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: COLORI-METRIC 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 be applied to the detection of toxic chemical compounds, such as toxic warfare compounds or toxic industrial chemical compounds (known as TIC). Prior art

[0005] CBRN-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 natural or environmental disasters, during which toxic compounds are released into the environment.

[0006] It is therefore important to be able to detect the presence of such toxic compounds in the event of CBRN-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, hereafter [1]) developed a spray comprising a polyprolactone polymer and one or two colored indicators in chloroform solution for the detection of Fe2+ ions, Fe3+ ions, and ammonia only. This spray is applied as nanofibers to various types of surfaces simply using compressed gas. The nanofibers are generated only during the spraying step. Moreover, since the colored indicators in this spray are in chloroform solution, they can easily interact with each other before being sprayed as nanofibers.

[0009] The inventors have therefore set themselves the goal of providing a colorimetric detection device that does not have the above disadvantages, that is to say a device that can detect and, ideally, discriminate 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 having to use a solvent that is hazardous to health and the environment, such as a chlorinated solvent. Description 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 sprayer and containing a composition which includes a dispersing phase in which is dispersed at least one colored indicator capable of changing color 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 what follows, the device of the invention can more simply be called a “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 includes a dispersing phase in which several colored indicators are dispersed in the form of a plurality of solid particles.

[0014] A "color indicator" is understood to mean a substance which takes on at least one characteristic color in the presence of a chemical compound, or, in other words, a chemical substance which has 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 within the dispersing phase and thus 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 within such a device, since these colored indicators cannot interact with each other. This then allows for 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 coloured indicator or encapsulating the coloured indicator can 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 copolymer 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 copolymer material.

[0019] Such particles can be obtained by polymerization of one or more monomers - this polymerization can then be a bulk, solution, suspension, dispersion or emulsion polymerization, 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 a suitable solvent.

[0020] In the case where the particles are made of a crosslinked polymeric or copolymer material, then this crosslinking can result in: - of a 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 polymerization and crosslinking are carried out in two steps; or - in the case of a copolymer 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 in the dispersing phase.

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

[0023] In any event, the solid particles are preferably microparticles, that is to say, they have an average number size of between 0.1 µm and 100 µm and, even better, between 5 µm and 50 µm. This average number size can be determined by laser diffraction particle size analysis, for example using a laser particle size analyzer such as the one 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 any color change (or so-called colorimetric change) of the colored indicator, when it is in the presence of the chemical compound, even when the latter is present only 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 the surface of a tire, a garment or even a shoe.

[0028] Furthermore, the dispersing phase of the composition contained in the device can be an aqueous or organic phase and may optionally include 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 by 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 detached from the surface by simple cleaning with water, whereas when the dispersing phase is an organic phase, the composition can be detached 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 one wishes to detect.

[0033] Even better, when several colored indicators are used, they are advantageously chosen so that each of them exhibits at least one color change that contrasts with the others when in contact with at least one specific chemical compound. This allows for the discrimination of chemical compounds when several chemical compounds are present. These colored indicators may advantageously be those that exhibit 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 be colorless.

[0034] Depending on the chemical compound to be detected, the colored indicator can be chosen from among anthraquinone compounds, azo compounds, triarylmethane compounds, xanthenic compounds, indigo compounds, metal complexes, compounds comprising at least one stilbene group, coumarine 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.

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

[0036] By way of 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" according to 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, the 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" according to English terminology), 2,2'-[[4-[(4-nitrophenyl)ado]phenyl]imino]bisethanol (also known as "Disperse Red 19" according to English terminology), (4Z)-4-[(l-hydroxynaphthalen-2-yl-hydrazi-nylidene]-7-nitro-3-oxo Y-naphthalene-l-sulfonate sodium (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) English terminology), methyl orange (also called helianthin), 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), 4-amino-5-hydroxy-3-(4-nitrophenylazo)-6-(phenylazo)naphthalene-2,7-sodium disulfonate (also known as "Blue Black Naphthol"), the, (2,2-dimethyl-l,3-dihydroperimidine-6-yl)-(4-phenylazo-l-naphthyl)diazene (also known as "Sudan Black B" according to English terminology), disodium 6-hydroxy-5-[(4-sulfonatophenyl)azo]naphthalene-2-sulfonate (also known as "Sunset Yellow S"), tartrazine, Evans blue, 4-[4-(phenylazo)phenylazo]-o-cresol (also known as "Disperse Yellow 7" according to English terminology), 4'-nitro-4-dimethylaminoazobenzene.

