COLORIMETRIC DETECTION DEVICE IN THE FORM OF A SPRAYER FOR THE DETECTION OF CHEMICAL COMPOUNDS

Abstract

The invention relates to a colorimetric detection device for detecting at least one chemical compound, in the form of a spray containing a composition comprising a dispersing phase in which at least one colored indicator is dispersed, capable of changing color in the presence of the chemical compound. The colored indicator is present in the dispersing phase in the form of a plurality of solid particles impregnated with the colored indicator or in which the colored indicator is encapsulated. The invention also relates to a method for detecting the presence or absence of at least one chemical compound by implementing a device as described above. Applications: detection of chemical compounds, toxic chemical warfare agents, or toxic industrial chemical compounds.

Description

Title of the invention: COLORIMETRIC DETECTION DEVICE IN THE FORM OF A SPRAYER FOR THE DETECTION OF CHEMICAL COMPOUNDS Technical field

[0001] The present invention relates to a colorimetric detection device.

[0002] More specifically, the invention relates to a colorimetric detection device, in the form of a sprayer for the detection of chemical compounds by means of colored indicators.

[0003] It also relates to a method for detecting the presence or absence of chemical compounds, by implementing the colorimetric detection device.

[0004] The present invention can find application for the detection of toxic chemical compounds, such as toxic war compounds or toxic industrial chemical compounds (known as TIC). State of the prior art

[0005] NRBC-E risks (for "nuclear, radiological, biological, chemical and explosive risks") constitute a high threat to the civilian population. They result in particular from industrial accidents, criminal acts (such as the use of toxic weapons) or even natural or environmental disasters, during which toxic compounds spread into the environment.

[0006] It is therefore important to be able to detect the presence of such toxic compounds in the event of NRBC-E risks.

[0007] To date, it is possible to use a detector paper comprising colored indicators of the toxic compounds to be detected, but this paper does not allow a resistant deposition of these colored indicators on a surface likely to be contaminated and, in particular, on surfaces that are too complex.

[0008] Furthermore, sprays have been proposed as colorimetric detectors. For example, Shrishty Bakshi et al. (Advanced Functional Materials, 2022,32, 2103496, hereinafter [1]) have developed a spray comprising a polyprolactone polymer and one or two colored indicators in solution in chloroform for the detection of Fe2+ ions, Fe3+ ions and ammonia only. This spray is sprayed in the form of nanofibers onto different types of surfaces, simply using compressed gas. The nanofibers are generated only during the spraying step. Furthermore, since the colored indicators included in this spray are in solution in chloroform, they can easily interact with each other before being sprayed in the form of nanofibers.

[0009] The inventors therefore set themselves the goal of providing a colorimetric detection device which does not have the above drawbacks, that is to say a device making it possible to detect and, ideally, discriminate between more complex chemical compounds (such as toxic chemical compounds) on a complex surface and in which any interaction between the colored indicators is avoided.

[0010] They also set themselves the goal of providing such a device without the need to use a solvent that is dangerous to health and the environment, such as a chlorinated solvent. Statement of the invention

[0011] The invention therefore relates, firstly, to a colorimetric detection device for the detection of at least one chemical compound, in the form of a spray and containing a composition which comprises a dispersing phase in which is dispersed at least one colored indicator capable of changing in the presence of the chemical compound, characterized in that the colored indicator is present in the dispersing phase in the form of a plurality of solid particles which are impregnated with the colored indicator or in which the colored indicator is encapsulated.

[0012] In the following, the device of the invention can more simply be called “spray”.

[0013] It should be noted that the device of the invention may be capable of detecting several chemical compounds, in which case the composition contained in this device comprises a dispersing phase in which several colored indicators are dispersed in the form of a plurality of solid particles.

[0014] The term "colored indicator" means a substance which takes on at least one characteristic color in the presence of a chemical compound, i.e., in other words, a chemical substance which exhibits at least two colored states, one colored state existing when the chemical substance is not in the presence of the chemical compound to be detected and at least one other colored state when the chemical substance is in the presence of the chemical compound to be detected.

