 3-glycidoxypropyltrimethoxysilane.

5. The functionalized hybrid material of claim 1, wherein said at least an alkoxysilane crosslinking agent is an aliphatic trialkoxysilane having formula (I): ##STR00005## where X is an alkoxy group, R is a C4-C20 aliphatic chain, and Y is a methyl, amino, or thiolic group.

6. The functionalized hybrid material of claim 5, comprising a sepiolite functionalized with a mixture of a) at least an epoxy trialkoxysilane and b) at least an aliphatic trialkoxysilane having formula (I), wherein a) and b) are in weight ratio of 5:1 to 1:5.

7. The functionalized hybrid material of claim 6, comprising a sepiolite functionalized with a mixture of 3-glycidoxy propyltrimethoxysilane and hexadecyltrimethoxysilane.

8. The functionalized hybrid material of claim 7, wherein 3-glycidoxy propyltrimethoxysilane and hexadecyltrimethoxysilane are in weight ratio of 2:1 to 1:2.

9. A method of absorbing and degrading substrate of hydrocarbon pollutant with of the functionalized hybrid material of claim 1, said method comprising activating hydrocarbonoclastic bacteria with said functionalized hybrid material, and obtaining environmental recovery and restoration.

10. Product for the recovery and environmental remediation, comprising the functionalized hybrid material of claim 1, said product being a fabric, a sponge or a polymeric foam.

11. The functionalized hybrid material of claim 1, wherein said at least an alkoxysilane crosslinking agent is hexadecyltrimethoxysilane.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0047] The characteristics and advantages of the present invention will be apparent from the following detailed description, the embodiments provided as illustrative and non-limiting examples, and the annexed figures, wherein:

[0048] FIG. 1 shows SEM images of untreated cotton reported at different magnitudes and cuts, as per Example 1,

[0049] FIG. 2 shows SEM images of the cotton treated with the siliceous sol, as per Example 1,

[0050] FIG. 3 shows the EDX mapping spectrum and the percentage distribution of C, O, Al (carrier), and Si, of the cotton treated with the siliceous sol, as per Example 1,

[0051] FIG. 4 shows a comparison between the IR spectra of Sepiolite and of Sepiolite functionalized through various procedures, as per Example 1,

[0052] FIG. 5 shows the bacterial abundance (DAPI count) of the microbial population developed during the experimentation performed with natural seawater (SW), as per Example 1,

[0053] FIG. 6 shows the bacterial abundance (DAPI count) of the microbial population developed during the experiments performed with natural seawater (SW) and inorganic nutrients (IN), as per Example 1,

[0054] FIG. 7 shows the qualitative and quantitative hydrocarbon analysis (GC-FID analysis) expressed as a percentage (%) of oil present in different experiments performed with natural seawater (SW), as per Example 1,

[0055] FIG. 8 shows the qualitative and quantitative analysis of hydrocarbons (GC-FID analysis) expressed as a percentage (%) of oil present in different experiments carried out with natural seawater (SW) and inorganic nutrients (IN), as per Example 1,

[0056] FIG. 9 shows the visual analysis of the oil absorption by the various sepiolite samples as per Example 1, and

[0057] FIG. 10 shows a visual analysis of the oil absorption by the various sepiolite samples as per Example 1.

DETAILED DESCRIPTION OF THE INVENTION

[0058] The invention therefore relates to a functionalized hybrid material comprising sepiolite functionalized with at least one alkoxysilane cross-linking agent, wherein said at least one cross-linking agent comprises an epoxy trialkoxysilane.

[0059] It has, indeed, surprisingly been found that this functionalization allows to obtain a hybrid material which is advantageously able to absorb the hydrocarbon pollutants, as will also be seen in the working examples provided below.

[0060] In preferred embodiments, said at least one cross-linking agent and said sepiolite are in a weight ratio of 5:1 to 1:5.

[0061] More preferably, said at least one cross-linking agent and said sepiolite are in a weight ratio of 2:1 to 1:2.

[0062] Sepiolite is a non-swelling, lightweight, porous clay (with a large specific surface area), whose individual particles have a needle-like shape. There are very few commercially exploited deposits in the world. Production comes mainly from the south-eastern United States (Miocene fields in Florida and Georgia), which amounted to about 1.8 million tonnes in 1989, and—to a much lesser extent—from Senegal, Spain, Australia, India, Turkey, South Africa and France. Together with palygorskite, it is referred to as a “special clay”.

[0063] The large surface area and high porosity, as well as the needle-like shape of the particles of this clay explain its absorbency and it is rheological and catalytic properties, which make it a valuable material for a wide range of applications.

[0064] Chemically, sepiolite is a hydrated magnesium silicate with the ideal formula Si.sub.12Mg.sub.8O.sub.30(OH).sub.4(OH.sub.2).sub.4.8H.sub.2O. Unlike other clays, Sepiolite is not a layered phyllosilicate.

[0065] Remediation of soil contaminated with heavy metals and wastewater treatment have become hot topics in environmental science and engineering. In the present invention, said sepiolite functionalized with alkoxysilane fractions has been used to improve bioremediation of oil pollutants in the marine environment.

[0066] Functionalization of Sepiolite

[0067] For the purposes of the present invention, sepiolite is functionalized so as to acquire specific characteristics such as increased hydrophilicity with respect to the aqueous matrix (such as, in this case, seawater), or lipophilicity, for a greater absorption of oil, with a quantitative reaction yield of 95%. Depending on the silane used, it is possible to change the final properties of the hybrid material in order to obtain, for example, materials that can also immobilize heavy metals.

[0068] In this sense, suitable silanes are:

