Photoresponse supramolecular surfactant as well as preparation method and application thereof

Abstract

The invention relates to a photoresponse supramolecular surfactant and a preparation method and application thereof, the photoresponse supramolecular surfactant is obtained by a hydrophobic host molecule and a hydrophilic guest molecule through host-guest complexation, the hydrophobic host molecule is a hydrophobic cyclodextrin compound, and the hydrophilic guest molecule is a hydrophilic cyclodextrin compound. The hydrophilic guest molecule is hydrophilic modified methyl yellow. The photoresponse supramolecular surfactant disclosed by the invention is simple in raw materials, green, environment-friendly and high in salt resistance, has an amphiphilic structure and photoresponse characteristics, and can realize self-demulsification under a certain illumination condition when being used in thickened oil recovery, so that the use amount of the surfactant is reduced, the thickened oil recovery cost is remarkably reduced, and the recovery efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a light-responsive supramolecular surfactant and a preparation method and application thereof. BACKGROUND

[0002] One of the methods for exploiting heavy oil is conventional water injection development. Due to the high viscosity and low mobility of heavy oil, and the high mobility of water, the water-oil mobility ratio is large when water flooding, and the displacement fluid is easy to break through the oil phase during the water flooding process, resulting in low sweep efficiency, small heavy oil producing area and low oil displacement efficiency. Water flooding can only recover 10-20% of the original reserves of heavy oil. On the basis of water flooding, chemical flooding can effectively improve the displacement effect. Surfactants have wettability modification properties, which can reverse the wettability of oil-wet wellbore and pipeline to water-wet. Surfactants have emulsifying and dispersing effects, which can emulsify and disperse heavy oil into O / W emulsion, reduce viscosity, and at the same time, surfactants also have wettability modification effects, which can prevent oil droplets from being adsorbed on the rock surface again, and enhance the flowability of emulsified heavy oil in low porosity. Emulsified heavy oil has the problem of difficult demulsification, and a large amount of demulsifiers are often consumed in oilfield production and refining. Therefore, a large amount of emulsifiers and demulsifiers are applied to the whole process of oil exploitation and processing, which has high investment cost. SUMMARY

[0003] The purpose of the present disclosure is to provide a supramolecular surfactant with light-responsive properties and a preparation method and application thereof.

[0004] In order to achieve the above-mentioned purpose, the first aspect of the present disclosure provides a light-responsive supramolecular surfactant, which is obtained by host-guest complexation of a hydrophobic host molecule and a hydrophilic guest molecule, wherein the hydrophobic host molecule is a hydrophobic cyclodextrin compound, and the hydrophilic guest molecule is a hydrophilic modified methyl yellow.

[0005] Optionally, the hydrophobic cyclodextrin compound has a structure as shown in general formula (1): (1) In formula (1), R is selected from C4-C14 alkyl, and n is 5-7.

[0006] Optionally, the hydrophilic modified methyl yellow is obtained by hydrophilic modification of methyl yellow using a hydrophilic modification reagent, wherein the hydrophilic modification reagent includes at least one of 1,3-propanesulfonic acid lactone, 1,4-butanesulfonic acid lactone, 2,4-butanesulfonic acid lactone, 5-methylthiopentane 2,2-dioxide, 3-chloro-2-hydroxypropane sodium sulfonate and 3-chloro-2-hydroxypropane sodium acetate.

[0007] Optionally, the molar ratio of the hydrophobic host molecule to the hydrophilic guest molecule is (1-3):1.

[0008] Optionally, the molar ratio of the hydrophobic host molecule to the hydrophilic guest molecule is (1-2):1.

[0009] In a second aspect of the present disclosure, a method for preparing the light-responsive supramolecular surfactant of the first aspect of the present disclosure is provided, and the method comprises: contacting methyl yellow with a hydrophilic modification reagent in the presence of a first solvent to perform a nucleophilic addition reaction to obtain a hydrophilic modified methyl yellow; contacting the hydrophilic modified methyl yellow with a hydrophobic cyclodextrin compound in the presence of a second solvent to obtain the light-responsive supramolecular surfactant through host-guest complexation.