[0015] The fact that the colored indicator is present in the dispersing phase in the form of a plurality of solid particles, makes it possible in particular to limit the migration of the colored indicator in the dispersing phase and thus to limit any interaction between colored indicators in this dispersing phase. Thus, the device of the invention also has the advantage of being able to use different colored indicators in the same composition contained in such a device, since these colored indicators will not be able to interact with each other. This then allows the detection and, even better, the discrimination of chemical compounds, when several chemical compounds are present.

[0016] The expression “different colored indicators” means that each colored indicator reacts to at least one different specific chemical compound.

[0017] The particles impregnated with the colored indicator or encapsulating the colored indicator may be made of an inorganic material, for example based on silica, alumina, zinc oxide, titanium oxide or zeolite, preferably based on silica, or organic, in which case they are typically made of a polymeric or copolymeric material, crosslinked or not.

[0018] Among these particles, preference is given to particles made of an organic material and, more specifically, of a polymeric or copolymeric material.

[0019] Such particles can be obtained by polymerization of one or more monomers - this polymerization can then be a polymerization in mass, in solution, in suspension, in dispersion or in emulsion, induced by heat or UV, in the presence or absence of a polymerization initiator - or by solubilization / precipitation of one or more polymers or copolymers in an appropriate solvent.

[0020] In the case where the particles are made of a crosslinked polymeric or copolymeric material, then this crosslinking can result: - functionalization of the monomer(s) prior to polymerization, in which case the polymerization is accompanied by crosslinking; - functionalization of the monomer(s) after polymerization, in which case the polymerization and crosslinking are carried out in two stages; or - in the case of a copolymeric material, a copolymerization of one or more monofunctional monomers and one or more multifunctional monomers.

[0021] Crosslinking makes it possible to limit as much as possible the migration of the colored indicator into the dispersing phase.

[0022] According to the invention, the particles made of a polymeric or copolymeric material comprise at least one monomer preferably chosen from ethylene, methyl (meth)acrylate and trimethylolpropane triacrylate and, better still, chosen from methyl (meth)acrylate and trimethylolpropane triacrylate.

[0023] In any event, the solid particles are preferably microparticles, that is to say they have a number average size of between 0.1 qm and 100 qm and, better still, between 5 qm and 50 qm. This number average size can be determined by laser diffraction granulometry, for example using a laser granulometer such as that marketed by Malvem Panalytical, under the reference Mastersizer™ 3000.

[0024] In this regard, it is specified that “size” means the largest of the three dimensions of the microparticles.

[0025] The colorimetric detection device according to the invention is particularly suitable for the detection of chemical compounds in the form of a liquid or a solid.

[0026] This device allows easy reading of a possible change in color (or so-called colorimetric shift) of the colored indicator, when it is in the presence of the chemical compound, even when the latter is only present in small quantities, for example in the form of a droplet.

[0027] It is also particularly suitable for detecting the chemical compound present on a complex or flexible surface, such as on the surface of a tire, clothing or even a shoe.

[0028] Furthermore, the dispersing phase of the composition contained in the device may be an aqueous or organic phase and may optionally comprise a surfactant.

[0029] The composition contained in the device, intended to be sprayed onto a surface, can subsequently be detached from this surface mechanically and / or using water or suitable solvents.

[0030] For example, when the dispersing phase of the composition contained in the device is an aqueous phase, then the composition can be detachable from the surface by simple cleaning with water, whereas when the dispersing phase is an organic phase, the composition can be detachable from the surface by rubbing and / or using decane.

[0031] This can be extremely interesting in the context of a potential reuse of the surface.

[0032] On the other hand, the colored indicator is chosen so that it obviously exhibits at least one colorimetric change in the presence of the chemical compound that it is desired to detect.

[0033] Better still, when several colored indicators are used, they are advantageously chosen so that each of them has at least one contrasting colorimetric change relative to each other when they are in contact with at least one specific chemical compound. This allows discrimination of the chemical compounds, when several chemical compounds are present. These colored indicators may be those which advantageously have a similar initial color (i.e. without exposure to one or more chemical compounds), and, preferably, a light color (for example, in shades of pale yellow), or even are colorless.

[0034] Depending on the chemical compound that one wishes to detect, the colored indicator can be chosen from anthraquinone compounds, azo compounds, tria-rylmethane compounds, xanthene compounds, indigo compounds, metal complexes, compounds comprising at least one stilbene group, coumarin compounds, compounds comprising at least one cyanine group, compounds comprising at least one phthalocyanine group, compounds comprising at least one porphyrin group, the compounds comprising at least one hydrazone group.