[0037] By way of 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, 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-phenylbenzenemethanol.

[0038] Examples of xanthenic compounds may include [9-(2-carboxyphenyl)-6-diethylamino-3-xanthenylidene]-diethylammonium chloride (also known as "Rhodamine 610"), rhodamine 6G possibly in the form of the perchlorate salt, rhodamine B, hydrated sulforhodamine 101, fluoresceinamine (in particular Isomer I), and rhodamine 110 chloride.

[0039] Indigo may be mentioned as an example of indigo-based compounds.

[0040] As examples of metal complexes, mention may be made of trisodium 5-nitroso-6-oxidonaphthalene-2-sulfonate complexed with iron (III) (also called "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 known as "Coumarin 30"), 2,3,6,7-tetrahydro-10-(3-pyridyl)-1H,5H,1llH-[1]benzopyrano[6,7,8-11]quinolizin-11-one (also known as "Coumarin 510"), 3-(2-Benzothiazolyl)-7-(diethylamino)coumarin (also known as "Coumarin 6").

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

[0044] Examples of compounds comprising a phthalocyanine group may include 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 mono-nosodium hydrated oxygen salt.

[0045] Does the invention also relate to a method for detecting the presence or absence of at least one chemical compound?

[0046] According to a first particular embodiment, the process comprises at least the following successive steps: - a step of spraying the composition contained in the colorimetric detection device as defined above, onto a surface likely to include 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 color change.

[0047] The spraying step is advantageously implemented here once the surface on which the presence or absence of at least one chemical compound is to be detected has been brought into contact with a medium containing 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 includes an aqueous dispersing phase. Indeed, once the deduction step has been carried out, it will be easy to clean the surface onto which the composition has been sprayed with water, allowing the surface to be reused.

[0050] According to a second particular embodiment, the process comprises at least the following successive steps: - a step of spraying the composition contained in the colorimetric detection device as defined above, onto a surface not containing 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 color change.

[0051] The spraying step is therefore advantageously implemented here before the surface on which the presence or absence of at least one chemical compound is to be detected is brought into contact with a medium containing 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 preferable that the composition contained in the device be water-resistant. Therefore, it is advantageous to use a composition contained in the spray that includes an organic dispersing phase. Indeed, once the deduction step has been carried out, it will be easy to clean the surface onto which the composition has been sprayed by rubbing and / or using decane, thus allowing the surface to be reused.

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

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

[0056] The deduction step can easily be carried out with the naked eye, upon observation of a color change on 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 that can be detected by the process of the invention can be toxic compounds, such as toxic warfare compounds or toxic industrial compounds.

[0058] More specifically, toxic warfare compounds can be G-series organophosphorus compounds (such as Sarin or Tabun), V-series organophosphorus compounds (such as compound VX), other organophosphorus compounds such as compounds A-232, A-230, A-234 and A-242, vesicant compounds (such as Sulphur Mustard, Nitrogen Mustard and Lewisite) or even arsenic compounds (such as Clark 1 and Clark 2 compounds).

[0059] Other features and advantages of the invention will become apparent from the following supplementary description.

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

[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 procedure: 1°) weighing the powder in a flask; 2°) weighing the quantity of coloured indicator required (0.1% or 0.5% mass of coloured indicator relative to the mass of powder) in a pillbox; 3°) adding a solvent allowing the coloured indicator to be solubilised in the pillbox so as to have a concentration of approximately 30 mg / mL; 4°) pouring the colored indicator solution into the flask over 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 during 10 minutes to homogenize the suspension in the balloon and raise the temperature; *slow pressure reduction down to 400 mbar to slowly distill the solvent; *when the powders begin to clump together to form a ring that attaches to the wall of the balloon, the pressure has dropped more rapidly until complete drying.

