Fluorescent nano demulsifier as well as preparation method and application thereof

Abstract

The invention discloses a fluorescent nano demulsifier as well as a preparation method and application thereof. The method comprises the following steps: (1) preparing a modified nano material; (2) dispersing the modified nano material in a solvent C, and reacting with polystyrene maleic anhydride in the presence of a catalyst to obtain modified nano material grafted polystyrene maleic anhydride; and (3) dispersing the modified nano-material grafted polystyrene maleic anhydride in a solvent D, then adding porphyrin-based polyamine resin into the solvent D, and carrying out a reaction so as to obtain the fluorescent nano demulsifier containing the porphyrin fluorophore after the reaction is finished. The demulsifying and deoiling agent has the following beneficial effects: (1) the demulsifying and deoiling agent has good demulsifying and deoiling functions; (2) generation of aged oil and oil sludge can be avoided; (3) the molecular movement process and demulsification process of the fluorescent nano demulsifier can be observed; and (4) when the nano particles are nano Fe3O4, the prepared fluorescent nano demulsifier has magnetism and can be recycled and reused in a magnetic field.

Description

Technical Field

[0001] This invention relates to the field of oilfield chemistry, specifically to a fluorescent nano-demulsifier, its preparation method, and its application. Background Technology

[0002] As my country's major oilfields have successively entered the middle and late stages of exploitation, chemical flooding technology has been implemented on an industrial scale to improve crude oil recovery.

[0003] my country needs to treat approximately 100 million cubic meters of polymer-containing produced water generated by chemical flooding annually. This produced water has a complex composition, containing emulsified crude oil, oil-displacing surfactants and polymers, asphaltenes and gums from the crude oil, suspended solids, microorganisms, and other complex oil-in-water emulsions. The residual oil-displacing surfactants and polymers, as well as the asphaltenes and gums from the crude oil, make the emulsion exceptionally stable, hindering demulsification and oil-water separation. One of the current challenges in my country's produced water treatment is the demulsification, oil-water separation, and resource utilization of produced water.

[0004] Traditionally, the treatment of oil-bearing produced water involves adding demulsifiers. For example, Chinese invention patent CN108864421B discloses a multibranched cationic polyether reverse demulsifier, its preparation method, and its application. This method first prepares hydroxymethyl BPA, then reacts it with polyene amines to prepare a multibranched BPA-type phenolic amine resin. The synthesis process of this phenolic amine resin effectively avoids the side reactions of formaldehyde and ethylene amine, and ensures complete reaction of the ortho- and ortho-positions of the phenolic hydroxyl groups. The BPA-type phenolic amine resin is reacted with ethylene oxide to obtain a multibranched polyether demulsifier. This polyether reverse demulsifier is then cationically modified using a quaternary ammonium salt and applied to the treatment of oily wastewater in oilfield produced fluids.

[0005] In 2022, Kou Zimin et al. disclosed the synthesis and application performance study of a cationic-nonionic reverse demulsifier in pages 1516-1519 of *Liaoning Chemical Industry*. Using water-based polyether, epichlorohydrin, and trimethylamine as raw materials, they synthesized the reverse demulsifier BH-587, investigated the effects of raw material ratio, reaction time, and reaction temperature on product performance, and determined that the optimal molar ratio of epichlorohydrin to trimethylamine was 1:1.4, the optimal reaction temperature was 75℃, and the optimal reaction time was 4 hours. This reverse demulsifier has a simple preparation method, excellent water-based performance, and is worthy of widespread application.

[0006] However, cationic demulsifiers remove emulsified crude oil, negatively charged suspended solids, and other particles from water through charge neutralization-flocculation. Because this charge neutralization reaction and flocculation technology are non-selective towards negatively charged substances and particles in water, it reacts not only with negatively charged emulsified oil but also with suspended solids, residual oil-displacing polymers, and other negatively charged particles, forming aggregated flocs containing crude oil and solid particles—i.e., sludge. This causes pipe blockage, prevents filters from functioning properly, and pollutes the environment.

[0007] Meanwhile, a large amount of polymers in produced water cannot be effectively reused, resulting in resource waste. Cationic demulsifiers are extremely unsuitable for chemical flooding produced water, and there is an urgent need to develop nonionic reverse demulsifiers that can retain polymers.

[0008] Demulsifiers, as surfactants, exhibit a certain concentration distribution in oil and water. With the development of demulsifier technology, understanding the molecular motion of demulsifier molecules in oil-water systems and tracking their distribution in production systems has become a technological trend. Fluorescent demulsifiers have emerged as a result. For example, Chinese invention patent CN 110157471 B discloses a method for preparing a fluorescently visualized magnetic MOFs demulsifier. The preparation method of the fluorescently visualized magnetic MOFs demulsifier is as follows: Using iron, copper, and zinc metal salts as precursors and trimesic acid as a ligand, and doped with non-precious metals such as nickel, manganese, cobalt, and zirconium, magnetic MOFs materials are prepared via a solvothermal method. These materials are then reacted with traditional polyether-based commercial demulsifiers, again using iron, copper, and zinc metal salts as precursors, to obtain the fluorescently visualized magnetic MOFs demulsifier. Its fluorescent group emits strong fluorescence under ultraviolet light, allowing observation of the demulsification process under a confocal microscope. However, the preparation process is complex and may cause water pollution due to heavy metal residues.

[0009] The excellent surface effect, small size effect, and macroscopic quantum tunneling effect of nano-demulsifiers can enhance their demulsification effect, attracting research attention. For example, Chinese invention patent application CN 113769441 A discloses a method for preparing magnetic nanosphere reverse demulsifiers and their applications. First, Fe3O4 nanoparticles are synthesized via a solvothermal method. Then, dopamine (DA) is reacted with the nano-Fe3O4 microspheres in Tris-HCl reagent, causing dopamine to polymerize and encapsulate on the Fe3O4 surface, yielding PDA@Fe3O4 microspheres. Next, polyquaternary ammonium salt (PQA) is synthesized through the reaction of dimethylamine, organic amine crosslinking agents, and epichlorohydrin. Finally, PDA@Fe3O4 and PQA are mixed and reacted in Tris-HCl reagent, causing PQA to graft onto the PDA surface, yielding PQA-PDA@Fe3O4 nanospheres. However, the above technical solution is still a cationic demulsifier. For example, Chinese invention patent application CN111925820 A discloses a method for preparing a dodecylamine-modified carbon nanotube demulsifier, comprising the following steps: (1) oxidizing carbon nanotubes with an ammonium persulfate sulfuric acid solution to obtain carbon nanotube oxides with carboxyl groups on the surface; (2) grafting dodecylamine onto the surface of the carbon nanotube oxides to obtain a dodecylamine-modified carbon nanotube demulsifier. However, the above-mentioned dodecylamine-modified carbon nanotube demulsifier is only suitable for demulsifying water-in-oil emulsions. Summary of the Invention

[0010] Purpose of the invention: In view of the shortcomings of existing cationic reverse demulsifiers, which are prone to producing sludge, existing fluorescent demulsifiers, which have the problem of heavy metal pollution, and existing non-cationic nano-demulsifiers, which are only suitable for water-in-oil emulsions, the purpose of this invention is to provide a fluorescent, non-sludge-producing non-ionic nano-demulsifier suitable for oil-in-water emulsions, as well as its preparation method and application.

[0011] Technical solution: A fluorescent nano-demulsifier, wherein the fluorescent nano-demulsifier uses polystyrene maleic anhydride as a bridging polymer, and the anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials and porphyrin-based polyamine resins respectively to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein:

[0012] In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:(0.1~1):(0.1~1);

[0013] The molecular weight range of the polystyrene maleic anhydride is 2000 to 100000;

[0014] Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 5-50 wt%.

[0015] The modified nanomaterial is one or more of the following: modified nano-TiO2, modified nano-ZnO, modified nano-SiO2, modified nano-Fe3O4, modified graphene oxide, and modified carbon nanotubes.

[0016] The porphyrin-based polyamine resin is a compound represented by formula (I), (II), or (III) below:

[0017]

[0018]

[0019] Where 0 < m ≤ 3;

[0020] R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C, respectively. n H 2n+1 or OC n H 2n+1 One of the following, wherein n = 1 to 20. Further, the molecular weight of the polystyrene maleic anhydride is in the range of 10,000 to 50,000, and / or the content of the maleic anhydride is 10 to 40 wt% based on the mass of the polystyrene maleic anhydride.

[0021] Furthermore, the porphyrin-based polyamine resin is a compound represented by formula (I), (II), or (III) below:

[0022]

[0023] Where 1 ≤ m ≤ 3; R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C, respectively. n H 2n+1 or OC n H 2n+1 One of them, where n = 1 to 10.

[0024] The preparation method of the above-mentioned fluorescent nano-demulsifier, by weight, includes the following steps:

[0025] (1) Modify nanomaterials by reacting them with dopamine hydrochloride, tannic acid, or silane coupling agent.

[0026] (2) The modified nanomaterial is dispersed in solvent C and reacted with polystyrene maleic anhydride in the presence of catalyst p-toluenesulfonic acid or sulfuric acid to obtain modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs).

[0027] (3) The modified nanomaterial grafted with polystyrene maleic anhydride is dispersed in solvent D, and then porphyrin-based polyamine resin is added to it for reaction. After the reaction is completed, a fluorescent nano-demulsifier containing porphyrin fluorescent groups is obtained.

[0028] Further, the nanomaterials mentioned in step (1) are one or more of nano TiO2, nano ZnO, nano SiO2, nano Fe3O4, graphene oxide, and carbon nanotubes.

[0029] Furthermore, the nano-Fe3O4 is prepared by a solvothermal method, and the specific steps are as follows (by weight):

[0030] One part of ferric chloride hexahydrate, 1-5 parts of sodium acetate, and 1-5 parts of polyethylene glycol are dissolved in an appropriate amount of solvent, stirred evenly, and then transferred to a polytetrafluoroethylene reactor. The mixture is heated at at least 120°C, preferably 120-240°C, for at least 4 hours, preferably 4-20 hours, to obtain a black product. The product is washed at least three times with ultrapure water and anhydrous ethanol, and then vacuum dried at at least 40°C, preferably 40-80°C, for at least 3 hours, preferably 3-12 hours, to obtain nano-Fe3O4.

[0031] Furthermore, the solvent is one or more of water, ethylene glycol, and propylene glycol, and / or

[0032] The amount of solvent used, calculated based on the amount of ferric chloride hexahydrate, is 6–20 mL / g.

[0033] Furthermore, the modification reaction between the nanomaterial and dopamine hydrochloride in step (1) is as follows:

[0034] Dopamine hydrochloride and nanomaterials were placed in a reactor at a mass ratio of 0.1 to 10:10. A Tris-HCl solution of 2 to 20 times the mass of the nanomaterials was added. The reactor was sealed and ultrasonically dispersed in an ultrasonic oscillator for at least 0.5 hours, preferably 0.5 to 2 hours. The mixture was then transferred to a constant-temperature water bath oscillator and oscillated at room temperature at a frequency of at least 100 rpm, preferably 100 to 300 rpm, for at least 4 hours, preferably 4 to 24 hours. After the reaction was completed, the mixture was centrifuged or filtered, washed at least three times with ultrapure water and anhydrous ethanol, and vacuum dried at at least 30°C, preferably 30 to 60°C, for at least 12 hours to obtain polydopamine hydrochloride modified nanomaterials.