[0069] (3 -glycidyloxypropyl)trimethoxy silane (GPTMS), hexadecyltrimethoxysilane (C16), diethoxy(3-glycidyloxypropyl)methylsilane, triethoxy(ethyl)silane, triacetoxy(methyl)-silane, tris(2-methoxyethoxy)(vinyl)silane, mpeg20k-silane, mpeg5k-silane, trichloro(phenyl)silane, trichloro(hexyl)silane, triethoxy(octyl)silane, trichloro-(phenethyl)silane, trimethoxy [2-(7-oxabicyclo[4.1.0]hept-3-yl)ethyl]silane, trichloro-(dichloromethyl)silane, silane A 174, triacetoxy(vinyl)silane, triethyl(silane-d), diphenyl(silane-d2), trimethoxy(propyl)silane, tris(trimethylsilyl)silane, trichloro-(octadecyl)silane, trimethoxy(octyl)silane, trimethoxy(octadecyl)silane, isobutyl-(trimethoxy) silane, triethyl(trifluoromethyl)silane, chloromethyl(dimethyl)silane, trichloro(octyl)silane, trimethyl(phenyl)silane, trimethyl(propargyl)silane, trimethyl-(trifluoromethyl)silane, tetrakis(trimethylsilyl)silane, tris (dimethylamino) silane, trimethyl(tributylstannyl)silane, trimethyl[(tributylstannyl)ethynyl]silane, tris(trimethylsiloxy)silane, tert-butyldimethyl(2-propynyloxy)silane, trimethoxy(7-octen-1-yl)silane, chlorotris(trimethylsilyl)silane, (3-aminopropyl)tris(trimethylsiloxy)silane, trimethoxy-[3-(methylamino)propyl]silane, trichloro(3,3,3 -trifluoropropyl)silane, trimethoxy(3,3,3-trifluoropropyl)silane, trimethyl(trifluoromethyl)silane solution, (3-mercaptopropyl)-trimethoxy-d9-silane, chloro-dimethyl(3,3,3-trifluoropropyl)silane, (3-chloropropyl)-tris(trimethylsiloxy)silane, chlorodimethyl(pentafluorophenyl)silane, butyldimethyl-(dimethylamino)silane, trimethoxy(2-phenylethyl)silane, trimethyl(phenylthio)silane, dimethoxy-methyl(3,3,3-trifluoropropyl)silane, tetrakis(trimethylsilyloxy)silane, tris(trimethylsiloxy)(vinyl)silane, trimethyl(phenoxy)silane, trimethyl(propoxy)silane, diisopropyl(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)silane, triethoxy-(1-phenylethenyl)silane, trichloro[2-(chloromethyl)allyl]silane, trimethyl(2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl)silane, trimethyl(methylthio)silane, chlorodi-methyl(2,3,4,5-tetramethyl-2,4-cyclopentadien-1-yl)silane, chlorotris(triethylsilyl)silane, trimethyl(phenylthiomethyl)silane, chlorotris(trimethylsilyl)silane solution, methyltris(tri-sec-butoxysilyloxy)silane, tris(triethylsilyl)silane, (chloromethyl)methyl-bis(pentafluorophenyl)silane, 3-methacrylamidopropyltris(trimethylsiloxy)silane, diisopropyl(3,3,4,4,5,5,6,6,6-nonafluorohexyl)silane, dimethyl-di(methacroyloxy-1-ethoxy)silane, isopropoxy(phenyl)silane, trichloro(1h,1h,2h,2h-perfluorooctyl)silane, chlorotrimethylsilane, dichlorodimethylsilane, vinyltrimethoxysilane, chlorotriethylsilane, methyltrichlorosilane, 3-(trimethoxysilyl)propylmethacrylate, chloro-dimethyl-octadecylsilanesolution, dichloro-methyl-octadecylsilane, dichloro(chloromethyl)methylsilane, cyanomethyl [3-(trimethoxysilyl)propyl]trithiocarbonate, 3-(triethoxysilyl)propylisocyanate, vinyltrimethylsilane, tetraallylsilane, isobutyltriethoxysilane, tris(dimethylsiloxy)phenylsilane, 1-phenyl-2-trimethylsilyl-acetylene, 3-trimethylsiloxy-1-propyne, chlorodimethylphenethylsilane, 2-(allyldimethylsilyl)pyridine, 3-[tris(trimethylsiloxy)silyl]propylmethacrylate, n-[3-(trimethoxysilyl)propyl]aniline, tetramethyl-d12 orthosilicate, 3-cyanopropyl-trichlorosilane, 2-(dimethylsilyl)pyridine, (2-thienyl)trimethylsilane, 5-(tert-butyldimethylsilyloxy)-1-pentyne,allyl(4-methoxyphenyl)dimethylsilane, n-octadecyltriethoxysilane, chloro(dimethyl)thexylsilane, 1h,1h,2h,2h-perfluoro-octyltriethoxysilane, silicon 2,3-naphthalocyanine bis(trihexylsilyloxide),1-(1-naphthyl)-2-(trimethylsilyl)acetylene, 2-tert-butyldimethylsiloxybut-3-yne, (e)-3-(tert-butyldimethylsilyloxy)propene-1-yl-boronic acid pinacolester, (3-phenylpropyl)silane, (1-bromo-2,2-diphenylcyclopropyl)(trimethyl)silane, (1-hydroxy-allyl)-tri-methyl-silane, (2,2-dibromocyclopropyl)(trimethyl)silane, (2-biphenylyl)tris(decyl)silane, (2-isopropyl-1-cyclopropen-1-yl)(triphenyl)silane, (2-methyl-1-cyclopropen-1-yl)(triphenyl)silane, (2-methyl-allyl)-triphenyl-silane, (3-biphenylyl)tris(3-phenyl-propyl)silane, (3-methyl-3-butenyl)(triphenyl)silane, (4-bromobutoxy)(trimethyl)silane, (4-chlorobenzoyl)(triphenyl)silane, (4-fluorobenzoyl)(triphenyl)silane, (4-iodo-1-butynyl)(trimethyl)silane, (4-methoxy-1-cyclohexen-1-yl)(trimethyl)silane, {[(4-methoxybenzyl)oxy]methyl}(trimethyl)silane, {[(4-methoxybenzyl)oxy]methyl}-(trimethyl)silane, [(4-methoxyphenoxy)methyl](trimethyl)silane, (4-methoxyphenyl)-tri(o-tolyl)silane, (4-methoxyphenyl)tris(4-(dimethylamino)phenyl)silane, (4-nitrobenzoyl)(triphenyl)silane, (4-phenoxyphenyl)(phenyl)(o-tolyl)silane, (4-tert-butyl-1-cyclohexen-1-yl)(trimethyl)silane,(4-tert-butylbenzoyl)(triphenyl)silane, (4-tert-butylcyclohexyl)(trimethyl)silane, (4-tert-butylphenyl)diphenyl(o-tolyl)silane, (5,5-dimethyl-1-cyclopenten-1-yl)(trimethyl)silane,(5-iodo-1-pentynyl)(trimethyl)silane, (6,6-dimethyl-1-cyclohexen-1-yl)(trimethyl)silane, (7-bromo-2-aphthyl)(trimethyl)-silane, (9,10-dihydro-9-anthracenyl)trimethyl-silane, (chloromethyl)dimethyl(pentafluorophenyl)silane, (o-tolyloxy)tri(o-tolyl)silane, (p-tolyl)tris(1-naphthyl)silane, 1,3-diphenyl-1-propenyloxy(dimethyl)(pentafluorophenyl)silane, 1,3-diphenyl-1-propenyloxy(dimethyl)(trimethylsilylmethyl)silane, [1-(1-chloro-2-cyclopropylidene-ethyl)cyclopropyl](trimethyl)silane,[1-(1-cyclohexen-1-yl)cyclopropyl](trimethyl)silane, [1-(bromomethyl)cyclopropyl](trimethyl)silane, [1-(cyclohexylidenemethyl)cyclopropyl](trimethyl)silane, [1-(cyclopentylidenemethyl)cyclopropyl](trimethyl)silane, [1-(dimethoxymethyl)cyclopropyl](trimethyl)silane, 1-cyclododecen-1-yl(trimethyl)silane, 1-cyclohepten-1-yl(trimethyl)silane, 1-cyclopenten-1-yl(trimethyl)silane, [2-(cyclohexylmethyl)-2-propenyl](trimethyl)silane, [2-chloro-2-(phenylsulfonyl)ethyl](trimethyl)silane, 2-cyclohexen-1-yl(trimethyl)silane, 2-cycloocten-1-yl(trimethyl)silane, allyl(methyl)1-naphthyl(phenyl)silane, benzoyl(tris(4-tert-butylphenyl))silane, benzyl(3-phenylpropyl)silane, benzyltris(3-phenylpropyl)-silane, benzyltris(p-terphenylyl)silane, bis(2-chlorobenzyl)silane, bis(3-phenylpropyl)silane, butyldimethyl(2,3,4,5-tetrafluorophenyl)silane, butyldimethyl(2,3,5,6-tetrafluoro-phenyl)silane, butyldimethyl(pentafluorophenyl)silane, chlorodiphenyl(diphenyl-methyl)silane, chloromethyl-triethyl-silane, chloromethyldimethyl(pentachloro-phenyl)silane, chlorotri(2-biphenylyl)silane, chlorotri(o-tolyl) silane, chlorotris (1-naphthyl) silane, chlorotris (2-methoxyphenyl) silane, dibenzyldi(m-tolyl) silane, dicyclohexyl-methyl-silane, dimethyl(2,3,5,6-tetrafluorophenyl) silane, dimethyl(2,3,6-trichlorophenyl) silane, dimethyl(2,4,6-trichlorophenyl) silane, dimethyl(3,4,5-trichloro-2-thienyl)silane, dimethyl(3-(pentachlorophenyl)propyl)(pentafluorophenyl) silane, dimethyl(3-phenylpropyl)silane, dimethyl(diphenylmethoxy)(pentafluorophenyl)silane, dimethyl(pentachlorophenyl)silane, dimethyl(pentafluorophenyl)(3-(pentafluoro-phenyl)propyl) silane, diphenyl(1-naphthyl)silane, diphenyl(3-phenylpropyl)silane, diphenyl(4-methoxyphenyl)silane, diphenyl(4-phenoxyphenyl)silane, diphenyl(9-fluorenyl)silane, diphenyl(diphenylmethoxy)(diphenylmethyl)silane, diphenyl(diphenyl-methyl)silane, diphenyl(m-tolyl)silane, diphenyl(o-tolyl) (4-trimethylsilyl)phenyl) silane, diphenyl(p-tolyl)silane, diphenyl(pentachlorophenyl)silane, diphenyldi(m-tolyl)silane, diphenyldi(o-tolyl)silane, diphenylmethyl(o-tolyl)silane, diphenylmethyl(pentachloro-phenyl)silane, diphenylmethyl(pentafluorophenyl)silane, diphenylphenethyl(o-tolyl)silane, dodecyltris(2-biphenylyl)silane, dodecyltris(2-cyclohexylethyl)silane, dodecyltris(3-chlorophenyl)silane, dodecyltris (3-fluorophenyl)silane, dodecyltris(m-tolyl)silane, ethoxytri(o-tolyl)silane, ethoxytris(2-methoxyphenyl)silane, ethyl-bis-(2,4,6-trimethyl-phenyl)-silane, ethylenebis(tris(decyl)silane), hexadecyl-sulfanylethynyl-trimethyl-silane, hexadecyltris(3-chlorophenyl)silane, hexadecyltris(3-fluorobenzyl)silane, hexadecyltris(3-phenylpropyl)silane, hexadecyltris(4-chloro-phenyl)silane, methylphenyl(-(trimethylsilylmethyl)phenyl)silane, methylphenyl(m-tolyl)silane, methyltris(2-methoxyethoxy)silane, methyltris(3,4,5-trichloro-2-thienyl)silane, methyltris(p-terphenyl-4-yl)silane, methyltris(pentafluorophenyl)silane, octadecyltris(2-biphenylyl) silane, octadecyltris(2-cyclohexylethyl)silane, octadecyltris-(3-chlorophenyl)silane, octadecyltris(3-fluorophenyl)silane, octadecyltris(4-chlorophenyl)silane, phenyl(o-tolyl)silane, phenyltri(m-tolyl)silane, phenyltri(o-tolyl)silane, phenyltri(p-tolyl)silane, phenyltris(2-cyclohexylethyl)silane, phenyltris (2-ethyl-hexyl)silane, phenyltris(3-fluorophenyl)silane, phenyltris(3-phenylpropyl)silane, phenyltris(4-(trimethylsilyl)phenyl)silane, phenyltris (4-fluorobenzyl)silane, phenyltris(9-ethyl-3-carbazolyl)silane, phenyltris (9-fluorenyl)silane, phenyltris(p-terphenylyl)silane, tert-butyl(dimethyl)[(2e)-2,4-pentadienyloxy]silane, tetra(phen-ethyl)silane, tetrakis((p-tolyl)thiomethyl)silane, tetrakis((trimethylsilyl)methyl)silane, tetrakis(2-cyclohexylethyl)silane, tetrakis(2-ethylhexyl)silane, tetrakis(2-methoxyphenyl)silane, tetrakis(2-naphthyl)silane, tetrakis(3,4,5-trichloro-2-thienyl)-silane, tetrakis(3-(trifluoromethyl)phenyl)silane, tetrakis(3-chlorophenyl)silane, tetrakis(3-fluorophenyl)silane, tetrakis(3-phenylpropyl)silane, tetrakis(4-(dimethyl-amino)phenyl)silane, tetrakis(4-(trimethylsilyl)phenyl)silane, tetrakis(4-biphenylyl)-silane, tetrakis(dimethylphenylsilyl)silane, tetrakis(p-tolyl)silane, tetrakis(pentafluorophenyl)silane, tetrakis(phenylthiomethyl)silane,tetrakis(triphenylstannyl)silane, trans-styryltris(pentafluorophenyl)silane, tri(o-tolyl)silane, triethyl(triphenylgermyl)silane, trihexadecyl(4-(trimethyl silyl)phenyl)silane, trimethyl[(1z)-1-propyl-1-butenyl]silane, trimethyl[(2e)-3-phenyl-2-propenyl]silane, trimethyl[1-(trimethylsilyl)vinyl]silane, trimethyl[2-[(trimethylsilyl)methyl]-2-propenyl]silane, trimethyl[2-(1-phenylvinyl)-cyclopropyl]silane, trimethyl[6-(trimethylsilyl)-1,5-hexadiynyl]silane, trimethyl(1-methyl-1,2-diphenylethyl)silane, trimethyl(1-naphthylmethyl)silane, trimethyl(1-phenyl-2-propenyl)silane, trimethyl(3-phenyl-2-cyclohexen-1-yl)silane, trimethyl(4-(trimethylsilyl)butoxy)silane, trimethyl(4-methyl-1,5-cyclohexadien-1-yl)silane, trimethyl(4-methyl-3-penten-1-ynyl)silane, trimethyl(5-methyl-1,5-cyclohexadien-1-yl)silane, trimethyl(6-methyl-1-cyclohexen-1-yl)silane, trimethyl(6-phenyl-1-cyclo-hexen-1-yl)silane, trimethyl(pentafluorophenyl)silane, trimethyl-(1-methyl-1-phenylpropoxy)silane, trimethyl-(4-nitro-phenylethynyl)-silane, triphenyl(1,2,2-triphenylethyl)silane, triphenyl(3-(triphenylgermyl)propyl)silane, triphenyl(triphenylmethyl)silane, triphenyl(undecyl)silane, tris(1-naphthyl)silane, tris(2-biphenyl)silane, tris(2-chlorobenzyl)silane, tris(3,4,5-trichloro-2-thienyl)silane, tris(3-biphenylyl)silane, tris(4-(trimethylsilyl)phenyl)silane, tris(4-bromophenyl)silane, tris(decyl)silane, tris(hexadecyl)silane, tris(pentachlorophenyl)silane, tris(pentafluorophenyl)silane, tris(phenethyl)silane, ([4,4-dimethyl-3-[2-(2-methyl-1,3-dioxolan-2-yl)ethyl]-1-cyclo-penten-1-yl]oxy)(trimethyl)silane, ((1e)-3-[[tert-butyl(dimethyl)silyl]oxy]-1-propenyl)(trimethyl)silane, {[(1r,2s,5r)-2-isopropyl-5-methylcyclohexyl]oxy}(methyl)1-naphthyl-(phenyl)silane, {[(1r,2s,5r)-2-isopropyl-5-methylcyclohexyl]oxy}(trimethyl)silane, {[(1s)-1-isopropyl-5,5-dimethyltricyclo[4.1.0.0(2,4)]hept-4-yl]oxy}(trimethyl) silane, [(1z)-1-ethyl-1-propenyl](methyl)1-naphthyl(phenyl)silane, (2-{[(3-bromo-2-cyclo-hexen-1-yl)oxy]methoxy}ethyl)(trimethyl)silane, [(2-isopropyl-5-methylcyclohexyl)-oxy](methyl)1-naphthyl(phenyl)silane, [[(2s)-3-chloro-3,7,7-trimethyltricyclo-[4.1.1.0(2,4)]oct-2-yl]oxy](trimethyl)silane, (4,4-dimethyl-1,5-cyclohexadien-1-yl)-(methyl)1 1-naphthyl(phenyl)silane, [(4s,5r)-5-ethyl-4-methyl-1-cyclopenten-1-yl](trimethyl)silane, (6-isopropyl-3-methyl-1-cyclohexen-1-yl)(trimethyl)silane, [1-[(1z)-1-ethyl-1-propenyl]cyclopropyl](trimethyl)silane, [1-[(2,6-dimethyl-2-cyclohexen-1-ylidene)methyl]cyclopropyl](trimethyl)silane, [1-[(7,9-dimethyl-1,4-dioxaspiro-[4.5]dec-8-ylidene)methyl]cyclopropyl](trimethyl)silane, [1-[bis(phenylsulfanyl)-methyl]cyclopropyl](trimethyl)silane, 1-cyclohexen-1-yl(methyl)1-naphthyl(phenyl)-silane, 1-cycloocten-1-yl(methyl)1-naphthyl(phenyl)silane, 1-oxaspiro[2.2]pent-4-yl(triphenyl)silane, [2,2-dimethyl-3-(tetrahydro-2h-pyran-2-yloxy)propoxy](trimethyl)-silane, [2-({[(2e,6s)-2,6-dimethyl-7-(2-oxiranyl)-2-heptenyl]oxy}methoxy)ethyl]-(trimethyl)silane, [2-([[tert-butyl(dimethyl)silyl]oxy]methyl)-2-propenyl](trimethyl)-silane, [3,7-dimethoxy-6-(trimethylsilyl)dibenzo[b,d]furan-4-yl](trimethyl)silane, [3-([[tert-butyl(dimethyl)silyl]oxy]methyl)-2,2-dichlorocyclopropyl](trimethyl)silane, 