Method for rapidly detecting excessive methanol in gasoline on site

Abstract

The invention discloses a method for rapidly detecting overproof methanol in gasoline on site, and belongs to preparation of a phosphorescent sensing material with afterglow response to overproof methanol in gasoline and a method for rapidly detecting gasoline with overproof methanol content on site by using the phosphorescent sensing material. The phosphorescent sensing material disclosed by the invention does not contain toxic and harmful substances and is low in manufacturing cost. According to a detection method based on the sensing material, macroscopic afterglow is used as a detection index, and whether the content of methanol in gasoline exceeds the standard or not can be judged within four minutes. The method has the advantages of good selectivity to methanol, simple detection operation, obvious phenomenon, no need of professional training of personnel, no use of toxic and harmful reagents in the detection process, and no pollution to the environment. The sensing material and the detection method can completely meet the requirements of the national standard on rapid on-site detection of the methanol content in gasoline.

Description

Technical Field

[0001] The invention belongs to the field of on-site rapid detection of methanol content, and particularly relates to the preparation of a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline, and a method for using the same for on-site rapid detection of gasoline with excessive methanol content. Background Art

[0002] Since methanol has the characteristics of low price, good flammability and good solubility in gasoline, the problem of illegally adding methanol to gasoline has always existed. The national standard stipulates that the methanol content in gasoline shall not exceed 0.3% (mass fraction). When gasoline with excessive methanol is burned in an internal combustion engine, it will emulsify the lubricating oil, increase friction, and cause damage to the engine, oil pump, and oil gauge sensor materials. Gasoline with excessive methanol also has a strong corrosive effect on oil pipelines. Long-term use will cause oil leakage and the risk of vehicle spontaneous combustion. Therefore, the detection of methanol content in gasoline is a necessary part of gasoline quality control.

[0003] Gasoline is a fast-moving consumer product, and delayed test results are of little significance for the quality control of fast-moving consumer products. In the actual sales process, the oil products are often delivered to consumers before the test results come out. Since oil quality problems occur from time to time, it is of great significance to conduct on-site rapid testing of gasoline quality at gas stations to ensure the last checkpoint of oil quality, which is of great significance to ensuring user safety, maintaining the order of the fuel market, and combating oil-related crimes. Major domestic gasoline sales companies have listed whether the methanol content in gasoline exceeds the standard as a mandatory inspection item.

[0004] There are several methods for detecting methanol, including gas chromatography, liquid chromatography, colorimetry, and spectrophotometry. Gas chromatography, liquid chromatography, and spectrophotometry all rely on tester materials, require fixed testing sites, have long testing processes, and are complex and time-consuming to measure, and are not suitable for on-site testing. Although the colorimetric method does not require complex instrument materials and has low testing costs, it requires the use of an oxidant to oxidize methanol into formaldehyde, then add a color developer to develop color, and then compare colors. The oxidants used in this method include potassium permanganate, concentrated sulfuric acid, nitric acid, vanadate, cerium nitrate, etc., all of which are strong oxidants. The use of these strong oxidants in places such as gas stations poses a safety hazard, and after use, hazardous waste will be generated, increasing the cost of use and environmental pollution. In addition, this method has many steps, requires professional operation, and is time-consuming. In addition, since the oxidation reaction is difficult to carry out quantitatively, the accuracy and detection limit of its determination cannot meet the national standard requirements. At present, some methanol detection sensing materials, material parts, and test barrels disclosed in invention patents or utility model patents have simple detection steps, but these methods all use one or more of strong acids, strong bases, and strong oxidants, which pose safety hazards and environmental impacts. Moreover, the accuracy and detection limits of these methods cannot meet the national standards. Therefore, it is urgent to develop a fast, simple, low-cost, and hazardous waste-free on-site rapid detection method for methanol. Summary of the invention

[0005] Compared with fluorescent sensing materials, room temperature phosphorescent materials have the advantages of long luminescence lifetime, large Stokes shift and high signal-to-noise ratio, showing great application prospects in the field of sensing. In particular, room temperature phosphorescent materials with a lifetime greater than 100 ms can emit a long afterglow visible to the naked eye, which is more conducive to the development of room temperature phosphorescent materials into sensing materials for rapid on-site detection. However, since room temperature phosphorescent materials are very sensitive to water and oxygen in the environment, their application is greatly limited.