[0035] Furthermore, the modification reaction between the nanomaterials and tannic acid in step (1) is as follows:

[0036] Tannic acid and nanomaterials were placed in a reactor at a mass ratio of 0.1 to 10:10. Solvent A was added at a mass ratio of 2 to 20 times that of the nanomaterials. The reactor was sealed and ultrasonically dispersed in an ultrasonic oscillator for at least 2 hours. Then, the mixture was transferred to a constant temperature water bath oscillator and oscillated at room temperature at a frequency of at least 100 rpm, preferably 100 to 300 rpm, for at least 4 hours, preferably 4 to 24 hours. After the reaction was completed, the mixture was separated by centrifugation or filtration. The mixture was washed at least three times with ultrapure water and anhydrous ethanol, and then vacuum dried at at least 30°C, preferably 30 to 60°C, for at least 12 hours to obtain tannic acid-modified nanomaterials.

[0037] Furthermore, solvent A is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

[0038] Furthermore, the specific steps of the modification reaction between the nanomaterial and the silane coupling agent in step (1) are as follows:

[0039] Take silane coupling agent and nanomaterials in a mass ratio of 0.1 to 10:10 and place them in a reactor. Add solvent B in a volume of 2 to 20 times the mass of the nanomaterials. Disperse the nanomaterials by ultrasonication in an ultrasonic oscillator for at least 0.5 hours, preferably 0.5 to 2 hours. Then transfer the mixture to a constant temperature magnetic stirrer and stir the reaction at 30°C, preferably 30 to 100°C, for at least 2 hours, preferably 2 to 18 hours. After the reaction is complete, separate the mixture by centrifugation or filtration, wash it at least three times with ultrapure water and anhydrous ethanol, and vacuum dry it at at least 30°C, preferably 30 to 60°C, for at least 12 hours to obtain silane coupling agent modified nanomaterials.

[0040] Furthermore, solvent B is one or more of methanol, ethanol, n-propanol, isopropanol, formic acid, and acetic acid, and / or

[0041] The silane coupling agent is one or more of 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (KH550), and diethylenetriaminopropyltrimethoxysilane.

[0042] Furthermore, the specific steps of step (2) are as follows:

[0043] (21) Place 0.1 to 1 part of modified nanomaterial, 0.1 to 1 part of catalyst p-toluenesulfonic acid or sulfuric acid and 1 part of polystyrene maleic anhydride in a reactor, and then add 2 to 6 parts of solvent C. Sonicate the nanomaterial in an ultrasonic oscillator for at least 0.5 h, preferably 0.5 to 2 h to obtain a mixture.

[0044] (22) Transfer the mixture to a constant temperature magnetic stirrer and stir at at least 40°C, preferably 40-120°C for at least 4 hours, preferably 4-24 hours. After the reaction is completed, centrifuge or filter to obtain a solid product. Wash the solid product with solvent C at least 3 times, and finally wash it with anhydrous ethanol at least 2 times. Vacuum dry at at least 60°C, preferably 60-80°C for at least 12 hours to obtain the modified nanomaterial grafted polystyrene maleic anhydride.

[0045] Furthermore, the solvent C is one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

[0046] Furthermore, the specific steps of step (3) are as follows:

[0047] (31) The modified nanomaterials obtained in step (2) are grafted with polystyrene maleic anhydride and 0.1 to 1 part of porphyrin-based polyamine resin in a reactor, and then solvent D with a mass of 2 to 10 times that of porphyrin-based polyamine resin is added to it. The mixture is ultrasonically dispersed in an ultrasonic oscillator for at least 0.5 h, preferably 0.5 to 2 h, to obtain a mixture.

[0048] (32) Transfer the mixture to a constant temperature magnetic stirrer and stir the reaction at at least 40°C, preferably 40-120°C, for at least 4 hours, preferably 4-24 hours. After the reaction is completed, centrifuge or filter to separate the solid product. Wash the solid with distilled water and anhydrous ethanol at least 3 times in sequence, and vacuum dry at at least 60°C, preferably 60-80°C, for at least 12 hours to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups.

[0049] Furthermore, the solvent D is one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

[0050] Furthermore, the specific steps of the preparation method of the porphyrin-based polyamine resin, in molar amounts, are as follows:

[0051] One part of hydroxyphenyl porphyrin and 2 to 10 parts of polyamine are dissolved in an organic solvent with a mass of 2 to 10 times that of the polyamine to obtain a mixture. The mixture is then transferred to a reactor equipped with a stirrer, a water separator and a dropping funnel, and the reactor is placed in a constant temperature oil bath.

[0052] Dissolve 2-50 parts of paraformaldehyde in 1-5 times its mass of an organic solvent to obtain a paraformaldehyde organic solvent solution. Then, transfer the paraformaldehyde organic solvent solution to a dropping funnel in the reactor. Control the reaction temperature at 90-150°C and reflux the reaction system. Under heating and stirring conditions, slowly add the paraformaldehyde organic solvent solution dropwise into the reactor through a constant pressure dropping funnel. Stop the reaction after at least 6 hours, preferably 6-48 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain porphyrin-based polyamine resin.

[0053] Furthermore, the organic solvent is one or more of benzene, toluene, and xylene, and / or

[0054] The hydroxyphenyl-containing porphyrin has one of the following structures:

[0055]

[0056] Among them, R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C. n H 2n+1 or OC n H 2n+1 One of them, where n = 1 to 20, and / or

[0057] The polyamine is a polyethylene polyamine, preferably one or more of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0058] A fluorescent nano-demulsifier is prepared by any one of the methods described above.

[0059] The above-mentioned fluorescent nano-demulsifiers are used as demulsifiers in the treatment of chemical flooding produced fluids.

[0060] In the technical solution of this invention:

[0061] 1. The porphyrin-based polyamine resin introduced into the molecular structure of the fluorescent nano-demulsifier is a hyperbranched polyamine with water-clearing function. It can break up oil-in-water emulsions without producing oil sludge and retaining polymers in the produced fluid.

[0062] 2. By crosslinking polystyrene maleic anhydride (SMA) with porphyrin-based polyamine resin, the molecular weight of the demulsifier is further increased. The crosslinked nanomaterials in polystyrene maleic anhydride are hydrophilic nanomaterials, which endow the demulsifier with excellent surface effect, small size effect and macroscopic quantum tunneling effect, thereby improving the demulsification effect of the demulsifier.

[0063] 3. The principle of fluorescence visualization of demulsifiers has been improved. Existing fluorescence visualization magnetic demulsifiers may cause heavy metal residue pollution. The present invention contains a porphyrin fluorescent group in its molecule, which will not cause heavy metal pollution.

[0064] 4. When the nanoparticles are nano-Fe3O4, the prepared fluorescent nano-demulsifier is magnetic and can be recovered under a magnetic field. Beneficial Effects: The fluorescent nano-demulsifier, its preparation method, and its application disclosed in this invention have the following beneficial effects:

[0065] (1) The porphyrin polyamine resin in the molecular structure of the fluorescent nano demulsifier is a hyperbranched polyamine with water-clearing function. After cross-linking with polystyrene maleic anhydride (SMA), the molecular weight of the demulsifier is further increased. The cross-linked nanomaterials in polystyrene maleic anhydride are hydrophilic nanomaterials, which endow the demulsifier with excellent surface effect, small size effect and macroscopic quantum tunneling effect, thereby improving the demulsification effect of the demulsifier.

[0066] (2) The large number of benzene rings in polystyrene maleic anhydride endows this fluorescent nano-demulsifier with good compatibility with crude oil. This demulsifier has good demulsification and oil removal functions for polymer-containing produced water, and will not react with negatively charged substances in the water, thus avoiding the generation of aged oil and sludge;

[0067] (3) Because the fluorescent nano-demulsifier contains porphyrin groups in its molecules, the molecular motion and demulsification process of the fluorescent nano-demulsifier can be observed under a fluorescence microscope, and the position and concentration of the demulsifier can also be detected by a UV-Vis spectrophotometer. Therefore, this fluorescent nano-demulsifier can also be used as a probe to study the demulsification mechanism and guide the design and development of new demulsifiers;

[0068] (4) When the nanoparticles are nano Fe3O4, the prepared fluorescent nano-demulsifier is magnetic and can be recycled and reused under a magnetic field. Attached Figure Description

[0069] Figure 1 The image shows the infrared spectrum of monohydroxyphenylporphyrin in Example 1.

[0070] Figure 2 The image shows the infrared spectrum of polystyrene maleic anhydride (SMA) from Example 1.

[0071] Figure 3 The infrared spectrum of the monohydroxyphenylporphyrin polyamine resin prepared in Example 1 is shown.

[0072] Figure 4 The image shows the infrared spectrum of nano-TiO2 in Example 1.

[0073] Figure 5 The infrared spectrum of the monohydroxyphenylporphyrin polyamine resin-TiO2 fluorescent nano-demulsifier prepared in Example 1 is shown. Detailed Implementation

[0074] The specific embodiments of the present invention are described in detail below.

[0075] The "range" disclosed in this invention is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if a range of 10–50 is listed for a specific parameter, it is also expected that ranges of 10–40 and 20–50 are also included. Furthermore, if the minimum range values ​​are 1 and 2, and the maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0–5" means that all real numbers between "0–5" have been listed herein; "0–5" is merely a shortened representation of these numerical combinations.

[0076] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0077] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0078] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0079] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0080] Unless otherwise specified, the reaction will proceed under normal temperature and pressure conditions.

[0081] Unless otherwise specified, all parts or percentages are by weight or by weight percentage.

[0082] In this invention, all the substances used are known substances that can be purchased or synthesized by known methods.

[0083] In this invention, all the devices or equipment used are conventional devices or equipment known in the art and are readily available.

[0084] A fluorescent nano-demulsifier is disclosed, wherein the fluorescent nano-demulsifier uses polystyrene maleic anhydride (SMA) as a bridging polymer, and the anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials (NPs) and porphyrin-based polyamine resins, respectively, to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein:

[0085] In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:(0.1~1):(0.1~1);

[0086] The molecular weight range of the polystyrene maleic anhydride is 2000 to 100000;

[0087] Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 5-50 wt%.

[0088] The modified nanomaterial is one or more of the following: modified nano-TiO2, modified nano-ZnO, modified nano-SiO2, modified nano-Fe3O4, modified graphene oxide (GO), and modified carbon nanotubes (CNT).

[0089] The porphyrin-based polyamine resin is a compound represented by formula (I), (II), or (III) below:

[0090]

[0091]

[0092] Where 0 < m ≤ 3;

[0093] R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C, respectively. n H 2n+1 or OC n H 2n+1 One of the following, wherein n = 1 to 20. Further, the molecular weight of the polystyrene maleic anhydride is in the range of 10,000 to 50,000, and / or the content of the maleic anhydride is 10 to 40 wt% based on the mass of the polystyrene maleic anhydride.

[0094] Furthermore, the porphyrin-based polyamine resin is a compound represented by formula (I), (II), or (III) below:

[0095]

[0096]

[0097] Where 1 ≤ m ≤ 3; R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C, respectively. n H 2n+1 or OC n H 2n+1 One of them, where n = 1 to 10.

[0098] In one embodiment, a fluorescent nano-demulsifier uses polystyrene maleic anhydride (SMA) as a bridging polymer. The anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials (NPs) and porphyrin-based polyamine resins, respectively, to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein:

[0099] In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:0.1:0.1.

[0100] The molecular weight of the polystyrene maleic anhydride is 100,000.

[0101] Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 5 wt%.

[0102] The modified nanomaterial is modified nano-TiO2;

[0103] The porphyrin-based polyamine resin is a compound represented by the following formula (I):

[0104]

[0105] Where m = 0.1;

[0106] R1 is H. In another embodiment, R1 is Cl. In another embodiment, R1 is Br. In another embodiment, R1 is NO2. In another embodiment, R1 is CH3. In another embodiment, R1 is n-decyl. In another embodiment, R1 is n-eicosyl. In another embodiment, R1 is or OCH3. In another embodiment, R1 is n-decyloxy (OC) 10 H 11 In another embodiment, R1 is n-eicosyloxy (OC) 20 H 21 ).

