METHOD FOR PREPARING A SOLID OZONE STORAGE MATERIAL BASED ON CARBOHYDRATES, SAID MATERIAL AND ITS USES

Abstract

The present invention relates to a method and installation for preparing a solid ozone storage material, the method comprising contacting carbohydrates and / or carbohydrate derivatives in solid form with a gas containing ozone, thereby obtaining a solid ozone storage material. The present invention also relates to the material thus prepared and its uses.

Description

Title of the invention: PROCESS FOR PREPARING A SOLID OZONE STORAGE MATERIAL BASED ON CARBOHYDRATES, SAID MATERIAL AND ITS USES Technical field

[0001] The present invention relates to the general technical field of ozone storage.

[0002] More particularly, the present invention provides a method and an installation for preparing a material in solid form and, therefore, easily handled, in which ozone is stored.

[0003] The present invention also relates to this ozone storage material, which makes it possible to increase the stability of ozone and therefore its lifespan, as well as the use of this material with oxidizing power in all applications aimed at taking advantage of the properties of ozone. State of the prior art

[0004] Due to its strong oxidizing power, ozone is currently used for many applications, such as, for example, disinfection and water treatment. The use of ozone is also being closely examined for potential applications such as plant treatment.

[0005] However, and even if some commercial sites display this treatment possibility, the application of ozone-enriched water in an open environment is not very relevant. Indeed, the water droplet will lose its ozone concentration very quickly through desorption and the ozone will therefore not be able to reach its target (the leaf if a plant is being treated).

[0006] Furthermore, ozone is a gas under ambient conditions which cannot be stored due to its instability. Thus, today this molecule must be produced as needed by an ozonator, a device also called an "ozone generator", which produces an electrical discharge in a flow of gas charged with oxygen (air, air enriched with dioxygen (O2) or pure O2) and which makes it possible to create the ozone molecule (O3). Ozone can also be produced by other processes involving a plasma or UV light, particularly at the wavelength of 185 nm. This ozone molecule has a limited lifespan, of the order of twenty minutes in water under ambient conditions. It cannot be stored, for example, in a bottle in its pure state or as a mixture.It should be noted that the risks of explosion are high when the mixture considered is a mixture of oxygen and ozone in which the ozone concentration is greater than 10-13% mol at atmospheric pressure and / or when this mixture is compressed to a pressure of the order of several tens of bars. The lifetime of ozone can be extended. for example by significantly lowering the temperature (liquid nitrogen for example), but there is currently no system that can sustainably store a large quantity of ozone.

[0007] This storage limitation poses problems for easily using this gas because an ozonator is required on site and, if this is the case, the gas produced must be used very quickly. In addition, depending on the intended applications, the need to have an ozonator on site may be considered too expensive, too bulky or too technical.

[0008] The very short lifespan of ozone is linked to the fact that the ozone molecule is unstable: when two ozone molecules meet, they can decompose into three molecules of dioxygen according to the reaction 2 O3 -> 3 O2. This decomposition is favored by an increase in temperature and / or the presence of catalyst elements such as certain solid materials, certain molecules or certain humidity conditions. Thus, the half-life of ozone in air is theoretically 3 days but, as this gas reacts with almost all surrounding materials, it is in practice a few seconds. It is therefore very difficult to limit the decomposition reaction of ozone, except at very low temperatures which favor a reduced movement of the molecules. Furthermore, the pressurization of ozone leads to an increase in its instability (bringing the molecules closer together) and therefore to a reduction in its lifespan.

[0009] Several strategies have already been proposed to solve the technical problem of ozone storage.

[0010] Research conducted in the 1960s proposed a theoretical way of storing liquid ozone, by stabilizing it with fluorine, chlorine trifluoride and nitric acid, but this research did not lead to any follow-up, probably due to the danger of these products. The storage of liquid O2 / O3 mixture under high pressure was also considered and tested but never commercialized because it was extremely dangerous. Indeed, there are risks of explosion if the percentage of liquid ozone is too high and / or if the oxygen evaporates and creates an explosive atmosphere. In addition, the risks of thermal decomposition of ozone added to the risks of decomposition in contact with solids or molecules led the research teams involved to abandon these themes.

[0011] For some time, Air Liquide marketed a safer storage of liquid ozone in cryogenic liquid (Freon). But the difficulty in separating the two gases and the problems of ozone decomposition definitively put an end to the marketing of this product.

[0012] Ozone storage in a gas hydrate has also been proposed. This concept was first shown in 1964 by McTurk and Waller who succeeded in form a mixed hydrate tetrachloromethane (CC14) + O3, by saturating a solution of CC14 with ozone at -2°C. However, CC14 is an extremely toxic product that is not considered in many applications using ozone as an oxidant or disinfectant [1]. Mixed hydrates containing ozone formed by bringing an O2 / O3 mixture into contact with an auxiliary gas ("help gas") were studied mainly by a Japanese team (Ohmura and Mori) between 2010 and 2014. Among the works published by this team, we can cite Nakagima et al, 2012 which studies the phase equilibrium and the composition of the mixed hydrate O2 / O3 + CO2[2]. It has been shown in this work that an O2 / O3 mixture containing 10-12 mol% O3 mixed with CO2 in a molar ratio of 1 / 7 formed at a pressure of 19 bar and a temperature of 0.1°C is stable in aerated conditions (tube open to the air) for more than 20 days at -25°C and can store an amount of ozone of 0.1% by mass.

[0013] At present, ozonated water and ozonated ice can be used. Thus, patent application JP 2007 / 210881 in the name of Kurita Water Ind. Ltd., published on August 23, 2007 [3] proposes a method for preparing ozonated ice. However, the ozone concentration in ozonated water and ozonated ice remains very low with a fairly short lifetime.

[0014] In order to increase the lifetime of ozone in ozonated water and to obtain prolonged reactivity, it has been proposed to trap, in the aqueous phase, ozone in a cyclodextrin of the hydroxypropyl-[3-cyclodextrin type [4]. Similarly, patent application US 2018 / 0178263 in the name of OXYTEC LLC, published on June 28, 2018 [5] proposes a method for reducing contamination in water or soil, consisting of injecting an aqueous solution of an ozone clathrate using a cyclic oligosaccharide such as a cyclodextrin. In these documents, the cyclodextrin is always dissolved in water and then ozone in gaseous form is injected into this solution.

[0015] International application WO 2013 / 126047 in the name of Empire Technology Development LLC, published on August 29, 2013, proposes a material for food packaging comprising voids in which there is a food preservation gas which may be ozone [6]. This material may be in the form of a gelled foam or a film-forming polymer, both of which may contain a polysaccharide. During the preparation of this material and in particular during contact with the preservation gas, the elements constituting the gelled foam or the film-forming polymer are in liquid form.

[0016] In a separate aspect of ozone storage, the patent application US 2016 / 0367967 on behalf of Temple University of the Commonwealth System of Higher Education, published on December 22, 2016 [7] relates to systems and methods for regenerating an adsorbent of the [3-cyclodextrin] type after its use in a water decontamination process. The regeneration process is based on the treatment of [3-cyclodextrin with ozone gas used to destroy contaminants trapped in the cavity of [3-cyclodextrin. The used [3-cyclodextrin adsorbent can be regenerated and reused for many treatment cycles thanks to this ozonation process, in liquid phase.

[0017] The inventors set themselves the goal of developing a material that is easy to prepare, easy to use and capable of storing ozone in large quantities and in a lasting manner so as to remove a certain number of obstacles to the practical use of this gas. Description of the invention

[0018] The present invention makes it possible to achieve the goal set by the inventors and to solve all or part of the problems of the ozone storage methods and materials of the state of the art.

[0019] Indeed, the inventors have developed a process for producing an ozone storage material in solid form and therefore easy to handle and use. The preparation process according to the invention makes it possible to obtain a powder which can be used as is by dusting, in the form of a gel by deposition or in the form of a solution, dispersion, emulsion or suspension by deposition or by spraying, or even in a more compacted form, in particular to make pellets.

[0020] Furthermore, the solid storage material prepared in accordance with the method according to the invention makes it possible to store ozone sustainably since the non-optimized tests carried out by the inventors have shown that ozone can be stored therein for several days at room temperature, which corresponds to a significant improvement with regard to the half-life of ozone, at room temperature, which is of the order of twenty minutes in ozonated water. It is therefore not only an ozone storage material but also an ozone stabilizing material. This material also offers a large potential ozone storage capacity. Some of the materials described in the experimental part below have a storage capacity 400 times greater, in particular 800 times greater and even 950 times greater than that of ozonated water.

[0021] The fact that the solid storage material prepared in accordance with the method according to the invention is easy to handle while ensuring long-term stabilization of the ozone makes it possible to separate the place of production from the place of use or even to envisage a storage place separate from the place of production and the place of use. The ozone storage material according to the invention therefore also constitutes a material for transporting ozone, and this in complete safety.

[0022] All these advantages are obtained by implementing a simple process, easily industrializable, not requiring risky operating conditions and using easily accessible and relatively cheap carbohydrate-type raw materials. Indeed, carbohydrates, already widely used in particular in cosmetic and pharmaceutical formulations, constitute natural, non-hazardous, eco-compatible products that degrade in the natural environment. Carbohydrates correspond to a family of compounds likely to have different properties, particularly in terms of solubility, hydrophilicity, hydrophobicity, complexing properties, and the ability to form gels, which makes it possible to envisage the preparation of a modular and versatile solid ozone storage material, suitable for targeted uses.