[0010] Optionally, the conditions of the nucleophilic addition reaction comprise a temperature of 50-100℃ and a time of 24-72h.

[0011] Optionally, the weight ratio of the methyl yellow, the hydrophilic modification reagent, and the first solvent is 1:(0.5-1):(100-200). The first solvent comprises at least one of isopropyl alcohol, N,N-dimethylformamide, dimethyl sulfoxide, and dichloromethane.

[0012] Optionally, the weight ratio of the hydrophilic modified methyl yellow and the second solvent is 1:(100-200). The second solvent comprises at least one of water, methanol, dimethyl sulfoxide, and N,N-dimethylformamide.

[0013] In a third aspect of the present disclosure, the light-responsive supramolecular surfactant of the first aspect of the present disclosure is applied in heavy oil exploitation.

[0014] Through the above technical solution, the present disclosure uses a hydrophobic cyclodextrin compound as a host molecule and a hydrophilic modified methyl yellow as a guest molecule, and the two can form a supramolecular surfactant through host-guest complexation. The supramolecular surfactant has simple raw materials, is green and environmentally friendly, has strong salt tolerance, and has an amphiphilic structure and light-responsive performance. In heavy oil exploitation, the surfactant can achieve self-demulsification under certain light conditions, thereby reducing the amount of surfactant used, significantly reducing the cost of heavy oil exploitation, and improving the efficiency of exploitation.

[0015] Other features and advantages of the present disclosure will be described in detail in the following specific embodiments section. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings are included to provide a further understanding of the present disclosure and constitute a part of the specification, illustrate the present disclosure and, together with the specific embodiments described below, serve to explain the present disclosure, but do not constitute a limitation on the present disclosure. In the drawings: Figure 1 is a mass spectrum of the hydrophilic guest molecule in the light-responsive supramolecular surfactant of Example 1. DETAILED DESCRIPTION

[0017] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure, and do not limit the present disclosure.

[0018] In a first aspect of the present disclosure, a light-responsive supramolecular surfactant is provided, which is obtained by host-guest complexation of a hydrophobic host molecule and a hydrophilic guest molecule, wherein the hydrophobic host molecule is a hydrophobic cyclodextrin compound, and the hydrophilic guest molecule is a hydrophilic modified methyl yellow.

[0019] According to the present disclosure, the hydrophobic host molecule is a hydrophobic cyclodextrin compound, which is a bio-based raw material, having the advantages of green, pollution-free and low cost. The hydrophobic cyclodextrin compound can be an alkylated cyclodextrin, an alkoxylated cyclodextrin, etc. In one specific embodiment, the hydrophobic cyclodextrin compound has a structure as shown in general formula (1): (1), In formula (1), R is selected from C4-C14 alkyl, preferably selected from butane, decane, dodecane, and tetradecane, and n is 5-7.

[0020] In one specific embodiment, the hydrophobic cyclodextrin compound can include at least one of C4-C14 alkyl-modified α-cyclodextrin, β-cyclodextrin, and γ-cyclodextrin. The hydrophobic cyclodextrin compound can be a commercially available product or prepared by a method in the prior art.

[0021] According to the present disclosure, the hydrophilic modified methyl yellow can exhibit a light-responsive performance under light conditions, specifically, it can undergo photolysis under ultraviolet light irradiation, causing changes in its molecular structure and photophysical properties. Using the hydrophilic modified methyl yellow as the hydrophilic guest molecule can enable the supramolecular surfactant of the present disclosure to have the performance of light-regulated surface activity.

[0022] Specifically, the hydrophilic modified methyl yellow has a structure as shown in formula (2): (2), In formula (2), L is selected from n-propylene, 2-hydroxy-propylene, 1-methyl-propylene, 3-methyl-propylene, n-butylene, preferably selected from n-propylene and 2-hydroxy-propylene; R2 is selected from sulfonic acid group and carboxylic acid group, preferably sulfonic acid group.