[0107] R2 is Cl. In another embodiment, R2 is H. In another embodiment, R2 is Br. In another embodiment, R2 is NO2. In another embodiment, R2 is CH3. In another embodiment, R2 is n-decyl. In another embodiment, R2 is n-eicosyl. In another embodiment, R2 is or OCH3. In another embodiment, R2 is n-decyloxy (OC) 10 H 11 In another embodiment, R2 is n-eicosyloxy (OC) 20 H 21 ).

[0108] R3 is NO2. In another embodiment, R3 is H. In another embodiment, R3 is Br. In another embodiment, R3 is Cl. In another embodiment, R3 is CH3. In another embodiment, R3 is n-decyl. In another embodiment, R3 is n-eicosyl. In another embodiment, R3 is or OCH3. In another embodiment, R3 is n-decyloxy (OC) 10 H 11 In another embodiment, R3 is n-eicosyloxy (OC) 20 H 21 ).

[0109] In another embodiment, a fluorescent nano-demulsifier is provided, wherein the fluorescent nano-demulsifier uses polystyrene maleic anhydride (SMA) as a bridging polymer, and the anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials (NPs) and porphyrin-based polyamine resins, respectively, to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein:

[0110] In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:1:1.

[0111] The molecular weight of the polystyrene maleic anhydride is 2000;

[0112] Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 50 wt%.

[0113] The modified nanomaterial is modified nano-ZnO;

[0114] The porphyrin-based polyamine resin is a compound represented by the following formula (II):

[0115]

[0116] Where m = 3;

[0117] R1 is n-decyloxy (OC) 10 H 11 );

[0118] R2 is CH3.

[0119] In another embodiment, a fluorescent nano-demulsifier is provided, wherein the fluorescent nano-demulsifier uses polystyrene maleic anhydride (SMA) as a bridging polymer, and the anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials (NPs) and porphyrin-based polyamine resins, respectively, to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein:

[0120] In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:0.5:0.4.

[0121] The molecular weight of the polystyrene maleic anhydride is 20,000;

[0122] Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 10 wt%.

[0123] The modified nanomaterial is modified nano Fe3O4;

[0124] The porphyrin-based polyamine resin is a compound represented by formula (III):

[0125]

[0126] Where m = 1.

[0127] In another embodiment, a fluorescent nano-demulsifier is provided, wherein the fluorescent nano-demulsifier uses polystyrene maleic anhydride (SMA) as a bridging polymer, and the anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials (NPs) and porphyrin-based polyamine resins, respectively, to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein:

[0128] In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:0.2:0.4.

[0129] The molecular weight of the polystyrene maleic anhydride is 10,000;

[0130] Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 40 wt%.

[0131] The modified nanomaterial is modified graphene oxide (GO);

[0132] The porphyrin-based polyamine resin is a compound represented by formula (III):

[0133]

[0134] Where m = 2.

[0135] In another embodiment, a fluorescent nano-demulsifier is provided, wherein the fluorescent nano-demulsifier uses polystyrene maleic anhydride (SMA) as a bridging polymer, and the anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials (NPs) and porphyrin-based polyamine resins, respectively, to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein:

[0136] In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:0.1:0.2.

[0137] The molecular weight range of the polystyrene maleic anhydride is 50,000.

[0138] Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 25 wt%.

[0139] The modified nanomaterial is a modified carbon nanotube (CNT);

[0140] The porphyrin-based polyamine resin is a compound represented by formula (III):

[0141]

[0142] Where m = 2.

[0143] The preparation method of the above-mentioned fluorescent nano-demulsifier, by weight, includes the following steps:

[0144] (1) Modify nanomaterials by reacting them with dopamine hydrochloride, tannic acid, or silane coupling agent respectively.

[0145] (2) Disperse 0.1 to 1 part of the modified nanomaterial in solvent C, and react with 1 part of polystyrene maleic anhydride in the presence of the catalyst p-toluenesulfonic acid or sulfuric acid to obtain modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs).

[0146] (3) The modified nanomaterial grafted with polystyrene maleic anhydride is dispersed in solvent D, and then 0.1 to 1 part of porphyrin-based polyamine resin is added to it for reaction. After the reaction is completed, a fluorescent nano-demulsifier containing porphyrin fluorescent groups is obtained.

[0147] Further, the nanomaterials mentioned in step (1) are one or more of nano TiO2, nano ZnO, nano SiO2, nano Fe3O4, graphene oxide (GO), and carbon nanotubes (CNT).

[0148] Furthermore, the nano-Fe3O4 is prepared by a solvothermal method, and the specific steps are as follows (by weight):

[0149] One part of ferric chloride hexahydrate, 1-5 parts of sodium acetate, and 1-5 parts of polyethylene glycol are dissolved in an appropriate amount of solvent, stirred evenly, and then transferred to a polytetrafluoroethylene reactor. The mixture is heated at at least 120°C, preferably 120-240°C, for at least 4 hours, preferably 4-20 hours, to obtain a black product. The product is washed at least three times with ultrapure water and anhydrous ethanol, and then vacuum dried at at least 40°C, preferably 40-80°C, for at least 3 hours, preferably 3-12 hours, to obtain nano-Fe3O4.

[0150] Furthermore, the solvent is one or more of water, ethylene glycol, and propylene glycol, and / or

[0151] The amount of solvent used, calculated based on the amount of ferric chloride hexahydrate, is 6–20 mL / g.

[0152] Furthermore, the modification reaction between the nanomaterial and dopamine hydrochloride in step (1) is as follows:

[0153] Dopamine hydrochloride (DA) and nanomaterials were placed in a reactor (e.g., an Erlenmeyer flask) at a mass ratio of 0.1–10:10. A Tris-HCl solution of 2–20 times the mass of the nanomaterials was added, and the reactor was sealed. The nanomaterials were dispersed by ultrasonication in an ultrasonic oscillator for at least 0.5 h, preferably 0.5–2 h. Then, the mixture was transferred to a constant-temperature water bath oscillator and oscillated at room temperature at a frequency of at least 100 rpm, preferably 100–300 rpm, for at least 4 h, preferably 4–24 h. After the reaction was complete, the mixture was centrifuged or filtered, washed at least three times with ultrapure water and anhydrous ethanol, and vacuum dried at at least 30°C, preferably 30–60°C, for at least 12 h to obtain polydopamine hydrochloride-modified nanomaterials. In the above process, dopamine hydrochloride polymerizes to form polydopamine hydrochloride, which adheres to the surface of the nanomaterials. The catechol groups in the polydopamine hydrochloride react with the hydroxyl groups on the surface of the nanomaterials to achieve loading.

[0154] Furthermore, the modification reaction between the nanomaterials and tannic acid in step (1) is as follows:

[0155] Tannic acid (TA) and nanomaterials were placed in a reactor (e.g., an Erlenmeyer flask) at a mass ratio of 0.1–10:10. Solvent A was added in an amount 2–20 times the mass of the nanomaterials. The reactor was sealed and ultrasonically dispersed in an ultrasonic oscillator for at least 2 hours. The mixture was then transferred to a constant-temperature water bath oscillator and oscillated at room temperature at a frequency of at least 100 rpm, preferably 100–300 rpm, for at least 4 hours, preferably 4–24 hours. After the reaction was complete, the mixture was centrifuged or filtered, washed at least three times with ultrapure water and anhydrous ethanol, and vacuum dried at at least 30°C, preferably 30–60°C, for at least 12 hours to obtain tannic acid-modified nanomaterials. In the above process, tannic acid adheres to the surface of the nanomaterials, achieving loading.

[0156] Furthermore, solvent A is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

[0157] Furthermore, the specific steps of the modification reaction between the nanomaterial and the silane coupling agent in step (1) are as follows:

[0158] Take silane coupling agent and nanomaterials in a mass ratio of 0.1 to 10:10 in a reactor (such as a three-necked flask), add solvent B in a mass ratio of 2 to 20 times that of the nanomaterials, and sonicate in an ultrasonic oscillator to disperse the nanomaterials for at least 0.5 h, preferably 0.5 to 2 h. Then transfer to a constant temperature magnetic stirrer and stir at 30 °C, preferably 30 to 100 °C, for at least 2 h, preferably 2 to 18 h. After the reaction is completed, centrifuge or filter to separate the nanomaterials, wash them at least 3 times with ultrapure water and anhydrous ethanol, and vacuum dry them at at least 30 °C, preferably 30 to 60 °C, for at least 12 h to obtain silane coupling agent modified nanomaterials.

[0159] Furthermore, solvent B is one or more of methanol, ethanol, n-propanol, isopropanol, formic acid, and acetic acid, and / or

[0160] The silane coupling agent is one or more of 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (KH550), and diethylenetriaminopropyltrimethoxysilane.

[0161] Furthermore, the specific steps of step (2) are as follows:

[0162] (21) Place 0.1 to 1 part of modified nanomaterial, 0.1 to 1 part of catalyst p-toluenesulfonic acid or sulfuric acid and 1 part of polystyrene maleic anhydride in a reactor (three-necked flask), and then add 2 to 6 parts of solvent C. Sonicate the mixture in an ultrasonic oscillator to disperse the nanomaterial for at least 0.5 h, preferably 0.5 to 2 h, to obtain a mixture.

[0163] (22) Transfer the mixture to a constant temperature magnetic stirrer and stir at at least 40°C, preferably 40-120°C, for at least 4 hours, preferably 4-24 hours. After the reaction is completed, centrifuge or filter to obtain a solid product. Wash the solid product with solvent C at least 3 times, and finally wash it with anhydrous ethanol at least 2 times. Vacuum dry at at least 60°C, preferably 60-80°C, for at least 12 hours to obtain the modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs).

[0164] Furthermore, the solvent C is one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

[0165] Furthermore, the specific steps of step (3) are as follows:

[0166] (31) The modified nanomaterials obtained in step (2) are grafted with polystyrene maleic anhydride and 0.1 to 1 part of porphyrin-based polyamine resin in a reactor (such as a three-necked flask), and then solvent D with a mass of 2 to 10 times that of porphyrin-based polyamine resin is added to it. The mixture is ultrasonically dispersed in an ultrasonic oscillator for at least 0.5 h, preferably 0.5 to 2 h, to obtain a mixture.

[0167] (32) Transfer the mixture to a constant temperature magnetic stirrer and stir the reaction at at least 40°C, preferably 40-120°C, for at least 4 hours, preferably 4-24 hours. After the reaction is completed, centrifuge or filter to separate the solid product. Wash the solid with distilled water and anhydrous ethanol at least 3 times in sequence, and vacuum dry at at least 60°C, preferably 60-80°C, for at least 12 hours to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups.

[0168] Furthermore, the solvent D is one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

[0169] Furthermore, the specific steps of the preparation method of the porphyrin-based polyamine resin, in molar amounts, are as follows:

[0170] One part of hydroxyphenyl porphyrin and 2 to 10 parts of polyamine are dissolved in an organic solvent with a mass of 2 to 10 times that of the polyamine to obtain a mixture. The mixture is then transferred to a reactor (such as a four-necked flask) equipped with a stirrer, a water separator and a dropping funnel. The reactor is then placed in a constant temperature oil bath.

[0171] Dissolve 2-50 parts of paraformaldehyde in 1-5 times its mass of an organic solvent to obtain a paraformaldehyde organic solvent solution. Then, transfer the paraformaldehyde organic solvent solution to a dropping funnel in the reactor. Control the reaction temperature at 90-150°C and reflux the reaction system. Under heating and stirring conditions, slowly add the paraformaldehyde organic solvent solution dropwise into the reactor through a constant pressure dropping funnel. Stop the reaction after at least 6 hours, preferably 6-48 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain porphyrin-based polyamine resin.