[0064] The table below shows the two prepared impregnated powders, with details of the nature of the powder, the color indicator, the proportion of color 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 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 in a co-material Lymeric

[0069] 2.1 Encapsulation of bromocresol green in copolymer 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 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 (MMA / TMPTA mass ratio 20 / 80) is introduced into the suspension using a syringe, under agitation; 4°) The suspension obtained at the end of point 3°) is irradiated under UV light 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 MMA copolymer particles / 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-dinitrophenyl)hvdrazine in MMA / TMPTA copolar 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 (MMA / TMPTA mass ratio 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 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 eliminate 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 copolar 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 ratio 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 any 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 brought into 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 limits 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 deposited on the surface of these particles. A color change is then observed: the particles change from yellow to blue. This confirms that the simulant penetrates the particles and that they 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, compared to simulants

[0082] 4.1 Spraying of a composition comprising an organic dispersing phase and one or more colored indicators on contaminated surfaces after exposure to DPCP and caustic soda

[0083] 4.1.1. Composition comprising a single color indicator

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

[0085] In parallel, 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 the 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 spots at the contaminated areas, confirming that Disperse Black 9 reacted well 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 previously prepared Disperse Black 9 suspension (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 bromocresol purple suspension are added to the 200 mL bottle, along with 12.65 g of cyclohexane; the mixture is then introduced into a mechanical trigger sprayer and 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 stains at the locations that were contaminated respectively by DPCP and soda, confirming that the two color indicators reacted well to the presence of these simulants.

[0092] 4.2 Spraying of a composition comprising an organic dispersing phase and several colored indicators, on a surface before exposure to DPCP and sodium hydroxide

[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 in a vortex.

[0095] A homogeneous suspension is then obtained, introduced into a spray bottle, and subsequently 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 sodium hydroxide.

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

[0098] 4.3 Spraying of a composition comprising an aqueous dispersing phase and a coloured indicator, on a surface contaminated after exposure to caustic soda.

[0099] A suspension is prepared by implementing the following steps: 1°) 0.96 g of Glucopon are solubilized in 20 g of water; 2°) the pH is adjusted to a value equal to 4, by adding phosphoric acid to IM; 3°) 400 mg of the particles encapsulating bromocresol green (obtained in point 2.1) are added; 4°) 16 glass beads with a diameter of 9 mm are added and then 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 sodium hydroxide diluted in 1-butanol.

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

[0102] 4.4 Spraying of a composition comprising an aqueous dispersing phase and a colored indicator, on a surface before exposure to sodium hydroxide

[0103] The suspension obtained in step 4.3 is sprayed twice onto a plastic film (of the same type 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 sodium hydroxide diluted in 1-butanol.

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

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

[0107] Three different sprays are used in this part: - the first spray includes 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 is 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 trade 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 in a vortex.

[0109] Next, 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 spraying.

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

[0112] The compound Sarin is an organophosphorus compound of the G series, Sulphur Yperite and Lewisite are both vesicant compounds.

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

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

[0115] It follows that: - the first spray allows the detection of Sarin, Sulphurous Mustard Gas and Lewisite; - the second spray allows for the detection of compound A-230; and - the third spray allows the detection of Sarin, compound A-230, sulfur mustard gas and Lewisite. References cited

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

Claims

Demands

1. A colorimetric detection device for the detection of at least one chemical compound, in the form of a sprayer and containing a composition which includes a dispersing phase in which is dispersed at least one colored indicator capable of changing color 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, wherein the solid particles are of an inorganic material selected from silica, alumina, zinc oxide, titanium oxide or zeolite, preferably silica.

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

4. Device according to any one of claims 1 to 3, wherein the solid particles have an average number 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 colour indicator is selected from anthraquinone compounds, azo compounds, triarylmethane compounds, xanthenic compounds, indigo compounds, metal complexes, compounds comprising at least one stilbene group, coumarinic 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. A 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 color change.

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