[0006] Cluster luminescent materials are non-traditional luminescent materials that have attracted much attention in recent years. Cluster luminescent materials can often emit phosphorescence due to the unique spatial conjugation effect and the suppression of non-radiative transitions by the three-dimensional structure, and some are even room temperature phosphorescent. Among them, polymer cluster luminescent phosphorescent materials have the advantages of simple synthesis, easy adjustment of phosphorescent properties, insensitivity to water and oxygen, processability, and low toxicity, which have attracted widespread attention. The luminescent properties of polymer cluster luminescent phosphorescent materials are directly related to the distance between polymers and the strength of the interaction between functional groups, so it is very sensitive to the structure of the object to be detected and can be used as a sensing material for specific identification of the target.

[0007] The purpose of the present invention is to focus on the structure, properties and influence of methanol on cluster luminescence, with the goal of specifically detecting methanol, select acrylamide cluster luminescent polymer, use light-triggered in-situ polymerization on porous materials, and construct a polymer material with a specific cluster structure by adopting an anti-solvent deposition method, and further use a water-soluble polymer film for encapsulation to prepare a sensing material for rapid on-site detection of methanol content in gasoline and a preparation method thereof. The sensing material uses afterglow as a detection index, and can realize rapid on-site determination of methanol content in gasoline. Take a certain amount of gasoline sample in a test tube, immerse the above-mentioned sensing material in gasoline, and let it stand for 4 minutes. Take out the sensing material and put it in a dark box or a room with a blackout curtain, irradiate the sensing material with an ultraviolet flashlight for 10 seconds, then turn off the light source, and observe the afterglow of the sensing material. For gasoline samples that meet the national standard, the sensing material presents an obvious green afterglow, while for gasoline samples whose methanol content exceeds the national standard, there is no afterglow.

[0008] The object of the present invention is achieved by providing a method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline, the specific steps of which are as follows: Add acrylamide, 3-substituted propylene derivatives and water into a photoreactor, then put in a strip-shaped porous material, stir and pass nitrogen to drive out oxygen for 15 minutes, add a photopolymerization initiator, continue stirring under nitrogen protection and light, and perform photo-initiated in-situ polymerization for a certain period of time. After the reaction is completed, take out the porous material after the photo-initiated in-situ polymerization, immerse it in an organic solvent containing methanol for a certain period of time for anti-solvent deposition, take out the porous material after the anti-solvent deposition, drain it, immerse it in an aqueous solution of a water-soluble polymer compound for packaging, take it out and drain it; put the drained porous material into an oven and dry it at a certain temperature for a certain period of time to obtain a methanol sensing material, and seal and store the dried methanol sensing material for standby use.

[0009] Furthermore, the 3-substituted propylene derivative, whose 3-position substituent is an N-substituted aromatic imide, includes but is not limited to 1,8-naphthalene diimide, 2,3-naphthalene diimide, phthalimide, 4,5-dichlorophthalimide, tetrachlorophthalimide, pyromellitic acid diimide, 1,8,4,5-naphthalenetetracarboxylic acid diimide, and 3,4,9,10-perylene dicarboximide.

[0010] Furthermore, the photopolymerization initiator is an acrylamide photopolymerization initiator.

[0011] Furthermore, the mass ratio of the 3-substituted propylene derivative to acrylamide is 1:50-100.