[0035] As examples of anthraquinone compounds, mention may be made of 1,4-dihydroxyanthraquinone, 1-aminoanthraquinone, carminic acid, 1,5-diaminoanthraquinone, 1,2-diaminoanthraquinone, 1,4-diamino-5-nitroanthraquinone, 1,4,5,8-tetraaminoanthraquinone (Disperse Blue 1), 1-methylamino-4-(2-hydroxyethyl)aminoanthraquinone (Disperse Blue 3), 1-amino-2-methylanthraquinone (Disperse Orange 11), 1,4-bis-(p-tolylamino)anthraquinone (Solvent Green 3).

[0036] As examples of azo compounds, mention may be made of 10-(2',4'-dinitrophenylazo)-9-phenanthrol, disodium 6-hydroxy-5-[(2-methoxy-5-methyl-4-sulfophenyl)azo]-2-naphthalenesulfonate (also known as Allura Red AC), 4-dimethylaminoazobenzene (also known as methyl yellow), 4-(2-carboxyphenylazo)-N,N-dipropylaniline (also known as "Propyl red" in English terminology), 3-(diethylamino)-7-{(E)-[4-(dimethylamino)phenyl]diazenyl}-5-phenylphenazin-5-iu m chloride (also known as "Janus Green B"), N,N-dimethyl-4,4'-azodianiline, N-ethyl-l-((4-phenyldiazenyl)phenyl)diazenyl)naphthalen-2-amine (also known as "Sudan Red 7B"), amaranth, 4-[[3-[(2,4-diaminophenyl)diazenyl]phenyl]diazenyl]benzene-l,3-diamine dihydrochloride (also known as "Bismarck Brown Y"), disodium 4-hydroxy-3-[(4-sulfo-l-naphthalenyl)azo]-l-naphthalenesulfonate (also known as "Chromotrope FB"),benzidinediazo-bis-l-naphthylamine-4-sulfonic acid (also known as "Congo Red"), 2,2'-[4-(4-Aminophenylazo)phenylimino]diethanol (also known as "Disperse Black 9" in English terminology), 2,2'-[[4-[(4-nitrophenyl)ado]phenyl]imino]bisethanol (also known as "Disperse Red 19" in English terminology), sodium (4Z)-4-[(l-hydroxynaphthalen-2-yl-hydrazi-nylidene]-7-nitro-3-oxo Y-naphthalene-l-sulfonate (also known as "Eriochrome Black T"), 4'-(4-(diethylamino)phenylazo)acetophenone, 4-[(E)-(4-nitrophenyl)diazenyl]-N-phenylaniline (also known as "Disperse Orange 1 » according to English terminology), helianthine (also called methyl orange), 4-(4-nitrophenylazo)aniline (also called “Disperse Orange 3” according to English terminology), 4-[4-(phenylazo)-l-naphthylazo]phenol (also called “Disperse Orange 13” according to English terminology),3-[N-ethyl-4-(4-nitrophenylazo)phenylamino]propionitrile (also known as “Disperse Orange 25” in English terminology), sodium 4-amino-5-hydroxy-3-(4-nitrophenylazo)-6-(phenylazo)naphthalene-2,7-disulfonate (also known as “Naphthol Blue Black”), , (2,2-dimethyl-l,3-dihydroperimidin-6-yl)-(4-phenylazo-l-naphthyl)diazene (also known as "Sudan Black B" in English terminology), disodium 6-hydroxy-5-[(4-sulfonatophenyl)azo]naphthalene-2-sulfonate (also known as "orange yellow S"), tartrazine, Evans blue, 4-[4-(phenylazo)phenylazo]-o-cresol (also known as "Disperse Yellow 7" in English terminology), 4'-nitro-4-dimethylaminoazobenzene.

