A method for using tadpole-shaped Janus single-chain particles for material surface modification

Abstract

A method for using tadpole-shaped Janus single-chain particles for material surface modification comprises: using N,N-dimethylformamide, methanol or chloroform as a solvent to configure the tadpole-shaped Janus single-chain particles into a Janus particle modification liquid; applying the Janus particle modification liquid to the surface of a metal, oxide or plastic material by immersion or spraying, so as to modify the tadpole-shaped Janus single-chain particles on the surface of the material to be modified. The tadpole-shaped Janus single-chain particles of the present invention have uniform size and clear structure, contain non-covalently cross-linked heads and linear chain tails, and can be used for surface modification of materials by simple immersion or spraying, and the molecular weight length of the brush layer can be adjusted over a wide range. The Janus particles of the present invention have strong surface binding force, excellent bonding stability, and present a configuration in which the non-covalently cross-linked heads are located on the surface of the modified layer, while the functional linear chain tails are located outside the coating, thereby achieving efficient functionalization of the material surface.

Description

Technical Field

[0001] The present invention relates to the field of nanomaterials, and in particular to a method for using tadpole-shaped Janus single-chain particles for material surface modification. Background Art

[0002] Polymer brushes are an important modification method for regulating the physical and chemical properties of material surfaces. They can impart functional properties such as corrosion resistance, anti-adhesion, lubrication, anti-protein adhesion, and antibacterial properties to material surfaces. This method is applicable to various surfaces, including those with complex curvatures. The thickness of the modified layer is at the nanometer scale, so it does not affect the gloss of the material itself. The methods for preparing polymer brushes are generally divided into two types: grafting from the surface ("Grafting From") and grafting onto the surface ("Grafting To"). "Grafting From" involves two steps: modifying the material surface with a small molecule initiator and initiator-induced monomer polymerization, and can usually produce polymer brushes with a high grafting density. However, due to the embedding of the active end during the polymerization process, the molecular weight of the grafted polymer is usually small and less uniform. "Grafting To" is to graft polymer chains with clear structural parameters onto the material surface. However, due to the excluded volume effect of the polymer chain, high molecular weight polymer chains are difficult to graft onto the material surface. The resulting polymer brush grafting density is usually very low (i.e., the grafting efficiency is very low), which is difficult to meet the actual functional modification requirements. In summary, existing polymer brush preparation methods still struggle to achieve efficient grafting of polymer chains with varying molecular weights (e.g., molecular weights ranging from several thousand to nearly one million). However, in practical functionalized grafting modification applications, different functional polymers with different compositions and molecular weights are required to meet different functionalization requirements. For example, grafting modification of anti-protein adhesion coatings requires a sufficiently high molecular weight of polymer chains and a high grafting density to achieve excellent anti-protein adhesion properties. Furthermore, polymer brushes need to have good stability to prolong their use.

[0003] Therefore, it is extremely important to develop a new stable grafting modification method that is universally applicable to polymer brushes of different compositions and molecular weights to achieve material surface functionalization. Summary of the Invention

[0004] Based on this, the present invention provides a method for using tadpole-shaped Janus single-chain particles for material surface modification, so as to solve the disadvantage that the surface modification methods in the prior art cannot simultaneously achieve the "contradictory" requirements of "high molecular weight" and "high chain density" of the modified layer polymer chains, thereby filling the technical gap in the field of material surface functionalization.

