Dandelion-shaped single-chain particle preparation method, product and application

Abstract

The invention discloses a preparation method of dandelion-shaped single-chain particles, a product and application, and belongs to the technical field of Janus nanoparticles. The preparation method of the dandelion-shaped single-chain particle comprises the following steps: synthesizing a poly (benzyl methacrylate)-b-poly (dimethylaminoethyl methacrylate)-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer; sequentially carrying out photo-crosslinking reaction and quaternization reaction on the poly (benzyl methacrylate)-b-poly (dimethylaminoethyl methacrylate)-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer, so as to obtain the poly (benzyl methacrylate)-b-poly (dimethylaminoethyl methacrylate)-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer. And carrying out photo-initiated'sulfydryl-ene 'click chemistry on the quaternization product and sulfydryl-terminated poly (4-vinylpyridine), so as to obtain the dandelion-shaped single-chain particles. The preparation process and operation are simple, the cost is low, the preparation method can be suitable for large-scale production, and the blank of the preparation process of the dandelion-shaped polymer-polymer Janus particles is filled.

Description

Technical Field

[0001] The present application belongs to the technical field of Janus nanoparticles, and particularly discloses a preparation method, product and application of dandelion-shaped single-chain particles. Background Art

[0002] Emulsion is a thermodynamically unstable dispersion system consisting of a dispersed phase dispersed in a continuous phase in the form of droplets. It will demulsify over time under the influence of various factors. In order to make the emulsion stable for a long time, emulsifiers are usually added during the preparation of the emulsion to improve the stability of the emulsion. Pickering emulsion is a new type of emulsion prepared with ultrafine solid particles or solid colloidal particles as emulsifiers. It has the advantages of good stability, easy regulation, environmental friendliness, and low cost. It has been widely used in many fields such as petroleum, water treatment, cosmetics, food, and medicine.

[0003] The stability of Pickering emulsions is directly related to the characteristics of the solid emulsifier / stabilizer particles used. At present, the solid emulsifier / stabilizer particles used are generally divided into inorganic / organic solid particles, organic-inorganic composite solid particles and Janus particles, among which Janus particles have great application advantages in stabilizing Pickering emulsions due to their good dispersibility, high stability and easy manipulation.

[0004] However, there are still some problems in the existing preparation process of Janus particles, such as: the preparation process is complicated, the shape of Janus particles cannot be accurately controlled, the production cost is high, and it is difficult to prepare on a large scale; in addition, there are no reports on the preparation process of dandelion-shaped polymer-polymer Janus particles. Summary of the invention

[0005] The present application aims to solve the above-mentioned problems existing in the preparation process of the existing Janus particles and the technical problem of the blank preparation process of the dandelion-shaped polymer-polymer Janus particles by disclosing a preparation method, product and application of dandelion-shaped single-chain particles.

[0006] In order to achieve the above objectives, the technical solution adopted in this application is:

[0007] The first aspect of the present application provides a method for preparing dandelion-shaped single-chain particles. The method for preparing dandelion-shaped single-chain particles of the present application comprises the following steps:

[0008] Synthesis of polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer;

[0009] Performing a photocrosslinking reaction on the polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer to obtain a tadpole-shaped single-chain particle intermediate;

[0010] The tadpole-shaped single-chain particle intermediate is quaternized, and the quaternized product undergoes photo-initiated "thiol-ene" click chemistry with thiol-terminated poly(4-vinylpyridine) to obtain dandelion-shaped single-chain particles.

[0011] In some embodiments, the preparation method of the polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer comprises:

[0012] benzyl methacrylate, a thioester chain transfer agent and an azo initiator are mixed to carry out a reversible addition-fragmentation transfer radical polymerization reaction to obtain polybenzyl methacrylate-CTA;

[0013] The polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator are mixed to carry out a reversible addition-fragmentation transfer radical polymerization reaction to obtain a polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer.

[0014] In some embodiments, when the benzyl methacrylate, the thioester chain transfer agent and the azo initiator are mixed to carry out the reversible addition-fragmentation transfer radical polymerization reaction, the reaction temperature is 60-70° C. and the reaction time is 4-12 hours.

[0015] In some embodiments, the molar ratio of the benzyl methacrylate, the thioester chain transfer agent and the azo initiator is 500-1200:1:0.2.

[0016] In some embodiments, when the polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator are mixed for reversible addition-fragmentation transfer radical polymerization, the reaction temperature is 65-70° C. and the reaction time is 12-24 hours.

[0017] In some embodiments, the molar ratio of the polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator is 1:300-1200:60-400:0.2.

[0018] In some embodiments, the method for preparing the thiol-terminated poly(4-vinylpyridine) comprises:

[0019] 4-vinylpyridine, a thioester chain transfer agent and an azo initiator are mixed to undergo a reversible addition-fragmentation transfer radical polymerization reaction to obtain poly(4-vinylpyridine)-CTA;

[0020] In an inert atmosphere, the poly(4-vinylpyridine)-CTA is subjected to a reduction reaction, and the reduction product is sequentially precipitated, centrifuged and vacuum dried to obtain thiol-terminated poly(4-vinylpyridine).

[0021] In some embodiments, quaternizing the tadpole-shaped single-chain particle intermediate comprises:

[0022] The tadpole-shaped single-chain particle intermediate is mixed with a quaternary ammonium reagent containing a carbon-carbon double bond and reacted for 36-45 hours, wherein the molar ratio of the halogen atom in the quaternary ammonium reagent containing a carbon-carbon double bond to the dimethylaminoethyl methacrylate block in the tadpole-shaped single-chain particle intermediate is ≥60:1.

[0023] In some embodiments, when the photo-initiated "thiol-ene" click chemistry occurs, the molar ratio of the thiol groups in the thiol-terminated poly(4-vinylpyridine) to the ene groups in the quaternized product is 2-10:1.

[0024] In some embodiments, the polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer contains:

[0025] Polybenzyl methacrylate blocks having a degree of polymerization of 250-645;

[0026] A polydimethylaminoethyl methacrylate block having a degree of polymerization of 170-877; and

[0027] Poly(7-(2-methacryloyloxyethoxy)-4-methylcoumarin) blocks having a degree of polymerization of 30-200.

[0028] The second aspect of the present application provides dandelion-shaped single-chain particles prepared by the preparation method of the present application.

[0029] The third aspect of the present application provides the use of the dandelion-shaped single-chain particles described in the present application for providing oil-water interface stabilization.