[0037] As examples of triarylmethane compounds, mention may be made of aniline diammonium blue, bromophenol blue, m-cresol violet, cresol red, gentian violet (also called "Crystal Violet" in English terminology), chlorophenol red, the sodium salt of (4-(a-(p-(diethylamino)phenyl)-2,4-disulfobenzylidene)-2,5-cyclohexadien-l-ylidene)diethylammonium hydroxide (also called "Patent blue V sodium salt"), methyl blue, rosolic acid, pyrocatechol violet, brilliant green BS, pararosaniline base, fuchsin, thymol blue, 4-(dimethylamino)-a-[4-(dimethylamino)phenyl]-a-phenyl-benzenemethanol.

[0038] As examples of xanthenic compounds, mention may be made of [9-(2-carboxyphenyl)-6-diethylamino-3-xanthenylidene]-diethylammonium chloride (also called “Rhodamine 610”), rhodamine 6G optionally in the form of perchlorate salt, rhodamine B, sulforhodamine 101 hydrate, fluoresceinamine (in particular Isomer I), rhodamine 110 chloride.

[0039] As examples of indigo compounds, mention may be made of indigo.

[0040] As examples of metal complexes, mention may be made of trisodium 5-nitroso-6-oxidonaphthalene-2-sulfonate complexed with iron (III) (also known as “Naphthol Green B”).

[0041] As examples of compounds comprising at least one stilbene group, mention may be made of the dye known under the English terminology “Fluorescent Brightener 28”.

[0042] As examples of coumarin compounds, mention may be made of 7-amino-4-(trifluoromethyl)coumarin, 7-amino-4-methylcoumarin, 3-(2-N-Methylbenzimidazolyl)-7-N,N-diethylaminocoumarin (also called "Coumarin 30"), 2,3,6,7-tetrahydro-10-(3-pyridyl)-1H,5H,11H-[1]benzopyrano[6,7,8-ij]quinolizin-11-one (also called "Coumarin 510"), 3-(2-Benzothiazolyl)-7-(diethylamino)coumarin (also called "Coumarin 6").

[0043] As examples of compounds comprising a cyanine group, mention may be made of indocyanine green, 5,5'-dichloro-11-diphenylamino-3,3'-diethyl-10,12-ethylenethiatricarbocyanine perchlorate (also known as IR 140).

[0044] As examples of compounds comprising a phthalocyanine group, mention may be made of iron (III) phthalocyanine chloride, iron (III) phthalocyanine-4,4',4”,4”'-tetrasulfonic acid, cobalt (II) 1,2,3,4,8,9,10,11,15,16,17,18,22,23,24,25-hexadecafluoro-29H,31H-phthalocyanine, copper (II) phthalocyanine, compounds comprising a hydrated oxygen monosodium salt.

[0045] The invention also relates to a method for detecting the presence or absence of at least one chemical compound.

[0046] According to a first particular embodiment, the method comprises at least the following successive steps: - a step of spraying the composition contained in the colorimetric detection device as defined previously, onto a surface likely to comprise the chemical compound to be detected; - a step of deducing the presence or absence of the chemical compound on the surface, based on a possible colorimetric change.

[0047] The spraying step is, here, advantageously implemented once the surface on which it is desired to detect the presence or absence of at least one chemical compound has been brought into contact with a medium comprising this chemical compound to be detected.

[0048] In other words, this first embodiment makes it possible to detect, a posteriori, the chemical compound deposited on the surface.

[0049] According to this first embodiment, it is advantageous to use the composition contained in the spray which comprises an aqueous dispersing phase. Indeed, once the deduction step has been carried out, it will be easy to clean with water the surface on which the composition has been sprayed, allowing the reuse of this surface.

[0050] According to a second particular embodiment, the method comprises at least the following successive steps: - a step of spraying the composition contained in the colorimetric detection device as defined previously, onto a surface not comprising the chemical compound; - a step of bringing the surface into contact with a medium likely to include the chemical compound; - a step of deducing the presence or absence of the chemical compound on the surface, based on a possible colorimetric change.

[0051] The spraying step is therefore, here, advantageously implemented before the surface on which it is desired to detect the presence or absence of at least one chemical compound is brought into contact with a medium comprising this chemical compound to be detected.

[0052] In other words, this second embodiment makes it possible to detect in real time the chemical compound which is deposited on the surface.

[0053] According to this second embodiment, it is preferred that the composition contained in the device is water-resistant. Also, it is advantageous to use the composition contained in the spray which comprises an organic dispersing phase. Indeed, once the deduction step has been carried out, it will be easy to clean the surface on which the composition has been sprayed by rubbing and / or using decane, which makes it possible to reuse this surface.