[0005] To achieve the above object, the present invention provides a method for using tadpole-shaped Janus single-chain particles for material surface modification, which comprises the following steps:

[0006] S1. Using N,N-dimethylformamide or chloroform as a solvent, preparing tadpole-shaped Janus single-chain particles into a Janus particle modification solution, wherein the tadpole-shaped Janus single-chain particles contain a non-covalently cross-linked head and a linear molecular chain tail grafted to one side of the head; the tadpole-shaped Janus single-chain particles are obtained by intrachain non-covalently cross-linking a cross-linkable block in a diblock copolymer, wherein the cross-linkable block in the diblock copolymer has a weight-average molecular weight in the range of 9k-200k, and the non-cross-linkable block in the diblock copolymer has a weight-average molecular weight in the range of 5k-700k;

[0007] S2. Applying a Janus particle modification liquid to the surface of a material to be modified, the surface of which can interact with the head of the tadpole-shaped Janus single-chain particle, by immersion or spraying, to modify the tadpole-shaped Janus single-chain particle on the surface of the material to be modified, so that the head of the tadpole-shaped Janus single-chain particle non-covalently interacts with the material surface to form a modification layer, while the linear molecular chain tail is located outside the modification layer. The head of the tadpole-shaped Janus single-chain particle interacts with the surface of the material to be modified by forming one or more of hydrogen bonds, coordination bonds, and ionic bonds. The material to be modified is a metal, an oxide, a plastic, or an elastomer.

[0008] As a further preferred technical solution of the present invention, the dispersity index of the polymer molecular weight of the diblock copolymer is below 1.2.

[0009] As a further preferred technical solution of the present invention, the tadpole-shaped Janus single-chain particles are obtained by intrachain non-covalent crosslinking of the crosslinkable block in the diblock copolymer under the action of a crosslinking agent, and the molar ratio of the crosslinking agent to the repeating unit content of the crosslinkable block is controlled at 0.1-1 times.

[0010] As a further preferred technical solution of the present invention, the cross-linking agent is 1,4-dibromobutane.

[0011] As a further preferred technical solution of the present invention, the cross-linkable block in the diblock copolymer is poly(4-vinylpyridine); and the non-cross-linkable block in the diblock copolymer is hydrophobic polystyrene.

[0012] As a further preferred technical solution of the present invention, the Janus particle modification solution prepared in step S1 has a concentration of 0.5-50 g / L and a viscosity of less than 500 mPa·s, and the tadpole-shaped Janus single-chain particles are 5-20 nm and uniform in size. The viscosity is preferably 200-500 mPa·s.

[0013] As a further preferred technical solution of the present invention, the material to be modified is subjected to surface cleaning treatment using plasma or an organic solvent before being surface modified by the Janus particle modification liquid.

[0014] As a further preferred technical solution of the present invention, the material to be modified is a gold sheet, a copper sheet, a silicon sheet, a silicon dioxide sheet, glass, mica, titanium dioxide, indium tin oxide, fluorine-doped tin oxide, polyethylene, polydimethylsiloxane, polyetheretherketone or polyimide.

[0015] As a further preferred technical solution of the present invention, in step S2, the spraying time ranges from 5 to 10 seconds, and the modification reaction time of the Janus particle modification liquid and the material to be modified ranges from 1 to 10 minutes.

[0016] The method of using tadpole-shaped Janus single-chain particles for material surface modification of the present invention, using the above technical solution, can achieve the following beneficial effects:

[0017] 1) The surface modification method of the present invention has a strong bonding force between the Janus particles and the material surface, and will not fall off in various harsh environments (such as: different solvent washing, temperature, solvent vapor);

[0018] 2) The surface modification method of the present invention, after surface modification of each material, shows that the non-covalent cross-linked head is located on the surface of the modified layer, while the non-cross-linked segment as the linear molecular chain tail that provides function is always located on the outside of the coating, thereby facilitating efficient functionalization of the material surface.

[0019] Compared with the existing technology, the present invention can be generally applied to the surface modification of various metals, oxides and plastic products, and the length of the linear molecular chain tail located on the outside of the modified layer can be selected within a very large molecular weight range (5k-700k), thereby preparing a series of functional surfaces such as hydrophobic and oleophobic, lubricating, anti-protein adhesion, antibacterial, and anti-corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 This is an atomic force microscope image of the silicon wafer surface modified with tadpole-shaped Janus single-chain particles in Example 1, where the modification solvent is DMF.