6,9-dihydro-5h-benzo[a]cyclohepten-7-yl(trimethyl)silane, bicyclo[2.2.2]oct-2-yl(trimethyl)silane, bicyclo[3.1.0]hex-6-yl(trimethyl)silane, bicyclo[3.2.1]oct-2-en-3-yl-(trimethyl)silane, bicyclo[4.1.0]hept-2-en-7-yl(trimethyl)silane, bis(pentafluorophenyl)methyl(alpha-styryl)silane, dimethylphenyl(phenyl(2,3,5,6-tetrachloro-4-pyridyl)methoxy)silane, methyl(4-methyl-1-cyclohexen-1-yl)1-naphthyl(phenyl)silane, tert-butyl(dimethyl)[(1,7,7-trimethylbicyclo[2.2.1]hept-2-en-2-yl)oxy]silane, tert-butyl(dimethyl)[[(2r)-2-methyl-3-(phenylsulfonyl)propyl]oxy]silane, tert-butyl(dimethyl)-[(3,3,9,9-tetrachlorotricyclo[6.1.0.0(2,4)]non-6-yl)oxy]silane, tert-butyl(dimethyl)[(4-methyl-4-pentenyl)oxy]silane, tert-butyl(dimethyl)[(5s)-tricyclo[6.1.0.0(2,4)]non-6-en-5-yloxy]silane, tert-butyl(dimethyl){2-methyl-2-[(2s)-2-oxiranyl]propoxy}silane, tert-butyl(dimethyl){[3-(trimethylstannyl)-3-butenyl]oxy}silane, tert-butyl(dimethyl)[[4-(tributylstannyl)-3-furyl] methoxy]silane, tert-butyl(dimethyl)(tetracyclo-[7.1.0.0(2,4).0(5,7)]dec-8-yloxy)silane, tert-butyl(diphenyl)(2,3,5,6-tetrabromo-4-{[tert-butyl(diphenyl)silyl]oxy}phenoxy)silane, tert-butyl-(2,2-dimethyl-(1,3)dioxolan-4-ylmethoxy)-diphenyl-silane, trimethyl[(1e)-1-methyl-3-(triphenylstannyl)-1-propenyl]-silane, trimethyl{(3s)-4-methyl-2-(phenylsulfonyl)-3-[(phenylsulfonyl)methyl]pentyl}-silane, trimethyl[(4-methyl-3-cyclohexen-1-yl)methyl]silane, trimethyl[1-[(2-methyl-2-cyclohexen-1-ylidene)methyl]cyclopropyl]silane, trimethyl[1-(7-oxabicyclo-[4.1.0]hept-1-yl)cyclopropyl]silane, trimethyl[2-[8-(phenylsulfonyl)-1,4-dioxaspiro-[4.5]dec-8-en-7-yl]ethyl]silane, trimethyl[2-({[(2s)-2-methyl-3-butynyl]oxy}methoxy)ethyl]silane, trimethyl(13-oxabicyclo[10.1.0]tridec-1-yl)silane, trimethyl(2-phenyl-1,1-bis(trimethyl-silyl)ethyl)silane, trimethyl(6-phenyl-7-oxabicyclo[4.1.0]hept-2-yl)silane, trimethyl(7-oxabicyclo[4.1.0]hept-1-yl)silane, trimethyl(spiro[4.5]dec-6-en-6-yl)silane, trimethyl-(tricyclo[4.1.0.0(2,7)]hept-1-yl)silane, trimethyl-(4′-naphthalen-1-yl-biphenyl-4-yl)-silane, ({2-[2-(methoxymethoxy)ethyl]-5,5-bis[(3e)-5-(phenylsulfanyl)-3-pentenyl]-1-cyclopenten-1-yl}oxy)(trimethyl)silane, ({4-[1-({[tert-butyl(dimethyl)silyl]oxy}-methyl)-2-methylpropyl]-2-methyl-1,5-cyclohexadien-1-yl}oxy)(trimethyl)silane, {[(1ar,3r,11as,11br)-3-methoxy-1,1-dimethyl-1a,2,3,5,6,7,10,11,11a,11b-decahydro-1h-cyclopropa[3,4]benzo[1,2-a]cyclodecen-9-yl]oxy}(trimethyl)silane, [[(1r,2ar,4ar,6as,6br)-1-vinyl-1,2,2a,4a,6a,6b-hexahydrocyclopenta[cd]pentalen-1-yl]oxy](trimethyl)-silane, (2,6-ditert-bu-4(3,5-ditert-bu-4((tri-me-silyl)oxy)benzyl)phenoxy)(tri-me)silane, (2-{[((2s,4as,5s,7s,7ar)-5-ethoxy-7-(iodomethyl)-2-(4-methoxyphenyl)dihydro-4h-furo [3,4-d][1,3]dioxin-4a(5h)-yl)oxy]methoxy}ethyl)(trimethyl)silane, (2-{[((2s,4as,7s,7ar)-5-ethoxy-7-(iodomethyl)-2-(4-methoxyphenyl)dihydro-4h-furo[3,4-d][1,3]-dioxin-4a(5h)-yl)oxy]methoxy}ethyl)(trimethyl)silane, [[(4s,4ar,5r,6s,8ar)-4-(3-butenyl)-3,4a,6-trimethyl-5-(3-methyl-3-butenyl)-1,4,4a,5,6,7,8,8a-octahydro-2-naphthalenyl]oxy](trimethyl)silane, {2,6-ditert-butyl-4-[{3,5-ditert-butyl-4-[(trimethylsilyl)oxy]pheny}(ethoxy)methyl]phenoxy}(trimethyl)silane, [2-[([(1s,3as,7ar)-3a-[(2-methoxyethoxy)methoxy]-7a-methyl-2,3,3a,6,7,7a-hexahydro-1h-inden-1-yl]oxy)methoxy]ethyl](trimethyl)silane, [2-({[(1r,3r,6s)-7,7-dimethyl-4-methylenebicyclo[4.1.0]hept-3-yl]oxy}methoxy)ethyl](trimethyl)silane, [2-({[(1s,6r)-3-bromo-7-oxabicyclo[4.2.0]oct-2-en-1-yl]oxy}methoxy)ethyl](trimethyl)silane, [2-({[(2e,6s)-7-(1,3-dithian-2-yl)-2,6-dimethyl-2-heptenyl]oxy}methoxy)ethyl](trimethyl)silane, [2-({[(2e,6s)-9-iodo-2,6-dimethyl-8-(tetrahydro-2h-pyran-2-yloxy)-2-nonenyl]oxy}-methoxy)ethyl](trimethyl)silane, tert-butyl(dimethyl)[[(2s,4s)-4-(2-phenylethyl)-3,4-dihydro-2h-pyran-2-yl]methoxy]silane, triethyl[((4z)-5-{(2s,3r)-2-methoxy-3-[(4-methoxybenzyl)oxy]-7,7-dimethyl-1-vinylbicyclo[2.2.1]hept-2-yl}-3-methylene-4-pentenyl)oxy]silane, trimethyl[[(1s,5r,6r,7r)-7-methyl-7-vinylbicyclo[3.2.0]hept-2-en-6-yl]oxy]silane, trimethyl[1-methyl-2-({1-[7-(1-{1-methyl-2-[(trimethylsilyl)oxy]-propoxy}vinyl)-2-naphthyl]vinyl}oxy)propoxy]silane, trimethyl({(4s)-4-methyl-3-[2-(2-methyl-1,3-dioxolan-2-yl)ethyl]-1-cyclopenten-1-yl}oxy)silane, ({(1bs,4ar,7ar,7br,8r)-1,1,8-trimethyl-7b-[(trimethylsilyl)oxy]-1a,1b,2,4a,5,6,7,7a,7b,8,9,9a-dodeca-hydro-1h-cyclopropa[3,4]benzo[1,2-e]azulen-4-yl}oxy)(trimethyl)silane, [(2r,3s,4r,5r,6s)-2-(iodomethyl)-6-{[(2r,3s,4s,5r,6s)-6-(iodomethyl)-3,4,5-tris(trimethylsilyl)tetrahydro-2h-pyran-2-yl]oxy}-4,5-bis(trimethylsilyl)tetrahydro-2h-pyran-3-yl](trimethyl)silane, {2-[({(3ar,5s,5ar,6s,9s,9br)-9-{[tert-butyl(dimethyl)silyl]oxy}-9b-[3-(methoxymethoxy)propyl]-2,3,3,5a-tetramethyl-5-[(triethylsilyl)oxy]-3a,4,5,5a,6,7,8,9,9a,9b-decahydro-3h-cyclopenta[a]naphthalen-6-yl}oxy)methoxy]-ethyl}(trimethyl)silane, 2,4,6,8-tetramethylcyclotetrasiloxane, ethynyltrimethylsilane, triethoxymethylsilane, trimethoxymethylsilane, triethoxyvinylsilane, hexachlorodisilane, dimethoxydimethylsilane, methoxytrimethylsilane, diethoxydimethylsilane,trichlorovinylsilane, methyldiethoxysilane, bis(trimethylsilyl)acetylene, ethoxytrimethylsilane,dimethoxymethylvinylsilane, tert-butyltrichlorosilane, (chloromethyl)triethoxysilane, trans-1-methoxy-3-trimethylsiloxy-1,3-butadiene, 1,2-bis(triethoxysilyl)ethane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(trichlorosilyl)ethane, 1,3-diethoxy-1,1,3,3-tetramethyldisiloxane, (3-aminopropyl)triethoxysilane, (triiso-propylsilyl)acetylene, tetraethylorthosilicate, diethoxy(3-glycidyloxypropyl)-methylsilane, (3-mercaptopropyl)trimethoxy silane, triethoxysilane,tetramethylsilane, phenylsilane, hexamethyldisiloxane, diphenylsilane, bromotrimethylsilane, tetramethylorthosilicate, triphenylsilane, diphenylsilanediol, dichlorodiphenylsilane, chlorotriphenylsilane, triphenylsilanol, allyltrichlorosilane, triethoxyphenylsilane, trihexylsilane, benzyldimethylsilane,tetravinylsilane, chlorotributylsilane, trichlorododecylsilane, chlorotrihexylsilane, hexamethyldisiloxane solution, chlorotrimethylsilanesolution, dichlorophenylsilane, tributylchlorosilane, dodecyltriethoxysilane, diethoxydiphenylsilane, hexylsilane, trioctylsilane, chlorotripropylsilane, (3-chloropropyl)triethoxysilane, 3-(triethoxysilyl)propionitrile, (chloromethyl)dimethylphenylsilane, (3-chloropropyl)trichlorosilane, trichloromethyl-silane, bis(dimethylamino)dimethylsilane, 3-(2-aminoethylamino)propyldimethoxy-methylsilane, trichlorocyclopentylsilane, (3-aminopropyl)trimethoxysilane, (2-bromoethoxy)-tert-butyldimethylsilane, methoxy(dimethyl)octylsilane, tert-butyldimethylsilylglycidylether, (3-bromopropyl)trimethoxysilane, methoxy(dimethyl)-octadecylsilane, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammoniumchloride solution, tetrafluoro-2-(tetrafluoro-2-iodoethoxy)ethanesulfonylfluoride, [3-(2-aminoethylamino)propyl]trimethoxysilane, (3-glycidyloxypropyl)triethoxysilane, (3-bromopropoxy)-tert-butyldimethylsilane.