[0054] Furthermore, the surface onto which the composition contained in the spray is sprayed may be any surface likely to have been in contact or to be in contact with a medium comprising the chemical compound to be detected. Such a surface may therefore be a complex or flexible surface, such as on the surface of a tire, a garment or even a shoe.

[0055] It is understood that the colorimetric detection device used in the context of the aforementioned method must be capable of detecting the chemical compound whose presence or absence is to be determined.

[0056] The deduction step can be easily done with the naked eye, upon observing a change in color of the surface onto which the composition contained in the device has been sprayed. However, the use of optical or optoelectronic devices can also be considered, if necessary, during this step.

[0057] According to the invention, the chemical compounds capable of being detected by the method of the invention may be toxic compounds, such as toxic war compounds or toxic industrial compounds.

[0058] More particularly, the toxic war compounds may be organophosphorus compounds of the G series (such as Sarin or Tabun), organophosphorus compounds of the V series (such as compound VX), other organophosphorus compounds such as compounds A-232, A-230, A-234 and A-242, vesicant compounds (such as sulfur mustard, nitrogen mustard and Lewisite) or even arsenic compounds (such as compounds Clark 1 and Clark 2).

[0059] Other characteristics and advantages of the invention will emerge from the additional description which follows.

[0060] It goes without saying that this additional description is given only as an illustration of the subject of the invention and must in no case be interpreted as a limitation of this subject.

[0061] Detailed description of particular embodiments

[0062] 1. Impregnation of particles with a colored indicator

[0063] This example illustrates the preparation of different particles impregnated with colored indicators according to the following operating protocol: 1°) weighing the powder in a flask; 2°) weighing the quantity of colored indicator required (0.1% or 0.5% by mass of colored indicator relative to the mass of powder) in a pillbox; 3°) addition of a solvent allowing the solubilization of the colored indicator in the pillbox and so as to have a concentration of approximately 30 mg / mL; 4) pouring the colored indicator solution into the flask onto the powder and rinsing the pillbox several times and pouring the rinsing solvent into the flask; 5°) depending on the appearance of the powder in the flask, add as much solvent as necessary to wet and suspend the powder; 6) evaporation in three stages: *rotation in the water bath (55°C) of the rotary evaporator for 10 minutes to homogenize the suspension in the flask and bring the temperature up; *slow pressure reduction to 400 mbar to slowly distill the solvent; *when the powders begin to group together to form a ring that attaches to the wall of the flask, the pressure is released more quickly until completely dry.

[0064] The table below sets out the two impregnated powders prepared, with the precision of the nature of the powder, the colored indicator, the proportion of colored indicator and the solvent.

[0065] [Tables 1] Color Indicator Indicator Proportion Solvent Powder Disperse Black 9 0.1% Ethanol Silica Bromocresol Purple as sodium salt 0.5% Ethanol Polyethylene

[0066] The silica is a silica having an average particle size of 2-25 qm and is supplied by Aldrich under the product reference 288500-1KG.

[0067] The polyethylene is a polyethylene having an average particle size of 30 qm and is supplied by Mitsui Chemicals under the product reference MIPELON XM-220.

[0068] 2. Colored indicators encapsulated in particles made of a co po material lymeric

[0069] 2.1 Encapsulation of bromocresol green in copolymeric particles of MMA / TMPTA

[0070] The encapsulation of bromocresol green by copolymerization of methyl methacrylate (denoted MM A) and trimethylolpropane triacrylate (denoted TMPTA) is prepared according to the following protocol: 1°) 5 mg of ground bromocresol green and 50 mg of Irgacure™ 819 photoinitiator (supplied by BASF with the commercial reference 56415892) are weighed, then suspended in 20 mL of cyclohexane in a 30 mL glass bottle and passed through ultrasound; 2°) the suspension is placed under magnetic stirring in a UV tank (supplied by Hônle, under the reference UVA-cubelOO; 365 nm; ~4 mW / cm2); 3°) a solution comprising 0.2 mL of MMA and 0.8 mL of TMPTA (mass proportion MMA / TMPTA 20 / 80) is introduced into the suspension using a syringe, with stirring; 4°) the suspension obtained at the end of point 3°) is irradiated under UV for 4 minutes; it then changes from a transparent appearance to a milky appearance. 5°) cyclohexane is then added to remove the residual photoinitiator. The suspension is centrifuged at 10,000 rpm for 5 minutes, then the cyclohexane is removed and replaced with ethanol. The suspension is centrifuged again at 10,000 rpm for 5 minutes to remove the residual unencapsulated bromocresol green; then, 6) the particles are recovered by filtration on a pleated filter, rinsed with water and dried at room temperature.