[0023] More particularly, the present invention relates to a process for preparing a solid ozone storage material comprising contacting carbohydrates and / or carbohydrate derivatives in solid form with a gas comprising ozone, provided that, when said carbohydrates and / or carbohydrate derivatives comprise cyclodextrins or cyclodextrin derivatives, the latter are mixed with at least one other carbohydrate other than a cyclodextrin or a cyclodextrin derivative and provided that said contacting is carried out in the absence of any liquid, whereby a solid ozone storage material is obtained.

[0024] By "carbohydrate" is meant an organic compound with at least three carbon atoms comprising a carbonyl function (aldehyde or ketone) or equivalent function and at least two hydroxyl radicals (-OH). By "function equivalent to a carbonyl function" is meant an acetal or hemiacetal function.

[0025] Among the carbohydrates that can be used in the context of the present invention, mention may be made of oses also known under the name of “simple carbohydrates” or "monosaccharides" and osides also known as "complex carbohydrates" corresponding to polymers of oses linked by alpha or beta glycosidic bonds and among which we find oligosaccharides and polysaccharides.

[0026] By "carbohydrate derivative" is meant a monosaccharide derivative, an oligosaccharide derivative or a polysaccharide derivative.

[0027] By "monosaccharide" is meant a ose comprising from 3 to 9 carbon atoms, this ose possibly being of L or D configuration. In particular, the monosaccharides which can be used in the context of the present invention are in particular oses with 3 carbon atoms (or trioses) such as glyceraldehyde and dihydroxyacetone; oses with 4 carbon atoms (or tetroses) such as erythrose, threose and erythrulose; oses with 5 carbon atoms (or (deoxy)pentoses) such as deoxyribose, ribose, arabinose, xylose, lyxose, ribulose and xylulose; oses with 6 carbon atoms (or (deoxy)hexoses) such as allose, altrose, galactose, glucose, dextrose, gulose, idose, mannose, talose, fructose, psicose, sorbose, tagatose, fucose and rhamnose; 7-carbon monosaccharides (or heptoses) such as sedoheptulose and mannoheptulose; 8-carbon monosaccharides (or octoses) such as heptahydroxyoctanal and 9-carbon monosaccharides (or nonoses) such as neuraminic acid or sialic acid. More particularly, the monosaccharides which can be used in the context of the present invention are chosen from the group consisting of deoxyribose, ribose, arabinose, xylose, ribulose, galactose, glucose, dextrose, mannose, fructose, fucose and rhamnose.

[0028] By "monosaccharide derivative" or "ose derivative" is meant a ose as previously defined in which at least one hydrogen atom and / or at least one hydroxyl radical and / or the carbonyl function of a ose as previously defined is substituted by an atom or a chemical group such as a halogen atom, an alkyl group, a hydroxyalkyl group, a thioalkyl group, a sulfhydryl group, an acetyl group, a silyl group, an acyl group, a sulfonyl group, an amine group, a sulfoalkylether group, a sulfate group, a phosphate group, a carboxyl group, a carboxylester group, a quaternary ammonium group, a glucosyl group, a maltosyl group, a chlorotriazinyl group or a quaternary ammonium group.As particular examples of monosaccharide derivatives which can be used in the context of the present invention, mention may be made of gluconic acid, glucuronic acid, mannuronic acid, guluronic acid, galacturonic acid, iduronic acid, ascorbic acid (or oxo-3-gulofuranolactone acid), glucosamine, N-acetylglucosamine, N-acetylmannuronic acid, sucralose, erythritol, xylitol, arabitol (or lyxitol), ribitol (or adonitol), sorbitol (or gulitol), dulcitol (or galactitol), mannitol and volemitol.

[0029] By "oligosaccharide" is meant a polymer of oses and / or ose derivatives, identical or different, each comprising from 3 to 9 carbon atoms and in particular from 5 to 9 carbon atoms in which the number of oses is determined and greater than or equal to two. Among the oligosaccharides which can be used in the context of the present invention, mention may be made of disaccharides (or diholosides), trisaccharides (or tri-holosides), tetrasaccharides (or tetraholosides), and oligosaccharides with 5 or more oses.

[0030] By "disaccharide" is meant a compound formed by two identical or different oses, two identical or different ose derivatives, or one ose and one ose derivative, each comprising from 3 to 9 carbon atoms and in particular from 5 to 9 carbon atoms. Among the disaccharides which can be used in the context of the present invention, mention may be made of reducing disaccharides such as lactose, maltose, cellobiose and isomaltose and non-reducing disaccharides such as sucrose and trehalose. More particularly, the disaccharides which can be used in the context of the present invention are chosen from reducing disaccharides and in particular from the group consisting of lactose, maltose, cellobiose and isomaltose.

[0031] By "trisaccharide" is meant a compound formed by three identical or different oses, three identical or different ose derivatives, two identical or different oses, and one ose derivative or one ose and two identical or different ose derivatives, each comprising from 3 to 9 carbon atoms and in particular from 5 to 9 carbon atoms. Among the trisaccharides which can be used in the context of the present invention, mention may be made of acarbose, erlose (or glucosylsucrose), fucosyllactose, lactosucrose, isokestose, isomaltotriose, inulotriose, [3-glucotriose, kestose, maltotriose, nigerotriose, panose, raffinose, rhamninose, raffinose, theanderose, melezitose and gentianose.

[0032] By "tetrasaccharide" is meant a compound formed by four oses, identical or different, four ose derivatives, identical or different, one ose and three ose derivatives, identical or different, two oses, identical or different, and two ose derivatives, identical or different, or three oses, identical or different, and one ose derivative, each comprising from 3 to 9 carbon atoms and in particular from 5 to 9 carbon atoms. Among the tetrasaccharides that can be used in the context of the present invention, mention may be made of lychnose (or 1-a-galactosyl-raffinose), maltotetraose, nigerotetraose, nystose, sesamose and stachyose.

[0033] By "oligosaccharide with 5 or more oses" is meant a polymer of oses and / or ose derivatives, identical or different, each comprising from 3 to 9 carbon atoms and in particular from 5 to 9 carbon atoms in which the total number of oses and ose derivatives is determined and greater than or equal to five. Such an oligosaccharide may be linear, branched or cyclic. A particular example of oligosaccharides with 5 or more oses is a cyclodextrin.

[0034] It should be noted that, in the context of the present invention, if the carbohydrates used are cyclodextrins and / or cyclodextrin derivatives, the latter must be used in a mixture with at least one other carbohydrate other than a cyclodextrin or one of its derivatives.

[0035] Alternatively, however, the carbohydrates used may be cyclodextrins and / or cyclodextrin derivatives without mixing with any other carbohydrate or carbohydrate derivative. In this case, the carbohydrates and / or carbohydrate derivatives used in the present invention may be any of the carbohydrates and / or carbohydrate derivatives or mixture of carbohydrates and / or carbohydrate derivatives as described herein.

[0036] By "cyclodextrin" is meant a cyclic oligosaccharide of formula (C6Hio05)n composed of n glucopyranose subunits of formula C6Hi0O5 linked in a-(1,4) with n representing an integer. The terms "cyclodextrin", "cycloamylose", "cycloglucan", "cyclomaltooside" and "Schardinger dextrin" are equivalent and can be used interchangeably.

[0037] The cyclodextrins used in a mixture with another carbohydrate in the context of the invention have an annular structure, forming a cage in the shape of a truncated cone delimiting a cavity whose size is dependent on the number n of glucopyranose subunits and which can stabilize other molecules, where n is advantageously between 6 and 35.

[0038] As particular examples of cyclodextrins which can be used in a mixture with another carbohydrate in the context of the present invention, mention may be made of cyclomaltohexaoses, cyclohexaamylose, α-cycloamylases or α-cyclodextrins (α-CD) in which n represents 6, cyclomaltoheptaoses or β-cyclodextrins (β-CD) in which n represents 7 and cyclomaltooctaoses or γ-cyclodextrins (γ-CD) in which n represents 8, cyclomaltononaoses in which n is equal to 9, cyclomaltohenei-cosaoses in which n is equal to 21, cyclomaltodoicosaoses in which n is equal to 22 and cyclomaltohentricontaoses in which n is equal to 31.

[0039] By "cyclodextrin derivative" is meant a cyclodextrin as previously defined, chemically modified, crosslinked, immobilized and / or organized in a molecular superstructure. Whatever the variant envisaged, a cyclodextrin derivative used in a mixture with another carbohydrate in the invention always has a cavity capable of stabilizing other molecules.

[0040] A chemically modified cyclodextrin derivative is obtained by substituting at least one hydrogen atom and / or at least one hydroxyl radical of a cyclodextrin as previously defined by an atom or a chemical group such as a halogen atom, an alkyl group, a hydroxyalkyl group, a thioalkyl group, a sulfhydryl group, an acetyl group, a silyl group, an acyl group, a sulfonyl group, an amine group, a sulfoalkylether group, a sulfate group, a phosphate group, a carboxyl group, a carboxylester group, a quaternary ammonium group, a glucosyl group, a maltosyl group, a chlorotriazinyl group or a quaternary ammonium group. Depending on the chemical nature of the substituent group(s) used, the cyclodextrin derivative can be ionic or amphiphilic.