[0012] Furthermore, the methanol-containing organic solvent is ethanol, acetone, acetonitrile, butanone, ethyl acetate, an organic solvent that has a certain degree of miscibility with water, a mixture of one or more of them with methanol, and the volume ratio of methanol in the methanol-containing organic solvent is not less than 50%.

[0013] Furthermore, the water-soluble polymer compound is selected from: sodium carboxymethyl cellulose, polyvinyl alcohol, water-soluble starch, gum arabic, sodium alginate, bone meal, gelatin, casein, polyethylene glycol, or a mixture of several of them, and the mass concentration of the aqueous solution of the water-soluble polymer compound is 0.5~30%.

[0014] Furthermore, the strip-shaped porous material includes: porous membranes of various polymer materials, silica gel plates, filter papers, and the size is 3 cm long × 1 cm wide.

[0015] Furthermore, the method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline is characterized in that the time for in-situ polymerization is 10 to 100 minutes with continuous stirring under nitrogen protection and illumination.

[0016] Furthermore, the time for immersing the porous material after light-induced in-situ polymerization in the organic solvent containing methanol is 10 to 20 minutes.

[0017] The sensor material for on-site rapid detection of methanol in gasoline prepared by the above-mentioned preparation method of the present invention is used for on-site rapid detection of whether the methanol content in gasoline exceeds the national standard. The specific detection steps are as follows: Take 5 mL of gasoline sample in a test tube, immerse a sensing material for on-site rapid detection of methanol in gasoline prepared by the above preparation method into the gasoline, let it stand for 4 minutes, take out the sensing material and put it in a dark box or a room with a blackout curtain, irradiate the sensing material with an ultraviolet flashlight for 10 seconds, then turn off the light source and observe the afterglow of the sensing material. For gasoline samples that meet the national standards, the sensing material shows an obvious green afterglow, while for gasoline samples with methanol content exceeding the national standard, the sensing material has no afterglow.

[0018] Specifically, to achieve the purpose of the present invention, the present invention adopts the following technical solutions, and the specific technical methods are as follows: Add acrylamide, 3-substituted propylene derivatives and water to the photoreactor, then put in a strip of porous material (3 cm long × 1 cm wide), stir and pass nitrogen to drive oxygen for 15 minutes, add a photopolymerization initiator, continue stirring under nitrogen protection and light, and perform photoinitiated in-situ polymerization for a certain period of time. After the reaction is completed, take out the porous material and immerse it in an organic solvent containing methanol for a certain period of anti-solvent deposition. Take out the porous material and drain it, then immerse it in an aqueous solution of a water-soluble polymer compound for encapsulation, take it out and drain it. Put the porous material in an oven and dry it at a certain temperature for a certain period of time to obtain a methanol sensing material. The dried sensing material is sealed and stored for standby use.

[0019] The 3-substituted propylene derivative described in the above method, whose 3-position substituent group is an N-substituted aromatic imide, includes but is not limited to 1,8-naphthalene diimide, 2,3-naphthalene diimide, phthalimide, 4,5-dichlorophthalimide, tetrachlorophthalimide, pyromellitic acid diimide, 1,8,4,5-naphthalenetetracarboxylic acid diimide, and 3,4,9,10-perylene dicarboximide.

[0020] The photopolymerization initiator described in the above method is a commercially available acrylamide photopolymerization initiator.

[0021] The mass ratio of the 3-substituted propylene derivative described in the above method to acrylamide is 1:50-100.

[0022] The methanol-containing organic solvent described in the above method is ethanol, acetone, acetonitrile, butanone, ethyl acetate, etc., an organic solvent that has a certain miscibility with water, a mixture of one or more of them with methanol, and the volume ratio of methanol in the methanol-containing organic solvent is not less than 50%.

[0023] The water-soluble polymer compound described in the above method includes: sodium carboxymethyl cellulose, polyvinyl alcohol, water-soluble starch, gum arabic, sodium alginate, bone meal, gelatin, casein, polyethylene glycol, one or a mixture of several thereof, and the mass concentration of the aqueous solution is 0.5-30%.