[0071] 2.2 Encapsulation of Disperse Black 9 in copolymeric particles of MMA / TMPTA

[0072] The encapsulation of Disperse Black 9 by copolymerization of MMA and TMPTA is prepared according to the same protocol described in point 2.1 above.

[0073] 2.3 Encapsulation of 4-nitrobenzaldehvde(2.4-dinitrophenvl) hvdrazine in MMA / TMPTA copolymer particles

[0074] The encapsulation of 4-nitrobenzaldehyde(2,4-dinitrophenyl)hydrazine by copolymerization of MMA and TMPTA is prepared according to the following protocol: 1°) 0.2 mL of MMA and 0.8 mL of TMPTA (mass ratio MMA / TMPTA 20 / 80) are placed in a pillbox; 2°) 50 mg of Irgacure™ 819 are added, then the mixture is placed under magnetic stirring in a UV tank (of the same reference as that used in point 2.1 above); 3°) 5 mg of hydrazine in cyclohexane are added to the UV tank; 4) the suspension is irradiated under UV for 4 minutes; it then changes from a transparent appearance to a milky appearance; 5°) cyclohexane is added to remove the residual photoinitiator. The suspension is centrifuged at 10,000 rpm for 5 minutes. The cyclohexane is removed and replaced with ethanol. The suspension is centrifuged again at 10,000 rpm for 5 minutes, to remove residual unencapsulated hydrazine; then, 6°) the particles are recovered by filtration on a pleated filter, then placed in 10 mL of cyclohexane.

[0075] 2.4 Encapsulation of bromocresol purple, in the form of sodium salt, in d MMA / TMPTA copolymer particles

[0076] The encapsulation of bromocresol purple by copolymerization of MMA and TMPTA is prepared according to the following protocol: 1°) 10 mg of bromocresol purple and 113 mg of Irgacure™ 819 are weighed and solubilized, if necessary using ultrasound, in 0.4 mL of MMA and in 1.6 mL of TMPTA (MMA / TMPTA mass proportion 22 / 78); 2°) the above mixture is then introduced by pipette into 20 mL of cyclohexane; 3°) the solution obtained in point 2°) is mixed manually until a homogeneous mixture is obtained; 4) the solution is irradiated under UV for 2 minutes; it then changes from a transparent yellow appearance to a milky yellow appearance; 5°) the solution is centrifuged at 10,000 rpm for 5 minutes, then the cyclohexane is removed and replaced with ethanol. The solution is centrifuged again at 10,000 rpm for 5 minutes to rinse the particles, remove the photoinitiator and the residual unencapsulated bromocresol purple; then, 6) the particles are recovered by filtration in a pleated filter, rinsed with water and dried at 80°C.

[0077] 3. Resistance to a solvent and exposure to a simulant of MMA particles / TMPTA encapsulating bromocresol purple

[0078] The particles obtained at the end of point 2.4 are placed in contact with ethanol for approximately 5 minutes.

[0079] As a result, after this contact, the particles did not dissolve. This confirms that they are perfectly resistant to ethanol, which makes it possible to limit the migration of the colored indicator into the solvent.

[0080] A drop of sodium hydroxide - simulating a toxic compound to be detected - diluted in 1-butanol, is then placed on the surface of these particles. A change in color is then observed: the particles go from yellow to blue. This therefore confirms that the simulant reaches the interior of the particles and that these allow the detection of the presence of a chemical compound.