[0041] As illustrative and non-limiting examples of chemically modified cyclodextrin derivatives, mention may be made of a randomly methylated α-CD, β-CD or γ-CD; a methyl-α-CD; a methyl-β-CD; a methyl-γ-CD; heptakis(2,3,6-tri-O-methyl)-β-CD; a weakly methylated α-CD, β-CD or γ-CD; methylated in position 2 (2-O-methylated); a dimethylated a-CD, [3-CD or y-CD; a permethylated a-CD, [3-CD or y-CD; a perpentylated a-CD, [3-CD or y-CD; an acetylated a-CD, [3-CD or y-CD; a peracetylated a-CD, [3-CD or y-CD; a hydroxypropylated a-CD, [3-CD or y-CD; a hydroxyethylated a-CD, [3-CD or y-CD; a sulfated a-CD, [3-CD or y-CD; a phosphated a-CD, [3-CD or y-CD; a carboxymethylated a-CD, [3-CD or y-CD; a carboxymethylethereal a-CD, [3-CD or y-CD; a 3-trimethylammonium-2-hydroxypropyl-ether-a-CD; a 3-trimethylammonium-2-hydroxypropyl-ether-[3-CD; a 3-trimethylammonium-2-hydroxypropyl-ether-y-CD; mono-(6-mercapto-6-deoxy)-[3-CD; mono-(6-amino-6-deoxy)-[3-CD; heptakis(6-amino-6-deoxy)-[3-CD; mono-(6-(diethylenetriamine)-6-deoxy)-[3-CD; hexakis-(6-iodo-6-deoxy)-a-CD; a sulfobutylether-a-CD; a sulfobutylether-[3-CD; a sulfobutylether-y-CD;3-trimethylammonium-2-hydroxylpropylether-a-CD; 3-trimethylammonium-2-hydroxylpropylether-[3-CD; 3-trimethylammonium-2-hydroxylpropylether-y-CD; glucosyl-a-CD; glucosyl-[3-CD; glucosyl-y-CD; maltosyl-a-CD; maltosyl-[3-CD; maltosyl-y-CD; chlorotriazinyl-a-CD; chlorotriazinyl-[3-CD; and chlorotriazinyl-y-CD. ;

[0042] A crosslinked cyclodextrin derivative is typically obtained by forming bonds between cyclodextrins or chemically modified cyclodextrins as previously defined using a crosslinking agent such as epichlorohydrin, 1,4-butanedioldiglycidyl ether, 1,2-epoxypropane, 1,3-diglycidylglycerol, 1,4-phenyldiisocyanate, 2,4-toluene diisocyanate, glutaraldehyde or citric acid. A crosslinked cyclodextrin derivative is in the form of a soluble or insoluble polymer such as crosslinked gels or hydrogels. Thus, cyclodextrin polymers are examples of crosslinked cyclodextrin derivatives. This type of derivative can be prepared in two steps with, first, crosslinking of the CD molecules by epichlorohydrin in the presence of another cationic crosslinking agent and then carboxymethylation of the surface crosslinked particles.As a particular example, we can cite an amphoteric gel of cyclodextrins crosslinked by epichlorohydrin in the presence of 3-chloride-2-hydroxypropyl trimethylammonium, and carboxymethylated [8].

[0043] A derivative of the immobilized cyclodextrin type corresponds to cyclodextrins or chemically modified cyclodextrins as previously defined, grafted onto polymers such as polyalkylamines, polyethylene imines, polyal-lylamines or polyacrylates; onto membranes such as supported liquid membranes or dense membranes; onto textiles; onto inorganic beads such as silica or activated carbon beads; or on organic resins.

[0044] As illustrative and non-limiting examples of derivatives of the immobilized cyclodextrin type, mention may be made of poly(vinyl acetate)-[3-CD] membranes crosslinked with diepoxide, mixed polysiloxane-[3-CD] membranes on ceramic membrane, poly(vinyl acetate)-a-CD membranes crosslinked with hexamethylene dii-socyanate, [3-CD] fixed on polyacrilonitrile or polyester fibers, CDs grafted onto chitosan, monochlorotriazinyl-[3-CD] fixed on cotton, cotton / polyurethane or cotton / polyamide fibers and wool, cellulose or poly(ethylene terephthalate) fibers treated with the [3-CD] / 1,2,3,4-butanetetracarboxylic acid system.

[0045] As examples of derivatives of the cyclodextrin type organized in a molecular superstructure, mention may be made of polyrotaxanes, polypseudorotaxanes consisting of a poly(ethylene glycol) chain constituting the stator complexed by several cyclodextrins constituting the mobile part or rotor and the molecular tubes.

[0046] The carbohydrates used in the context of the present invention may also be polysaccharides.

[0047] By "polysaccharide" is meant a polymer of oses, identical or different, and / or of ose derivatives, identical or different, each comprising from 3 to 9 carbon atoms and in particular from 5 to 9 carbon atoms in which the number of oses and / or of ose derivatives is undetermined and typically greater than 10 and in particular greater than 20.

[0048] Among the polysaccharides that can be used in the context of the present invention, a distinction is made between polysaccharides consisting of the same ose or the same ose derivative, i.e. polymers of identical oses or derivatives of identical oses, also designated under the names "homopolysaccharides" or "homoglycans", and polysaccharides formed from oses and derivatives of oses, from different oses and / or from different derivatives of oses, i.e. polymers of oses and derivatives of oses, from different oses and / or from different derivatives of oses, also designated under the names "heteropolysaccharides" or "heteroglycans".

[0049] Among the homopolysaccharides that can be used in the context of the present invention, mention may be made of fructans; glucans (or dextrans); galactans such as agar-agar and carrageenans; xylans; mannans; amyloses; amylopectins; celluloses; chitins; starches and glycogens.

[0050] Among the heteropolysaccharides that can be used in the context of the present invention, mention may be made of hemicelluloses, gum arabic, guar gum, alginates, xanthans, chitosans, hyaluronic acids and xyloglucans.

[0051] Furthermore, depending on the architecture of their chain, polysaccharides can be (i) linear such as, for example, celluloses or amyloses; (ii) branched such as, for example example, amylopectins, dextrans or hemicelluloses or even (iü) mixed ones like starches and glycogens.

[0052] By "oligosaccharide or polysaccharide derivative" is meant an oligosaccharide or polysaccharide as previously defined in which at least one hydrogen atom and / or at least one hydroxyl radical and / or at least one carbonyl function is substituted by an atom or a chemical group such as a halogen atom, an alkyl group, a hydroxyalkyl group, a thioalkyl group, a sulfhydryl group, an acetyl group, a silyl group, an acyl group, a sulfonyl group, an amine group, a sulfoalkylether group, a sulfate group, a phosphate group, a carboxyl group, a carboxylester group, a quaternary ammonium group, a glucosyl group, a maltosyl group, a chlorotriazinyl group or a quaternary ammonium group.

[0053] As particular examples of oligosaccharide or polysaccharide derivatives which can be used in the context of the present invention, mention may be made of maltitol, isomaltitol, lactitol as well as oligosaccharides and polysaccharides as previously defined, substituted by at least one hydroxyalkyl group and in particular by at least one hydroxypropyl group.

[0054] As more specific examples of oligosaccharide or polysaccharide derivatives which can be used in the context of the present invention, mention may be made of hydroxypropylcelluloses; hydroxypropylmethylcelluloses; hydroxypropylfructans; hydroxypropylglucans (or hydroxypropyldextrans); hydroxypropylgalactans such as agar-agar substituted by at least one hydroxypropyl group and carrageenans substituted by at least one hydroxypropyl group; hydroxypropylxylans; hydroxypropylmannans; hydroxypropylamyloses; hydroxypropylamylopectins; hydroxypropylchitins; hydroxypropylstarches; hydroxypropylglycogens; hydroxypropylhemicelluloses; gum arabic substituted by at least one hydroxypropyl group; guar gum substituted with at least one hydroxypropyl group; hydroxypropylalginates; hydroxypropylxanthans; hydroxypropylchitosans;hyaluronic acids substituted by at least one hydroxypropyl group and hydroxypropylxyloglucans.;

[0055] In a particular embodiment, the carbohydrates and / or carbohydrate derivatives used in the context of the present invention are oligosaccharides, oligosaccharide derivatives, polysaccharides and / or polysaccharide derivatives.

[0056] The method according to the present invention envisages implementing (i) a set of identical or different carbohydrates belonging to the same family or to different families chosen from monosaccharides, oligosaccharides and polysaccharides carbohydrates as previously defined, (ii) a set of identical or different carbohydrate derivatives belonging to the same family or to different families chosen from monosaccharide derivatives, oligosaccharide derivatives and polysaccharide derivatives as previously defined, or (iii) a set of carbohydrates, identical or different belonging to the same family or to different families chosen from monosaccharide derivatives, oligosaccharide derivatives and polysaccharide derivatives as previously defined and carbohydrate derivatives, identical or different belonging to the same family or to different families chosen from monosaccharide derivatives, oligosaccharide derivatives and polysaccharide derivatives as previously defined.Furthermore, in variants (i) to (iii) above, the carbohydrates and / or carbohydrate derivatives used may be used in a mixture with cyclodextrins and / or cyclodextrin derivatives as previously defined.