[0070] The sol-gel technique is a very simple synthetic method which allows the formation of an inorganic/organic siliceous-based network. The network is formed through hydrolysis and condensation of a metal-organic precursor, such as an alkoxide M(OR).sub.n. The organic molecules can be incorporated into this solid matrix, giving rise to a functionalized sol with high thermal and mechanic stability.

[0071] In this sense, the trialkoxysilanes are preferably functional molecules which can be utilised as cross-linking reagents for the functionalization of appropriate nanofillers and the dispersion thereof inside a sol-gel-based hybrid polymeric matrix, allowing the formation of a nanohybrid material or of a functional nanocomposite, is also utilizable for coating surfaces. Functionalizable surfaces can include textile fibres which, after the application of functional coatings, can be used to create technical, innovative, or smart fabrics. Indeed, natural plant fibres, such as cotton, are mainly compounds of cellulose, a natural polymer which has as its structural unit glucose joined with β-glycosidic bonds and features external —OH groups. These functional groups lend themselves well to the grafting processes which allow the inclusion—therewithin or on the surface of fabric—of a different type of nanostructure, to introduce a new functions or implement the physical/mechanical properties of cotton fibres.

[0072] Preferred trialkoxysilanes are those comprising at least one epoxydic group, also known as epoxydic trialkoxysilanes, which lend the sepiolite specific characteristics such as increased hydrophilia, in relation to the aqueous matrix (such as, on this case, sea the water). Preferably then, said at least one cross-linking agent is an epoxydic trialkoxysilane.

[0073] Among the suitable epoxydic trialkoxysilanes, 3-glycidoxypropyltrimethoxysilane (GPTMS) is particularly preferred.

[0074] In order to create the sol-gel matrices, wherein including the nanofillers of organic or inorganic origin, which were then also applied to the fabrics, so as to implement the physical/chemical properties and the mechanical characteristics of the sepiolite and of the fabric fibres, it was decided to modify a sol-gel synthesis approach, based on GPTMS:

##STR00001##

[0075] The 3-glycidoxypropyltrimethoxysilane or GPTMS acts as a linker between the fabric and said nanofiller. Indeed, owing to its bifunctionality, through its trimethoxysilane end, GPTMS allows the formation of a sol-gel network or anchorage to the sepiolite or to the fabric, through condensation with —OH groups, and release of MeOH, while—through the epoxydic ring (following a nucleophile coupling with consequent opening of said ring)—it produces the formation of a heterolytic covalent bond in the presence of a nucleophile:

##STR00002##

[0076] The synthesis of hybrid materials based on the GPTMS epoxydic molecule is therefore a process involving multiple steps, comprising the formation of a siliceous-based network and the functionalization of the epoxide, with the opening of said epoxydic ring.

[0077] When instead it is desirable to increase the lipophilia of the sepiolite and consequently the affinity for oil of the end hybrid material, then long-chain aliphatic trialkoxysilanes are preferred. Preferably then, said at least one cross-linking agent is aliphatic trialkoxysilane having the following formula (I):

##STR00003##

where X is an alkoxy group, and R is a C4-C20 aliphatic chain, and Y is methyl, an amine group or a thiol group.

[0078] Among the long-chain aliphatic trialkoxysilanes, hexadecyltrimethoxysilane (C16) is particularly preferred as it features both a trimethoxysilane group which can be coordinated with the sepiolite and a long hydrocarbon tail:

##STR00004##

[0079] In preferred embodiments, the functionalized hybrid material comprises sepiolite functionalized with a mixture of a) at least one epoxydic trialkoxysilane and b) at least one aliphatic trialkoxysilane having formula (I).

[0080] In particularly preferred embodiments, the functionalized hybrid material comprises sepiolite functionalized with a mixture of a) at least one trialkoxysilane epoxydic and b) at least one aliphatic trialkoxysilane having formula (I), wherein a) and b) are in a weight ratio of 5:1 to 1:5.

[0081] More preferable are the embodiments wherein the functionalized hybrid material comprises sepiolite functionalized with a mixture of GPTMS and C16, wherein GPTMS and C16 are in a weight ratio of 2:1 to 1:2. Preferably, said mixture and said sepiolite are in a weight ratio of 2:1 to 1:2, more preferably about 1:1.

[0082] The common feature of sepiolite nanofibres is that they have external and internal —OH groups, as well as water molecules. These groups allow an alkoxysilane to be anchored to said structure, which could then be used as a linker with the —OH groups belonging to the glucose molecules of cellulose, which is a constituent of cotton. The use of the molecule 3-glycidoxypropyltrimethoxysilane, or GPTMS, is therefore particularly suitable, as it can bind—through the methoxysilane end—to the nanofillers by condensation with the —OH group and release of MeOH, and in any case it has an epoxy group which is available, in the presence of a suitable catalyst, to open following nucleophilic coupling by the —OH groups of the cellulose or by a chromophore or other molecule present in the solution, to which it binds by an ester bridge.

[0083] In another aspect, the present invention also concerns a process for the preparation of the functionalized hybrid material comprising the following steps:

[0084] 1) providing sepiolite,

[0085] 2) adding the alkoxysilane cross-linking agent,

[0086] 3) adding water, an organic solvent, or a mixture thereof, and preferably adjusting the pH to neutral,

[0087] 4) leaving to react under stirring for at least 6 hours,

[0088] 5) separating the sepiolite thus functionalized, and

[0089] 6) desiccating, thus obtaining the functionalized hybrid material.