[0030] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0031] The preparation method provided by the present application is to perform ultraviolet light crosslinking and quaternization on the block copolymer of polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) in sequence, and then perform photo-initiated "thiol-ene" click chemistry on the quaternized product and the thiol-terminated poly(4-vinylpyridine), so as to form dandelion-shaped single-chain particles by highly selective crosslinking. The preparation process and operation are simple and the production cost is low, which is suitable for large-scale production. At the same time, the dandelion-shaped single-chain particles provided by the present application are constructed with dandelion-shaped crosslinking heads by hydrophilic polymer nanoparticles and hydrophilic poly(4-vinylpyridine) chains, which can not only make the nanoparticles have good rigidity and effectively improve the firmness of the solid interface film, but also effectively improve the wetting ability of the nanoparticles. The synergistic effect of the two further improves the stability of the emulsion, and the size and morphology of the nanoparticles can be regulated by the molecular weight of the polymer block and the number of intramolecular bonds, thereby giving the prepared nanoparticles better emulsification properties and wider applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 PBzMA 350 -CTA and PBzMA 350- bP(DMAEMA 370 -co-CMA 65 )'s H NMR spectrum;

[0034] Figure 2 H NMR spectra of TSCNPs-g-1 and DK-1;

[0035] Figure 3 TEM image of DK-1 stained with silver nitrate;

[0036] Figure 4 Optical microscope image and laser confocal microscope image of DK-1 stabilized emulsion;

[0037] Figure 5 Optical image of the emulsion stabilized by DK-1. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] In the following description of this article, the term "and / or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, B exists alone, and A and B exist at the same time. Among them, A and B can be singular or plural; the single symbol " / " means "or".

[0040] In the following description herein, the term "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or plural. For example, "at least one of A, B or C", or "at least one of A, B and C", all mean any one of A, B, C, or A+B, or A+C, or B+C, or A+B+C, where A, B, C can be single or multiple, respectively.

[0041] In the following description of this article, the order of serial numbers does not mean the order of execution. Some or all of the steps can be executed in parallel or one after the other. The execution order of each process should be determined based on its function and internal logic, and should not constitute any limitation on the implementation process of this embodiment.

[0042] In the following description herein, the numerical range should be understood to also specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value in the stated range and any other stated value or intermediate value in the stated range is also included in the present embodiment, and the upper and lower limits of the smaller range can be independently included or excluded in the range.

[0043] Unless otherwise stated, the terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present application only describes preferred methods and materials, any similar or equivalent methods and materials may also be used in the implementation or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this article shall prevail.

[0044] In a first aspect, an embodiment of the present application provides a method for preparing dandelion-shaped single-chain particles. The preparation method of the embodiment of the present application preferably comprises:

[0045] Synthesis of polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer (PBzMA-bP(DMAEMA-co-CMA));

[0046] The polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer is subjected to a photocrosslinking reaction to obtain a tadpole-shaped single-chain particle intermediate (TSCNPs-1);

[0047] The tadpole-shaped single-chain particle intermediate is quaternized, and the quaternized product (TSCNPs-g-1) is subjected to photo-initiated "thiol-ene" click chemistry with thiol-terminated poly (4-vinylpyridine) to obtain dandelion-shaped single-chain particles.

[0048] Among them, the preparation method provided in the embodiment of the present application is to subject the synthesized polybenzyl methacrylate-b-poly (dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer to ultraviolet irradiation treatment, so that the coumarin group in the molecular structure specifically undergoes a [2+2] cycloaddition reaction to form a tadpole-shaped single-chain particle intermediate, and then an excessive amount of quaternization treatment is performed to form a double bond functional group at the "head" of the tadpole-shaped single-chain particle intermediate, and finally the tadpole-shaped single-chain particle intermediate with a double bond functional group is reacted with a thiol-terminated polymer. (4-vinylpyridine) for photo-initiated "thiol-ene" click chemistry, thereby highly selectively cross-linking to form dandelion-shaped single-chain particles, the preparation process and operation are relatively simple, the production cost is low, and each reaction is highly controllable, suitable for large-scale production; and the dandelion-shaped single-chain particles prepared in this application are constructed by hydrophilic polymer nanoparticles and hydrophilic poly (4-vinylpyridine) chains. Dandelion-shaped cross-linked heads can not only make the nanoparticles have good rigidity and effectively improve the firmness of the solid interface film, but also can effectively improve the wetting ability of the nanoparticles, and the synergistic effect of the two further improves the stability of the emulsion. In addition, the size and morphology of the nanoparticles can be regulated by the molecular weight of the polymer block and the number of intramolecular bonds, thereby giving the prepared nanoparticles better emulsification properties and a wider range of applications.

[0049] Those skilled in the art should understand that the block copolymer used to prepare dandelion-shaped single-chain particles in the embodiment of the present application is only a preferred embodiment. For ordinary technicians in this field, other block copolymers of the same structural type as this embodiment can also be used without paying creative labor, which will not be repeated here.

[0050] It should be noted that the photo-cross-linking reaction refers to a photo-cross-linking reaction triggered by ultraviolet light irradiation. The embodiment of the present application does not specifically limit the wavelength of the ultraviolet light, on the basis of being able to promote the rapid occurrence of the photo-cross-linking reaction involved, and may preferably be 365 nm. At the same time, the embodiment of the present application does not limit the ultraviolet light action time, on the basis of being able to allow the relevant photo-cross-linking reactions involved to occur fully and completely, and may preferably be 12 h or more.

[0051] It should be noted that after each step of the reaction, a post-treatment step of separation and purification is also included. The embodiments of the present application do not specifically limit the specific operations of each post-treatment step, and the target product can be separated from the reaction products of each step. For example, after the photo-crosslinking reaction, the product solution can be sequentially subjected to n-hexane precipitation and vacuum drying; after the quaternization reaction, the product solution can be dialyzed and switched to THF solvent for concentration precipitation and suction filtration and drying; after click chemistry, the product solution can be dialyzed and switched to THF solvent for concentration precipitation and suction filtration and drying.

[0052] In an exemplary embodiment, the present application also provides a method for preparing a polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer, preferably comprising the steps of:

[0053] benzyl methacrylate, a thioester chain transfer agent and an azo initiator are mixed to carry out a reversible addition-fragmentation transfer radical polymerization reaction to obtain polybenzyl methacrylate-CTA;

[0054] The polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator are mixed to carry out a reversible addition-fragmentation transfer radical polymerization reaction to obtain a polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer.

[0055] Among them, the embodiment of the present application synthesizes polybenzyl methacrylate-CTA by reversible addition-fragmentation transfer radical polymerization reaction using benzyl methacrylate as a monomer, and uses polybenzyl methacrylate-CTA as a macromolecular chain transfer agent to carry out reversible addition-fragmentation transfer radical polymerization reaction with dimethylaminoethyl methacrylate and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin, so as to synthesize an amphiphilic diblock copolymer capable of intramolecular cross-linking, provide a specific functionalization basis for subsequent photocross-linking reaction and quaternization, and the preparation process and operation are simple, and it is easy to scale up production.

[0056] It should be noted that the two-step reversible addition-fragmentation transfer radical polymerization reaction is carried out in a good solvent for each raw material. The optional good solvent includes but is not limited to dioxane, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), and the good solvents used in the two-step reversible addition-fragmentation transfer radical polymerization reaction can be the same or different.