[0057] The carbohydrates and / or carbohydrate derivatives used in the context of the invention are in granular solid form, more or less in powder form. The particle size of the solid depends on the type of carbohydrates used. Typically, the average diameter of the carbohydrate grains and / or carbohydrate derivatives is between 10 nm and 10 mm and in particular between 10 μm and 5 mm.

[0058] The carbohydrates and / or carbohydrate derivatives used in the context of the invention may also be in compact solid form, in particular in the form of a solid block or an assembly of several solid blocks.

[0059] In the native state, i.e. either after their natural production or after their chemical synthesis, the carbohydrates and / or solid carbohydrate derivatives used in the context of the invention may be stabilized by one or more water molecules adsorbed on their surface and / or present in their cavity, in the case of cyclodextrins or cyclodextrin derivatives. Advantageously, when brought into contact with the gas comprising ozone, the carbohydrates and / or carbohydrate derivatives used in the context of the invention are free of any molecule other than a water molecule and capable of reacting with ozone.

[0060] Furthermore, the method according to the present invention may have a step prior to bringing the carbohydrates and / or carbohydrate derivatives into contact with the gas comprising ozone aimed at removing all or part of the water molecules associated with the carbohydrates. By way of examples, such a treatment may be a heat treatment or a vacuum extraction. Alternatively, the method according to the present invention may have a step prior to bringing the carbohydrates and / or carbohydrate derivatives into contact with the gas comprising ozone aimed at replacing all or part of the water molecules absorbed on the surface of the carbohydrates and / or carbohydrate derivatives and / or present in the cavities of the carbohydrates and / or carbohydrate derivatives, when they present, by a substance not reactive to ozone such as carbon dioxide. For example, such treatment may consist of bringing carbohydrates and / or carbohydrate derivatives into contact with CO2 under pressure.

[0061] Advantageously, the gas comprising ozone used in the context of the present invention is a gas mixture comprising ozone and at least one other gas such as dioxygen, carbon dioxide, nitrogen or one of their mixtures. When the gas mixture comprises ozone and dioxygen, this mixture is produced from an ozone generator or ozonizer, typically supplied with ambient air, dry air, humid air, compressed air or pure oxygen. The ozone concentration in the gas mixture at the outlet of the ozone generator is between 10 g / Nm3 and 180 g / Nm3. The production of ozone in such an ozone generator or ozonizer may involve an electrical discharge, a plasma or UV light, in particular at the wavelength of 185 nm.

[0062] Typically, in the method according to the invention, the contacting between the carbohydrates and the gas comprising ozone is carried out at a temperature between 0°C and 80°C, in particular between 5°C and 70°C, in particular between 10°C and 60°C, more particularly between 15°C and 55°C and, more particularly still, between 15°C and 40°C. Thus, this contacting can be carried out at room temperature. By "room temperature" is meant any temperature between 18°C ​​and 28°C.

[0063] Typically, in the method according to the invention, the contact between the carbohydrates and / or carbohydrate derivatives and the gas comprising ozone lasts between 1 min and 8 h, in particular between 15 min and 6 h and, in particular, between 30 min and 4 h. More particularly, this contact can last, for example, of the order of 1 h (i.e. 1 h ± 15 min), of the order of 2 h (i.e. 2 h ± 15 min) or of the order of 3 h (i.e. 3 h ± 15 min).

[0064] Furthermore, the contact between the carbohydrates and / or carbohydrate derivatives and the gas comprising ozone is carried out in the absence of any liquid such as, for example, glycerin.

[0065] In the method according to the invention, the contacting between the carbohydrates and / or carbohydrate derivatives and the gas comprising ozone can be carried out in the presence of an inert solid compound. By "inert solid compound" is meant a solid compound which does not store ozone and which does not react with the carbohydrates and / or carbohydrate derivatives, nor with the gas comprising ozone. Such an inert solid compound can be, for example, quartz, mica, natural silica, fumed silica, precipitated silica, feldspar, steatite, chalk, carbon black, barium sulfate, barium ferrite, alumina (A12O3), sand, talc, kaolin, titanium oxide, calcium carbonate, magnesium carbonate, sodium bicarbonate, calcium phosphate or a mixture thereof. Adding an inert solid compound to carbohydrates and / or carbohydrate derivatives in the reactor can advantageously allow the ozone concentration in the solid ozone storage material to be varied by varying the ratio [inert solid compound] / [carbohydrates and / or carbohydrate derivatives].

[0066] In the process according to the invention, the contacting between the carbohydrates and / or carbohydrate derivatives and the gas comprising ozone can be carried out in any system allowing a so-called "gas / solid" reaction, i.e. in an apparatus or device allowing a gas to be effectively contacted with a solid. Considering the solid phase corresponding, in the process according to the invention, to the carbohydrates and / or carbohydrate derivatives in solid form, the contacting can be discontinuous, semi-continuous or continuous.

[0067] In a discontinuous (or batch) process, the solid is loaded into a gas / solid contactor, operating in a fixed or fluidized bed.

[0068] In a semi-continuous (semi-batch) process, several contactors operate simultaneously either in a fixed bed or in a fluidized bed. By means of a set of valves, it is possible to load or unload a device in which the reaction is complete while another is reacting. In this way, a continuous process can be simulated.

[0069] In a continuous fluidized process, the solid may be expanded in the contactor or may flow countercurrently to the flow of reactant gas. The reaction takes place when the gas encounters the solid particles, whether moving or not. There may be moving beds, or multi-stage fluidized beds with recirculation of the solid between stages.

[0070] In a fixed bed, the solid particles are placed in a reactor having a porous bottom (called a "distributor") capable of allowing the gas comprising ozone to pass through this bottom from bottom to top while retaining the particles placed above this bottom. The bed is called "fixed" because it does not move (the solids remain immobile) the flow of gas taking place in the interstitial space left free between the fixed particles. The gas flow rate is, in this case, deliberately low so as not to set the particles in motion.

[0071] In a fluidized bed, the gas flow rate used is higher than in a fixed bed process. The gas velocity between the solid particles increases, and consequently, the friction of the gas on the surface of the particles also increases. When the friction of the gas creates a force sufficient to compensate for the weight of all the particles in the bed, the bed of particles is said to be fluidized. The gas velocity from which the bed is fluidized is called the "minimum fluidization velocity". Once this transition from the fixed bed state to the fluidized bed is achieved by maintaining the gas passage at the ad hoc flow rate, the layer of fluidized particles behaves like a liquid where, for example, lighter objects can float on its surface and heavier objects can sink.

[0072] In a moving bed, the gas flow rate used is even higher than that used previously. cedly. Thus, the particles can move apart from each other, leaving more free space between them and gas bubbles can appear. Solid particles can be entrained by the gas and leave the reactor. The solution considered is generally the installation of a cyclone after the reactor which separates the gas and solid particles by centrifugal force. The solid can then be collected and reinjected into the bottom of the reactor until the desired reaction time is reached.

[0073] In the method according to the invention, the contacting between the carbohydrates or carbohydrate derivatives and the gas comprising ozone can also be carried out in contactors such as powder mixers or stirred reactors. These mixers can be grouped into several categories: rotating tanks (closed rotating enclosures), convective mixers (consisting of a fixed tank or enclosure and a moving mechanical part (agitator, ribbon) inside this tank), high shear mixers (static tank in which an agitator rotates at high speed), static mixers (circulation of the powder in an enclosure containing internals), fluidized bed mixers (circulation of a gas within the powder bed allowing it to be set in motion within the apparatus), and apparatuses consisting of a combination of several mixers. These apparatuses can operate in continuous or discontinuous (batch) mode.For example, for discontinuous mixers, we can cite so-called conical screw mixers, paddle mixers, ribbon screw mixers, ploughshare mixers, twin-rotor paddle mixers, vertical mixers, hybrid mixers, etc. For continuous mixers, we can cite, for example, high-impact, modular, or rapid paddle mixers.

[0074] As explained above, the person skilled in the art will be able to adapt, without inventive effort, the gas flow rate during contact between the carbohydrates in solid form and the gas comprising ozone depending on the devices or installations chosen for this contact. Typically, the gas flow rate at the outlet of the gas source comprising ozone and in particular at the outlet of the ozonator is between 15 L / h and 1 m3 / h.

[0075] In the same way, a person skilled in the art will be able to choose, without inventive effort, the quantity of carbohydrates and / or carbohydrate derivatives in solid form to be used depending on the devices or installations chosen for this contact.

[0076] The method according to the present invention may comprise an additional step consisting of recovering the carbohydrates and / or carbohydrate derivatives following their contact with the gas comprising ozone. This recovery may consist of discharging the carbohydrates and / or carbohydrate derivatives from the reactor as previously defined in which the contacting took place.

[0077] The material obtained or recovered at the end of the process according to the invention has the same visual appearance as the carbohydrates and / or carbohydrate derivatives used during the process. It is therefore in solid form, which can range from powder to a solid block or solid block, the average grain diameter of which is typically between between 10 nm and 10 mm and in particular between 10 pm and 5 mm, or in compact solid form.