[0090] In preferred embodiments, the pH is adjusted by adding NaOH or KOH.

[0091] For the syntheses, various organic and halogenated solvents can be utilised. Suitable solvents include: acetaldehyde, acetic acid, acetylacetone, acetone, acetonitrile, acrylamide, acrylic acid, acrylonitrile, acrolein, iso-amyl alcohol, 2-aminoethanol, iso-amyl acetate, aniline, anisole, benzene, benzonitrile, benzyl alcohol, n-butanol, 1-butanol, 2-butanol, i-butanol, 2-butanone, t-butyl alcohol, iso-butyric acid, n-butyl acetate, iso-butyl acetate, di-n-butyl phthalate, chlorobenzene, carbon disulphide, carbon tetrachloride, chlorobenzene, chloroform, cyclohexane, cyclohexanol, cyclohexanone, p-cymene, n-decane, 1,1-dichloroethane, 1,2-dichloroethane, cis-1,2-dichloroethylene, o-dichlorobenzene, diethylene glycol, diglyme, dimethoxyethane, N, N-dimethylaniline, dimethylformamide (DMF), dimethyl phthalate, dimethyl sulphoxide (DMSO), dioxane, 1,4-dioxane, ethanol, ether, ethyl acetate, ethyl acetoacetate, ethyl acrylate, ethylbenzene, ethyl benzoate, diethyl ether, glycerin, n-heptane, 1-heptanol, n-hexane, 1-hexanol, 2-hexanone, hexamethylphosphoramide (HMPA), hexamethyl phosphoric triamide (HMPT), methanol, methacrylic acid, methyl acetate, methyl acrylate, methylcyclopentane, methyl cyclohexane, 2-methylcyclohexanone, methyl methacrylate, methyl t-butyl ether (MTBE), methyl t-methyl chloride, methyl t-methyl chloride, methyl t-butyl methyl, Nitrile acrylonitrile, n-nonane, 1-octanol, iso-octane, n-octane, pentane, 1-pentanol, 2-pentanol, 3-pentanol, 2-pentanone, 3-pentanone, 1-propanol, 2-propanol, n-propionic acid, iso-propyl acetate, n-propyl acetate, pyridine, styrene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,2,2-tetrachloroethane, trichlorethylene, tetrachlorethylene, tetrahydrofuran (THF), toluene, water, heavy water, p-xylene, m-xylene, o-xylene, or mixtures thereof.

[0092] Three different preparation approaches were preferably followed, in particular when that functionalization involves GPTMS and C16:

[0093] (i) in water with BF.sub.3O (C.sub.2H.sub.5) as a catalyst;

[0094] (ii) in ethanol using traces of acid (HCl) as a catalyst; or

[0095] (iii) with KOH in water, alcoholic solvents, organic solvents (toluene, THF), and halogenated solvents.

[0096] Various tests were performed before optimizing the reaction conditions, in terms of solvent, volume, catalyst concentration, nano-material and GPTMS, which allowed the best homogeneous sols and the lowest insoluble residue.

[0097] In the first aqueous or ethanolic solutions, the predetermined amounts of catalyst (BF.sub.3 or HCl) were added entirely at one time; this led to the formation of an insoluble residue within a few hours of the start of the reaction, thus decreasing the concentration of the sol.

[0098] In an attempt to avoid or limit the formation of insoluble material, the catalyst was then diluted; furthermore, it was added gradually in order to govern the reaction speed of the GPTMS on the nanofillers. In the case of the ethanolic solutions, it was decided to use a reflux temperature (T=70° C.) to activate the GPTMS siloxanes. In any case, the pH of the solution was brought back to a neutral value, at the end of the reaction, to stop said reaction. Finally, the solution was filtered with a Millipore filter to eliminate the insoluble component.

[0099] The following preparation processes are therefore particularly preferred:

[0100] a) Aqueous solution procedure: 200 mg sepiolite was dissolved in 200 ml aqueous solution, vigorous stirring was started, then 7 g 97% GPTMS was injected, and a 50 mL aqueous solution was prepared with 0.35 g BF.sub.3, which was added at a rate of 10 mL every 30 minutes. The total reaction time starting from the first addition of BF.sub.3 was approximately 24 hours, at the end of which the pH of the solution was checked and brought to above 5 with a small amount of 0.1M NaOH. The solution was then filtered with a Millipore filter to separate it from the undissolved part.

[0101] b) Ethanolic solution procedure: 200 mg sepiolite was dissolved in 200 mL ethanolic solution, under stirring at 70° C. in a continuous reflux setup. Immediately afterwards, 97% GPTMS and 2 mL 0.1 M HCl were added as a catalyst. The total reaction time starting from the addition of HCl was approximately 24 h, at the end of which the pH of the solution was checked and brought to above 5 with a small amount of 0.1M NaOH. The solution was then filtered with a Millipore filter to separate it from the undissolved part and then applied

[0102] c) Procedure with various solvents with GPTMS and C16: 3 g sepiolite was reacted with 3 mL GPTMS (or C16, or GPTMS+C16) with KOH (2 tablets, about 300 mg), in 50 mL alcoholic solvents, organic solvents (e.g. toluene, THF) or halogenated solvents, in a reflux setup overnight.

[0103] d) Procedure c) with various solvents: with or without KOH (2 tablets, approximately 300 mg), in 50 mL alcoholic solvents, organic solvents (e.g. toluene, THF) or halogenated solvents, in a reflux setup overnight.

[0104] Procedures a) and b) were intended to fix the sepiolite on the fabric.

[0105] Procedure c) was used to obtain the solid material which is subsequently used in microbiological tests.

[0106] Procedure d) was the procedure performed using various solvents.

[0107] Functionalization of Fabrics and Other Surfaces

[0108] The hybrid materials thus obtained, preferably in water and ethanol, containing functionalized sepiolite, were applied to both natural and synthetic fibre fabrics.

[0109] The fabrics were functionalized by impregnating the aforesaid hybrid materials with sols.

[0110] Preferably, after the impregnation step, the fabrics are dried and then washed, sometimes several times.

[0111] In preferred embodiments, said fabrics are made of cotton or polyester fibre.

[0112] In other preferred embodiments, following impregnation, the fabric is first wrung between two rollers to quickly remove most of the solvent, and then undergoes heat treatment in the oven, to complete the drying.

[0113] Functionalization of the fabrics takes place preferably through the coupling of the epoxide of the alkoxysilane cross-linking agent on the structure of the fabrics. In the case of cotton, the —OH groups of glucose, a constituent molecule of cellulose fibres, are coupled by the epoxide. This whole process takes place during the polymerization of the alkoxysilane cross-linking agent with immobilization of the nano-structures within the sepiolite.

[0114] A preferred synthetic fabric is polyethylene terephthalate (PET), which is a type of polyester which is advantageous due to: (i) its excellent physical and chemical properties; (ii) its hydrophobic nature; and (iii) its highly compact molecular structure. The rigidity of the fabrics created increases according to the number of layers of sol-gel applied. At first glance, fabrics of the same type (e.g. all cottons) do not appear to be very different from one another. They are rough to the touch, which indicates that the application has been performed, and remain so even after 5 washing cycles, after which only in a few cases is a slight softening is perceived; this suggests that a small amount of sol, after not reacting correctly with the fabric, is lost in the wash, as confirmed by subsequent weighing. They are more rigid than non-applied fabrics and have low sol losses after washing.

[0115] By also adding alkoxysilanes with a suitable functionality (for example SH, NH.sub.2), the hybrid materials according to the invention can also be utilized to entrap metal cations and heavy metals (the most common environmental pollutants include: Sn.sup.2+, Cd.sup.2+, Zn.sup.2+, Hg.sup.2+, Pt.sup.2+, Cu.sup.2+) dissolved in aqueous solution.

[0116] Furthermore, products were developed in alternative or to complement the functionalized fabrics, such as for example polymeric foams and sponges.

[0117] As will also be seen from the examples below, one of the most significant advantages of the material according to the present invention is the induction of bacterial degradation by hydrocarbonoclastic bacteria (i.e. HCB), with an 80% reduction in oil after approximately 2 weeks, and equal increase in bacterial counts (as in the presence of nutrients), in addition to the absorption and the buoyancy of the material on the surface of the water.