[0024] The porous materials described in the above method include: porous membranes made of various polymer materials, silica gel plates, filter papers, etc.

[0025] The time for in-situ polymerization under nitrogen protection and light with continuous stirring described in the above method is 10 to 100 minutes.

[0026] The time for immersing the porous material in the organic solvent containing methanol in the above method is 10 to 20 minutes.

[0027] The above method is used to prepare a sensing material for rapid on-site detection of methanol in gasoline, which can be used to rapidly detect whether the methanol content in gasoline exceeds the national standard. The specific detection method is as follows: Take 5 mL of gasoline sample in a test tube, immerse the above-mentioned sensing material in gasoline, and let it stand for 4 minutes. Take out the sensing material and place it in a dark box or a room with a blackout curtain. Irradiate the sensing material with an ultraviolet flashlight for 10 seconds, then turn off the light source and observe the afterglow of the sensing material. For gasoline samples that meet the national standard, the sensing material shows an obvious green afterglow, while for gasoline samples with methanol content exceeding the national standard, the sensing material has no afterglow.

[0028] The beneficial effects of the present invention are as follows: the present invention targets the structure, properties and influence of methanol on cluster luminescence, takes the specific detection of methanol as the goal, selects acrylamide cluster luminescent polymer, adopts light-triggered in-situ polymerization on porous materials, and constructs a polymer material with a specific cluster structure by adopting the anti-solvent deposition method, so that its phosphorescence afterglow only responds specifically to methanol, but does not respond to other common organic solvents, and has strong anti-interference. Further, a water-soluble polymer film is used for encapsulation, which reduces the interference of water and oxygen in the air on the sensing material, so that the environmental adaptability of the sensing material is strong, and it is easier to store and use. More importantly, the sensing material does not contain toxic and harmful substances, and the detection process does not use toxic and harmful reagents, and there is no pollution to the environment. The detection method proposed by the present invention is simple to operate, the phenomenon is obvious, and it is easy to judge. Without professional training, it can detect whether the methanol content in gasoline exceeds the national standard within 4 minutes. The sensing material and the detection method can fully meet the requirements of the national standard for rapid on-site detection of methanol content in gasoline, and have a relatively broad market prospect. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. The described specific embodiments are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example 1: Preparation of sensing material for detecting methanol content in gasoline Add 10 g acrylamide, 0.2 g N-allyl-4,5-dichlorophthalimide and 80 mL water to a 250 mL photoreactor, make a commercially available nylon microporous filter membrane with a pore size of 0.45 μm into a size of 1 cm wide × 3 cm long (the size of the following embodiments is the same as this embodiment), and put it into the photoreactor. Stir and pass nitrogen to drive oxygen for 15 minutes, add 10 mL of an aqueous solution containing 0.02 g 2,2'-azo (2-amidinopropane) dihydrochloride (V-50), and irradiate the reaction for 60 minutes with a 250 W straight tube medium pressure mercury lamp under nitrogen protection. After the reaction is completed, take out the nylon microporous filter membrane, put it into a mixed solution of 20 mL methanol and acetone (V methanol: V acetone = 60:40), and let it stand for 10 minutes. Take it out and drain it, then immerse it in 20 mL of 15wt% polyvinyl alcohol (M = 20000) aqueous solution and let it stand for 5 minutes. The nylon microporous filter membrane was taken out and drained, and then placed in an oven and dried at 70° C. for 180 minutes to obtain a methanol sensing material. The dried sensing material was sealed and stored for later use.