[0172] Furthermore, the organic solvent is one or more of benzene, toluene, and xylene, and / or

[0173] The hydroxyphenyl-containing porphyrin has one of the following structures:

[0174]

[0175] Among them, R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C. n H 2n+1 or OC n H 2n+1 One of them, where n = 1 to 20, and / or

[0176] The polyamine is a polyethylene polyamine, preferably one or more of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0177] A fluorescent nano-demulsifier is prepared by any one of the methods described above.

[0178] The above-mentioned fluorescent nano-demulsifiers are used as demulsifiers in the treatment of chemical flooding produced fluids.

[0179] In one embodiment, the preparation method of the above-mentioned fluorescent nano-demulsifier, by weight, includes the following steps:

[0180] (1) The nanomaterials were modified by reacting them with dopamine hydrochloride to obtain modified nanomaterials;

[0181] (2) Disperse 0.1 parts of the modified nanomaterial in solvent C, and react with 1 part of polystyrene maleic anhydride in the presence of the catalyst p-toluenesulfonic acid or sulfuric acid to obtain modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs).

[0182] (3) The modified nanomaterial grafted with polystyrene maleic anhydride is dispersed in solvent D, and then 0.1 parts of porphyrin-based polyamine resin are added to it for reaction. After the reaction is completed, a fluorescent nano-demulsifier containing porphyrin fluorescent groups is obtained.

[0183] Furthermore, the nanomaterial mentioned in step (1) is nano Fe3O4.

[0184] Furthermore, the nano-Fe3O4 is prepared by a solvothermal method, and the specific steps are as follows (by weight):

[0185] One part of ferric chloride hexahydrate, one part of sodium acetate, and one part of polyethylene glycol were dissolved in an appropriate amount of solvent, stirred evenly, and then transferred to a polytetrafluoroethylene reactor. The mixture was heated at 120°C for 20 hours to obtain a black product. The product was washed three times with ultrapure water and anhydrous ethanol, and then vacuum dried at 40°C for 12 hours to obtain nano-Fe3O4.

[0186] Furthermore, the solvent is water, and / or

[0187] The amount of solvent used, calculated as ferric chloride hexahydrate, is 6 mL / g.

[0188] In another embodiment, the nano-Fe3O4 is prepared by a solvothermal method, and the specific steps are as follows (by weight):

[0189] One part of ferric chloride hexahydrate, five parts of sodium acetate, and five parts of polyethylene glycol were dissolved in an appropriate amount of solvent, stirred evenly, and then transferred to a polytetrafluoroethylene reactor. The mixture was heated at 240°C for 4 hours to obtain a black product. The product was washed four times with ultrapure water and anhydrous ethanol, and then vacuum dried at 80°C for 3 hours to obtain nano-Fe3O4.

[0190] Furthermore, the solvent is ethylene glycol, and / or

[0191] The amount of solvent used, calculated based on the amount of ferric chloride hexahydrate, is 20 mL / g.

[0192] In another embodiment, the nano-Fe3O4 is prepared by a solvothermal method, and the specific steps are as follows (by weight):

[0193] One part of ferric chloride hexahydrate, three parts of sodium acetate, and three parts of polyethylene glycol were dissolved in an appropriate amount of solvent, stirred evenly, and then transferred to a polytetrafluoroethylene reactor. The mixture was heated at 150°C for 8 hours to obtain a black product. The product was washed five times with ultrapure water and five times with anhydrous ethanol, and then vacuum dried at 60°C for 6 hours to obtain nano-Fe3O4.

[0194] Furthermore, the solvent is propylene glycol. In another embodiment, the solvent is a mixture of water, ethylene glycol, and propylene glycol in equal mass ratios, and / or

[0195] The amount of solvent used, calculated based on the amount of ferric chloride hexahydrate, is 10 mL / g.

[0196] Furthermore, the modification reaction between the nanomaterial and dopamine hydrochloride in step (1) is as follows:

[0197] Dopamine hydrochloride (DA) and nanomaterials were placed in a reactor (e.g., an Erlenmeyer flask) at a mass ratio of 0.1:10. Twice the mass of the nanomaterials in Tris-HCl solution was added, and the reactor was sealed. The nanomaterials were dispersed by ultrasonication in an ultrasonic oscillator for 0.5 h. Then, the mixture was transferred to a constant-temperature water bath oscillator and oscillated at 100 rpm for 24 h at room temperature. After the reaction was complete, the mixture was centrifuged, washed three times successively with ultrapure water and anhydrous ethanol, and vacuum dried at 30 °C for 24 h to obtain polydopamine hydrochloride-modified nanomaterials. In the above process, dopamine hydrochloride polymerized to form polydopamine hydrochloride, which adhered to the surface of the nanomaterials. The catechol groups in the polydopamine hydrochloride reacted with the hydroxyl groups on the surface of the nanomaterials to achieve loading.

[0198] In another embodiment, the modification reaction between the nanomaterial and dopamine hydrochloride in step (1) is as follows:

[0199] Dopamine hydrochloride (DA) and nanomaterials were placed in a reactor (such as an Erlenmeyer flask) at a mass ratio of 10:10. Tris-HCl solution with a mass of 20 times that of the nanomaterials was added, and the mixture was sealed. The nanomaterials were dispersed by ultrasonication in an ultrasonic oscillator for 2 hours. Then, the mixture was transferred to a constant temperature water bath oscillator and oscillated at a frequency of 300 rpm at room temperature for 4 hours. After the reaction was completed, the mixture was centrifuged and washed four times with ultrapure water and anhydrous ethanol. The mixture was then vacuum dried at 60°C for 12 hours to obtain polydopamine hydrochloride modified nanomaterials.

[0200] In yet another embodiment, the modification reaction between the nanomaterial and dopamine hydrochloride in step (1) is as follows:

[0201] Dopamine hydrochloride (DA) and nanomaterials were placed in a reactor (such as an Erlenmeyer flask) at a mass ratio of 1:10. Tris-HCl solution with a mass of 10 times that of the nanomaterials was added, and the mixture was sealed. The nanomaterials were dispersed by ultrasonication in an ultrasonic oscillator for 1 hour. Then, the mixture was transferred to a constant temperature water bath oscillator and oscillated at a frequency of 200 rpm for 12 hours at room temperature. After the reaction was completed, the mixture was filtered and separated. It was washed five times with ultrapure water and anhydrous ethanol, and then vacuum dried at 40°C for 16 hours to obtain polydopamine hydrochloride modified nanomaterials.

[0202] Furthermore, the specific steps of step (2) are as follows:

[0203] (21) Place 0.1 parts of modified nanomaterial, 0.1 parts of catalyst p-toluenesulfonic acid and 1 part of polystyrene maleic anhydride in a reactor (three-necked flask), then add 2 parts of solvent C, and sonicate the nanomaterial in an ultrasonic oscillator for 0.5 h to obtain a mixture.

[0204] (22) The mixture was transferred to a constant temperature magnetic stirrer and stirred at 40°C for 24 h. After the reaction was completed, the solid product was obtained by filtration and separation. The solid product was washed three times with solvent C and then washed twice with anhydrous ethanol. The modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs) was obtained by vacuum drying at 60°C for 24 h.

[0205] Furthermore, the solvent C is toluene.

[0206] Furthermore, the specific steps of step (3) are as follows:

[0207] (31) The modified nanomaterials obtained in step (2) are grafted with polystyrene maleic anhydride and 0.1 parts of porphyrin-based polyamine resin into a reactor (such as a three-necked flask), and then solvent D with a mass of 2 times that of porphyrin-based polyamine resin is added to it. The mixture is ultrasonically dispersed in an ultrasonic oscillator for 0.5 h to obtain a mixture.

[0208] (32) The mixture was transferred to a constant temperature magnetic stirrer and stirred at 40°C for 24 hours. After the reaction was completed, the solid product was obtained by centrifugation or filtration. The solid was washed three times with distilled water and anhydrous ethanol, and then dried under vacuum at 60°C for 24 hours to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups.

[0209] Furthermore, the solvent D is toluene.

[0210] Furthermore, the specific steps of the preparation method of the porphyrin-based polyamine resin, in molar amounts, are as follows:

[0211] One part of hydroxyphenyl porphyrin and two parts of polyamine are dissolved in an organic solvent with a mass twice that of the polyamine to obtain a mixture. The mixture is then transferred to a reactor (such as a four-necked flask) equipped with a stirrer, a water separator and a dropping funnel, and the reactor is placed in a constant temperature oil bath.

[0212] Two parts of paraformaldehyde were dissolved in an organic solvent of equal mass to obtain a paraformaldehyde organic solvent solution. The paraformaldehyde organic solvent solution was then transferred to a dropping funnel in the reactor. The reaction temperature was controlled at 90°C, and the reaction system was refluxed. Under heating and stirring conditions, the paraformaldehyde organic solvent solution was slowly added dropwise to the reactor through a constant pressure dropping funnel. The reaction was stopped after 6 hours. The solvent and unreacted formaldehyde were removed by vacuum distillation to obtain porphyrin-based polyamine resin.

[0213] Furthermore, the organic solvent is benzene, and / or

[0214] The hydroxyphenyl-containing porphyrin has one of the following structures:

[0215]

[0216] R1 is H. In another embodiment, R1 is Cl. In another embodiment, R1 is Br. In another embodiment, R1 is NO2. In another embodiment, R1 is CH3. In another embodiment, R1 is n-decyl. In another embodiment, R1 is n-eicosyl. In another embodiment, R1 is or OCH3. In another embodiment, R1 is n-decyloxy (OC) 10 H 11 In another embodiment, R1 is n-eicosyloxy (OC) 20 H 21 ).

[0217] R2 is Cl. In another embodiment, R2 is H. In another embodiment, R2 is Br. In another embodiment, R2 is NO2. In another embodiment, R2 is CH3. In another embodiment, R2 is n-decyl. In another embodiment, R2 is n-eicosyl. In another embodiment, R2 is or OCH3. In another embodiment, R2 is n-decyloxy (OC) 10 H 11 In another embodiment, R2 is n-eicosyloxy (OC) 20 H 21 ).

[0218] R3 is NO2. In another embodiment, R3 is H. In another embodiment, R3 is Br. In another embodiment, R3 is Cl. In another embodiment, R3 is CH3. In another embodiment, R3 is n-decyl. In another embodiment, R3 is n-eicosyl. In another embodiment, R3 is or OCH3. In another embodiment, R3 is n-decyloxy (OC) 10 H 11 In another embodiment, R3 is n-eicosyloxy (OC) 20 H 21 ), and / or

[0219] The polyamine is diethylenetriamine.

[0220] A fluorescent nano-demulsifier is prepared by any one of the methods described above.

[0221] The above-mentioned fluorescent nano-demulsifiers are used as demulsifiers in the treatment of chemical flooding produced fluids.

[0222] In another embodiment, the preparation method of the above-mentioned fluorescent nano-demulsifier, by weight, includes the following steps:

[0223] (1) Modified nanomaterials are obtained by reacting nanomaterials with tannic acid.

[0224] (2) Disperse 1 part of the modified nanomaterial in solvent C, and react it with 1 part of polystyrene maleic anhydride in the presence of the catalyst p-toluenesulfonic acid to obtain modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs).

[0225] (3) The modified nanomaterial grafted with polystyrene maleic anhydride is dispersed in solvent D, and then 1 part of porphyrin-based polyamine resin is added to it for reaction. After the reaction is completed, a fluorescent nano-demulsifier containing porphyrin fluorescent groups is obtained.

[0226] Furthermore, the nanomaterial mentioned in step (1) is nano-TiO2.