[0022] Figure 2 This is the stability of the surface modified tadpole-shaped Janus single-chain particles tracked using a dissipative quartz crystal microbalance in Example 1. It can be seen that after immersion and washing in various solvents, their mass and viscoelasticity remain unchanged.

[0023] Figure 3 These are atomic force microscopy images of tadpole-shaped Janus single-chain particles grafted onto gold sheets, mica, silica sheets, indium tin oxide glass, and glass surfaces in Examples 5-9. The modification solvent is DMF.

[0024] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0025] The following describes the specific embodiments of the present invention in detail 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 invention and are not intended to limit the present invention.

[0026] Unless otherwise defined, the technical terms used in the following examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples, unless otherwise specified, are conventional biochemical reagents; the experimental methods described, unless otherwise specified, are conventional methods.

[0027] Example 1

[0028] The diblock copolymer selected was polystyrene-b-poly(4-vinylpyridine) (PS 300k -b-P4VP 175k , subscripts indicate molecular weight, the same below), tadpole-shaped Janus single-chain particles were obtained by intrachain non-covalent cross-linking of P4VP blocks with 1,4-dibromobutane (DBB).

[0029] The method for using tadpole-shaped Janus single-chain particles for material surface modification proposed in this embodiment is specifically as follows:

[0030] PS-b-P4VP was dissolved in N,N-dimethylformamide (DMF) and stirred for 2 hours to fully dissolve, reaching a concentration of 0.5 g / L. The crosslinker, DBB, was added with vigorous stirring at a molar ratio of 1:1 to the pyridine unit in P4VP. After crosslinking at 95°C for 48 hours, the mixture was returned to room temperature and dialyzed into methanol to remove unreacted DBB. The mixture was concentrated, settled, and dried to obtain a uniformly sized, tadpole-shaped, single-chain Janus particle powder.

[0031] Prepare Janus particle modification solution (solvent is N,N-dimethylformamide, concentration is 0.2g / L) and stir overnight to fully dissolve. Use detergent solution, water, and ethanol in sequence to thoroughly clean the surface of the silicon wafer, then use argon to blow dry the surface of the silicon wafer and dry it in an oven at 85°C for 4h. Then place the cleaned silicon wafer in an oxygen plasma cleaner and treat it at 80W power for 1min. Subsequently, immerse the silicon wafer in the Janus particle modification solution for 10min. After the modification is completed, use DMF to thoroughly clean the surface, and further vacuum dry it after drying with argon to obtain the following: Figure 1The surface shown is a silicon wafer modified with tadpole-shaped single-chain Janus particles. Testing showed that the surface was hydrophilic before grafting, but became hydrophobic after grafting, achieving the highest contact angle of 80° for PS chain modification.

[0032] The bonding stability of the modified surface was tested using a dissipative quartz microbalance. The modified surface was rinsed with DMF, toluene, chloroform, methanol, and DMF for a long time (total time not less than 12 hours). Figure 2 As shown in the figure, it can be found that the surface modification quality remains unchanged, indicating that the modified surface has not fallen off.

[0033] Example 2

[0034] The diblock copolymer selected was polystyrene-b-poly(4-vinylpyridine) (PS 575k -b-P4VP 175k ), tadpole-shaped Janus single-chain particles were obtained by intrachain non-covalent cross-linking of P4VP blocks with 1,4-dibromobutane (DBB).

[0035] In this example, tadpole-shaped Janus single-chain particles are used to modify the surface of a silicon wafer, which is the same as in Example 1. Atomic force microscopy images show that the surface of the silicon wafer has uniformly modified particles.

[0036] Comparative Example 1

[0037] This comparative example serves as a comparative experiment of Example 1. The surface of the silicon wafer is modified in the same manner. Compared with Example 1, the difference is that the solvent DMF for preparing the Janus particle modification solution is replaced by toluene.