[0031] Example 2: Preparation of sensing material for detecting methanol content in gasoline 10 g acrylamide, 0.2 g N-allyl-1,8-naphthalimide and 80 mL water were added to a 250 mL photoreactor, and a commercially available nylon microporous filter membrane with a pore size of 0.45 μm was made into a size of 1 cm × 3 cm and placed in the photoreactor. Stir and pass nitrogen to drive oxygen for 15 minutes, add 10 mL of an aqueous solution containing 0.015 g 2,2-dimethoxy-2-phenylacetophenone, and irradiate the reaction with a 250 W straight tube medium pressure mercury lamp for 100 minutes under nitrogen protection. After the reaction, take out the nylon microporous filter membrane, put it into a mixed solution of 20 mL methanol and ethanol (V methanol: V ethanol = 90:10), and let it stand for 20 minutes. Take it out and drain it, and then immerse it in 20 mL of a 30wt% polyethylene glycol 2000 aqueous solution and let it stand for 5 minutes. Take out the nylon microporous filter membrane, drain it, put it in an oven and dry it at 70 ° C for 180 minutes to obtain a methanol sensing material. Seal and store the dried sensing material for future use.

[0032] Example 3: Preparation of sensing material for detecting methanol content in gasoline Add 10 g acrylamide, 0.1 g N-allyl-2,3-naphthalimide and 80 mL water to a 250 mL photoreactor, make a commercially available nylon microporous filter membrane with a pore size of 0.45 μm into a size of 1 cm × 3 cm, and put it into the photoreactor. Stir and drive out oxygen with nitrogen for 15 minutes, add 10 mL of an aqueous solution containing 0.01 g 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylacetone (Irgacure2959), and irradiate the reaction with a 250 W straight tube medium pressure mercury lamp for 10 minutes under nitrogen protection. After the reaction is completed, remove the nylon microporous filter membrane, put it into a mixed solution of 20 mL methanol and acetonitrile (V methanol: V acetonitrile = 50:50), and let it stand for 15 minutes. Take it out and drain it, then immerse it in 20 mL of 5wt% sodium carboxymethyl cellulose aqueous solution and let it stand for 5 minutes. The nylon microporous filter membrane was taken out and drained, and then placed in an oven and dried at 70° C. for 180 minutes to obtain a methanol sensing material. The dried sensing material was sealed and stored for later use.

[0033] Example 4: Preparation of sensing material for detecting methanol content in gasoline 10 g acrylamide, 0.15 g N-allyl-phthalimide and 80 mL water were added to a 250 mL photoreactor. A commercially available nylon microporous filter membrane with a pore size of 0.45 μm was made into a size of 1 cm × 3 cm and placed in the photoreactor. Stir and drive out oxygen with nitrogen for 15 minutes, add 10 mL of an aqueous solution containing 0.03 g 2-hydroxy-2-methylpropiophenone (HMPP), and irradiate the reaction with a 250 W straight tube medium pressure mercury lamp for 90 minutes under nitrogen protection. After the reaction, the nylon microporous filter membrane was taken out and placed in a mixed solution of 20 mL methanol and butanone (V methanol: V butanone = 80:20) and allowed to stand for 17 minutes. Take it out and drain it, then immerse it in an aqueous solution of 20 mL of a total concentration of 4wt% water-soluble starch and sodium alginate (mass ratio of 1:1) and let it stand for 5 minutes. The nylon microporous filter membrane was taken out and drained, and then placed in an oven and dried at 70° C. for 180 minutes to obtain a methanol sensing material. The dried sensing material was sealed and stored for later use.