[0118] In a further aspect, therefore, the present invention relates to the use of this functionalized hybrid material as a substrate for absorbing and degrading hydrocarbon pollutants, by activating hydrocarbonoclastic bacteria, for environmental recovery and remediation.

[0119] In a still further aspect, the present invention regards a product for environmental remediation and recovery, comprising said functionalized hybrid material, said product being a fabric, a sponge or a polymeric foam.

[0120] In an additional aspect, the present invention regards a method for environmental remediation and recovery, through the use of the functionalized hybrid material and the product comprising the same.

[0121] It should be understood that all the possible combinations of the preferred aspects of the components of the hybrid material disclosed above are described herein and therefore are also preferred.

[0122] It should also be understood that all aspects identified as preferred and advantageous for the hybrid material should be deemed to be similarly preferable and advantageous also for the preparation and the uses of said hybrid material.

[0123] Below are working examples of the present invention provided for illustrative purposes.

EXAMPLES

Example 1

Materials and Methods

[0124] The microcosm systems were developed in sterilized 250 mL Erlenmeyer flasks. The microcosms were incubated at 22±1° C. for 7 days under stirring (100 rpm). All experiments were carried out twice.

[0125] In the first experiment (referred to as “SW”), natural seawater was used (which was not sterilized in all the experiments); in the second experiment (referred to as “SW+IN”), the microcosms were made in sterile natural seawater with added inorganic nutrients (10:1 vol/vol) to reach higher concentrations than those obtained in natural water (final concentrations: KH.sub.2PO.sub.4 0.077 g L.sup.−1, NH.sub.4Cl 0.2 g L.sup.−1 and NaNO.sub.3 0.1 g L.sup.−1).

[0126] As shown in Table 1, ten different combinations of experiments were developed. In particular:

[0127] i) the control (referred to as “K1”) made using seawater with the addition of crude oil (OIL);

[0128] ii) seawater, crude oil (OIL), and sepiolite (O+S);

[0129] iii) seawater+OIL+0.1 g sepiolite C16 (“O+S.C16.”);

[0130] iv) seawater+OIL+0.1 g sepiolite GPTMS (“O+S.G.”);

[0131] v) seawater+OIL+0.1 g sepiolite GPTMS C16 (“O+S.G.C16”);

[0132] vi) a second control (referred to as “K2”) made using seawater, with the addition of crude oil and ONR7a;

[0133] vii) seawater+ONR7a+OIL+0.1 g sepiolite (“M+O+S”);

[0134] viii) seawater+ONR7a+OIL+0.1 g sepiolite C16 (“M+O+S.C16);

[0135] ix) seawater+ONR7a+OIL+0.1 g sepiolite GPTMS (“M+O+S.G.”); and

[0136] x) seawater+ONR7a+OIL+0.1 g sepiolite GPTMS-C16 (“M+O+S.G.C16”).

[0137] Untreated microcosms (sterile seawater) were used in each series of experiments as a negative (abiotic) control.

[0138] At the beginning of the experiments (T0), 0.1% crude oil (Arabian Light Crude Oil; ENI Technology S.p.A.) was added to the SW and SW+IN microcosms. The crude oil was added to the microcosm systems after physical treatments (100 rpm, 25° C. for 48 h); the crude oil was added with 0.1% (v/v) squalene (C.sub.30H.sub.50, Sigma-Aldrich, Milan) as an internal reference for measuring the rate of bio-degradation.

TABLE-US-00002 TABLE 1 Set-up of the experiments developed during the study. Key: *M, ONR7a; O, Crude oil; S, Sepiolite; S..sub.C16, Sepiolite with C.sub.16;S..sub.G., Sepiolite with GPTMS; S..sub.G.C16, Sepiolite with GPTMS-C.sub.16. SEP- SEP- Experiment SW ONR7a Oil SEP. SEP..sub.c16 GPTMS GPTMS-C16 Code* 1 X X K1 2 X X X O ← S 3 X X X O ← S..sub.C16 4 X X X O ← S..sub.O 5 X X X O ← S..sub.O.C.16 6 X X X K2 7 X X X X M + O ← S 8 X X X X M + O ← S..sub.C16 9 X X X X M + O ← S..sub.O. 10 X X X X M + O ← S..sub.O.C.16

[0139] Sampling strategy and parameters analyzed. Subsamples of each bacterial culture were collected aseptically at the beginning (T.sub.0) and at the end (T.sub.7) of the experimental period. Direct bacterial count measurements (DAPI) and oil degradation measurements (GC-FID analysis) were carried out. All the experiments were conducted twice and all the parameters were measured three times.

[0140] Total bacterial abundance (DAPI count). DAPI staining (4,6-diamidino-2-phenylindole 2HCl, Sigma-Aldrich, Milan, Italy) on formaldehyde-fixed specimens (2% final concentration), according to Porter and Feig (1980). The slides were examined by epifluorescence microscopy with an Axioplan 2 Imaging microscope (Zeiss) (Carl Zeiss, Thornwood, N.Y., USA) as stated in Cappello et al., (2007). The results were expressed as number of cells ml.sup.−1.

[0141] Hydrocarbon analysis. The composition of the total extracted and resolved hydrocarbons (TERHCs) and the derivatives thereof were analyzed using a high resolution GC-FID (DANI Master GC Fast Gas Chromatograph System, DANI Instruments S.p.A., Milan). After seven days, the TERHCs of different samples were extracted using dichloromethane (CH.sub.2Cl.sub.2, Sigma-Aldrich, Milan; 10% v/v). This procedure was repeated three times, and the CH.sub.2Cl.sub.2 phase was treated with anhydrous sodium sulphate (Na.sub.2SO.sub.4, Sigma-Aldrich, Milan) to remove water residues (Ehrhardt et al., 1991; Wang et al., 1998; Dutta and Harayama 2001; Denaro et al., 2005). The extracts were concentrated to 1 ml by rotavapor (Rotavapor model R110; BiichiLabortechnik AG, Switzerland) at room temperature (<30° C.). All measurements were performed using a DANI Master GC instrument (Development Analytical Instruments), equipped with an SSL injector and FID. Samples (1 μl) were injected in splitless mode at 330° C. The analytical column was a Restek Rxi-5 Sil MS with Integra-Guard, 30 m×0.25 mm (ID×0.25 lm film thickness). The carrier gas, helium, was maintained at a constant flow of 1.5 ml min.sup.−1. The total hydrocarbons were also calculated for each sample (Genovese et al., 2014). The ratios selected for this study were: n-C17/Pristane (nC17/Pr), n-C18/Phytane (nC18/Ph) to assess the relative biodegradation of n-alkanes.

[0142] TERHC biodegradation efficiency (BE). TERHC degradation was expressed as the percentage of degraded TERHCs in relation to the amount of the remaining fractions in the appropriate control samples. The biodegradation efficiency (BE), based on the decrease in the total hydrocarbon concentration, was calculated using the expression described by Michaud et al., 2004: 100−(As*100/Aac) where As=total area of the peaks in each sample, Aac=total area of the peaks in the appropriate abiotic control, and BE (%)=Biodegradation Efficiency.

Chemical Functionalization of Sepiolite

[0143] Different preparations were used for sepiolite sol-gels, as stated below:

[0144] (a) Aqueous solution procedure: 200 mg sepiolite was dissolved in 200 ml aqueous solution, vigorous stirring was started, then 7 g 97% GPTMS was injected, and a 50 mL aqueous solution was prepared with 0.35 g BF.sub.3, which was added at a rate of 10 mL every 30 minutes. The total reaction time starting from the first addition of BF.sub.3 was approximately 24 h, at the end of which the pH of the solution was checked and brought to above 5 with a small amount of 0.1M NaOH. The solution was then filtered with a Millipore filter to separate it from the undissolved part.

[0145] (b) Ethanolic solution procedure: 200 mg sepiolite was dissolved in 200 mL ethanolic solution, under stirring at 70° C. in a continuous reflux setup. Immediately afterwards, 7 g 97% GPTMS and 2 mL 0.1 M HCl were added as a catalyst. The total reaction time starting from the addition of HC1 was approximately 24 h, at the end of which the pH of the solution was checked and brought to above 5 with a small amount of 0.1M NaOH. The solution was then filtered with a Millipore filter to separate it from the undissolved part and applied.