[0227] Furthermore, the modification reaction between the nanomaterials and tannic acid in step (1) is as follows:

[0228] Tannic acid (TA) and nanomaterials were placed in a reactor (e.g., an Erlenmeyer flask) at a mass ratio of 0.1:10. Solvent A, twice the mass of the nanomaterials, was added, and the reactor was sealed. The nanomaterials were dispersed by ultrasonication in an ultrasonic oscillator for 2 hours. Then, the mixture was transferred to a constant-temperature water bath oscillator and oscillated at room temperature at a frequency of at least 100 rpm for 24 hours. After the reaction was complete, the mixture was filtered and separated, washed three times successively with ultrapure water and anhydrous ethanol, and then vacuum-dried at 30°C for 24 hours to obtain tannic acid-modified nanomaterials. In the above process, tannic acid adhered to the surface of the nanomaterials, achieving loading.

[0229] Furthermore, solvent A is N,N-dimethylformamide.

[0230] In another embodiment, the modification reaction between the nanomaterial and tannic acid in step (1) is as follows:

[0231] Tannic acid (TA) and nanomaterials were placed in a reactor (e.g., an Erlenmeyer flask) at a mass ratio of 10:10. Solvent A, at a mass ratio of 20 times that of the nanomaterials, was added. The reactor was sealed and ultrasonically dispersed in an ultrasonic oscillator for 6 hours. Then, the mixture was transferred to a constant-temperature water bath oscillator and oscillated at 300 rpm for 4 hours at room temperature. After the reaction was complete, the mixture was centrifuged and washed four times successively with ultrapure water and anhydrous ethanol. The mixture was then vacuum-dried at 60°C for 12 hours to obtain tannic acid-modified nanomaterials. In this process, tannic acid adhered to the surface of the nanomaterials, achieving loading.

[0232] Furthermore, solvent A is N,N-dimethylacetamide.

[0233] In yet another embodiment, the modification reaction between the nanomaterial and tannic acid in step (1) is as follows:

[0234] Tannic acid (TA) and nanomaterials were placed in a reactor (e.g., an Erlenmeyer flask) at a mass ratio of 5:10. Solvent A, in an amount 10 times the mass of the nanomaterials, was added. The reactor was sealed and ultrasonically dispersed in an ultrasonic oscillator for 4 hours. Then, the mixture was transferred to a constant-temperature water bath oscillator and oscillated at 200 rpm for 12 hours at room temperature. After the reaction was complete, the mixture was centrifuged and washed five times successively with ultrapure water and anhydrous ethanol. The mixture was then vacuum-dried at 40°C for 15 hours to obtain tannic acid-modified nanomaterials. In this process, tannic acid adhered to the surface of the nanomaterials, achieving loading.

[0235] Furthermore, solvent A is tetrahydrofuran. In another embodiment, solvent A is dioxane. In another embodiment, solvent A is dimethyl sulfoxide. In another embodiment, solvent A is N-methylpyrrolidone. In yet another embodiment, solvent A is a mixture of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone in equal mass ratios.

[0236] Furthermore, the specific steps of step (2) are as follows:

[0237] (21) Place 1 part of modified nanomaterial, 1 part of catalyst p-toluenesulfonic acid and 1 part of polystyrene maleic anhydride in a reactor (three-necked flask), and then add 6 parts of solvent C. Disperse the nanomaterial in an ultrasonic oscillator for 2 hours to obtain a mixture.

[0238] (22) The mixture was transferred to a constant temperature magnetic stirrer and stirred at 120°C for 4 hours. After the reaction was completed, the solid product was obtained by centrifugation. The solid product was washed 5 times with solvent C and finally washed 4 times with anhydrous ethanol. The modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs) was obtained by vacuum drying at 80°C for 12 hours.

[0239] Furthermore, the solvent C is xylene.

[0240] Furthermore, the specific steps of step (3) are as follows:

[0241] (31) The modified nanomaterials obtained in step (2) are grafted with polystyrene maleic anhydride and 1 part of porphyrin-based polyamine resin into a reactor (such as a three-necked flask), and then solvent D with 10 times the mass of porphyrin-based polyamine resin is added to it. The mixture is ultrasonically dispersed in an ultrasonic oscillator for 2 hours to obtain a mixture.

[0242] (32) The mixture was transferred to a constant temperature magnetic stirrer and stirred at 120°C for 4 hours. After the reaction was completed, the solid product was separated by centrifugation. The solid was washed 5 times with distilled water and anhydrous ethanol in sequence and then dried under vacuum at 80°C for at least 12 hours to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups.

[0243] Furthermore, the solvent D is xylene.

[0244] Furthermore, the specific steps of the preparation method of the porphyrin-based polyamine resin, in molar amounts, are as follows:

[0245] One part of hydroxyphenyl porphyrin and 10 parts of polyamine are dissolved in an organic solvent with a mass of 10 times that of the polyamine to obtain a mixture. The mixture is then transferred to a reactor (such as a four-necked flask) equipped with a stirrer, a water separator and a dropping funnel, and the reactor is placed in a constant temperature oil bath.

[0246] 50 parts of paraformaldehyde were dissolved in 5 times its mass of an organic solvent to obtain a paraformaldehyde organic solvent solution. The paraformaldehyde organic solvent solution was then transferred to a dropping funnel in the reactor. The reaction temperature was controlled at 150°C, and the reaction system was refluxed. Under heating and stirring conditions, the paraformaldehyde organic solvent solution was slowly added dropwise to the reactor through a constant pressure dropping funnel. The reaction was stopped after 48 hours. The solvent and unreacted formaldehyde were removed by vacuum distillation to obtain porphyrin-based polyamine resin.

[0247] Furthermore, the organic solvent is xylene, and / or

[0248] The hydroxyphenyl-containing porphyrin has one of the following structures:

[0249]

[0250] R1 is n-decyloxy (OC) 10 H 11 R2 is CH3, and / or

[0251] The polyamine is tetraethylenepentamine.

[0252] A fluorescent nano-demulsifier is prepared by any one of the methods described above.

[0253] The above-mentioned fluorescent nano-demulsifiers are used as demulsifiers in the treatment of chemical flooding produced fluids.

[0254] In yet another embodiment, the preparation method of the above-mentioned fluorescent nano-demulsifier, by weight, includes the following steps:

[0255] (1) Modify the nanomaterials by reacting them with a silane coupling agent to obtain modified nanomaterials;

[0256] (2) Disperse 0.5 parts of the modified nanomaterial in solvent C, and react with 1 part of polystyrene maleic anhydride in the presence of sulfuric acid catalyst to obtain modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs).

[0257] (3) The modified nanomaterial grafted with polystyrene maleic anhydride is dispersed in solvent D, and then 0.5 parts of porphyrin-based polyamine resin are added to it for reaction. After the reaction is completed, a fluorescent nano-demulsifier containing porphyrin fluorescent groups is obtained.

[0258] Further, the nanomaterial described in step (1) is nano-ZnO. In another embodiment, the nanomaterial described in step (1) is nano-SiO2. In another embodiment, the nanomaterial described in step (1) is graphene oxide (GO). In another embodiment, the nanomaterial described in step (1) is carbon nanotubes (CNTs).

[0259] Furthermore, the specific steps of the modification reaction between the nanomaterial and the silane coupling agent in step (1) are as follows:

[0260] Take silane coupling agent and nanomaterials in a reactor (such as a three-necked flask) at a mass ratio of 5:10, add solvent B in a volume of 10 times the mass of nanomaterials, and sonicate the nanomaterials in an ultrasonic oscillator for 1 hour. Then transfer the mixture to a constant temperature magnetic stirrer and stir the reaction at 500°C for 12 hours. After the reaction is complete, filter and separate the nanomaterials, wash them five times with ultrapure water and anhydrous ethanol, and vacuum dry them at 50°C for 16 hours to obtain silane coupling agent modified nanomaterials.

[0261] Furthermore, solvent B is methanol, and / or

[0262] The silane coupling agent is 3-aminopropyltrimethoxysilane (APTMS).

[0263] In another embodiment, the specific steps of the modification reaction between the nanomaterial and the silane coupling agent in step (1) are as follows:

[0264] The silane coupling agent and nanomaterials were placed in a reactor (such as a three-necked flask) at a mass ratio of 0.1:10. Solvent B, which was twice the mass of the nanomaterials, was added. The nanomaterials were dispersed by ultrasonication in an ultrasonic oscillator for 0.5 h. Then, the mixture was transferred to a constant temperature magnetic stirrer and stirred at 30 °C for 18 h. After the reaction was completed, the mixture was filtered and separated. It was washed three times with ultrapure water and anhydrous ethanol, and then vacuum dried at 30 °C for 24 h to obtain the silane coupling agent modified nanomaterials.

[0265] Furthermore, solvent B is ethanol, and / or

[0266] The silane coupling agent is 3-aminopropyltriethoxysilane (KH550).

[0267] In another embodiment, the specific steps of the modification reaction between the nanomaterial and the silane coupling agent in step (1) are as follows:

[0268] Take silane coupling agent and nanomaterials in a mass ratio of 10:10 in a reactor (such as a three-necked flask), add solvent B in a volume of 20 times the mass of nanomaterials, and sonicate the nanomaterials in an ultrasonic oscillator for 2 hours. Then transfer the mixture to a constant temperature magnetic stirrer and stir the reaction at 100°C for 2 hours. After the reaction is complete, centrifuge the mixture, wash it five times with ultrapure water and anhydrous ethanol, and vacuum dry it at 60°C for 12 hours to obtain silane coupling agent modified nanomaterials.

[0269] Furthermore, solvent B is n-propanol. In another embodiment, solvent B is isopropanol. In another embodiment, solvent B is formic acid. In another embodiment, solvent B is acetic acid. In yet another embodiment, solvent B is a mixture of methanol, ethanol, n-propanol, isopropanol, formic acid, and acetic acid in equal mass ratios.

[0270] Further, the silane coupling agent is diethylenetriaminepropyltrimethoxysilane. In another embodiment, the silane coupling agent is a mixture of 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (KH550), and diethylenetriaminepropyltrimethoxysilane in equal mass ratios.

[0271] Furthermore, the specific steps of step (2) are as follows:

[0272] (21) Place 0.5 parts of modified nanomaterial, 0.5 parts of catalyst sulfuric acid and 1 part of polystyrene maleic anhydride in a reactor (three-necked flask), then add 4 parts of solvent C, and sonicate the nanomaterial in an ultrasonic oscillator for 1 hour to obtain a mixture.

[0273] (22) The mixture was transferred to a constant temperature magnetic stirrer and stirred at 80°C for 12 hours. After the reaction was completed, the solid product was obtained by centrifugation. The solid product was washed 5 times with solvent C and then washed 4 times with anhydrous ethanol. The modified nanomaterial grafted polystyrene maleic anhydride (SMA-g-NPs) was obtained by vacuum drying at 70°C for 12 hours.

[0274] Furthermore, solvent C is N,N-dimethylformamide. In another embodiment, solvent C is N,N-dimethylacetamide. In another embodiment, solvent C is tetrahydrofuran. In another embodiment, solvent C is dioxane. In another embodiment, solvent C is dimethyl sulfoxide. In another embodiment, solvent C is N-methylpyrrolidone. In yet another embodiment, solvent C is a mixture of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone in equal mass ratios.

[0275] Furthermore, the specific steps of step (3) are as follows:

[0276] (31) The modified nanomaterials obtained in step (2) are grafted with polystyrene maleic anhydride and 0.5 parts of porphyrin-based polyamine resin in a reactor (such as a three-necked flask), and then solvent D with 5 times the mass of porphyrin-based polyamine resin is added to it. The mixture is ultrasonically dispersed in an ultrasonic oscillator for 1 hour to obtain a mixture.