[0038] Comparative Example 2

[0039] This comparative example serves as a comparative experiment of Example 1. The Janus particle modification liquid configured in Example 1 is selected, and the surface modification of the material is performed using a similar immersion method as in Example 1. The difference is that the modified material is replaced by polytetrafluoroethylene, a material whose surface has no non-covalent interaction with the head of the tadpole-shaped Janus single-chain particle.

[0040] Comparative Example 3

[0041] This comparative example serves as a comparative experiment of Example 1. The modified material in Example 1 is selected, and the surface of the material is modified using a similar immersion method as in Example 1, except that the modification liquid is replaced by a DMF solution (0.2 g / L) of PS-b-P4VP / 1-bromobutane non-cross-linked polymer.

[0042] The surface-modified materials of Comparative Examples 1-3 were tested, and the comparison results with those of Example 1 are shown in Table 1:

[0043] Table 1

[0044]

[0045]

[0046] Note: In Table 1, the hydrophobicity of the modified surface refers to GB / T 30447-2013 "Nanofilm Contact Angle Measurement Method", with a contact angle greater than 75° being considered "excellent", less than 69° being considered "very poor", and between 75° and 69° being considered "poor". In addition, polytetrafluoroethylene is a hydrophobic material and its hydrophobicity is not compared and is marked as "-". The solvent washing stability of the modified surface is determined by washing with DMF, toluene, chloroform, methanol, and DMF for 12 hours in sequence. "Excellent" is defined as the surface modification quality remaining unchanged, "very poor" is defined as the surface modification quality decreasing to less than 70%, and "poor" is defined as the surface modification quality decreasing but maintaining above 70%.

[0047] Example 3

[0048] Tadpole-shaped single-chain Janus particles from Example 1 were used, except that chloroform was used as the solvent for preparing the Janus particle modification solution (at a concentration of 0.2 g / L). Using the same impregnation method as in Example 1, the silicon wafer was thoroughly rinsed with chloroform and air-dried to obtain a surface-modified silicon wafer. Using the same testing methods as in Example 1, the hydrophobicity of the silicon wafer surface and the adhesion stability of the modified surface were similar to those in Example 1.

[0049] Example 4

[0050] Using the Janus particle modification solution prepared in Example 3, the surface of the silicon wafer was sprayed with a paint spray gun, allowed to stand, and then dried with argon gas to obtain a surface-modified silicon wafer. The spraying time was 5-10 seconds, and the standing time was 5 seconds. Using the same testing methods as in Example 1, the hydrophobicity of the silicon wafer surface and the adhesion stability of the modified surface were similar to those in Example 1.

[0051] Example 5

[0052] The Janus particle modification liquid configured in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of the gold sheet of the material to be modified.

[0053] Example 6

[0054] The Janus particle modification liquid prepared in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of the mica material to be modified.

[0055] Example 7

[0056] The Janus particle modification liquid prepared in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of the silicon dioxide wafer to be modified.

[0057] Example 8

[0058] The Janus particle modification liquid prepared in Example 1 was selected, and a similar immersion method as in Example 1 was used to modify the surface of the indium tin oxide (ITO) material to be modified.

[0059] Example 9

[0060] The Janus particle modification liquid prepared in Example 1 was selected, and a similar immersion method as in Example 1 was used to modify the surface of the glass material to be modified.

[0061] The atomic force microscopy images of the surfaces of the materials subjected to surface modification in Examples 5-9 are as follows: Figure 3 shown.

[0062] Example 10

[0063] The Janus particle modification liquid prepared in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of titanium dioxide, the material to be modified.

[0064] Example 11

[0065] The Janus particle modification liquid prepared in Example 1 was selected, and a similar immersion method as in Example 1 was used to modify the surface of the fluorine-doped tin oxide (FTO) material to be modified.

[0066] Example 12

[0067] The Janus particle modification liquid prepared in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of the polyethylene material to be modified.

[0068] Example 13

[0069] The Janus particle modification liquid prepared in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of the polyimide material to be modified.

[0070] Example 14

[0071] The Janus particle modification liquid prepared in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of the polyetheretherketone (PEEK) material to be modified.