[0081] 4. Use of a spray comprising particles impregnated with an indicator colored and / or particles encapsulating a colored indicator, versus simulants

[0082] 4.1 Spraying a composition which comprises an organic dispersant phase and one or more colored indicators on contaminated surfaces after exposure to DPCP and soda

[0083] 4.1.1. Composition comprising a single colored indicator

[0084] First of all, drops of diphenyl chlorophosphate (more simply noted DPCP), simulating a toxic substance to be detected, were deposited in several places on the following supports: - protective glasses (of the type used in chemistry laboratories); - nitrile gloves; and - absorbent paper.

[0085] At the same time, the silica particles impregnated with Disperse Black 9 (obtained in point 1 above) are suspended in 28.5 g of cyclohexane.

[0086] The suspension is then introduced into a mechanical spray and is sprayed onto the various supports contaminated by DPCP.

[0087] We then observe: - on the one hand, the deposition of a yellow layer on these supports, indicating good adhesion of the particles; and on the other hand, - purple stains in the contaminated areas, confirming that Disperse Black 9 has reacted to the presence of DPCP.

[0088] 4.1.2. Composition comprising two different colored indicators

[0089] Drops of DPCP and sodium hydroxide diluted in 1-butanol were deposited in several places on supports of the same type as those used in point 4.1.1.

[0090] The following protocol is then implemented: 1°) 17.59 g of the Disperse Black 9 suspension prepared previously (at point 4.1.1) in cyclohexane is poured into a 200 mL glass bottle; 2) the polyethylene particles impregnated with bromocresol purple (obtained in point 1) are suspended in 12.36 g of cyclohexane; 3°) 4.21 g of the bromocresol purple suspension are added to the 200 mL bottle, with 12.65 g of cyclohexane; the mixture is then introduced into a mechanical trigger spray and then sprayed onto the various contaminated surfaces.

[0091] We then observe: - on the one hand, the deposition of a yellow layer on these supports, indicating good adhesion of the particles; and on the other hand, - purple and blue spots at the locations contaminated by DPCP and soda respectively, confirming that the two colored indicators reacted well to the presence of these simulants.

[0092] 4.2 Spraying a composition which comprises an organic dispersant phase and several colored indicators, on a surface before exposure to DPCP and soda

[0093] The spray is here deposited in the form of a patch on a plastic film (supplied by Pavo PP, with commercial reference 8007882).

[0094] To do this: 1°) 21 mg of polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (noted PSPEPB) are dissolved in 20 g of cyclohexane; PSPEPB has a mass average molar mass Mw ~89,000 and is supplied by Sigma Aldrich with the commercial reference 200565-250G; 2°) 0.4 g of each of the particles encapsulating bromocresol green, Disperse Black 9 and 4-nitrobenzaldehyde(2,4-dinitrophenyl)hydrazine (respectively obtained in points 2.1, 2.2 and 2.3) are then added; then 3°) 16 glass beads with a diameter of 10 mm are added and the mixture is stirred for 5 minutes with a vortex.

[0095] A homogeneous suspension is then obtained, introduced into a spray and is then sprayed twice onto the plastic film, in the form of a patch. A drying time at room temperature is observed after each spraying.

[0096] The plastic film is then exposed to DPCP and soda.

[0097] Sharp color shifts are observed at the patch level.

[0098] 4.3 Spraying a composition which comprises an aqueous dispersant phase and a colored indicator, on a contaminated surface after exposure to soda.

[0099] A suspension is prepared by implementing the following steps: 1°) 0.96 g of Glucopon are dissolved in 20 g of water; 2°) the pH is adjusted to a value equal to 4, by adding 1M phosphoric acid; 3°) 400 mg of particles encapsulating bromocresol green (obtained in point 2.1) are added; 4) 16 glass beads with a diameter of 9 mm are added and the mixture is vortexed for 10 minutes; 5°) 4 mL of THF are added to break the foam formed; a suspension of a flaky solid is obtained and is introduced into a mechanical trigger spray.

[0100] The suspension is then sprayed onto a plastic film (of the same reference as that used in point 4.2), which includes a drop of soda diluted in 1-butanol.

[0101] A colorimetric shift towards light blue is observed when the suspension and the soda are brought into contact.

[0102] 4.4 Spraying a composition which comprises an aqueous dispersant phase and a colored indicator, on a surface before exposure to soda

[0103] The suspension obtained in point 4.3 is sprayed twice onto a plastic film (of the same reference as those used above), in the form of a patch. A drying time, at room temperature, is observed after each spraying.