[0277] (32) The mixture was transferred to a constant temperature magnetic stirrer and stirred at 80°C for 12 hours. After the reaction was completed, the solid product was obtained by centrifugation. The solid was washed five times with distilled water and anhydrous ethanol, and then dried under vacuum at 70°C for 12 hours to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups.

[0278] Furthermore, solvent D is N,N-dimethylformamide. In another embodiment, solvent D is N,N-dimethylacetamide. In another embodiment, solvent D is tetrahydrofuran. In another embodiment, solvent D is dioxane. In another embodiment, solvent D is dimethyl sulfoxide. In another embodiment, solvent D is N-methylpyrrolidone. In yet another embodiment, solvent D is a mixture of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone in equal mass ratios.

[0279] Furthermore, the specific steps of the preparation method of the porphyrin-based polyamine resin, in molar amounts, are as follows:

[0280] One part of hydroxyphenyl porphyrin and five parts of polyamine are dissolved in an organic solvent with a mass of five times that of the polyamine to obtain a mixture. The mixture is then transferred to a reactor (such as a four-necked flask) equipped with a stirrer, a water separator and a dropping funnel, and the reactor is placed in a constant temperature oil bath.

[0281] Twenty parts of paraformaldehyde were dissolved in three times its mass of an organic solvent to obtain a paraformaldehyde organic solvent solution. The paraformaldehyde organic solvent solution was then transferred to a dropping funnel in the reactor. The reaction temperature was controlled at 130°C, and the reaction system was refluxed. Under heating and stirring conditions, the paraformaldehyde organic solvent solution was slowly added dropwise to the reactor through a constant pressure dropping funnel. The reaction was stopped after 24 hours. The solvent and unreacted formaldehyde were removed by vacuum distillation to obtain porphyrin-based polyamine resin.

[0282] Furthermore, the organic solvent is toluene, and / or

[0283] The hydroxyphenyl-containing porphyrin has one of the following structures:

[0284]

[0285] In this embodiment, the polyamine is triethylenetetramine. In another embodiment, the polyamine is a mixture of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine in equal mass ratios.

[0286] A fluorescent nano-demulsifier is prepared by any one of the methods described above.

[0287] The above-mentioned fluorescent nano-demulsifiers are used as demulsifiers in the treatment of chemical flooding produced fluids.

[0288] Example 1

[0289] The preparation method of fluorescent nano-demulsifier includes the following steps:

[0290] (1) Take 1g of dopamine hydrochloride (DA) and 5g of nano TiO2 (particle size 20nm) into an Erlenmeyer flask, add 20mL of Tris-HCl solution, seal, and sonicate in an ultrasonic oscillator to disperse the nano TiO2 material for 1h. Then transfer to a constant temperature water bath oscillator and oscillate at a frequency of 150rpm for 12h at room temperature. During the above process, DA polymerizes to generate PDA, which adheres to the surface of TiO2. The catechol groups in PDA react with the hydroxyl groups on the surface of nano TiO2 to achieve loading. After the reaction is completed, centrifuge and wash three times with ultrapure water and anhydrous ethanol, and vacuum dry at 40℃ for 12h to obtain PDA modified TiO2.

[0291] (2) Take 2g of PDA-modified TiO2, 0.5g of p-toluenesulfonic acid and 5g of polystyrene maleic anhydride (molecular weight 7000, maleic anhydride content 35wt%) into a three-necked flask, add 20mL of toluene, and sonicate the nano-PDA-modified TiO2 material in an ultrasonic oscillator for 0.5h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 12h. After the reaction is completed, centrifuge the solid, wash the solid 3 times with toluene, and finally wash it 2 times with anhydrous ethanol. Dry it under vacuum at 80℃ for 12h to obtain SMA-g-TiO2.

[0292] (3) Take 2g of SMA-g-TiO2 and 2g of monohydroxyphenylporphyrin polyamine resin into a three-necked flask, add 10g of toluene, and sonicate the SMA-g-TiO2 in an ultrasonic oscillator for 2h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 8h. After the reaction is completed, centrifuge the solid and wash it three times with distilled water and anhydrous ethanol. Dry it under vacuum at 60℃ for 12h to obtain monohydroxyphenylporphyrin polyamine resin-TiO2 fluorescent nano demulsifier, named demulsifier-1#.

[0293] Furthermore, the preparation method of the monohydroxyphenyl porphyrin polyamine resin is as follows:

[0294] Dissolve 1 mole of monohydroxyphenylporphyrin and 2 moles of tetraethylenepentamine in 5 times the mass of toluene. Then transfer the solution to a four-necked flask equipped with a stirrer, a water separator and a dropping funnel. Place the four-necked flask in a constant temperature oil bath.

[0295] Dissolve 8 moles of paraformaldehyde in twice its mass of toluene, and then transfer the solution to a dropping funnel. Control the reaction temperature at 130°C and reflux the reaction system. Under heating and stirring, slowly add the paraformaldehyde solution dropwise to a four-necked flask through a constant-pressure dropping funnel. As the reaction proceeds, water can be observed flowing out of the water separator. Stop the reaction after 18 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain monohydroxyphenylporphyrin polyamine resin.

[0296] Furthermore, the structural formula of monohydroxyphenylporphyrin is as follows:

[0297] in:

[0298] R1 is H;

[0299] R2 is Cl;

[0300] R3 is C 10 H 21 (Positive Gui Base).

[0301] Infrared spectroscopy was performed on the raw materials in Example 1: monohydroxyphenylporphyrin, polystyrene maleic anhydride, and nano-TiO2. The results are as follows: Figure 1 , Figure 2 and Figure 4 As shown. Figure 1 As shown, at 1500, 1550 and 1600 cm -1 Skeletal vibrations of the benzene ring were observed nearby. 3100-3700 cm⁻¹ -1 The peak at 968 cm⁻¹ represents the stretching vibration peaks of OH and NH, while the bending vibration peak of NH appears at 968 cm⁻¹. -1 Nearby. For example, Figure 2 As shown, 1850cm -1 and 1780cm -1 The two absorption peaks at that location are attributed to the stretching vibration characteristic peaks of the anhydride groups in SMA. For example... Figure 4 As shown, 3400cm -1 and 1620cm -1 The peak at 500-800 cm⁻¹ is the absorption peak of OH in TiO₂. -1 The peak at this location is a characteristic peak of the titanium dioxide lattice.

[0302] The intermediate product of Example 1, monohydroxyphenyl porphyrin polyamine resin, was analyzed by infrared spectroscopy, and the results are as follows: Figure 3 As shown. Figure 3 As shown, 3000-3700cm -1 The peak at 2750-3000 cm⁻¹ is the NH vibration peak of porphyrin grafted amine group; -1 An alkyl CH vibration peak appears at 1650 cm⁻¹. -1The nearby peaks are CN bond vibration peaks in polyamine resins, at 1600 and 1460 cm⁻¹. -1 Skeletal vibrations of the benzene ring were observed nearby.

[0303] Infrared spectroscopy was performed on the monohydroxyphenyl porphyrin polyamine resin-TiO2 fluorescent nano-demulsifier-1# prepared in Example 1, and the results are as follows: Figure 5 As shown. Figure 5 As shown, the infrared spectrum of monohydroxyphenyl porphyrin polyamine resin-TiO2 demulsifier is similar to that of monohydroxyphenyl porphyrin polyamine resin. Figure 5 It can be seen from 540cm -1 A peak appears at a certain point, which is the characteristic peak of the titanium dioxide lattice.

[0304] Example 2

[0305] The preparation method of fluorescent nano-demulsifier includes the following steps:

[0306] (1) Take 1g of dopamine hydrochloride (DA) and 5g of graphene oxide into an Erlenmeyer flask, add 20mL of Tris-HCl solution, seal, and sonicate in an ultrasonic oscillator to disperse the nanomaterial (graphene oxide) for 1h. Then transfer to a constant temperature water bath oscillator and oscillate at a frequency of 150rpm for 12h at room temperature. During the above process, DA polymerizes to generate PDA, which adheres to the surface of graphene oxide. The catechol groups in PDA react with the hydroxyl groups on the surface of graphene oxide to achieve loading. After the reaction is completed, centrifuge and wash three times with ultrapure water and anhydrous ethanol, and vacuum dry at 40℃ for 12h to obtain PDA-modified GO.

[0307] (2) Take 2g of PDA-modified GO, 1g of p-toluenesulfonic acid and 5g of polystyrene maleic anhydride (molecular weight 3000, maleic anhydride content 45wt%) into a three-necked flask, add 20mL of N,N-dimethylformamide, and sonicate the PDA-modified GO in an ultrasonic oscillator for 0.5h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 12h. After the reaction is completed, centrifuge the solid, wash the solid 3 times with N,N-dimethylformamide, and finally wash it 2 times with anhydrous ethanol. Dry it under vacuum at 80℃ for 12h to obtain SMA-g-GO.

[0308] (3) Take 2g of SMA-g-GO and 2g of dihydroxyphenylporphyrin polyamine resin into a three-necked flask, add 10g of N,N-dimethylformamide, and sonicate the SMA-g-GO in an ultrasonic oscillator for 2h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 8h. After the reaction is completed, centrifuge the solid and wash it three times with distilled water and anhydrous ethanol. Dry it under vacuum at 60℃ for 12h to obtain dihydroxyphenylporphyrin polyamine resin-GO fluorescent nano demulsifier, named demulsifier-2#.

[0309] Furthermore, the preparation method of the dihydroxyphenylporphyrin polyamine resin is as follows:

[0310] Dissolve 1 mole of dihydroxyphenylporphyrin and 4 moles of tetraethylenepentamine in xylene, which is 8 times the mass of tetraethylenepentamine. Then transfer the solution to a four-necked flask equipped with a stirrer, a water separator and a dropping funnel. Place the four-necked flask in a constant temperature oil bath.

[0311] Dissolve 16 moles of paraformaldehyde in twice its mass of xylene, and then transfer the solution to a dropping funnel. Control the reaction temperature at 150°C and reflux the reaction system. Under heating and stirring, slowly add the paraformaldehyde solution dropwise to a four-necked flask through a constant-pressure dropping funnel. As the reaction proceeds, water can be observed flowing out of the water separator. Stop the reaction after 24 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain dihydroxyphenylporphyrin polyamine resin.

[0312] Furthermore, the structural formula of dihydroxyphenylporphyrin is as follows:

[0313] in:

[0314] R1 is NO2;

[0315] R2 is OCH3.

[0316] Example 3

[0317] The preparation method of fluorescent nano-demulsifier includes the following steps:

[0318] (1) Take 1g of tannic acid (TA) and 5g of nano SiO2 into an Erlenmeyer flask, add 15mL of tetrahydrofuran, seal, and sonicate in an ultrasonic oscillator to disperse the nanomaterials for 1h. Then transfer to a constant temperature water bath oscillator and oscillate at a frequency of 200rpm for 10h at room temperature. During the above process, tannic acid (TA) adheres to the surface of the nano SiO2 material to achieve loading. After the reaction is completed, centrifuge and separate, wash with ultrapure water and anhydrous ethanol three times in sequence, and vacuum dry at 50℃ for 12h to obtain TA modified nano SiO2.

[0319] (2) Take 2g of TA-modified nano-SiO2, 1g of p-toluenesulfonic acid and 5g of polystyrene maleic anhydride (molecular weight 30000, maleic anhydride content 35wt%) into a three-necked flask, add 20mL of N,N-dimethylacetamide, and sonicate the TA-modified nano-SiO2 in an ultrasonic oscillator for 0.5h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 12h. After the reaction is completed, centrifuge the solid, wash the solid 3 times with N,N-dimethylacetamide, and finally wash it 2 times with anhydrous ethanol. Dry it under vacuum at 80℃ for 12h to obtain SMA-g-SiO2.