[0023] In a specific embodiment, the hydrophilic modified methyl yellow can be obtained by hydrophilic modification of methyl yellow using a hydrophilic modification reagent. The chemical formula of methyl yellow (i.e. p-dimethylaminoazobenzene) is C 14 H 15 N3, and the CAS number is 129-25-3. The hydrophilic modification reagent can be a common organic substance for providing a hydrophilic group (such as sulfonic acid group, carboxylic acid group, etc.), and specifically, the hydrophilic modification reagent can include at least one of 1,3-propanesulfonic acid lactone, 1,4-butanesulfonic acid lactone, 2,4-butane sulfonic lactone, 5-methylthiopentyl 2,2-dioxide, 3-chloro-2-hydroxypropane sulfonic acid sodium, and 3-chloro-2-hydroxypropane acetic acid sodium.

[0024] According to the present disclosure, the ratio of the hydrophobic host molecule to the hydrophilic guest molecule can be adjusted within a certain range, and specifically, the molar ratio of the hydrophobic host molecule to the hydrophilic guest molecule can be (1-3):1, preferably (1-2):1.

[0025] In the present disclosure, the hydrophobic host molecule and the hydrophilic guest molecule are combined through host-guest complexation (usually non-covalent interaction, such as hydrogen bond, van der Waals force, etc.) to obtain a light-responsive supramolecular surfactant with amphiphilic structure and light-regulated function. Under certain light conditions, the hydrophobic host molecule and the hydrophilic guest molecule of the supramolecular surfactant are decomplexed, thereby triggering changes in surface activity, dispersibility, aggregation behavior, etc. Thus, by controlling the intensity, wavelength, and time of light, etc., the surface activity of the supramolecular surfactant can be regulated. The light-responsive supramolecular surfactant of the present disclosure has simple raw materials, is green and environmentally friendly, has strong salt tolerance, and is a stimulus-responsive surfactant with light-responsive characteristics, which has important research significance for realizing the performance regulation of surfactants using light energy.

[0026] In a second aspect of the present disclosure, a method for preparing the light-responsive supramolecular surfactant of the first aspect of the present disclosure is provided, which comprises the following steps S1-S2: S1, contacting methyl yellow with a hydrophilic modification reagent in the presence of a first solvent to perform a nucleophilic addition reaction, thereby obtaining a hydrophilically modified methyl yellow; S2, contacting the hydrophilically modified methyl yellow with a hydrophobic cyclodextrin compound in the presence of a second solvent, and obtaining a light-responsive supramolecular surfactant through host-guest complexation.

[0027] In step S1, the type of the hydrophilic modification reagent is as described above, and the first solvent can include at least one of isopropyl alcohol, N,N-dimethylformamide, dimethyl sulfoxide and dichloromethane. The weight ratio of the methyl yellow, the hydrophilic modification reagent and the first solvent can be 1: (0.5-1): (100-200), preferably 1: (0.5-0.7): (100-150); the conditions of the nucleophilic addition reaction can include a temperature of 50-100°C, preferably 80-90°C; a time of 24-72h, preferably 48-56h; and the obtained hydrophilic modified methyl yellow, i.e. the hydrophilic guest molecule.

[0028] In step S2, the type of the hydrophobic cyclodextrin compound, i.e. the hydrophobic host molecule, is as described above, and the second solvent can include at least one of water, methanol, dimethyl sulfoxide and N,N-dimethylformamide. The weight ratio of the hydrophilic modified methyl yellow and the second solvent is 1: (100-200); and the use amount of the hydrophilic modified methyl yellow and the hydrophobic cyclodextrin compound is such that the hydrophilic guest molecule and the hydrophobic host molecule have the molar ratio described above. In order to improve the complexing effect, the contact between the hydrophilic modified methyl yellow and the hydrophobic cyclodextrin compound can be carried out by using common mixing means, such as vigorous stirring, stirring and then standing, ultrasonic-assisted dissolution, etc.