[0078] On the other hand, the material obtained or recovered is chemically distinct from the starting material corresponding to the carbohydrates and / or carbohydrate derivatives used during the process, i.e. the carbohydrates and / or carbohydrate derivatives not having been brought into contact with the gas containing ozone. Indeed, the material obtained or recovered is positive in the test resulting from the potassium iodide / thiosulfate dosage, unlike the starting material. The material obtained or recovered also has clear oxidizing and biocidal properties, which the starting material does not have. In addition, the material obtained or recovered releases ozone during tests carried out with an ozone detector in a closed container (tests carried out dry or in solution and at room temperature or above, depending on the carbohydrate or carbohydrate derivative used).In fact, the ozone concentration increases over time in the container containing this material obtained or recovered, whereas no release of ozone is observed with the starting material.

[0079] These various elements associated with the fact that the material obtained or recovered loses part of its oxidizing activity over time constitute proof that the material obtained or recovered contains ozone. In other words, following their contact with a gas comprising ozone, at least part of the carbohydrates and / or carbohydrate derivatives in solid form contain ozone, the latter being able to be in molecular, ionic and / or radical form. The material obtained or recovered therefore constitutes a solid ozone storage material.

[0080] By "ozone storage" is meant, in the context of the present invention, a physical and / or chemical storage of ozone. A physical storage of ozone is a storage without chemical modification of ozone such as dissolution, adsorption, complexation, weak bonding (hydrogen bonding, van der Walls bonding) .... A chemical storage of ozone is a storage involving chemical bonds (chemesorption) or a chemical reaction, such as, for example, a chemical reaction between ozone and carbohydrates and / or carbohydrate derivatives.Thus, following their contact with a gas comprising ozone, the carbohydrates and / or carbohydrate derivatives in solid form contain, for example, ozone (physical storage) and / or ozone (chemical storage) stabilized by reaction with the carbohydrates and / or carbohydrate derivatives, or possibly by reaction with water molecules and / or with other species present in the gas comprising ozone.

[0081] The present invention also relates to an installation capable of being implemented within the framework of the preparation process as previously defined. This installation comprises at least one reactor containing carbohydrates and / or carbohydrate derivatives in solid form as previously defined in connection fluidics with a source of a gas comprising ozone.

[0082] The reactor of the installation according to the invention is in particular a gas / solid contactor, operating in a fixed or fluidized bed, a powder mixer or a stirred reactor, and this, in all the variants previously described.

[0083] When the gas comprising ozone is a mixture comprising oxygen and ozone, the source is an ozone generator. Here too, all the information previously provided to characterize such an ozone generator also applies to the installation according to the invention.

[0084] Advantageously, the installation according to the invention further comprises one or more element(s) chosen from the group consisting of a filter, an ozone destructor, a flow meter, temperature probes, ozone analyzers and valves. In particular, the installation according to the invention comprises all of these elements. The experimental part below describes a particular form of implementation of an installation according to the present invention.

[0085] The present invention also relates to a solid ozone storage material capable of being prepared by a preparation method as previously defined. Typically, the solid ozone storage material which is the subject of the present invention comprises carbohydrates and / or carbohydrate derivatives in solid form, containing ozone (physical storage) and / or ozone (chemical storage) stabilized by reaction with the carbohydrates and / or carbohydrate derivatives, or optionally by reaction with water molecules and / or with other species present in the gas comprising ozone.In a particular embodiment, the solid ozone storage material of the present invention consists of carbohydrates and / or carbohydrate derivatives in solid form, containing ozone (physical storage) and / or ozone (chemical storage) stabilized by reaction with the carbohydrates and / or carbohydrate derivatives, or optionally by reaction with water molecules and / or with other species present in the gas comprising ozone.

[0086] Everything previously described in relation to carbohydrates, carbohydrate derivatives, material obtained or recovered also applies to this aspect of the invention.

[0087] Advantageously, the solid ozone storage material according to the invention is in compacted form and / or in packaged form.

[0088] When the solid ozone storage material according to the invention is in compacted form, it may be in the form of granules, a pellet and / or a briquette.

[0089] When the solid ozone storage material according to the invention, compacted or not, is in packaged form, it is placed in a container such as a sachet, a tube, box, bottle, column, capsule or gel cap. This container may optionally be hermetically sealed. This container may optionally be the reactor in which the contact took place.

[0090] Whether the solid ozone storage material according to the invention is in compacted form and / or in packaged form, it can be stored at a temperature between -80°C and 50°C and in particular between -80°C and 40°C, under vacuum, under ambient air, under humid air, under dry air, under carbon dioxide, under inert gas such as argon, nitrogen or one of their mixtures.

[0091] The present invention finally relates to the use of a solid ozone storage material as previously defined or of a solid ozone storage material capable of being prepared by a preparation process as previously defined as a disinfectant (in particular eliminating viruses), depolluting, cleaning or biocidal agent (in particular fungicide, bactericide or herbicide). The activity of the solid material according to the invention as a disinfectant, depolluting, cleaning or biocidal agent is generated by the ozone stored, in physical and / or chemical form, in this material.

[0092] In other words, the present invention relates to a method for disinfecting, depolluting or cleaning a fluid or a surface, consisting of bringing this fluid or this surface into contact with a solid ozone storage material as previously defined or a solid ozone storage material capable of being prepared by a preparation method as previously defined.

[0093] By "disinfecting, depolluting or cleaning a fluid or a surface" is meant in the context of the present invention reducing the quantity or activity of biological agents or chemical compounds present in the fluid or on the surface before contact with the solid ozone storage material according to the invention. This reduction in quantity may involve the elimination or destruction of these agents or compounds and / or their transformation into less harmful elements.

[0094] Any fluid likely to be contaminated by one or more biological agent(s) or one or more chemical compound(s) may be subjected to a disinfection, decontamination or cleaning process according to the present invention. By "fluid" is meant either a gas or a liquid.More particularly, such a fluid may be chosen from the ambient air or the gaseous atmosphere of a site such as a domestic room, a cold room or a confined industrial space; city water, river water, well water, groundwater, pond water, lake water, swimming pool water, aquarium water, cooling water from air conditioning systems or cooling towers; a sample from a chemical reactor; domestic wastewater; a product, in particular a liquid, an effluent or wastewater originating in particular from intensive livestock farming or from industries or installations in the chemical, pharmaceutical, cosmetic, agricultural, agri-food, maritime, aeronautical or space sectors; or one of their mixtures. It should be noted that, when the fluid is ambient air or a gaseous atmosphere, the solid ozone storage material as previously defined or the solid ozone storage material capable of being prepared by a preparation process as previously defined makes it possible to treat the latter by depolluting it, disinfecting it and / or eliminating odors.

[0095] Any surface likely to be contaminated by one or more biological agent(s) or one or more chemical compound(s) may be subjected to a disinfection, decontamination or cleaning process according to the present invention. Advantageously, within the framework of the present invention, the surface to be disinfected, decontaminated or cleaned may be an inorganic surface and in particular a surface made of metal such as aluminum, metal alloy, steel and in particular stainless steel, tinplate, silicon, glass generally containing silicates, silica glass, ceramic, brick, porcelain, cement, concrete, asphalt, stone, granite, plastic or any of their combinations.More particularly, such a surface may be chosen from large installations such as an industrial object such as an electronic device or a machine used in the food industry, a vehicle, a carcass, an aircraft, a tank, a restaurant kitchen, a cold room, a sanitary facility, a container, a part of a dwelling such as a roof, a facade, a terrace, a driveway; and small installations such as systems embedded in space, in boats or in submarines, medical devices or pipes. It may also be an organic surface such as soil or earth, wood or a plant surface. By "plant surface" is meant a plant, a part of a plant such as leaves, stems, roots, fruits or seeds, or a set of plants.

[0096] By "biological agent" is meant both natural microorganisms such as bacteria, archaea, parasites, protozoa, fungi, yeasts or viruses, toxins produced or not by such microorganisms, pathogenic agents of a protein nature such as prions and genetically modified microorganisms as well as plants such as plants or mosses or parts of plants such as seeds, fruits, leaves, stems or roots.

[0097] In view of the above, it is clear that plants or parts of plants may be, in certain applications, the surface to be treated. In this case, the solid ozone storage material as previously defined or the solid ozone storage material capable of being prepared by a preparation method as previously defined serves to eliminate microorganisms such as fungi or bacteria present on these plants or parts of these plants or to limit the activity of these plants. In other applications, the plants or parts of plants constitute the biological agent to be eliminated and the solid ozone storage material as previously defined or the solid ozone storage material capable of being prepared by a preparation process as previously defined becomes a herbicidal agent. A person skilled in the art will be able to determine without inventive effort and if necessary with the aid of routine tests, the quantity of material to be used depending on the intended application.

[0098] By "chemical compound" is meant an unwanted compound such as a pollutant or contaminant that may be present or present in a fluid or on a surface.By way of illustrative and non-limiting examples, the compound may be chosen from nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), acrolein, a phenol, an insecticide, a pesticide, a sulfur compound such as hydrogen sulfide (H2S), a thiol or a mercaptan, a saturated or unsaturated hydrocarbon such as an alkene or a polycyclic aromatic hydrocarbon, a volatile organic compound such as an aldehyde, formaldehyde, acetaldehyde, naphthalene, a primary amine, in particular an aromatic amine, indole, skatole, tryptophan, urobilinogen, pyrrole, benzene, ethylbenzene, toluene, xylene, styrene, naphthalene, a halogenated compound, a toxin, a peptide, a protein, a glycoprotein, a pharmaceutical compound, a pharmaceutical derivative or a mixture thereof.