[0057] It should be noted that the thioester chain transfer agent is preferably one of a dithioester chain transfer agent or a trithioester chain transfer agent, specifically including but not limited to 4-cyano-4-(phenylcarbonylthio) valeric acid (CPADB), 2-cyano-2-propylbenzodisulfide (CPBD), 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl] valeric acid (CDCTPA), 2-cyano-2-propyldodecyl trithiocarbonate (CPDTC); the azo initiator is preferably a water-soluble azo initiator, including but not limited to 4,4'-azobis(4-cyanovaleric acid) (ACVA), azobisisobutyronitrile (AIBN), and the thioester chain transfer agent and azo initiator used in the two-step reversible addition-fragmentation transfer radical polymerization reaction may be the same or different.

[0058] In the exemplary embodiment, when the benzyl methacrylate, the thioester chain transfer agent and the azo initiator are mixed for reversible addition-fragmentation transfer radical polymerization, the reaction temperature is 60-70° C. and the time is 4-12 hours. The reaction temperature can be 60° C., 65° C., 70° C. or any one or interval within the range, and the time can be 4 hours, 6 hours, 8 hours, 10 hours, 12 hours or any one or interval within the range.

[0059] In the exemplary embodiment, the molar ratio of the benzyl methacrylate, the thioester chain transfer agent and the azo initiator is 500-1200:1:0.2, which can be exemplified as (500:1:0.2), (700:1:0.2), (1200:1:0.2) or any interval within the range. In particular, the embodiment of the present application controls the molar ratio to regulate the degree of polymerization of the prepared polybenzyl methacrylate-CTA, so that the finally prepared dandelion-shaped single-chain particles have good emulsification stability.

[0060] In an exemplary embodiment, when the poly(benzyl methacrylate)-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator are mixed for reversible addition-fragmentation transfer radical polymerization, the reaction temperature is 65-70°C and the time is 12-24h. The reaction temperature can be 65°C, 66°C, 68°C, 69°C, 70°C or any one or interval within the range, and the time can be 12h, 15h, 18h, 20h, 22h, 24h or any one or interval within the range.

[0061] In the exemplary embodiment, the molar ratio of the polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator is 1:300-1200:60-400:0.2, which can be exemplified as (1:700:300:0.2), (1:1200:400:0.2), (1:700:60:0.2), (1:300:100:0.2) or any range within the range. In particular, the embodiment of the present application can control the degree of polymerization of the prepared polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer by controlling the molar ratio, so that the finally prepared dandelion-shaped single-chain particles have good emulsification stability.

[0062] In an exemplary embodiment, the present application also provides a method for preparing a thiol-terminated poly (4-vinyl pyridine), preferably comprising the steps of:

[0063] 4-vinylpyridine, a thioester chain transfer agent and an azo initiator are mixed to undergo a reversible addition-fragmentation transfer radical polymerization reaction to obtain poly(4-vinylpyridine)-CTA;

[0064] In an inert atmosphere, the poly(4-vinylpyridine)-CTA is subjected to a reduction reaction, and the reduction product is sequentially precipitated, centrifuged and vacuum dried to obtain thiol-terminated poly(4-vinylpyridine).

[0065] It should be noted that the reducing agent for reducing poly(4-vinylpyridine)-CTA is not particularly limited in the embodiments of the present application, as long as the thioester group contained in the molecular structure of poly(4-vinylpyridine)-CTA can be reduced, and preferably n-butylamine, hexylamine, ammonia water, etc.

[0066] Among them, the embodiment of the present application uses 4-vinylpyridine as a monomer to carry out a reversible addition-fragmentation transfer radical polymerization reaction, and reduces the generated poly(4-vinylpyridine)-CTA, so that the thioester group in the poly(4-vinylpyridine)-CTA is reduced to a thiol group, thereby highly selectively grafting the poly(4-vinylpyridine) onto the "head" nanoparticle of the tadpole-shaped single-chain particle intermediate based on the photo-initiated "thiol-ene" click chemistry to form dandelion-shaped single-chain particles. The preparation process and operation are simple, and the product yield is high.

[0067] In an exemplary embodiment, the quaternization of the tadpole-shaped single-chain particle intermediate comprises:

[0068] The tadpole-shaped single-chain particle intermediate is mixed with a quaternary ammonium reagent containing a carbon-carbon double bond and reacted for 36-45 hours, and the molar ratio of the halogen atoms in the quaternary ammonium reagent containing a carbon-carbon double bond to the dimethylaminoethyl methacrylate block in the tadpole-shaped single-chain particle intermediate is ≥ 60: 1. In this embodiment of the present application, the quaternary ammonium degree of the tadpole-shaped single-chain particle is changed by controlling the molar ratio of the halogen atoms in the quaternary ammonium reagent containing a carbon-carbon double bond to the dimethylaminoethyl methacrylate block in the tadpole-shaped single-chain particle intermediate, thereby changing the number of double bonds modified in the "head".

[0069] It should be noted that the embodiments of the present application do not specifically limit the specific substance type of the quaternary ammonium agent containing a carbon-carbon double bond, and can be any one of the quaternary ammonium agents containing a carbon-carbon double bond known in the art, including but not limited to 6-bromo-1-hexene, 5-bromo-1-pentene, and 7-bromo-1-heptene.

[0070] In the exemplary embodiment, when the quaternary ammonium product containing a carbon-carbon double bond undergoes photo-initiated "thiol-ene" click chemistry with the thiol-terminated poly(4-vinylpyridine), the molar ratio of the thiol in the thiol-terminated poly(4-vinylpyridine) to the olefin in the quaternary ammonium product is 2-10:1, which can be exemplified as (2:1), (5:1), and (10:1). In the embodiment of the present application, the molar ratio of the thiol in the thiol-terminated poly(4-vinylpyridine) to the olefin in the quaternary ammonium product is controlled to change the grafting rate, that is, the amount of poly(4-vinylpyridine) grafted to the "head".

[0071] In an exemplary embodiment, the polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer preferably contains:

[0072] Polybenzyl methacrylate blocks having a degree of polymerization of 250-645;

[0073] A polydimethylaminoethyl methacrylate block having a degree of polymerization of 170-877; and

[0074] Poly(7-(2-methacryloyloxyethoxy)-4-methylcoumarin) blocks having a degree of polymerization of 30-200.

[0075] Among them, the embodiment of the present application controls the degree of polymerization of the blocks contained in the polybenzyl methacrylate-b-poly (dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer, thereby being able to effectively control the morphological size of the prepared dandelion-shaped single-chain particles, thereby being able to effectively regulate the number and density of amphiphilic particles arranged at the oil-water two-phase interface, and ultimately improving the stability of the emulsion.