[0320] (3) Take 2g of SMA-g-SiO2 and 5g of tetrahydroxyphenylporphyrin polyamine resin into a three-necked flask, add 10g of tetrahydrofuran, and sonicate the SMA-g-SiO2 in an ultrasonic oscillator for 2h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 8h. After the reaction is completed, centrifuge the solid and wash it three times with distilled water and anhydrous ethanol. Dry it under vacuum at 60℃ for 12h to obtain tetrahydroxyphenylporphyrin polyamine resin-SiO2 fluorescent nano demulsifier, named demulsifier-3#.

[0321] Furthermore, the preparation method of tetrahydroxyphenylporphyrin polyamine resin is as follows:

[0322] Dissolve 1 mole of tetrahydroxyphenylporphyrin and 8 moles of tetraethylenepentamine in xylene, which is 8 times the mass of tetraethylenepentamine. Then transfer the solution to a four-necked flask equipped with a stirrer, a water separator and a dropping funnel. Place the four-necked flask in a constant temperature oil bath.

[0323] Dissolve 20 moles of paraformaldehyde in twice its mass of xylene, and then transfer the solution to a dropping funnel. Control the reaction temperature at 150°C and reflux the reaction system. Under heating and stirring, slowly add the paraformaldehyde solution dropwise to a four-necked flask through a constant-pressure dropping funnel. As the reaction proceeds, water can be observed flowing out of the water separator. Stop the reaction after 36 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain tetrahydroxyphenylporphyrin polyamine resin.

[0324] Furthermore, the structural formula of tetrahydroxyphenylporphyrin is as follows:

[0325]

[0326] Example 4

[0327] The preparation method of fluorescent nano-demulsifier includes the following steps:

[0328] (1) Take 1g of tannic acid (TA) and 5g of multi-walled carbon nanotubes into an Erlenmeyer flask, add 15mL of N-methylpyrrolidone, seal, and sonicate in an ultrasonic oscillator to disperse the carbon nanotubes for 1h. Then transfer to a constant temperature water bath oscillator and oscillate at a frequency of 200rpm for 10h at room temperature. During the above process, tannic acid (TA) adheres to the surface of carbon nanotubes to achieve loading. After the reaction is completed, centrifuge to separate, wash with ultrapure water and anhydrous ethanol three times in sequence, and vacuum dry at 50℃ for 12h to obtain TA modified carbon nanotubes.

[0329] (2) Take 2g of TA-modified carbon nanotubes, 1g of p-toluenesulfonic acid and 5g of polystyrene maleic anhydride (molecular weight 60000, maleic anhydride content 30wt%) into a three-necked flask, add 20mL of N-methylpyrrolidone, and sonicate the TA-modified carbon nanotubes in an ultrasonic oscillator for 0.5h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 12h. After the reaction is completed, centrifuge the solid, wash the solid three times with N-methylpyrrolidone, and finally wash it twice with anhydrous ethanol. Dry it under vacuum at 80℃ for 12h to obtain SMA-g-CNT.

[0330] (3) Take 2g of SMA-g-CNT and 5g of dihydroxyphenylporphyrin polyamine resin into a three-necked flask, add 10g of N-methylpyrrolidone, and sonicate the SMA-g-CNT in an ultrasonic oscillator for 2h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 8h. After the reaction is completed, centrifuge the solid and wash it three times with distilled water and anhydrous ethanol. Dry it under vacuum at 60℃ for 12h to obtain dihydroxyphenylporphyrin polyamine resin-CNT fluorescent nano-demulsifier, named demulsifier-4#.

[0331] Furthermore, the preparation method of the dihydroxyphenylporphyrin polyamine resin is as follows:

[0332] Dissolve 1 mole of dihydroxyphenylporphyrin and 4 moles of triethylenetetramine in xylene in 8 times the mass of triethylenetetramine. Then transfer the solution to a four-necked flask equipped with a stirrer, a water separator and a dropping funnel. Place the four-necked flask in a constant temperature oil bath.

[0333] Dissolve 16 moles of paraformaldehyde in twice its mass of xylene, and then transfer the solution to a dropping funnel. Control the reaction temperature at 150°C and reflux the reaction system. Under heating and stirring, slowly add the paraformaldehyde solution dropwise to a four-necked flask through a constant-pressure dropping funnel. As the reaction proceeds, water can be observed flowing out of the water separator. Stop the reaction after 24 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain dihydroxyphenylporphyrin polyamine resin.

[0334] Furthermore, the structural formula of dihydroxyphenylporphyrin is as follows:

[0335] in:

[0336] R1 is Br;

[0337] R2 is C 20 H 21 (eicosyl)

[0338] Example 5

[0339] The preparation method of fluorescent nano-demulsifier includes the following steps:

[0340] (1) Take 1g of silane coupling agent APTMS and 5g of nano ZnO into a three-necked flask, add 20mL of a mixed solution of water and ethanol (volume ratio 1 / 3), and sonicate the nano ZnO in an ultrasonic oscillator for 1h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 80℃ for 12h. After the reaction is completed, centrifuge the separation, wash it three times with ultrapure water and anhydrous ethanol, and vacuum dry it at 30-60℃ for 12h to obtain APTMS modified nano ZnO.

[0341] (2) Take 2g of APTMS modified nano-ZnO, 0.2g of p-toluenesulfonic acid and 5g of polystyrene maleic anhydride (molecular weight 10000, maleic anhydride content 35wt%) into a three-necked flask, add 20mL of N,N-dimethylacetamide, and sonicate the APTMS modified nano-ZnO material in an ultrasonic oscillator for 0.5h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 12h. After the reaction is completed, centrifuge the solid, wash the solid 3 times with N,N-dimethylacetamide, and finally wash it 2 times with anhydrous ethanol. Dry it under vacuum at 80℃ for 12h to obtain SMA-g-ZnO.

[0342] (3) Take 2g of SMA-g-ZnO and 5g of tetrahydroxyphenylporphyrin polyamine resin into a three-necked flask, add 10g of tetrahydrofuran, and sonicate the SMA-g-ZnO in an ultrasonic oscillator for 2h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 8h. After the reaction is completed, centrifuge the solid and wash it three times with distilled water and anhydrous ethanol. Dry it under vacuum at 60℃ for 12h to obtain ZnO nanomaterials and TA1031 demulsifier, named demulsifier-5#.

[0343] Furthermore, the preparation method of the tetrahydroxyphenylporphyrin polyamine resin is as follows:

[0344] Dissolve 1 mole of tetrahydroxyphenylporphyrin and 8 moles of triethylenetetramine in xylene, which is 8 times the mass of triethylenetetramine. Then transfer the solution to a four-necked flask equipped with a stirrer, a water separator and a dropping funnel. Place the four-necked flask in a constant temperature oil bath.

[0345] Dissolve 20 moles of paraformaldehyde in twice its mass of xylene, and then transfer the solution to a dropping funnel. Control the reaction temperature at 150°C and reflux the reaction system. Under heating and stirring, slowly add the paraformaldehyde solution dropwise to a four-necked flask through a constant-pressure dropping funnel. As the reaction proceeds, water can be observed flowing out of the water separator. Stop the reaction after 36 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain tetrahydroxyphenylporphyrin polyamine resin.

[0346] Furthermore, the structural formula of tetrahydroxyphenylporphyrin is as follows:

[0347]

[0348] Example 6

[0349] The preparation method of fluorescent nano-demulsifier includes the following steps:

[0350] (1) Take 1g of dopamine hydrochloride (DA) and 5g of nano Fe3O4 material into an Erlenmeyer flask, add 20mL of Tris-HCl solution, seal, and sonicate in an ultrasonic oscillator to disperse the nano Fe3O4 material for 1h. Then transfer to a constant temperature water bath oscillator and oscillate at a frequency of 150rpm for 12h at room temperature. During the above process, DA polymerizes to generate PDA, which adheres to the surface of Fe3O4. The catechol groups in PDA react with the hydroxyl groups on the surface of nano Fe3O4 to achieve loading. After the reaction is completed, centrifuge and wash three times with ultrapure water and anhydrous ethanol, and vacuum dry at 40℃ for 12h to obtain PDA-modified Fe3O4.

[0351] (2) Take 2g of PDA-modified Fe3O4, 0.5g of p-toluenesulfonic acid and 5g of polystyrene maleic anhydride (molecular weight 7000, maleic anhydride content 35wt%) into a three-necked flask, add 20mL of toluene, and sonicate the Fe3O4 nanomaterials in an ultrasonic oscillator for 0.5h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 12h. After the reaction is completed, centrifuge the solid, wash the solid 3 times with toluene, and finally wash it 2 times with anhydrous ethanol. Dry it under vacuum at 80℃ for 12h to obtain SMA-g-Fe3O4.

[0352] (3) Take 2g of SMA-g-Fe3O4 and 2g of monohydroxyphenylporphyrin polyamine resin into a three-necked flask, add 10g of toluene, and sonicate the SMA-g-Fe3O4 in an ultrasonic oscillator for 2h. Then transfer it to a constant temperature magnetic stirrer and stir the reaction at 60℃ for 8h. After the reaction is completed, centrifuge the solid and wash it three times with distilled water and anhydrous ethanol. Dry it under vacuum at 60℃ for 12h to obtain monohydroxyphenylporphyrin polyamine resin-Fe3O4 fluorescent magnetic nano-demulsifier, named demulsifier-6#.

[0353] Furthermore, the preparation method of the nano-Fe3O4 material in step (1) is as follows:

[0354] Ferric chloride hexahydrate, sodium acetate, and polyethylene glycol were dissolved in ethylene glycol at a mass ratio of 1:2:2, with the amount of ethylene glycol being 10 mL / g based on the amount of ferric chloride hexahydrate. The mixture was stirred until homogeneous and then transferred to a polytetrafluoroethylene reactor. The reactor was heated at 200°C for 12 hours to obtain a black product. The product was washed three times with ultrapure water and three times with anhydrous ethanol, and then vacuum dried at 60°C for 12 hours to obtain nano-Fe3O4 material.

[0355] Furthermore, the preparation method of the monohydroxyphenyl porphyrin polyamine resin in step (3) is as follows:

[0356] Dissolve 1 mole of monohydroxyphenylporphyrin and 2 moles of tetraethylenepentamine in 5 times the mass of toluene. Then transfer the solution to a four-necked flask equipped with a stirrer, a water separator and a dropping funnel. Place the four-necked flask in a constant temperature oil bath.

[0357] Dissolve 8 moles of paraformaldehyde in twice its mass of toluene, and then transfer the solution to a dropping funnel. Control the reaction temperature at 130°C and reflux the reaction system. Under heating and stirring, slowly add the paraformaldehyde solution dropwise to a four-necked flask through a constant-pressure dropping funnel. As the reaction proceeds, water can be observed flowing out of the water separator. Stop the reaction after 18 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain monohydroxyphenylporphyrin polyamine resin.

[0358] Furthermore, the structural formula of monohydroxyphenylporphyrin is as follows:

[0359] R1 is OC 20 H 21 ;

[0360] R2 is Br;

[0361] R3 is NO2.

[0362] Test Experiment Example 1

[0363] The relative dehydration rate and relative oil removal rate of the demulsifier were determined according to the enterprise standard QSHCG0006-2021 of China Petroleum & Chemical Corporation (Sinopec) for oilfield water treatment. The treatment target was polymer-containing produced water from Shengli Oilfield, and the treatment temperature was 45℃. The water content of the crude oil was tested by distillation, the oil content of the water after demulsification was tested by spectrophotometry, and the polymer content in the water after demulsification was determined by liquid chromatography. The polymer retention rate was obtained by comparing the polymer content with that in the produced fluid. The experimental results are shown in Table 1. Table 1 shows that the demulsifier prepared in this invention has a good demulsification and water-clearing effect on polymer-containing produced water and can retain the polymers in the water.