[0099] The contact between the fluid or the surface and the solid ozone storage material according to the invention can be implemented in different ways and in particular depending on the gaseous or liquid nature of the fluid. Thus, the solid ozone storage material can be introduced into the liquid fluid, the solid ozone storage material can be deposited or applied to the surface, the ozone storage material can be placed in the presence of the gaseous fluid (static exposures) or the fluid, in particular the gaseous fluid, can be circulated over the solid ozone storage material (dynamic exposure). The solid ozone storage material according to the invention can be dissolved in a solvent before being brought into contact with the fluid or the surface. The solvent will be chosen according to the properties of the native material and / or those of the solid ozone storage material according to the invention (solubility, stability in solution).

[0100] In some of these variants, it may thus be advantageous to use aqueous or organic solvents, solutions of metallic and / or organic salts, ionic liquids or supercritical fluids. Such a solvent may thus be chosen from water, an alcohol such as, for example, ethanol or methanol, an optionally concentrated or diluted acid such as sulfuric acid, an optionally concentrated or diluted base such as sodium hydroxide or potassium hydroxide, an ether, an oil such as a vegetable oil, a wax such as, for example, a white wax, lanolin or wax camauba, a hydrocarbon and silicone such as, for example, vaseline oil, paraffin or silicone oil, cadmium ethylenediamine (Cadoxen), cupraammonium hydroxide (Cuam), cupriethylenediamine hydroxide (Cuen), N,N-dimethylacetamide (DMAc), l,3-dimethyl-2-imidazolidinone (DMI), dimethylformamide (DMF), dimethylsulfoxide (DMSO), N-methylmorpholine N-oxide (NMMO), organic solutions comprising lithium chloride salt (LiCl), polyethylene glycol (PEG) and a mixture thereof.

[0101] In other of these variants, it may be advantageous to package the solid ozone storage material according to the invention, in particular in the form of a column in which the material according to the invention corresponds to a fluidized bed in which the liquid or gaseous fluid ensures the fluidization.

[0102] In the case where the solid ozone storage material according to the invention is applied to a surface, this application can be done by sprinkling the solid material, by depositing a gel containing the material or by depositing or spraying a solution, a dispersion, an emulsion, a microemulsion or a suspension containing the material.

[0103] In the case where the material is introduced into the liquid fluid, it may be advantageous to stir the mixture thus obtained.

[0104] In a particular embodiment, the method for disinfecting, depolluting or cleaning a fluid or a surface according to the invention comprises the steps consisting of:

[0105] - preparing a solid ozone storage material according to the preparation method as previously defined;

[0106] - possibly recover the solid ozone storage material thus prepared Then

[0107] - bringing this fluid or this surface into contact with a solid storage material the ozone thus prepared or possibly thus recovered.

[0108] In this particular embodiment, it is possible to bring the solid ozone storage material into contact with the fluid or with the surface immediately after its preparation or recovery. Alternatively, once prepared and before contacting, the solid ozone storage material can be preserved or stored. Typically, this preservation or storage can be carried out at a temperature between -80°C and 50°C, and in particular between -80°C and 40°C, and this, under vacuum, under ambient air, under humid air, under dry air, under carbon dioxide or under inert gas such as argon, nitrogen or one of their mixtures.

[0109] The present invention also relates to a solid ozone storage material as previously defined or a solid ozone storage material capable of being prepared by a preparation method as previously defined for use as a medicament. Indeed, due to the biostatic and / or biocidal properties of this material, it can be considered to be used for the treatment or prevention of pathologies or disorders caused by a microorganism as previously defined. In particular, these pathologies or disorders are skin pathologies or disorders. Illustrative examples of such pathologies or disorders include impetigo, lymphangitis, a boil, an abscess, a carbuncle, a mycosis, a wart, eczema, seborrheic dermatitis, shingles and herpes. The term "medicine" means both a human and a veterinary medicinal product.

[0110] The present invention also relates to the use of a solid ozone storage material as previously defined or of a solid ozone storage material capable of being prepared by a preparation method as previously defined as a chemical reagent. Indeed, this material can be used as an oxidizing agent during a chemical reaction and / or to provide ozone during a chemical reaction requiring it.

[0111] Other characteristics and advantages of the present invention will become apparent to those skilled in the art upon reading the examples below given for illustrative and non-limiting purposes, with reference to the appended figures. Brief description of the figures

[0112] [Fig. 1] shows a diagram of an installation capable of being implemented within the framework of the present invention with 1. Ozonator; 2. Reactor; 3. Thermostatic bath; 4. Vacuum pump; 5. Filter; 6. Destroyer; Fl, F2. Flow meters; Tl. Temperature probe; PI, P2. Pressure sensors; Al. Ozone analyzer; VI, V2, V3, V4, V5, V6, V7, V8, V9, VIO, Vil. Valves.

[0113] [Fig.2A] presents the results of the biological tests under the conditions detailed in point II.3 and in Table 3 (counting of colony-forming units (CFU) of the plates with agar medium as a function of the material tested and the bacteria brought into contact).

[0114] [Fig.2B] presents the results of the biological tests under the conditions detailed in point II.3 and in Table 3 (photographs of the dishes with agar medium depending on the material tested and the bacteria brought into contact).

[0115] [Fig.3] shows the evolution of the ozone concentration, in materials A and B according to the invention, over time for storage in a freezer at -20°C.

[0116] [Fig.4] shows the results of the Indigo tests.

[0117] Detailed description of the particular embodiments

[0118] I. Installation and method for preparing the material according to the invention.

[0119] A particular example of an installation used to prepare a material with oxidative activity according to the invention is described [Fig.l].

[0120] This installation consists of an ozonator (1), a reactor (2), a thermostatic bath (3), a vacuum pump (4), a filter (5) and an ozone destructor (6). Valves (VI) and (V2) allow the choice of the ozonator feed gas (oxygen or air). Valves (V3) and (V10) allow nitrogen or CO2 to circulate in the process, if necessary. Valve (V4) allows the gas coming from the ozonator to be directed to the reactor (2). Valve (V5) directs the gas to the destructor (5). Valves (V6) and (V8) allow the reactor (2) to be isolated, and valve (V7) allows the reactor (2) to be bypassed. Valve (V9) allows the vacuum pump (4) to be connected to the process, and valve (V11) allows the reactor (2) purge circuit to be closed to evacuate the installation.The process parameters are monitored using various sensors, some of which are connected to an acquisition system and a computer: a volume flow meter (ball rotameter (Fl)) placed at the ozonator outlet to adjust the feed gas flow rates of the reactor (2), a mass flow meter (F2) to precisely measure the feed flow rate of the reactor (2), an ozone analyzer (Al) to measure the ozone concentration of the feed gas of the reactor (2), two pressure sensors (PI) and (P2) to measure the pressure upstream and downstream of the reactor (2), and a temperature probe (Tl) to measure the temperature within the reactor (2).

[0121] The synthesis of the material of interest is carried out by direct gas / solid reaction between carbohydrates or carbohydrate derivatives and a gas mixture containing ozone (O3). The carbohydrates and carbohydrate derivatives used in the experimental part in connection with this installation are hydroxypropyl cellulose (HPC, supplied by Sigma-Aldrich, batch S12E055), microcrystalline cellulose (CellmC, supplied by Accros Organics, batch A0411090) and xanthan gum (XAN, supplied by Sigma-Aldrich, batch SLBZ5317).

[0122] The reactor (2) used is entirely made of stainless steel. It is a tubular reactor with a diameter of 17 mm, a total length of 200 mm and a useful length of 100 mm. It is equipped with a double stainless steel jacket in which a heat transfer fluid circulates through flexible pipes. These pipes are connected to the thermostatically controlled bath (3) which ensures the temperature setting and circulation of the heat transfer fluid in the double jacket of the reactor. The reactor is mounted in a vertical position, with a gas supply in the lower part, and is connected to the rest of the process by double stainless steel ring fittings.

[0123] The material before reaction, consisting of carbohydrates or native carbohydrate derivatives, is initially manually loaded into the reactor (2). The solid in powder form is held in the reactor via two frits positioned upstream and downstream of the powder.

[0124] The vacuum pump (4) makes it possible to put the reactor and part of the installation under vacuum, when necessary.

[0125] The filter (5) prevents fine particles from being drawn into the shredder.

[0126] The ozone destructor (6) is a thermo-catalytic destructor. In contact with the catalyst and under the effect of temperature, the ozone molecules are decomposed into the form of oxygen molecules before being released into the atmosphere (wind).

[0127] For the start-up phase, the valves are initially positioned so that the gas leaving the ozonator is directed towards the ozone destructor via the reactor bypass: valves (V5), (V6) and (V8) closed, and valve (V7) open.

[0128] Ozone gas is generated by an ozonator (1) (model CFS-01-2G from Ozonia). It uses a dielectric discharge process from dry air or oxygen. Ozone production is regulated directly on the ozonator by a power value. The gas produced at the ozonator outlet is either an O2 / O3 mixture when pure oxygen is used as the ozonator feed gas, or an N2 / O2 / O3 mixture if air is used instead of pure oxygen. The flow rate of this gas at the ozonator outlet is regulated and measured using first the rotameter (Fl) then the flow meter (F2). The ozone concentration is measured using the analyzer (Al).