[0076] In the second aspect, the present invention provides a dandelion-shaped single-chain particle prepared by the above preparation method. The dandelion-shaped single-chain particle of the present invention is modified from tadpole-shaped single-chain nanoparticles and has a dandelion-shaped cross-linked head and a linear hydrophobic tail. Specifically, the dandelion-like cross-linked head is formed by grafting a poly(4-vinylpyridine) chain with poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) as the core. The pyridine groups on the poly(4-vinylpyridine) chain are easily protonated, which can make the dandelion "head" carry a high-density positive charge. In particular, the pyridine groups on the poly(4-vinylpyridine) chain have a higher degree of protonation under acidic conditions, which can increase the charge density and solubility of the dandelion "head" in water, so that the dandelion-like cross-linked head exhibits better hydrophilicity. Based on the synergistic effect of the hydrophilic dandelion "head" and the hydrophobic polybenzyl methacrylate chain, the dandelion-like nanoparticles can exhibit excellent emulsification properties in the pH range of 1.0-7.0. In addition, the high charge density of the dandelion "head" causes electrostatic repulsion between the emulsion droplets, which can prevent the aggregation of the emulsion droplets to a certain extent, thereby improving the emulsion stability.

[0077] In a third aspect, the embodiments of the present application also provide the use of the dandelion-like single-chain particles described above for providing oil-water interface stabilization. Among them, based on the excellent emulsification performance and the effect of preventing emulsion droplets from coalescing, the dandelion-like single-chain particles of the embodiments of the present application can effectively improve the stability of the emulsion after being used to provide oil-water interface stabilization.

[0078] The technical solution of the present application will be further described below in conjunction with specific embodiments.

[0079] Example 1

[0080] This example provides a preparation process of dandelion-like single-chain particles (Dandelion-Like SCNPs, DK-1), and the specific steps are as follows:

[0081] S1: Weigh CPADB chain transfer agent (20.0 mg, 0.072 mmol), ACVA azo initiator (4.2 mg, 0.015 mmol) and benzyl methacrylate (BzMA, 20 mL, 120 mmol) respectively, add them to 17 mL of dioxane, and stir and disperse them into a suspension in a 100 mL round-bottom flask; then pass argon gas into the suspension for 1 h to exclude oxygen, seal the round-bottom flask and place it in an oil bath at 65°C and stir to react for 4 h; after the reaction is completed, place the round-bottom flask in liquid nitrogen to cool, and expose the reaction solution to air to quench the reaction; the reaction solution is diluted with THF, precipitated with n-hexane six times, the precipitate is collected, and dried in vacuum at room temperature to obtain PBzMA 350 -CTA pink solid;

[0082] S2: Weigh PBzMA 350 -CTA (1.0 g, 0.016 mmol), ACVA azo initiator (1.5 mg, 0.0054 mmol), dimethylaminoethyl methacrylate (DMAEMA, 1.9 mL, 11.3 mmol) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA, 652 mg, 2.26 mmol) were added to 4 mL of dioxane and dispersed into a suspension in a 25 mL round-bottom flask under stirring; argon was then passed through the suspension for 1 h to exclude oxygen, the round-bottom flask was sealed and placed in an oil bath at 70 ° C. to stir and react for 24 h; after the reaction was completed, the round-bottom flask was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction; the reaction solution was diluted with THF, precipitated with n-hexane six times, the precipitate was collected, and vacuum dried at room temperature to finally obtain PBzMA 350 -bP(DMAEMA 370 -co-CMA 65 )Pink solid.

[0083] S3: Weigh PBzMA 350 -bP(DMAEMA 370 -co-CMA 65 ) was dissolved in THF to prepare a polymer solution with a concentration of 1.0 mg / mL, and the polymer solution was filtered through a hydrophilic polytetrafluoroethylene filter membrane with a pore size of 220 nm, the collected filtrate was placed in a quartz bottle and sealed, and then placed under ultraviolet light with a wavelength of 365 nm for photocrosslinking reaction for 12 hours, and then the illumination was stopped, the polymer solution after the reaction was concentrated, and precipitated in n-hexane, the precipitate was collected, and vacuum dried at room temperature to obtain a white solid tadpole-shaped single-chain particle intermediate (TSCNPs-1);

[0084] S4: Weigh TSCNPs-1 and dissolve it in DMF to prepare a 5.0 mg / mL solution. Add 6-bromo-1-hexene (n(Br - ):n(DMAEMA)=60:1); then stirred and reacted in an oil bath at 40°C for 36h; after the reaction, the solution was transferred to a dialysis bag, switched to THF solvent, concentrated and precipitated, and filtered and dried to obtain a quaternized product (TSCNPs-g-1);

[0085] S5: Weigh CPDTC chain transfer agent (348.5 mg, 1.0 mmol), AIBN azo initiator (16.4 mg, 0.1 mmol) and 4-vinylpyridine (5.25 g, 50 mmol) into a 100 mL round-bottom flask, then add 45 mL of DMF and dissolve it under stirring at room temperature. The resulting solution was degassed with argon bubbling for 1 h under stirring to remove oxygen in the system. After the reaction was completed, the reaction bottle was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction. The reaction solution was then added to 150 mL of dichloromethane and mixed thoroughly, and then ether was added dropwise for precipitation. The resulting solid was dried under vacuum to remove the residual solvent, then dissolved in dichloromethane, precipitated in n-hexane and dried under vacuum at room temperature for 24 h to obtain P4VP-CTA;

[0086] S6: P4VP-CTA was weighed and dissolved in DMF to prepare a 0.5 mmol / mL solution, and n-butylamine (30 M equivalent of P4VP-CTA) was used as a reducing agent. The reduction reaction was carried out under nitrogen at room temperature. The obtained colorless solution was dropped into ether for precipitation. Finally, it was centrifuged and vacuum dried at room temperature for 24 hours to obtain P4VP-SH;

[0087] S7: Weigh TSCNPs-g-1 and P4VP-SH and dissolve them in DMF to prepare a 1.0 mg / mL solution (n(-SH):n(enyne)=10:1), then add DMPA photoinitiator (n(-SH):n(DMPA)=10:1), then pass argon gas through the solution for 1 hour to remove oxygen, seal the reaction bottle and place it under ultraviolet light with a wavelength of 365nm for "thiol-ene" click chemistry for 6 hours, then transfer the reaction solution to a dialysis bag, switch to THF solvent, concentrate and precipitate to obtain dandelion-shaped single-chain particles DK-1.