[0034] Example 5: Preparation of sensing material for detecting methanol content in gasoline 10 g acrylamide, 0.19 g N-allyl-1,8,4,5-naphthalenetetracarboxylic acid diimide and 80 mL water were added to a 250 mL photoreactor. A commercially available nylon microporous filter membrane with a pore size of 0.45 μm was made into a size of 1 cm × 3 cm and placed in the photoreactor. Stir and pass nitrogen to drive out oxygen for 15 minutes, add 10 mL of an aqueous solution containing 0.01 g 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylacetone (Irgacure2959), and irradiate the reaction with a 250 W straight tube medium pressure mercury lamp under nitrogen protection for 30 minutes. After the reaction is completed, the nylon microporous filter membrane is removed and placed in a mixed solution of 20 mL methanol and ethyl acetate (V methanol: V ethyl acetate = 70:30), and allowed to stand for 10 minutes. Take out and drain, then immerse in 20 mL of 0.5wt% total concentration of arabic gum and polyethylene glycol 2000 (mass ratio 1:1) aqueous solution, and let stand for 5 minutes. Take out the nylon microporous filter membrane and drain, put it in an oven at 70 °C and dry it for 180 minutes to obtain a methanol sensing material. The dried sensing material is sealed and stored for later use.

[0035] Example 6: Preparation of sensing material for detecting methanol content in gasoline Add 10 g acrylamide, 0.1 g N-allyl-2,3-naphthalimide and 80 mL water to a 250 mL photoreactor, make a commercially available fluorescent-free thin-layer TLC aluminum foil plate of 1 cm × 3 cm size and place it in the photoreactor. Stir and drive out oxygen with nitrogen for 15 minutes, add 10 mL of an aqueous solution containing 0.01 g 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylacetone (Irgacure2959), and irradiate the reaction with a 250 W straight tube medium-pressure mercury lamp for 30 minutes under nitrogen protection. After the reaction is completed, take out the thin-layer TLC aluminum foil plate, put it into a mixed solution of 20 mL methanol and acetonitrile (V methanol: V acetonitrile = 60:40), and let it stand for 15 minutes. Take it out and drain it, then immerse it in 20 mL of 5wt% sodium carboxymethyl cellulose aqueous solution and let it stand for 5 minutes. The thin layer TLC aluminum foil plate was taken out and drained, and then placed in an oven and dried at 120° C. for 60 minutes to obtain a methanol sensing material. The dried sensing material was sealed and stored for later use.

[0036] Example 7: Preparation of sensing material for detecting methanol content in gasoline Add 10 g acrylamide, 0.1 g N-allyl-2,3-naphthalimide and 80 mL water to a 250 mL photoreactor, cut a commercial medium flow rate qualitative filter paper into 1 cm × 3 cm size, and put it into the photoreactor. Stir and drive oxygen with nitrogen for 15 minutes, add 10 mL of aqueous solution containing 0.01 g 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylacetone (Irgacure2959), and irradiate the reaction with a 250 W straight tube medium pressure mercury lamp for 30 minutes under nitrogen protection. After the reaction is completed, take out the medium flow rate qualitative filter paper, put it into 20 mL of a mixed solution of methanol and acetonitrile (Vmethanol: Vacetonitrile = 60:40), and let it stand for 15 minutes. Take it out and drain it, then immerse it in 20 mL of 5wt% sodium carboxymethyl cellulose aqueous solution and let it stand for 5 minutes. The medium flow rate qualitative filter paper was taken out and drained, and then placed in an oven and dried at 110° C. for 70 minutes to obtain a methanol sensing material. The dried sensing material was sealed and stored for later use.

[0037] Example 8: Detection of gasoline samples by sensing materials 5 mL of gasoline sample with a methanol content of 0.2 wt% was placed in a test tube, and the methanol sensing material prepared in Example 3 was immersed in the gasoline and allowed to stand for 4 minutes. The methanol sensing material was taken out, and a UV flashlight was used to illuminate the porous membrane in a dark box to reveal blue fluorescence. After 10 seconds of illumination, the flashlight was turned off and an obvious green afterglow could be seen.

[0038] Example 9: Detection of gasoline samples by sensing materials Take 5 mL of gasoline sample with a methanol content of 0.3 wt% in a test tube, immerse the methanol sensing material prepared in Example 3 in the gasoline, and let it stand for 4 minutes. Take out the methanol sensing material, illuminate the porous membrane with an ultraviolet flashlight in a dark box, and blue fluorescence can be seen. After 10 seconds of illumination, turn off the flashlight and no afterglow can be seen.