[0129] The power of the ozonator is increased until the desired ozone concentration in the gas is reached. During this transient phase, the gas flow does not pass into the reactor. During experiments carried out with this installation, the ozone concentration can be very high, for example equal to 165 g O3 / Nm3.

[0130] The temperature in the reactor is regulated by the thermostatically controlled bath (3). The temperature range of the experiments carried out with this installation is between 7 and 77°C, the temperature being adapted so that the native material is not degraded during the process (temperature lower than the melting temperature of the material for example).

[0131] Once the ozone concentration on the analyzer (A1) and the temperature (Tl) are stable and conform to the desired values, the gas leaving the ozonator is directed towards the reactor by closing the valve (V7) and opening the valves (V6) and (V8). In the experiments carried out, the gas flow rate can be variable, and has varied from 33 to 723 Normal liters per hour (Nl / h) with the flow meters (Fl) and (F2). The duration of contact of the powder with the gas containing ozone can also be variable, ranging from 0.5 to 6 h for these experiments.

[0132] When the desired reaction time is reached, the valves are positioned so that the gas leaving the ozonator is directed towards the destructor. The reactor is then dismantled from the support, the frits are removed.

[0133] The material obtained at the end of synthesis is a fine powder, resembling, to the naked eye, the material prior to the process according to the invention.

[0134] The ozone-treated powder is then recovered and stored in a glass bottle, or shaped (in the form of a pellet, for example).

[0135] II. Characterization of the material according to the present invention.

[0136] IL 1. Characterizations and dosages.

[0137] Characterization tests and assays (potassium iodide / sodium thiosulfate assay — assay method called “Kl method” or “Kl test” — to determine the amount of ozone contained in the powder) were carried out on some of the materials (at room temperature or with heating).

[0138] Note that the dissolution of native carbohydrates or carbohydrate derivatives (commercial product) in a Kl solution does not produce any coloration of the solution (negative Kl test). Only carbohydrates or carbohydrate derivatives having reacted with ozone obtained according to the process of the invention have a so-called "positive" Kl test: the solution becomes yellow / orange.

[0139] II.2. Protocol for biological tests

[0140] The microbiological tests aim to verify the biocidal effect of the material according to the present invention and thus to evaluate its potential for use in crop protection, for example.

[0141] Two species were tested: Escherichia coli and Streptococcus uberis (E. coli and S. uberis). The bacteria, which were previously stored in glycerol milk at -80°C, were placed in a liquid BCC (Brain Heart Broth) medium, previously autoclaved for 15 min at 121°C. In order to take them out of the lag phase and allow them to reach the exponential growth phase, the bacteria underwent a preculture of 4h and 4h30 respectively at 37°C with shaking at 150 rpm.

[0142] The strains were then brought into contact with the materials according to the invention, native or ozonated. The suspensions thus obtained underwent an incubation time of 20 minutes at 4°C. These suspensions are then diluted and then deposited on agar medium (3 repetitions / modality and dilution). After an incubation time of 24 hours at 37°C, the count is carried out in order to compare the different modalities.

[0143] II.3. Results

[0144] Tests were carried out to evaluate: (i) the effect of the type of carbohydrates or carbohydrate derivatives (HPC, CellmC and XAN); (ii) the effectiveness of the material (biological tests according to the protocol of point II.2. above); (iii) the quantity of ozone contained in the material; (iv) the stability of the material.

[0145] II.3.1. Synthesis of materials according to the invention

[0146] The syntheses were carried out with hydroxypropyl cellulose (HPC), microcrystalline cellulose (CellmC) and xanthan gum (XAN) according to the method described above (point L). The native products were used without any prior treatment.

[0147] The operating conditions of these syntheses are summarized in Table 1 below. The notations are: Tr (reactor temperature); [O3]g alim: ozone concentration in the feed gas; Q = gas flow rate; ts = synthesis time; m = mass of powder introduced into the reactor.

[0148] [Tableauxl] 320303^:^:1: 3(23333:^:^: gOgAAA T a / fe5 À<?' A ' ; tu 86 2 : 3 SPC S so.s î ù,.s sa î i?a ; S > SPC a 1 tvi Bï 3: 3 î CEiLriïC O î tu. ?? sUB: 5? « SW _________K_________ _______.ù 1 3'3 ________?a_______________ A________ _______1 ________ _________<_________ _______Al_______ Table 1: Operating conditions of the syntheses

[0149] II.3.2. Validation of the oxidizing character and ozone concentration of materials according to the invention

[0150] Materials A, B, C, D and E according to the invention synthesized in accordance with Table 1 above were tested. The results are summarized in Table 2 below. The notations are [O3]p = quantity of stored ozone obtained by volumetric dosage at KL

[0151] [Tables II] su material aebn Fh vent] on IggliOBiili ggg;g||g||g;g| K-test? 0 A HPC WB HP€ püaUS 10„2 GJC g™ CHLmC HPC pos^ pwU 03 ...... 03 E XA^ poàkif OA 03 Table 2: Kl tests and dosages

[0152] Ozonated materials A, B and D dissolve more difficultly in water than the native product, and produce a viscous solution after dissolution. A gel can be obtained if the concentration of ozonated powder is high. Material C is hardly soluble in water at room temperature. Material E is soluble in water and gives a very viscous gel.

[0153] Under identical operating conditions, it is noted that the ozone storage capacity is dependent on the nature of the carbohydrate or carbohydrate derivative used for the synthesis, the best results being obtained with HPC (materials A / B / D). Furthermore, for HPC, it should be noted that increasing the synthesis temperature from 25°C (materials A and D) to 50°C (material B) slightly reduces the ozone content in the final material.

[0154] II.3.3. Evaluation of the biocidal character of materials according to the invention on several bacterial strains

[0155] The results are summarized in Table 3 below as well as in Figures 2A and 2B.

[0156] [Tables III] Material according to the invention Pathogens Biological effectiveness A Bacteria Eco / / Proven limited) C Table 3: Biocidal character of the material according to the invention

[0157] The results show that the HPC according to the invention (material A) makes it possible to limit the development of the two bacterial strains compared to this same native material. This effect is less but also found for CellmC (material C) compared to native CellmC.

[0158] The addition of carbohydrates or carbohydrate derivatives prepared according to the method of the invention limits in both cases the development of bacteria while the controls (native materials) continue to develop during the hours of analysis. The newly obtained materials therefore have a bactericidal effect.

[0159] II.3.4. Stability of the material according to the present invention

[0160] The stability of the material according to the present invention was tested for materials A and B obtained according to the method of point II.3.1. The batch of powder at the end of synthesis was stored at -20°C.

[0161] The evolution of the ozone content of these two materials stored in closed bottles in the freezer (-20°C) was measured. The results are given in Table 4 and in [Fig.3].

[0162] [Tables IV] Material of the invention Storage time at Loss in Mene IIIBOiiil / % A ü 13.4 0.8 A' 11 12% -10 A" zS W as 22 B 0 10.2 a? fi r B 9.3 ■10 S” 22 9.6 as -Ê Table 4: Stability test data

[0163] From the two tests carried out, it can be concluded that the material is relatively stable over time when stored at -20°C. It retains its oxidizing properties, with a maximum average loss in ozone content of 22%. This loss can be estimated at less than 12% in 25 days taking into account the uncertainties.

[0164] In addition, an indigo test, known to be specific to ozone, was carried out with the products stored for 25 days (A”) and 22 days (B”). This assay method is based on the determination of a color difference: when ozone reacts with indigo trisulfonate (initially of an intense blue color), the solution discolors. The difference in color intensity is inversely proportional to the amount of ozone contained in the material. This test is said to be “positive” for an ozonated material when, for a given time, the discoloration of an indigo solution brought into contact with the ozonated material discolors more quickly than when the same indigo solution is brought into contact with the native, non-ozonated material.

[0165] An 8x106 mol / L indigo solution is brought into contact at 20°C with 150 mg of powder of A” in a first test tube and with 150 mg of powder of B” in a second test tube. The tubes are capped, shaken and left to stand for 24 hours.

[0166] [Fig.4] shows the results of the Indigo tests. In this figure, the notations are: T: control indigo solution 8x106 mol / L; N: indigo solution with 150 mg of native HPC; A”: indigo solution + 150 mg of ozonated powder A stored for 25 days at -20°C; B”: indigo solution + 150 mg of ozonated powder B stored for 22 days at -20°C. The photograph is taken 24 hours after the powders come into contact with the indigo solution.

[0167] After 24 hours of contact, it is noted that the native HPC (non-ozonated) partially discolors the indigo solution, since the blue color is lighter in shade than the control.

[0168] At the same time, the ozonated HPC (A” and B”) completely discolors the indigo solution, which confirms that the indigo test is positive, thus demonstrating the presence of ozone in these materials according to the invention.

[0169] This test is further evidence that demonstrates that ozone is indeed present in materials A and B, even after more than 20 days of storage at -20°C.

[0170] II.3.5. Storage of ozone by the material according to the present invention

[0171] In order to confirm the storage of ozone in the material according to the invention, an additional test was carried out with material A described in point II.3.2 above.

[0172] During the experiments, approximately 1 g of ozone storage material according to the invention in powder form was placed in a glass cup, itself placed in a glass reactor with a volume of 1.4 liters. The reactor can be hermetically sealed and was kept at room temperature (~ 20°C).