[0088] Example 2

[0089] This example provides a preparation process of dandelion-like single-chain particles (Dandelion-Like SCNPs, DK-2), and the specific steps are as follows:

[0090] S1: Preparation of PBzMA350 -CTA pink solid (same as Example 1);

[0091] S2: Weigh PBzMA 350 -CTA (1.0 g, 0.016 mmol), ACVA azo initiator (1.5 mg, 0.0054 mmol), dimethylaminoethyl methacrylate (DMAEMA, 0.82 mL, 4.78 mmol) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA, 469 mg, 1.62 mmol) were added to 4 mL of dioxane and dispersed into a suspension in a 25 mL round-bottom flask under stirring; argon was then passed through the suspension for 1 h to exclude oxygen, the round-bottom flask was sealed and placed in an oil bath at 70 ° C. to stir and react for 24 h; after the reaction was completed, the round-bottom flask was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction; the reaction solution was diluted with THF, precipitated with n-hexane six times, the precipitate was collected, and vacuum dried at room temperature to finally obtain PBzMA 350 -bP(DMAEMA 370 -co-CMA 65 )Pink solid.

[0092] S3: Weigh PBzMA 350 -bP(DMAEMA 170 -co-CMA 50 ) was dissolved in THF to prepare a polymer solution with a concentration of 1.0 mg / mL, and the polymer solution was filtered through a hydrophilic polytetrafluoroethylene filter membrane with a pore size of 220 nm, the collected filtrate was placed in a quartz bottle and sealed, and then placed under ultraviolet light with a wavelength of 365 nm for photocrosslinking reaction for 12 hours, and then the illumination was stopped, the polymer solution after the reaction was concentrated, and precipitated in n-hexane, the precipitate was collected, and vacuum dried at room temperature to obtain a white solid tadpole-shaped single-chain particle intermediate (TSCNPs-2);

[0093] S4: Weigh TSCNPs-2 and dissolve it in DMF to prepare a 5.0 mg / mL solution. Add 6-bromo-1-hexene (n(Br - ):n(DMAEMA)=60:1); then stirred and reacted in an oil bath at 40°C for 36h; after the reaction, the solution was transferred to a dialysis bag, switched to THF solvent, concentrated and precipitated, and filtered and dried to obtain a quaternized product (TSCNPs-g-2);

[0094] S5: Preparation of P4VP-SH (same as Example 1);

[0095] S6: Weigh TSCNPs-g-2 and P4VP-SH and dissolve them in DMF to prepare a 1.0 mg / mL solution (n(-SH):n(enyne)=10:1), then add DMPA photoinitiator (n(-SH):n(DMPA)=10:1), then pass argon gas through the solution for 1 hour to remove oxygen, seal the reaction bottle and place it under ultraviolet light with a wavelength of 365nm for "thiol-ene" click chemistry for 6 hours, then transfer the reaction solution to a dialysis bag, switch to THF solvent, concentrate and precipitate to obtain dandelion-shaped single-chain particles DK-2.

[0096] Example 3

[0097] This example provides a preparation process of dandelion-like single-chain particles (Dandelion-Like SCNPs, DK-3), and the specific steps are as follows:

[0098] S1: Preparation of PBzMA 350 -CTA pink solid (same as Example 1);

[0099] S2: Weigh PBzMA 350 -CTA (1.0 g, 0.016 mmol), ACVA azo initiator (1.5 mg, 0.0054 mmol), dimethylaminoethyl methacrylate (DMAEMA, 3.31 mL, 19.8 mmol) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA, 1.84 g, 6.4 mmol) were added to 10 mL of dioxane and dispersed into a suspension in a 25 mL round-bottom flask under stirring; argon was then passed through the suspension for 1 h to exclude oxygen, the round-bottom flask was sealed and placed in an oil bath at 70° C. to stir and react for 24 h; after the reaction was completed, the round-bottom flask was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction; the reaction solution was diluted with THF, precipitated with n-hexane six times, the precipitate was collected, and dried in vacuum at room temperature to finally obtain PBzMA 350 -bP(DMAEMA 600 -co-CMA 200 )Pink solid.

[0100] S3: Weigh PBzMA 350 -bP(DMAEMA 600 -co-CMA 200) was dissolved in THF to prepare a polymer solution with a concentration of 1.0 mg / mL, and the polymer solution was filtered through a hydrophilic polytetrafluoroethylene filter membrane with a pore size of 220 nm, the collected filtrate was placed in a quartz bottle and sealed, and then placed under ultraviolet light with a wavelength of 365 nm for photocrosslinking reaction for 12 hours, and then the illumination was stopped, the polymer solution after the reaction was concentrated, and precipitated in n-hexane, the precipitate was collected, and vacuum dried at room temperature to obtain a white solid tadpole-shaped single-chain particle intermediate (TSCNPs-3);

[0101] S4: Weigh TSCNPs-3 and dissolve it in DMF to prepare a 5.0 mg / mL solution. Add 6-bromo-1-hexene (n(Br - ):n(DMAEMA)=60:1); then stirred and reacted in an oil bath at 40°C for 36h; after the reaction, the solution was transferred to a dialysis bag, switched to THF solvent, concentrated and precipitated, and filtered and dried to obtain a quaternized product (TSCNPs-g-3);

[0102] S5: Preparation of P4VP-SH (same as Example 1);

[0103] S6: Weigh TSCNPs-g-3 and P4VP-SH and dissolve them in DMF to prepare a 1.0 mg / mL solution (n(-SH):n(enyne)=10:1), then add DMPA photoinitiator (n(-SH):n(DMPA)=10:1), then pass argon gas through the solution for 1 hour to remove oxygen, seal the reaction bottle and place it under ultraviolet light with a wavelength of 365nm for "thiol-ene" click chemistry for 6 hours, then transfer the reaction solution to a dialysis bag, switch to THF solvent, concentrate and precipitate to obtain dandelion-shaped single-chain particles DK-3.

[0104] Example 4

[0105] This example provides a preparation process of dandelion-like single-chain particles (Dandelion-Like SCNPs, DK-4), and the specific steps are as follows:

[0106] S1: Preparation of PBzMA 350 -CTA pink solid (same as Example 1);

[0107] S2: Weigh PBzMA 350-CTA (1.0 g, 0.016 mmol), ACVA azo initiator (1.5 mg, 0.0054 mmol), dimethylaminoethyl methacrylate (DMAEMA, 1.9 mL, 11.36 mmol) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA, 280 g, 0.97 mmol) were added to 5 mL of dioxane and stirred in a 25 mL round-bottom flask to disperse into a suspension; argon was then passed through the suspension for 1 h to exclude oxygen, the round-bottom flask was sealed and placed in an oil bath at 70 ° C. to stir and react for 24 h; after the reaction was completed, the round-bottom flask was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction; the reaction solution was diluted with THF, precipitated with n-hexane six times, the precipitate was collected, and vacuum dried at room temperature to finally obtain PBzMA 350 -bP(DMAEMA 370 -co-CMA 30 )Pink solid.