[0072] Example 15

[0073] The Janus particle modification liquid prepared in Example 1 was selected, and a similar soaking method as in Example 1 was used to modify the surface of the polydimethylsiloxane material to be modified.

[0074] The surface-modified materials of Examples 5-15 were tested, and the results are shown in Table 2.

[0075] Table 2

[0076]

[0077]

[0078] Note: For the classification criteria of hydrophobicity and solvent washing stability of the modified surface in Table 2, please refer to Table 1.

[0079] Although specific embodiments of the present invention are described above, those skilled in the art should understand that these are merely examples and that various changes or modifications may be made to the embodiments without departing from the principles and essence of the present invention. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. A method for using tadpole-shaped Janus single-chain particles for material surface modification, characterized in that: The following steps are involved: S1, N,N -dimethylformamide or chloroform as a solvent, preparing tadpole-shaped Janus single-chain particles into a Janus particle modification liquid, wherein the tadpole-shaped Janus single-chain particles contain a non-covalently cross-linked head and a linear molecular chain tail grafted to one side of the head; the tadpole-shaped Janus single-chain particles are obtained by intrachain non-covalent cross-linking of a cross-linkable block in a diblock copolymer, wherein the cross-linkable block in the diblock copolymer has a weight-average molecular weight in the range of 9k-200k, and the non-cross-linkable block in the diblock copolymer has a weight-average molecular weight in the range of 5k-700k; S2. Applying a Janus particle modification liquid to the surface of a material to be modified, the surface of which can interact with the head of the tadpole-shaped Janus single-chain particle, by immersion or spraying, to modify the tadpole-shaped Janus single-chain particle on the surface of the material to be modified, so that the head of the tadpole-shaped Janus single-chain particle non-covalently interacts with the material surface to form a modification layer, and the linear molecular chain tail is located outside the modification layer. The material to be modified is a metal, oxide, plastic, or elastomer that can form one or more of the following interaction modes: hydrogen bond, coordination bond, or ionic bond between the head of the tadpole-shaped Janus single-chain particle and the surface of the material to be modified.

2. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 1, characterized in that: The dispersity index of the polymer molecular weight of the diblock copolymer is below 1.

2.

3. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 2, characterized in that: The tadpole-shaped Janus single-chain particles are obtained by intrachain non-covalent crosslinking of the crosslinkable blocks in the diblock copolymer under the action of a crosslinking agent, and the molar ratio of the crosslinking agent to the repeating unit content of the crosslinkable blocks is controlled at 0.1-1 times.

4. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 3, characterized in that: The cross-linking agent is 1,4-dibromobutane.

5. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 1, characterized in that: The cross-linkable block in the diblock copolymer is poly(4-vinylpyridine); and the non-cross-linkable block in the diblock copolymer is hydrophobic polystyrene.

6. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 1, characterized in that: The concentration of the Janus particle modification solution prepared in step S1 is 0.5-50 g / L, the viscosity is less than 500 mPa·s, and the tadpole-shaped Janus single-chain particles are 5-20 nm and uniform in size.

7. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 1, characterized in that: Before the surface of the material to be modified is modified by the Janus particle modification liquid, the surface is cleaned by plasma or organic solvent.

8. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 1, characterized in that: The material to be modified is a gold sheet, a copper sheet, a silicon sheet, a silicon dioxide sheet, glass, mica, titanium dioxide, indium tin oxide, fluorine-doped tin oxide, polyethylene, polydimethylsiloxane, polyetheretherketone or polyimide.

9. The method for using tadpole-shaped Janus single-chain particles for material surface modification according to claim 1, characterized in that: In step S2, the spraying time range is 5-10 s.

10. The method for modifying the surface of a material using tadpole-shaped Janus single-chain particles according to any one of claims 1 to 9, characterized in that: In step S2, the time range for the modification reaction between the Janus particle modification liquid and the material to be modified is 1-10 minutes.

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