[0029] The light-responsive supramolecular surfactant prepared by the method of the present disclosure has the advantages of green raw material source, low preparation cost, mild reaction conditions, strong safety, etc., is easy to be scaled up industrially, has the prospect of popularization and application, and is especially suitable for use in heavy oil exploitation, can realize self-demulsification under certain light conditions, and has the advantages of reducing cost and improving exploitation efficiency, etc.

[0030] In a third aspect, the present disclosure provides the use of the light-responsive supramolecular surfactant of the first aspect of the present disclosure in heavy oil exploitation.

[0031] Specifically, the use can include: mixing a light-responsive supramolecular surfactant solution and heavy oil under stirring conditions to emulsify, and demulsifying the obtained emulsion under ultraviolet light irradiation conditions. The volume ratio of the light-responsive supramolecular surfactant solution to the heavy oil can be (2-4):1; the concentration of the light-responsive supramolecular surfactant solution can be 0.1% by weight; the stirring conditions can include a rotation speed of 600-1000 revolutions / minute; and the ultraviolet light irradiation conditions can include a wavelength of 300-365nm and a time of 30-60 minutes.

[0032] The thickened oil exploitation by using the light-responsive supramolecular surfactant disclosed by the present application can reduce the viscosity of the thickened oil, improve the flowability, promote the thickened oil recovery rate and the exploitation efficiency, and can realize the self-demulsification of the emulsified thickened oil under certain light conditions, thereby reducing the amount of surfactant, simplifying the subsequent processing flow and reducing the cost. In particular, the light-responsive supramolecular surfactant disclosed by the present application can realize the real-time monitoring and control of the thickened oil exploitation process. After the light-responsive supramolecular surfactant is injected into the oil well, the emulsification and separation process of the thickened oil can be regulated by remotely adjusting the light conditions, thereby realizing the real-time regulation and optimization of the thickened oil exploitation process.

[0033] The present application is described in detail by the following examples. In the following examples, the top of the window is as follows, unless otherwise specified, the instruments, reagents, materials and the like involved are conventional instruments, reagents, materials and the like in the prior art, which can be obtained through regular commercial channels.

[0034] Example 1 weighing α Cyclodextrin 10 mmol, 1,2-epoxydodecane 70 mmol were placed in a reaction bottle, then 20 mL of water, 0.05 mmol of 4-dimethylaminopyridine and a magnetic stirrer were added, the reaction system was stirred at 85℃ for 7 hours, the reaction was stopped, filtered and dried to obtain dodecyl-modified α-cyclodextrin.

[0035] Methyl yellow (purchased from Alfa, product number B21145), 1,3-propanesultone and isopropyl alcohol were mixed in a weight ratio of 1:0.5:100, heated to 90℃ for nucleophilic addition reaction for 8h, and cooled to room temperature to obtain the hydrophilic guest molecule, and the mass spectrum result is shown in Figure 1 The target molecule has a theoretical relative molecular mass [M-Na] of 347.13, and the experimental result is [M-Na+H] + : 348.12, which indicates that the 1,3-propanesulfonic acid modified methyl yellow is successfully synthesized as the hydrophilic guest molecule (the structural formula is ).

[0036] The dodecyl-modified α-cyclodextrin was used as the hydrophobic host molecule, and the above-mentioned hydrophilic guest molecule was mixed after being prepared into an aqueous solution, wherein the molar ratio of the hydrophobic host molecule to the hydrophilic guest molecule was 1.2:1, and the weight ratio of the hydrophobic host molecule to water was 1:130. The host-guest complexation was carried out under stirring to obtain the light-responsive supramolecular surfactant.

[0037] Example 2 The light-responsive supramolecular surfactant was prepared according to the method of Example 1, and the difference was that the molar ratio of the hydrophobic host molecule to the hydrophilic guest molecule was 3:1.

[0038] Comparative Example 1 The hydrophilic guest molecule in Example 1 was configured into an aqueous solution with a concentration of 2.2 mg / mL as the surfactant of the present comparative example.

[0039] Comparative Example 2 The hydrophobic host molecule in Example 1 was configured into an aqueous solution with a concentration of 7.8 mg / mL as the surfactant of the present comparative example.