[0039] Example 10: Detection of gasoline samples by sensing materials 5 mL of gasoline sample with a methanol content of 0.4 wt% was placed in a test tube, and the methanol sensing material prepared in Example 3 was immersed in the gasoline and allowed to stand for 4 minutes. The methanol sensing material was taken out, and a UV flashlight was used to illuminate the porous membrane in a dark box, and blue fluorescence was visible. After 10 seconds of illumination, the flashlight was turned off, and no afterglow was visible.

[0040] Example 11: Detection of gasoline samples by sensing materials Take 5 mL of gasoline sample with a methanol content of 0.wt2% in a test tube, immerse the methanol sensing material prepared in Example 2 in the gasoline, and let it stand for 4 minutes. Take out the methanol sensing material, and illuminate the porous membrane with an ultraviolet flashlight in a room with a blackout curtain, and blue fluorescence can be seen. After 10 seconds of irradiation, turn off the flashlight and you can see a clear green afterglow.

[0041] Example 12: Detection of gasoline samples by sensing materials 5 mL of gasoline sample with a methanol content of 0.2 wt% was taken into a test tube, and the methanol sensing material prepared in Example 7 was immersed in the gasoline and allowed to stand for 4 minutes. The methanol sensing material was taken out, and a blue fluorescence was observed when a UV flashlight was used to illuminate the porous membrane in a room with a blackout curtain. After 10 seconds of illumination, the flashlight was turned off and an obvious green afterglow was observed.

[0042] Example 13: Detection of gasoline samples by sensing materials 5 mL of gasoline sample with a methanol content of 0.3 wt% was taken into a test tube, and the methanol sensing material prepared in Example 2 was immersed in the gasoline and allowed to stand for 4 minutes. The methanol sensing material was taken out, and a UV flashlight was used to illuminate the porous membrane in a room with a blackout curtain, and blue fluorescence was visible. After 10 seconds of illumination, the flashlight was turned off, and no afterglow was visible.

[0043] Example 14: Detection of gasoline samples by sensing materials 5 mL of gasoline sample with a methanol content of 0.3 wt% was taken into a test tube, and the methanol sensing material prepared in Example 7 was immersed in the gasoline and allowed to stand for 4 minutes. The methanol sensing material was taken out, and a UV flashlight was used to illuminate the porous membrane in a room with a blackout curtain, and blue fluorescence was visible. After 10 seconds of illumination, the flashlight was turned off and no afterglow was visible.

[0044] Example 15: Detection of gasoline samples by sensing materials 5 mL of gasoline sample with a methanol content of 0.4 wt% was taken into a test tube, and the methanol sensing material prepared in Example 2 was immersed in the gasoline and allowed to stand for 4 minutes. The methanol sensing material was taken out, and a UV flashlight was used to illuminate the porous membrane in a room with a blackout curtain, and blue fluorescence was visible. After 10 seconds of illumination, the flashlight was turned off, and no afterglow was visible.

[0045] Example 16: Detection of gasoline samples by sensing materials 5 mL of gasoline sample with a methanol content of 0.4 wt% was taken into a test tube, and the methanol sensing material prepared in Example 7 was immersed in the gasoline and allowed to stand for 4 minutes. The methanol sensing material was taken out, and a UV flashlight was used to illuminate the porous membrane in a room with a blackout curtain, and blue fluorescence was visible. After 10 seconds of illumination, the flashlight was turned off, and no afterglow was visible.