[0104] The plastic film is then exposed to soda diluted in 1-butanol.

[0105] A sharp color shift is observed at the patch.

[0106] 5. Use of a spray comprising particles encapsulating an indicator colorful, facing toxic war compounds

[0107] Three different sprays are used in this part: - the first spray comprises the particles encapsulating Disperse Black 9, obtained in point 2.2; - the second spray comprises the particles encapsulating 4-nitrobenzaldehyde(2,4-dinitrophenyl)hydrazine, obtained in point 2.3; and - the third spray includes these two types of particles.

[0108] Each of these sprays are obtained by implementing the following steps: 1°) 21 mg of PSPEPB are dissolved in 20 g of cyclohexane; PSPEPB has a mass average molar mass Mw -89,000 and is supplied by Sigma Aldrich with the commercial reference 200565-250G; 2°) 0.4 g of the particles are then added; then 3°) 16 glass beads with a diameter of 10 mm are added and the mixture is stirred for 5 minutes with a vortex.

[0109] Then, each spray is sprayed twice, in the form of a patch, onto a separate plastic film. A drying time at room temperature is observed after each spray.

[0110] The plastic films are then exposed to the following 4 toxic war compounds: [YES] [Chem.l]

[0112] Sarin compound is a G-series organophosphorus compound, sulfur mustard and Lewisite are both vesicant compounds.

[0113] To do this, 1.2 pL of each of these toxic compounds are deposited on the plastic films via a multi-channel electronic pipette.

[0114] The supports are scanned before exposure to toxic compounds and then after 5 minutes and after 1 hour.

[0115] It follows that: - the first spray can detect Sarin, Sulphur Yperite and Lewisite; - the second spray allows the detection of compound A-230; and - the third spray can detect Sarin, compound A-230, sulfur mustard gas and Lewisite. References cited

[0116] [1] Shrishty Bakshi et al., Advanced Functional Materials, 2022,32, 2103496

Claims

Claims

1. A colorimetric detection device for detecting at least one chemical compound, in the form of a spray and containing a composition which comprises a dispersing phase in which is dispersed at least one colored indicator capable of changing in the presence of the chemical compound, characterized in that the colored indicator is present in the dispersing phase in the form of a plurality of solid particles which are impregnated with the colored indicator or in which the colored indicator is encapsulated.

2. Device according to claim 1, in which the solid particles are made of an inorganic material chosen from silica, alumina, zinc oxide, titanium oxide or zeolite, preferably silica.

3. Device according to claim 1, in which the solid particles are made of an organic material, preferably of a polymeric or copolymeric material comprising at least one monomer chosen from ethylene, methyl (meth)acrylate, and trimethylolpropane triacrylate and, better still, chosen from methyl (meth)acrylate and trimethylolpropane triacrylate.

4. Device according to any one of claims 1 to 3, wherein the solid particles have a number average size of between 0.1 pm and 100 pm, preferably between 5 pm and 50 pm.

5. Device according to any one of claims 1 to 4, wherein the colored indicator is chosen from anthraquinone compounds, azo compounds, triarylmethane compounds, xanthenic compounds, indigo compounds, metal complexes, compounds comprising at least one stilbene group, coumarin compounds, compounds comprising at least one cyanine group, compounds comprising at least one phthalocyanine group, compounds comprising at least one porphyrin group, compounds comprising at least one hydrazone group.

6. Method for detecting the presence or absence of at least one chemical compound, comprising at least the following successive steps: - a step of spraying the composition contained in the colorimetric detection device as defined according to claims 1 to 5, onto a surface capable of comprising the chemical compound to be detected; - a step of deducing the presence or absence of the chemical compound on the surface, based on a possible colorimetric change.

7. Method for detecting the presence or absence of at least one chemical compound, comprising at least the following successive steps: - a step of spraying the composition contained in the colorimetric detection device as defined according to claims 1 to 5, onto a surface not comprising the chemical compound; - a step of bringing the surface into contact with a medium likely to include the chemical compound; - a step of deducing the presence or absence of the chemical compound on the surface, based on a possible colorimetric change.

8. A detection method according to claim 6 or claim 7, wherein the chemical compound is selected from toxic warfare compounds and toxic industrial compounds.