[0040] Test Example The surface activity performance of the surfactants of the test example and comparative examples was tested, wherein the surfactant of the example was configured into an aqueous solution with a concentration of 10 mg / mL.

[0041] The test method was as follows: the surface tension of the mixed solution at the critical micelle concentration and the surface tension after ultraviolet light irradiation were tested by using a Kruss 100 surface tension meter according to the stepwise dilution method, wherein the ultraviolet light irradiation condition was as follows: wavelength 365 nm, time 30 minutes, and the results are shown in Table 1.

[0042] Table 1

[0043] As can be seen from Table 1, the surface tension of the supramolecular surfactant prepared in the example after ultraviolet light irradiation increased significantly, indicating that it has excellent light response performance.

[0044] The preferred embodiments of the present disclosure are described in detail above in combination with the drawings, but the present disclosure is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present disclosure within the technical concept of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

[0045] In addition, it should be noted that each specific technical feature described in the above specific embodiments can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present disclosure will not further describe various possible combination manners.

[0046] In addition, various different embodiments of the present disclosure can also be combined in any manner, as long as they do not deviate from the idea of the present disclosure, and they should also be considered as disclosed by the present disclosure.

Claims

1. A photo-responsive supramolecular surfactant, characterized in that, The light-responsive supramolecular surfactant is obtained by host-guest complexation of a hydrophobic host molecule and a hydrophilic guest molecule, wherein the hydrophobic host molecule is a hydrophobic cyclodextrin compound, and the hydrophilic guest molecule is a hydrophilic modified methyl yellow.

2. The light-responsive supramolecular surfactant of claim 1, wherein, The hydrophobic cyclodextrin compound has a structure as shown in general formula (1): （1） In formula (1), R is selected from C4-C14 alkyl, and n is 5-7.

3. The light-responsive supramolecular surfactant of claim 1, wherein, The hydrophilic modified methyl yellow is obtained by hydrophilic modification of methyl yellow using a hydrophilic modification reagent, wherein the hydrophilic modification reagent includes at least one of 1,3-propanesulfonic acid lactone, 1,4-butanesulfonic acid lactone, 2,4-butane sulfonic lactone, 5-methyl oxathiane 2,2-dioxide, 3-chloro-2-hydroxypropane sulfonic acid sodium, and 3-chloro-2-hydroxypropane sodium acetate.

4. The light-responsive supramolecular surfactant of claim 1, wherein, The molar ratio of the hydrophobic host molecule to the hydrophilic guest molecule is (1-3):

1.

5. The light-responsive supramolecular surfactant of claim 4, wherein, The molar ratio of the hydrophobic host molecule to the hydrophilic guest molecule is (1-2):

1.

6. A method for preparing the photo-responsive supramolecular surfactant according to any one of claims 1 to 5, characterized in that, The method comprises: contacting methyl yellow with a hydrophilic modification reagent in the presence of a first solvent to perform a nucleophilic addition reaction, to obtain a hydrophilic modified methyl yellow; contacting the hydrophilic modified methyl yellow with a hydrophobic cyclodextrin compound in the presence of a second solvent, and obtaining a light-responsive supramolecular surfactant by host-guest complexation.

7. The method of claim 6, wherein, The conditions of the nucleophilic addition reaction include a temperature of 50-100°C and a time of 24-72h.

8. The method of claim 6, wherein, The weight ratio of the methyl yellow, the hydrophilic modification reagent, and the first solvent is 1:(0.5-1):(100-200). The first solvent includes at least one of isopropyl alcohol, N,N-dimethylformamide, dimethyl sulfoxide, and dichloromethane.

9. The method of claim 6, wherein, The weight ratio of the hydrophilic modified methyl yellow and the second solvent is 1:(100-200). The second solvent includes at least one of water, methanol, dimethyl sulfoxide, and N,N-dimethylformamide.

10. Use of the light-responsive supramolecular surfactant in any one of claims 1-5 in heavy oil exploitation.

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