[0046] Example 17: Selectivity experiment of methanol sensing material Take 5 mL of gasoline samples containing 0.3wt% methanol, ethanol, acetone, acetic acid, formaldehyde, ethyl acetate, chloroform, dichloromethane, acetonitrile, and butanone in test tubes, immerse the methanol sensing materials prepared in Example 3 in the above ten gasoline samples, and let them stand for 4 minutes. Take out these methanol sensing materials, irradiate all methanol sensing materials with ultraviolet flashlight in a dark box, and blue fluorescence can be seen. Turn off the flashlight after irradiation for 10s, and the methanol sensing material immersed in the gasoline sample containing methanol has no afterglow, and other methanol sensing materials can see obvious green afterglow. This shows that the methanol sensing material has a good selective response to methanol.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline, the specific steps are as follows: Add acrylamide, 3-substituted propylene derivatives and water into a photoreactor, then put in a strip-shaped porous material, stir and pass nitrogen to drive out oxygen for 15 minutes, add a photopolymerization initiator, continue stirring under nitrogen protection and light, and perform photo-initiated in-situ polymerization for a certain period of time. After the reaction is completed, take out the porous material after the photo-initiated in-situ polymerization, immerse it in an organic solvent containing methanol for a certain period of time for anti-solvent deposition, take out the porous material after the anti-solvent deposition, drain it, immerse it in an aqueous solution of a water-soluble polymer compound for packaging, take it out and drain it; put the drained porous material into an oven and dry it at a certain temperature for a certain period of time to obtain a methanol sensing material, and seal and store the dried methanol sensing material for standby use.

2. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The 3-substituted propylene derivative, whose 3-position substituent is an N-substituted aromatic imide, includes but is not limited to 1,8-naphthalene diimide, 2,3-naphthalene diimide, phthalimide, 4,5-dichlorophthalimide, tetrachlorophthalimide, pyromellitic acid diimide, 1,8,4,5-naphthalenetetracarboxylic acid diimide, and 3,4,9,10-perylene dicarboximide.

3. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The photopolymerization initiator is an acrylamide photopolymerization initiator.

4. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The mass ratio of the 3-substituted propylene derivative to acrylamide is 1:50-100.

5. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The methanol-containing organic solvent is ethanol, acetone, acetonitrile, butanone, ethyl acetate, an organic solvent that has a certain degree of miscibility with water, a mixture of one or more of them with methanol, and the volume ratio of methanol in the methanol-containing organic solvent is not less than 50%.

6. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The water-soluble polymer compound is selected from: sodium carboxymethyl cellulose, polyvinyl alcohol, water-soluble starch, gum arabic, sodium alginate, bone meal, gelatin, casein, polyethylene glycol or a mixture thereof, and the mass concentration of the aqueous solution of the water-soluble polymer compound is 0.5-30%.

7. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The strip-shaped porous material includes: porous membranes of various polymer materials, silica gel plates, filter papers, and has a size of 3 cm in length and 1 cm in width.

8. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The in-situ polymerization is carried out for 10 to 100 minutes with continuous stirring under nitrogen protection and light irradiation.

9. The method for preparing a phosphorescent sensing material having an afterglow response to excessive methanol in gasoline according to claim 1, characterized in that: The time for immersing the porous material after light-induced in-situ polymerization in the organic solvent containing methanol is 10 to 20 minutes.

10. A sensing material for rapid on-site detection of methanol in gasoline prepared by the preparation method according to any one of claims 1 to 9, which is used for rapid on-site detection of whether the methanol content in gasoline exceeds the national standard, and the specific detection steps are as follows: Take 5 mL of gasoline sample in a test tube, immerse a sensing material for on-site rapid detection of methanol in gasoline prepared by the preparation method described in any one of claims 1 to 9 into the gasoline, let it stand for 4 minutes, take out the sensing material and place it in a dark box or a room with a blackout curtain, irradiate the sensing material with an ultraviolet flashlight for 10 seconds, then turn off the light source, and observe the afterglow of the sensing material. For gasoline samples that meet the national standards, the sensing material exhibits an obvious green afterglow, while for gasoline samples with a methanol content exceeding the national standard, the sensing material has no afterglow.