[0146] c) Procedure with various solvents: with KOH (2 tablets), in 50 mL of alcoholic solvents, organic solvents (toluene, THF) or halogenated solvents, in reflux set-up overnight.

[0147] d) Procedure with various solvents with GPTMS and C16: 3 g sepiolite was reacted with 3 mL GPTMS (or C16) with KOH (2 tablets), in 50 mL alcoholic solvents, organic solvents (toluene, THF) or halogenated solvents, in a reflux set-up overnight.

Functionalization of Fabrics and Other Surfaces

[0148] The hybrid sols thus obtained in water and ethanol containing GPTMS/C16 and the appropriate nanofillers (sepiolite) were applied to cotton (C) and polyester (PE) cloths. After the preparation of the sols, the next step was the impregnation on fabric. The cotton (C) and polyester (PE) cloths (20×30 cm.sup.2) were impregnated with the hybrid sol and then passed through a two-roller laboratory applicator (Werner Mathis, Zurich, Switzerland), operating at a pressure of 3 bar in order to obtain up to 70% water removal. After drying at 80° C. for 5 min, the fabrics were heat treated at 170° C. (C) and 215° C. (PE) for 4 min in a convection stove. At the end, the fabrics were washed repeatedly (1 wt % detergent, 1 and 5 wash cycles) to test the washing resistance of the fabric coating and to remove excess dye, if present, and then dried and stored in standard conditions in an environmental chamber. For comparison purposes, the corresponding fabrics were prepared by applying the sol without dye. All samples were characterized by UV-Vis reflectance measurements and by FT-IR spectroscopy. The weight of each fabric before and after impregnation was recorded, to assess the difference in weight in grams and as a percentage (Add-on). The fabrics were tested with an anti-flame test that revealed a reasonable resistance to burning.

[0149] Functionalization of the fabrics takes place through the coupling of the epoxide of the GPTMS nanofiller on the structure of the fabrics. In the case of cotton, the —OH groups of glucose, a constituent molecule of cellulose fibres, are coupled by the epoxide of the GPTMS. This whole process takes place during the polymerization of the GPTMS with immobilization of the nano-structures inside.

[0150] As a synthetic fabric, polyethylene terephthalate (PET) was used.

TABLE-US-00003 TABLE 2 Table summarizing the experimental conditions (weight, solvent, volumes) of certain syntheses of sols containing the appropriate nanofillers (NF). GPTMS: Sample.sup.a NF/g V.sub.Tot/mL GPTMS/g Catalyst.sup.a NF ratio 1SA 1.013 100 7 0.35  7:1 2SA 0.200 100 7 0.35 35:1 3SA 0.200 200 7 0.35 35:1 4SA 0.208 200 7 0.21 34:1 5SA 0.106 100 7 0 66:1 ISEt 1.014 100 7 2  7:1 2SEt 0.200 100 7 2 35:1 3SEt 0.201 200 7 2 35:1 .sup.aA = Reaction in water at room temperature with BF3 as catalyst (in g); Et = Reaction in Ethanol at 70° C. with HCl as catalyst (in mL); S = Sepiolite; with KOH as catalyst.

TABLE-US-00004 TABLE 3 Table summarizing the treated fabrics (weight, solution, loss after washing) after deposition of the Sepiolite sol-gels (S). Sol-Gel Loss Loss fabric Add-on (g) Add-on (%) wash 1 (%) wash 5 (%) t1T2c-ISA 0.7437 4.54 0.45 0.28 t2T3c-2SA 0.6102 5.30 3.09 2.69 t2T3pe-2SA 0.5103 4.92 0.58 0.48 t3T1c-4SA 0.3361 2.05 2.21 1.32 t3T1pe-4SA 0.1032 1.51 0.05 0.03 t1T4c-1SEt 1.1926 7.11 1.98 1.48 t2T4c-2SEt 0.6628 5.64 4.88 3.39 t2T4pe-2SEt 0.3819 3.98 2.56 2.71 t3T2c-3SEt 0.4214 2.68 2.59 2.58 t3T2pe-3SEt 0.0886 1.27 0.05 0.12 A = Reaction in water at room temperature with BF3 as catalyst (in g); Et = Reaction in Ethanol at 70° C. with HCl as catalyst (in mL); S = Sepiolite; C = Cotton; PE = Polyester

[0151] Sepiolite sol was applied to the following fabrics: Cotton, 4SA; Polyester, 4SA; Cotton, 3Set; Polyester, 3Set.

TABLE-US-00005 TABLE 4 Table showing the results of the flame-retardant tests on Cotton (C) samples with Sepiolite sol applied..sup.a Unwashed Flame Flame Unwashed flame Flame residue, Flame residue, Original Sol-Gel flame residue residue, wash 1 residue, wash 5 add-on fabric residue (g) (%) wash 1 (g) (%) wash 5 (g) (%) (%) t1T2c-1SA 0.0241 4.89 0.0145 3.30 0.0149 3.11 4.54 t1T4c-1SEt 0.0179 4.08 0.0147 3.22 0.0129 2.85 7.11 .sup.aA = Reaction in water at room temperature with BF.sup.3 as catalyst (in g); Et = Reaction in Ethanol at 70° C. with HCl as catalyst (in mL); S = Sepiolite; C = Cotton; PE = Polyester.

Structural Analysis by SEM/EDX Microscopy

[0152] SEM images and SEM-EDX mapping of treated and unanalyzed cotton samples were obtained with an SEM FEI Quanta FEG 450 microscope. The treated and then washed cotton samples, compared to untreated cotton (shown in FIG. 1), show the presence of GPTMS, as is clear in FIG. 2 The fibres appear to be glued together by the salicaceous matrix, while in the sample of untreated cotton, the fibres are well separated.

[0153] The EDX analysis in FIG. 3 shows the presence of the aforesaid matrix in the treated samples only. The other peaks refer to C (present in the graphitic adhesive and in the fabric), to oxygen (also present in the high-vacuum steam atmosphere), and aluminium from the SEM support. This shows that following treatment with GPTMS-based sols, there was a change in the fibres on a micrometric scale.

Characterization by IR spectrophotometry

[0154] FIG. 4 shows the comparison between the IR spectra of Sepiolite and of the Sepiolite functionalized through various procedures.

[0155] Stretching at 2917 cm.sup.−1, 2850 cm.sup.−1, 1468 cm.sup.−1, relating to the —CH.sub.3 and —CH.sub.2— groups confirm the functionalization of the sepiolite. —OH stretching can be seen at 1657 cm-.sup.1. At 1205 cm-.sup.1 are the lattice vibrations, in accordance with the high Si/Mg ratio of the reagent solution.

Results

[0156] FIGS. 5 and 6 show the bacterial abundance (DAPI count) of the microbial population developed during the experimentation carried out with, respectively, said natural seawater (SW) and ONR7 inorganic nutrients.

[0157] In FIG. 5, a high bacterial abundance can be noted for the O+S.sub.C16 samples, which contain seawater, oil, and C.sub.16, with a cell count of approximately 1.12×10.sup.8cell mL.sup.−1. Good bacterial growth was also shown by the Sepiolite GPTMS and GPTMS C.sub.16 samples.

[0158] FIG. 7 shows the percentage of oil obtained from the GC-FID analysis after an experimental period of seven days.

[0159] The lowest percentage refers to the O+S.sub.C16 sample (approximately 21%), while the slightly higher values refer to O+S, O+S.sub.G and O+S.sub.GC16 (22%, 28%, and 26%, respectively).

[0160] In FIG. 8, ONR7a inorganic nutrients were added to the samples.

[0161] The lowest percentage of residual oil was found in the M+O+S and M+O+S.sub.G samples (approximately 7% and 8%, respectively), while the highest values were found in the M+O+S.sub.C16 and M+O+S.sub.GC16 samples (approximately 19% and 10%, respectively).

[0162] FIG. 9 shows, visually, the oil absorption by the various samples analyzed. Visually, the O+S.sub.C16 sample gives the best results as regards oil absorption (the absorption for spent and non-spent oils was also tested) and material buoyancy. The sample O+S.sub.GC16 also shows a remarkable absorption, but the floating material is not agglomerated, but rather distributed over the surface of the water.