[0108] S3: Weigh PBzMA 350 -bP(DMAEMA 370 -co-CMA 30 ) was dissolved in THF to prepare a polymer solution with a concentration of 1.0 mg / mL, and the polymer solution was filtered through a hydrophilic polytetrafluoroethylene filter membrane with a pore size of 220 nm, the collected filtrate was placed in a quartz bottle and sealed, and then placed under ultraviolet light with a wavelength of 365 nm for photocrosslinking reaction for 12 hours, and then the illumination was stopped, the polymer solution after the reaction was concentrated, and precipitated in n-hexane, the precipitate was collected, and vacuum dried at room temperature to obtain a white solid tadpole-shaped single-chain particle intermediate (TSCNPs-4);

[0109] S4: Weigh TSCNPs-4 and dissolve it in DMF to prepare a 5.0 mg / mL solution. Add 6-bromo-1-hexene (n(Br - ):n(DMAEMA)=60:1); then stirred and reacted in an oil bath at 40°C for 36h; after the reaction, the solution was transferred to a dialysis bag, switched to THF solvent, concentrated and precipitated, and filtered and dried to obtain a quaternized product (TSCNPs-g-4);

[0110] S5: Preparation of P4VP-SH (same as in Example 1);

[0111] S6: Weigh TSCNPs-g-4 and P4VP-SH and dissolve them in DMF to prepare a 1.0 mg / mL solution (n(-SH):n(enyne)=10:1), then add DMPA photoinitiator (n(-SH):n(DMPA)=10:1), then pass argon gas through the solution for 1 hour to remove oxygen, seal the reaction bottle and place it under ultraviolet light with a wavelength of 365nm for "thiol-ene" click chemistry for 6 hours, then transfer the reaction solution to a dialysis bag, switch to THF solvent, concentrate and precipitate to obtain dandelion-shaped single-chain particles DK-4.

[0112] Example 5

[0113] This example provides a preparation process of dandelion-like SCNPs (DK-5), and the specific steps are as follows:

[0114] S1: Preparation of PBzMA 350 -CTA pink solid (same as Example 1);

[0115] S2: Weigh PBzMA 350 -CTA (1.0 g, 0.016 mmol), ACVA azo initiator (1.5 mg, 0.0054 mmol), dimethylaminoethyl methacrylate (DMAEMA, 1.9 mL, 11.36 mmol) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA, 1.4 g, 1.7 mmol) were added to 10 mL of dioxane and dispersed into a suspension in a 25 mL round-bottom flask under stirring; argon was then passed through the suspension for 1 h to exclude oxygen, the round-bottom flask was sealed and placed in an oil bath at 70 ° C. to stir and react for 24 h; after the reaction was completed, the round-bottom flask was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction; the reaction solution was diluted with THF, precipitated with n-hexane six times, the precipitate was collected, and vacuum dried to finally obtain PBzMA 350 -bP(DMAEMA 370 -co-CMA 100 )Pink solid.

[0116] S3: Weigh PBzMA 350 -bP(DMAEMA 370 -co-CMA 100) was dissolved in THF to prepare a polymer solution with a concentration of 1.0 mg / mL, and the polymer solution was filtered through a hydrophilic polytetrafluoroethylene filter membrane with a pore size of 220 nm, the collected filtrate was placed in a quartz bottle and sealed, and then placed under ultraviolet light with a wavelength of 365 nm for photocrosslinking reaction for 12 hours, and then the illumination was stopped, the polymer solution after the reaction was concentrated, and precipitated in n-hexane, the precipitate was collected, and vacuum dried at room temperature to obtain a white solid tadpole-shaped single-chain particle intermediate (TSCNPs-5);

[0117] S4: Weigh TSCNPs-5 and dissolve it in DMF to prepare a 5.0 mg / mL solution. Add 6-bromo-1-hexene (n(Br - ):n(DMAEMA)=60:1); then stirred in an oil bath at 40°C for 36h; after the reaction, the solution was transferred to a dialysis bag, switched to THF solvent, concentrated and precipitated, and filtered to obtain a quaternized product (TSCNPs-g-5);

[0118] S5: Preparation of P4VP-SH (same as in Example 1);

[0119] S6: Weigh TSCNPs-g-5 and P4VP-SH and dissolve them in DMF to prepare a 1.0 mg / mL solution (n(-SH):n(enyne)=10:1), then add DMPA photoinitiator (n(-SH):n(DMPA)=10:1), then pass argon gas through the solution for 1 hour to remove oxygen, seal the reaction bottle and place it under ultraviolet light with a wavelength of 365nm for "thiol-ene" click chemistry for 6 hours, then transfer the reaction solution to a dialysis bag, switch to THF solvent, concentrate and precipitate to obtain dandelion-shaped single-chain particles DK-5.

[0120] Example 6

[0121] This example provides a preparation process of dandelion-like SCNPs (DK-6), and the specific steps are as follows:

[0122] S1: Weigh CPADB chain transfer agent (20.0 mg, 0.072 mmol), ACVA azo initiator (4.2 mg, 0.015 mmol) and benzyl methacrylate (BzMA, 10 mL, 60 mmol) respectively, add them to 10 mL of dioxane, and stir and disperse them into a suspension in a 50 mL round-bottom flask; then pass argon gas into the suspension for 1 h to remove oxygen, seal the round-bottom flask and place it in an oil bath at 65°C to stir and react for 4 h; after the reaction is completed, place the round-bottom flask in liquid nitrogen to cool, and expose the reaction solution to air for quenching; the reaction solution is diluted with THF, precipitated with n-hexane six times, the precipitate is collected, and vacuum dried to obtain PBzMA 250-CTA pink solid;

[0123] S2: Weigh PBzMA 250 -CTA (2.5 g, 0.057 mmol), ACVA azo initiator (3.2 mg, 0.0114 mmol), dimethylaminoethyl methacrylate (DMAEMA, 6.7 g, 39.8 mmol) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA, 2.3 g, 7.98 mmol) were added to 10 mL of dioxane and dispersed into a suspension in a 25 mL round-bottom flask under stirring; argon was then passed through the suspension for 1 h to exclude oxygen, the round-bottom flask was sealed and placed in an oil bath at 70 ° C. to stir and react for 24 h; after the reaction was completed, the round-bottom flask was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction; the reaction solution was diluted with THF, precipitated with n-hexane six times, the precipitate was collected, and vacuum dried at room temperature to finally obtain PBzMA 250 -bP(DMAEMA 400 -co-CMA 100 )Pink solid.