[0364] The control example used an on-site reverse demulsifier, manufactured by Guangdong Shanmei Environmental Technology Co., Ltd., with the model number WDP-36.

[0365] Table 1. Demulsifying performance of demulsifiers on polymer-containing produced water.

[0366]

[0367]

[0368] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. A fluorescent nano-demulsifier, characterized in that, This fluorescent nano-demulsifier uses polystyrene maleic anhydride as a bridging polymer. The anhydride groups in the polystyrene maleic anhydride are crosslinked with modified nanomaterials and porphyrin-based polyamine resins, respectively, to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups, wherein: In the fluorescent nano-demulsifier, the mass ratio of the groups from the polystyrene maleic anhydride, the groups from the modified nanomaterial, and the groups from the porphyrin-based polyamine resin is 1:(0.1~1):(0.1~1); The molecular weight range of the polystyrene maleic anhydride is 2000 to 100000; Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 5-50 wt%. The modified nanomaterial is one or more of the following: modified nano-TiO2, modified nano-ZnO, modified nano-SiO2, modified nano-Fe3O4, modified graphene oxide, and modified carbon nanotubes. The porphyrin-based polyamine resin is a compound represented by formula (I), (II), or (III) below: Where 0 < m ≤ 3; R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C, respectively. n H 2n+1 or OC n H 2n+1 One of them, where n = 1 to 20.

2. The fluorescent nano-demulsifier as described in claim 1, characterized in that, The polystyrene maleic anhydride has a molecular weight range of 10,000 to 50,000, and / or Based on the mass of the polystyrene maleic anhydride, the content of the maleic anhydride is 10-40 wt%.

3. The fluorescent nano-demulsifier as described in claim 1, characterized in that, The porphyrin-based polyamine resin is a compound represented by formula (I), (II), or (III) below: Where 1 ≤ m ≤ 3; R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C, respectively. n H 2n+1 or OC n H 2n+1 One of them, where n = 1 to 10.

4. A method for preparing the fluorescent nano-demulsifier according to any one of claims 1-3, characterized in that, By weight, the following steps are included: (1) Modify nanomaterials by reacting them with dopamine hydrochloride, tannic acid, or silane coupling agent. (2) The modified nanomaterial is dispersed in solvent C and reacted with polystyrene maleic anhydride in the presence of a catalyst such as p-toluenesulfonic acid or sulfuric acid to obtain modified nanomaterial grafted with polystyrene maleic anhydride. (3) The modified nanomaterial grafted with polystyrene maleic anhydride is dispersed in solvent D, and then porphyrin-based polyamine resin is added to it for reaction. After the reaction is completed, a fluorescent nano-demulsifier containing porphyrin fluorescent groups is obtained.

5. The preparation method of the fluorescent nano-demulsifier as described in claim 4, characterized in that, The nanomaterials mentioned in step (1) are one or more of nano TiO2, nano ZnO, nano SiO2, nano Fe3O4, graphene oxide, and carbon nanotubes.

6. The method for preparing the fluorescent nano-demulsifier as described in claim 5, characterized in that, The nano-Fe3O4 was prepared by a solvothermal method, and the specific steps are as follows (by weight): One part of ferric chloride hexahydrate, 1-5 parts of sodium acetate, and 1-5 parts of polyethylene glycol are dissolved in an appropriate amount of solvent, stirred evenly, and then transferred to a polytetrafluoroethylene reactor. The mixture is heated at at least 120°C, preferably 120-240°C, for at least 4 hours, preferably 4-20 hours, to obtain a black product. The product is washed at least three times with ultrapure water and anhydrous ethanol, and then vacuum dried at at least 40°C, preferably 40-80°C, for at least 3 hours, preferably 3-12 hours, to obtain nano-Fe3O4.

7. The method for preparing the fluorescent nano-demulsifier as described in claim 6, characterized in that, The solvent is one or more of water, ethylene glycol, and propylene glycol, and / or The amount of solvent used, calculated based on the amount of ferric chloride hexahydrate, is 6–20 mL / g.

8. The method for preparing the fluorescent nano-demulsifier as described in claim 4, characterized in that, The steps of the modification reaction between the nanomaterials and dopamine hydrochloride in step (1) are as follows: Dopamine hydrochloride and nanomaterials were placed in a reactor at a mass ratio of 0.1 to 10:

10. A Tris-HCl solution of 2 to 20 times the mass of the nanomaterials was added. The reactor was sealed and ultrasonically dispersed in an ultrasonic oscillator for at least 0.5 hours, preferably 0.5 to 2 hours. The mixture was then transferred to a constant-temperature water bath oscillator and oscillated at room temperature at a frequency of at least 100 rpm, preferably 100 to 300 rpm, for at least 4 hours, preferably 4 to 24 hours. After the reaction was completed, the mixture was centrifuged or filtered, washed at least three times with ultrapure water and anhydrous ethanol, and vacuum dried at at least 30°C, preferably 30 to 60°C, for at least 12 hours to obtain polydopamine hydrochloride modified nanomaterials.

9. The preparation method of the fluorescent nano-demulsifier as described in claim 4, characterized in that, The steps of the modification reaction between the nanomaterials and tannic acid in step (1) are as follows: Tannic acid and nanomaterials were placed in a reactor at a mass ratio of 0.1 to 10:

10. Solvent A was added at a mass ratio of 2 to 20 times that of the nanomaterials. The reactor was sealed and ultrasonically dispersed in an ultrasonic oscillator for at least 2 hours. Then, the mixture was transferred to a constant temperature water bath oscillator and oscillated at room temperature at a frequency of at least 100 rpm, preferably 100 to 300 rpm, for at least 4 hours, preferably 4 to 24 hours. After the reaction was completed, the mixture was separated by centrifugation or filtration. The mixture was washed at least three times with ultrapure water and anhydrous ethanol, and then vacuum dried at at least 30°C, preferably 30 to 60°C, for at least 12 hours to obtain tannic acid-modified nanomaterials.

10. The method for preparing the fluorescent nano-demulsifier as described in claim 9, characterized in that, The solvent A is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

11. The method for preparing the fluorescent nano-demulsifier as described in claim 4, characterized in that, The specific steps of the modification reaction between the nanomaterial and the silane coupling agent in step (1) are as follows: Take silane coupling agent and nanomaterials in a mass ratio of 0.1 to 10:10 and place them in a reactor. Add solvent B in a volume of 2 to 20 times the mass of the nanomaterials. Disperse the nanomaterials by ultrasonication in an ultrasonic oscillator for at least 0.5 hours, preferably 0.5 to 2 hours. Then transfer the mixture to a constant temperature magnetic stirrer and stir the reaction at 30°C, preferably 30 to 100°C, for at least 2 hours, preferably 2 to 18 hours. After the reaction is complete, separate the mixture by centrifugation or filtration, wash it at least three times with ultrapure water and anhydrous ethanol, and vacuum dry it at at least 30°C, preferably 30 to 60°C, for at least 12 hours to obtain silane coupling agent modified nanomaterials.

12. The method for preparing the fluorescent nano-demulsifier as described in claim 11, characterized in that, Solvent B is one or more of methanol, ethanol, n-propanol, isopropanol, formic acid, and acetic acid, and / or The silane coupling agent is one or more of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and diethylenetriaminopropyltrimethoxysilane.

13. The method for preparing the fluorescent nano-demulsifier as described in claim 4, characterized in that, The specific steps of step (2) are as follows: (21) Place 0.1 to 1 part of modified nanomaterial, 0.1 to 1 part of catalyst p-toluenesulfonic acid or sulfuric acid and 1 part of polystyrene maleic anhydride in a reactor, and then add 2 to 6 parts of solvent C. Sonicate the nanomaterial in an ultrasonic oscillator for at least 0.5 h, preferably 0.5 to 2 h to obtain a mixture. (22) Transfer the mixture to a constant temperature magnetic stirrer and stir at at least 40°C, preferably 40-120°C for at least 4 hours, preferably 4-24 hours. After the reaction is completed, centrifuge or filter to obtain a solid product. Wash the solid product with solvent C at least 3 times, and finally wash it with anhydrous ethanol at least 2 times. Vacuum dry at at least 60°C, preferably 60-80°C for at least 12 hours to obtain the modified nanomaterial grafted polystyrene maleic anhydride.

14. The method for preparing the fluorescent nano-demulsifier as described in claim 13, characterized in that, The solvent C is one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

15. The method for preparing the fluorescent nano-demulsifier as described in claim 4, characterized in that, The specific steps of step (3) are as follows: (31) The modified nanomaterials obtained in step (2) are grafted with polystyrene maleic anhydride and 0.1 to 1 part of porphyrin-based polyamine resin in a reactor, and then solvent D with a mass of 2 to 10 times that of porphyrin-based polyamine resin is added to it. The mixture is ultrasonically dispersed in an ultrasonic oscillator for at least 0.5 h, preferably 0.5 to 2 h, to obtain a mixture. (32) Transfer the mixture to a constant temperature magnetic stirrer and stir the reaction at at least 40°C, preferably 40-120°C, for at least 4 hours, preferably 4-24 hours. After the reaction is completed, centrifuge or filter to separate the solid product. Wash the solid with distilled water and anhydrous ethanol at least 3 times in sequence, and vacuum dry at at least 60°C, preferably 60-80°C, for at least 12 hours to obtain a fluorescent nano-demulsifier containing porphyrin fluorescent groups.

16. The method for preparing the fluorescent nano-demulsifier as described in claim 15, characterized in that, The solvent D is one or more of toluene, xylene, N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, dioxane, dimethyl sulfoxide, and N-methylpyrrolidone.

17. The method for preparing the fluorescent nano-demulsifier as described in claim 15, characterized in that, The specific steps of the preparation method of the porphyrin-based polyamine resin, based on molar parts, are as follows: One part of hydroxyphenyl porphyrin and 2 to 10 parts of polyamine are dissolved in an organic solvent with a mass of 2 to 10 times that of the polyamine to obtain a mixture. The mixture is then transferred to a reactor equipped with a stirrer, a water separator and a dropping funnel, and the reactor is placed in a constant temperature oil bath. Dissolve 2-50 parts of paraformaldehyde in 1-5 times its mass of an organic solvent to obtain a paraformaldehyde organic solvent solution. Then, transfer the paraformaldehyde organic solvent solution to a dropping funnel in the reactor. Control the reaction temperature at 90-150°C and reflux the reaction system. Under heating and stirring conditions, slowly add the paraformaldehyde organic solvent solution dropwise into the reactor through a constant pressure dropping funnel. Stop the reaction after at least 6 hours, preferably 6-48 hours. Remove the solvent and unreacted formaldehyde by vacuum distillation to obtain porphyrin-based polyamine resin.

18. The method for preparing the fluorescent nano-demulsifier as described in claim 17, characterized in that, The organic solvent is one or more of benzene, toluene, and xylene, and / or The hydroxyphenyl-containing porphyrin has one of the following structures: Among them, R1, R2, and R3 are independently selected from H, Cl, Br, NO2, and C. n H 2n+1 or OC n H 2n+1 One of them, where n = 1 to 20, and / or The polyamine is a polyethylene polyamine, preferably one or more of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

19. A fluorescent nano-demulsifier, characterized in that, It is prepared by the method of any one of claims 4-18 for preparing fluorescent nano-demulsifier.

20. The application of the fluorescent nano-demulsifier according to any one of claims 1-3 and 19 as a demulsifier in the treatment of chemical flooding produced fluid.

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