[0173] A portable ozone detector (model X-an-5000 from Drâger, equipped with a specific XXS O3 cell for ozone detection, detection limit equal to 0.02 ppm and resolution equal to 0.01 ppm, response time < 10 s at 20°C) was introduced into the reactor and switched on near the powder cup. The detector thus placed makes it possible to continuously demonstrate the presence of ozone in the reactor, from an ozone concentration higher than the detection limit of 0.02 ppm.

[0174] The detector detects the presence of ozone without the need for the addition of water. On powder of material A tested immediately after synthesis or after 24 hours of storage in a freezer, the measured ozone concentration is high (several ppm). On powder of material A stored for 22 days in a freezer at -20°C, the measured ozone concentration is lower but significantly different from 0 (concentration of the order of 0.07 ppm; value equal to more than double the detection limit value (0.02 ppm) increased by the detector resolution (0.01 ppm), i.e. 0.03 ppm in total).

[0175] In another experiment carried out under exactly the same conditions, no ozone release was observed on the detector when native product (i.e. non-ozonated HPC) was used.

[0176] These experiments therefore confirm that the material manufactured according to the present invention does indeed store ozone, and that ozone in gaseous form can be released by this material.

[0177] II.4. Conclusions.

[0178] Contacting ozone with carbohydrates or carbohydrate derivatives, such as HPC, CellmC and XAN in the solid phase, results in the production of a material with powerful oxidative properties. The syntheses are reproducible, as are the results obtained (dosages, biological efficacy, etc.). The product obtained at the end of the synthesis is a powder that can be easily used for the intended applications.

[0179] Assuming that ozone molecules are stabilized within the material, the ozone concentrations obtained by dosing are very high. This concentration depends on several parameters, including the nature and properties of the carbohydrates or carbohydrate derivatives.

[0180] The storage capacity of the material depends strongly on the carbohydrate or carbohydrate derivative used as raw material. The best results were obtained with HPC, for which an ozone concentration equal to 13400 ± 800 pg / g of powder was found (three assays carried out). These values ​​are equivalent to a concentration approximately 950 times higher than for ozonated water at ambient temperature and pressure ([O3] ozonated water, 25°C, 1 bar, at 60-80 g / Nm3 (pH = 7) approximately 14 mg / L of water).

[0181] It has also been shown that the material maintains its oxidative properties for several tens of days. Measurements carried out with powders stored at low storage temperatures (-20°C) show that it is possible by this means of storage to limit the loss of ozone over time. References

[0182] [1] McTurk & Waller, 1964, “Ozone carbon tetrachloride double hydrate”, Nature, vol. 202, page 1107.

[0183] [2] Nakagima et al, 2012, “Molecular storage of ozone in a clathrate hydrate: an attempt for preserving ozone at high concentrations”, PlosOne, vol. 7:e48563.

[0184] [3] Patent application JP 2007 / 210881 in the name of Kurita Water Ind. Ltd., published on August 23, 2007.

[0185] [4] Dettmer et al, 2017, “Stabilization and prolonged reactivity of aqueous-phase ozone wuth cyclodextrin”, Journal of Contaminant Hydrology, vol. 196, pages 1-9.

[0186] [5] US patent application 2018 / 0178263 in the name of OXYTEC LLC, published on 28 June 2018.

[0187] [6] International application WO 2013 / 126047 in the name of Empire Technology De velopment LLC, published August 29, 2013.

[0188] [7] US patent application 2016 / 0367967 in the name of Temple University of the Com- United States System of Higher Education, published on December 22, 2016.

[0189] [8] International application WO 2006 / 134299 in the name of the University of Franche- County, published December 21, 2006.

Claims

Claims

1. A method for preparing a solid ozone storage material comprising contacting carbohydrates and / or carbohydrate derivatives in solid form with a gas comprising ozone, provided that when said carbohydrates and / or carbohydrate derivatives comprise cyclodextrins or cyclodextrin derivatives, the latter are mixed with at least one other carbohydrate other than a cyclodextrin or cyclodextrin derivative and provided that said contacting is carried out in the absence of any liquid, whereby a solid ozone storage material is obtained, said carbohydrates or carbohydrate derivatives being in granular solid form or in compact solid form, and said carbohydrates and carbohydrate derivatives being other than cellulose esters.

2. Method according to claim 1, characterized in that said (derivatives of) carbohydrates are chosen from (derivatives of) monosaccharides, (derivatives of) oligosaccharides and (derivatives of) polysaccharides.

3. Method according to claim 1 or 2, characterized in that said carbohydrates are chosen from the group consisting of fructans; glucans (or dextrans); galactans such as agar-agar and carrageenans; xylans; mannans; amyloses; amylopectins; celluloses; chitins; starches; glycogens; hemicelluloses; gum arabic; guar gum; alginates; xanthans; chitosans; hyaluronic acids and xyloglucans.

4. Process according to any one of claims 1 to 3, characterized in that said carbohydrate derivatives are chosen from the group consisting of hydroxypropylcelluloses; hydroxypropylmethylcelluloses; hydroxypropylfructans; hydroxypropylglucans (or hydroxypropylextrans); hydroxypropylgalactans such as agar-agar substituted by at least one hydroxypropyl group and carrageenans substituted by at least one hydroxypropyl group; hydroxypropylxylans; hydroxypropylmannans; hydroxypropyllamyloses; hydroxypropylamylopectins; hydroxypropylchitins; hydroxypropylstarches; hydroxypropylglycogens; hydroxypropylhemicelluloses; gum arabic substituted by at least one hydroxypropyl group; guar gum substituted by at least one hydroxypropyl group; hydroxypropylalginates; hydroxypropylxanthans; hydroxypropylchitosans; hyaluronic acids substituted by at least one hydroxypropyl group and hydroxypropylxyloglucans.

5. Method according to any one of claims 1 to 4, characterized in that said gas comprising ozone is a gas mixture comprising ozone and at least one other gas such as dioxygen, carbon dioxide, dinitrogen or one of their mixtures.

6. Method according to any one of claims 1 to 5, characterized in that the contacting between said carbohydrates and / or said carbohydrate derivatives and said gas comprising ozone is carried out at a temperature between 0°C and 80°C.

7. Method according to any one of claims 1 to 6, characterized in that the contact between said carbohydrates and / or said carbohydrate derivatives and said gas comprising ozone lasts between 1 min and 8 h.

8. Installation capable of being implemented within the framework of a preparation process as defined in any one of claims 1 to 7, said installation comprising at least one reactor containing carbohydrates and / or carbohydrate derivatives as defined in any one of claims 1 to 4, in solid form in fluidic connection with a source of a gas comprising ozone.

9. Installation according to claim 8, characterized in that said reactor is a gas / solid contactor, operating in a fixed or fluidized bed, a powder mixer or a stirred reactor and / or in that said ozone source is an ozone generator.

10. Installation according to claim 8 or 9, characterized in that it further comprises one or more elements chosen from the group consisting of a filter, an ozone destructor, a flow meter, temperature probes, ozone analyzers and valves.

11. A solid ozone storage material capable of being prepared by a preparation method as defined in any one of claims 1 to 7.

12. Solid ozone storage material according to claim 11, characterized in that it comprises carbohydrates and / or carbohydrate derivatives in solid form, containing ozone and / or ozone stabilized by reaction with said carbohydrates and / or carbohydrate derivatives or optionally with water molecules and / or with other species present in the gas comprising ozone.

13. Solid ozone storage material according to claim 11 or 12, said material being in compacted form and / or in conditioned form.

14. Use of a solid ozone storage material according to any one of claims 11 to 13 or capable of being prepared by a preparation process as defined in any one of claims 1 to 7, as a disinfectant, depollutant, cleaning or biocide agent.

15. Use of a solid ozone storage material according to any one of claims 11 to 13 or capable of being prepared by a preparation process as defined in any one of claims 1 to 7, for disinfecting, depolluting or cleaning a fluid or a surface.

16. Use according to claim 15, characterized in that said fluid is chosen from ambient air or the gaseous atmosphere of a site such as a domestic room, a cold room or a confined industrial space; city water, river water, well water, groundwater, pond water, lake water, swimming pool water, aquarium water, cooling water from air conditioning systems or cooling towers; a sample from a chemical reactor; domestic wastewater; a product, in particular a liquid product, an effluent or wastewater originating in particular from intensive livestock farming or from industries or installations in the chemical, pharmaceutical, cosmetic, agricultural, agri-food, maritime, aeronautical or space sectors; or a mixture thereof.

17. Use according to claim 15, characterized in that said surface is chosen from an industrial object such as an electronic device or a machine used in the food industry, a vehicle, a carcass, an aircraft, a tank, a restaurant kitchen, a cold room, a sanitary facility, a container, a part of a dwelling such as a roof, a facade, a terrace, a driveway, systems embedded in space, in boats or in submarines, medical devices, pipes, a floor or earth, wood and a plant surface.

18. A solid ozone storage material according to any one of claims 11 to 13 or capable of being prepared by a preparation process as defined in any one of claims 1 to 7 for use as a medicament.

19. Use of a solid ozone storage material according to one of the claims any of claims 11 to 13 or capable of being prepared by a preparation process as defined in any one of claims 1 to 7 as a chemical reagent.

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