[0124] S3: Weigh PBzMA 250 -bP(DMAEMA 400 -co-CMA 100 ) was dissolved in THF to prepare a polymer solution with a concentration of 1.0 mg / mL, and the polymer solution was filtered through a hydrophilic polytetrafluoroethylene filter membrane with a pore size of 220 nm, the collected filtrate was placed in a quartz bottle and sealed, and then placed under ultraviolet light with a wavelength of 365 nm for photocrosslinking reaction for 12 hours, and then the illumination was stopped, the polymer solution after the reaction was concentrated, and precipitated in n-hexane, the precipitate was collected, and vacuum dried at room temperature to obtain a white solid tadpole-shaped single-chain particle intermediate (TSCNPs-6);

[0125] S4: Weigh TSCNPs-6 and dissolve it in DMF to prepare a 5.0 mg / mL solution. Add 6-bromo-1-hexene (n(Br - ):n(DMAEMA)=60:1); then stirred and reacted in an oil bath at 40°C for 36h; after the reaction, the solution was transferred to a dialysis bag, switched to THF solvent, concentrated and precipitated, and filtered and dried to obtain a quaternized product (TSCNPs-g-6);

[0126] S5: Preparation of P4VP-SH (same as in Example 1);

[0127] S6: Weigh TSCNPs-g-6 and P4VP-SH and dissolve them in DMF to prepare a 1.0 mg / mL solution (n(-SH):n(enyne)=10:1), then add DMPA photoinitiator (n(-SH):n(DMPA)=10:1), then pass argon gas through the solution for 1 hour to remove oxygen, seal the reaction bottle and place it under ultraviolet light with a wavelength of 365nm for "thiol-ene" click chemistry for 6 hours, then transfer the reaction solution to a dialysis bag, switch to THF solvent, concentrate and precipitate to obtain dandelion-shaped single-chain particles DK-6.

[0128] Example 7

[0129] This example provides a preparation process of dandelion-like single-chain particles (Dandelion-Like SCNPs, DK-7), and the specific steps are as follows:

[0130] S1: Weigh CPADB chain transfer agent (20.0 mg, 0.072 mmol), ACVA azo initiator (4.2 mg, 0.015 mmol) and benzyl methacrylate (BzMA, 24 mL, 114 mmol) respectively, add them to 25 mL of dioxane, and stir and disperse them into a suspension in a 100 mL round-bottom flask; then pass argon gas into the suspension for 1 h to exclude oxygen, seal the round-bottom flask and place it in an oil bath at 65°C and stir to react for 4 h; after the reaction is completed, place the round-bottom flask in liquid nitrogen to cool, and expose the reaction solution to air to quench the reaction; the reaction solution is diluted with THF, precipitated with n-hexane six times, the precipitate is collected, and dried in vacuum at room temperature to obtain PBzMA 645 -CTA pink solid;

[0131] S2: Weigh PBzMA 645 -CTA (6.5 g, 0.057 mmol), ACVA azo initiator (3.2 mg, 0.0114 mmol), dimethylaminoethyl methacrylate (DMAEMA, 14.4 mL, 85.5 mmol) and 7-(2-methacryloyloxyethoxy)-4-methylcoumarin (CMA, 4.6 g, 15.0 mmol) were added to 20 mL of dioxane and stirred in a 100 mL round-bottom flask to disperse into a suspension; argon gas was then passed through the suspension for 1 h to exclude oxygen, the round-bottom flask was sealed and placed in an oil bath at 70 ° C. and stirred for 24 h; after the reaction was completed, the round-bottom flask was placed in liquid nitrogen for cooling, and the reaction solution was exposed to the air to quench the reaction; the reaction solution was diluted with THF, precipitated with n-hexane six times, the precipitate was collected, and vacuum dried at room temperature to finally obtain PBzMA 645 -bP(DMAEMA 877 -co-CMA 200 )Pink solid.

[0132] S3: Weigh PBzMA 645 -bP(DMAEMA 877 -co-CMA 200 ) was dissolved in THF to prepare a polymer solution with a concentration of 1.0 mg / mL, and the polymer solution was filtered through a hydrophilic polytetrafluoroethylene filter membrane with a pore size of 220 nm, the collected filtrate was placed in a quartz bottle and sealed, and then placed under ultraviolet light with a wavelength of 365 nm for photocrosslinking reaction for 12 hours, and then the illumination was stopped, the polymer solution after the reaction was concentrated, and precipitated in n-hexane, the precipitate was collected, and vacuum dried at room temperature to obtain a white solid tadpole-shaped single-chain particle intermediate (TSCNPs-7);

[0133] S4: Weigh TSCNPs-7 and dissolve it in DMF to prepare a 5.0 mg / mL solution. Add 6-bromo-1-hexene (n(Br - ):n(DMAEMA)=60:1); then stirred and reacted in an oil bath at 40°C for 36h; after the reaction, the solution was transferred to a dialysis bag, switched to THF solvent, concentrated and precipitated, and filtered and dried to obtain a quaternized product (TSCNPs-g-7);

[0134] S5: Preparation of P4VP-SH (same as Example 1);

[0135] S6: Weigh TSCNPs-g-7 and P4VP-SH and dissolve them in DMF to prepare a 1.0 mg / mL solution (n(-SH):n(enyne)=10:1), then add DMPA photoinitiator (n(-SH):n(DMPA)=10:1), then pass argon gas through the solution for 1 hour to remove oxygen, seal the reaction bottle and place it under ultraviolet light with a wavelength of 365nm for "thiol-ene" click chemistry for 6 hours, then transfer the reaction solution to a dialysis bag, switch to THF solvent, concentrate and precipitate to obtain dandelion-shaped single-chain particles DK-7.

[0136] In order to illustrate the structural properties of the dandelion-shaped single-chain particles prepared in the embodiment of the present application, DK-1 is used as a test sample for testing and characterization, specifically including:

[0137] 1. H NMR spectroscopy ( 1 H-NMR) characterization

[0138] PBzMA 350 -CTA, PBzMA 350 -bP(DMAEMA 370 -co-CMA 65 ), TSCNPs-g-1 and DK-1 were subjected to H NMR spectra ( 1 H-NMR) characterization, the results are Figures 1 to 2 As shown. Among them, Figure 1 PBzMA shown 350 -CTA and PBzMA 350- bP(DMAEMA 370 -co-CMA 65 )'s H NMR spectrum; Figure 2 Shown are the H NMR spectra of TSCNPs-g-1 and DK-1.

[0139] according to Figure 1 It can be seen that the peak with chemical shift δ = 4.88ppm is the characteristic peak of hydrogen atoms of methylene on PBzMA, and the peak with δ = 7.8ppm is the characteristic peak of hydrogen atoms of benzene ring on CPADB. The integrated area of ​​the two NMR peaks is 350.59:1, indicating that PBzMA with a degree of polymerization of 350 was obtained. 350 -CTA is a macromolecular initiator, and the peaks at chemical shifts δ=4.88ppm, δ=4.1ppm, and δ=6.2ppm represent the characteristic peaks of hydrogen atoms of the methylene group of PBzMA, the characteristic peaks of hydrogen atoms of the methylene group connected to the ester group of PDMAEMA, and the characteristic peaks of hydrogen atoms of the coumarin group of CMA, respectively. The integrated areas of the nuclear magnetic resonance peaks at chemical shifts δ=4.88ppm, δ=4.1ppm, and δ=6.2ppm are 1:1.06:0.09; This shows that Example 1 successfully prepared PBzMA 350 -bP(DMAEMA 370 -co-CMA 65 ).

[0140] according to Figure 2 It can be seen that in TSCNPs-g-1, a characteristic peak of hydrogen atoms on the β carbon of 6-bromo-1-hexene appears at the chemical shift δ=5.8ppm, and the integrated areas of the nuclear magnetic resonance peaks of δ=5.8ppm and δ=4.88ppm are 1:0.15, from which it can be calculated that the quaternization reaction efficiency is 30%; after grafting, a characteristic peak of hydrogen atoms at the meta position of the N atom in the pyridine group appears (δ=6.62ppm), and the integrated areas of the nuclear magnetic resonance peaks of δ=6.62ppm and δ=4.88ppm are 8.95:1; from this, it can be calculated that the number of P4VP grafted on each TSCNPs-g-1 polymer chain is 105.

[0141] 2. Transmission Electron Microscopy Characterization

[0142] DK-1 was dissolved in DMF to prepare a 1 mg / ml solution and stained with silver nitrate. The solution was dropped onto a copper grid and dried. The solution was then observed under TEM. The results were as follows: Figure 3 shown.

[0143] according to Figure 3 It can be seen that DK-1 has an irregular shape, and high contrast areas can be seen after magnification. This is mainly because the head of DK-1 contains Br - , can react with silver nitrate to form silver bromide precipitate, improving the contrast of electron microscope samples.

[0144] 3. Emulsion stability test

[0145] Dissolving DK-1 in water to prepare a 0.05% wt DK-1 aqueous solution to obtain a DK-1 aqueous solution;

[0146] 10 mg of Nile red dye was added to 1 ml of n-decane and stirred to dissolve; 1 ml of n-decane dyed with Nile red was added to 1 ml of DK-1 aqueous solution. Since the density of n-decane is less than that of water and n-decane is incompatible with water, a two-phase stratified solution was formed; the two-phase solution was homogenized in a cell crusher (70W, 1 min) to form an emulsion; the emulsion was allowed to stand, and samples were taken for optical microscope observation after the emulsion was stable. The specific test process is as follows:

[0147] 3.1 Microscope characterization

[0148] Take 10 μL of the emulsion and drop it on a glass slide. Cover it with a coverslip and observe it under an optical microscope. The results are as follows: Figure 4 -A; at the same time, 10 μL of the emulsion was dropped on a glass slide, covered with a coverslip and observed under a laser confocal microscope. Figure 4 -B.

[0149] according to Figure 4 -A to Figure 4 -B shows that the red color in the emulsion is the dyed oil phase, and the black color is the undyed water phase, which indicates that DK-1 has the ability to stabilize the oil-water interface and form an oil-in-water (O / W) emulsion.

[0150] 3.2 Characterization of emulsion stability

[0151] The emulsion was left to stand for 3 months and the changes in the emulsion level were observed. The results were as follows: Figure 5 shown.

[0152] according to Figure 5 It can be seen that after the emulsion was left standing for 6 months, the emulsion page stabilized by DK-1 had almost no change, which shows that the emulsion stabilized by DK-1 has excellent stability.

[0153] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0154] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for preparing dandelion-shaped single-chain particles, characterized in that: include: Synthesis of polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer; Performing a photocrosslinking reaction on the polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer to obtain a tadpole-shaped single-chain particle intermediate; The tadpole-shaped single-chain particle intermediate is quaternized, and the quaternized product undergoes photo-initiated "thiol-ene" click chemistry with thiol-terminated poly(4-vinylpyridine) to obtain dandelion-shaped single-chain particles.

2. The preparation method according to claim 1, characterized in that: The preparation method of the polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer comprises: benzyl methacrylate, a thioester chain transfer agent and an azo initiator are mixed to carry out a reversible addition-fragmentation transfer radical polymerization reaction to obtain polybenzyl methacrylate-CTA; The polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator are mixed to carry out a reversible addition-fragmentation transfer radical polymerization reaction to obtain a polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer.

3. The preparation method according to claim 2, characterized in that: When the benzyl methacrylate, the thioester chain transfer agent and the azo initiator are mixed to carry out a reversible addition-fragmentation transfer radical polymerization reaction, the reaction temperature is 60-70° C. and the reaction time is 4-12 hours; And / or, the molar ratio of the benzyl methacrylate, the thioester chain transfer agent and the azo initiator is 500-1200:1:0.

2.

4. The preparation method according to claim 2, characterized in that: When the polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator are mixed for reversible addition-fragmentation transfer radical polymerization, the reaction temperature is 65-70° C. and the reaction time is 12-24 hours; And / or, the molar ratio of the polybenzyl methacrylate-CTA, dimethylaminoethyl methacrylate, 7-(2-methacryloyloxyethoxy)-4-methylcoumarin and azo initiator is 1:300-1200:60-400:0.

2.

5. The preparation method according to claim 2, characterized in that: The preparation method of the thiol-terminated poly (4-vinyl pyridine) comprises: 4-vinylpyridine, a thioester chain transfer agent and an azo initiator are mixed to undergo a reversible addition-fragmentation transfer radical polymerization reaction to obtain poly(4-vinylpyridine)-CTA; In an inert atmosphere, the poly(4-vinylpyridine)-CTA is subjected to a reduction reaction, and the reduction product is sequentially precipitated, centrifuged and vacuum dried to obtain thiol-terminated poly(4-vinylpyridine).

6. The preparation method according to claim 1, characterized in that: The quaternization of the tadpole-shaped single-chain particle intermediate comprises: The tadpole-shaped single-chain particle intermediate is mixed with a quaternary ammonium agent containing a carbon-carbon double bond and reacted for 36-45 hours, wherein the molar ratio of the halogen atom in the quaternary ammonium agent containing a carbon-carbon double bond to the dimethylaminoethyl methacrylate block in the tadpole-shaped single-chain particle intermediate is ≥60:

1.

7. The preparation method according to claim 1, characterized in that: When the photo-initiated "thiol-ene" click chemistry occurs, the molar ratio of the thiol in the thiol-terminated poly(4-vinylpyridine) to the ene in the quaternized product is 2-10:

1.

8. The preparation method according to claim 1, characterized in that: The polybenzyl methacrylate-b-poly(dimethylaminoethyl methacrylate-co-7-(2-methacryloyloxyethoxy)-4-methylcoumarin) block copolymer contains: Polybenzyl methacrylate blocks having a degree of polymerization of 250-645; A polydimethylaminoethyl methacrylate block having a degree of polymerization of 170-877; and Poly(7-(2-methacryloyloxyethoxy)-4-methylcoumarin) blocks having a degree of polymerization of 30-200.

9. A dandelion-shaped single-chain particle, characterized in that: It is prepared by the method according to any one of claims 1 to 8.

10. Use of the dandelion-shaped single-chain particles according to claim 9 for stabilizing an oil-water interface.

Images