CN111333759A - Preparation method of zwitterionic polymer pattern on surface of solid substrate - Google Patents

Abstract

The invention provides a method for preparing a zwitterionic polymer pattern on the surface of a solid substrate, which mainly includes: cleaning the substrate, grafting an initiator to the substrate, and grafting the zwitterionic polymer to the surface of the substrate by atom transfer radical polymerization to obtain a Zwitterionic polymer micro-nanopatterned solid surface. The zwitterionic polymer layer obtained by this method is a solid surface modified by the zwitterionic polymer prepared by adopting the principle of atom transfer radical polymerization, and has the advantages of good uniformity of the zwitterionic polymer layer, and the layer is resistant to organic pollution and resistance. Biofouling properties, can be used for anti-biological pollution and anti-biological corrosion on the surface of materials.

Description

A kind of preparation method of zwitterionic polymer pattern on the surface of solid substrate

technical field

The invention relates to the technical field of material surface chemistry, in particular to a method for preparing a zwitterionic polymer pattern on the surface of a solid substrate.

Background technique

Zwitterionic polymers are a very important class of macromolecular materials, which range from naturally occurring biopolymers such as proteins and nucleotides to synthetic tackifiers and soaps. Zwitterionic polymers can be roughly divided into the following two categories, one is betaine: that is, there are both anionic and cationic groups on the same monomer unit, such as sulfobetaine, carboxybetaine and Phosphobetaine; the second is polyampholyte, also known as alternating block copolymer, that is, with 1:1 positive and negative charges on different monomer units; the chemical structures of these two types of compounds contain the same amount. The negative and positive charges of the zwitterionic polymer make it electrically neutral as a whole, and due to the combination of electrostatic interactions and hydrogen bonding, the surface of the zwitterionic polymer can form a superhydrophilic polymer with superhydrophilicity and strong resistance to non-specific proteins. water layer.

At present, there are few reports on the preparation of polymer layers on metallic and inorganic non-metallic solid surfaces. For example, it has been reported that the gold substrate modified with 4-nitrobiphenyl-4'-thiol is patterned by electron beam, the nitro group is reduced to an amino group and then reacted with bromoisobutyryl bromide to connect to atom transfer radicals. The initiating group for polymerization, and then N-isopropylacrylamide was polymerized to obtain micro-nanopatterns of thermosensitive poly(N-isopropylacrylamide) polymer brushes; The gold nanoparticle core-shell structure was also prepared by grafting poly(4-vinylpyridine) on the surface of the gold nanoparticle by combining with the surface of the gold nanoparticle by atom transfer radical polymerization. In addition, some people have used RAFT technology to prepare zwitterionic polymer molecular brushes composed of methacrylic acid and dimethylaminoethyl methacrylate on glass substrates, and proved that this zwitterionic polymer molecular layer can improve the performance of glass substrates. Antifouling properties; another example, a random mixture of pre-synthesized [2-(methacryloyloxy)ethyl]-dimethyl-acetic acid-ammonium and p-trimethoxysilylstyrene (9:1) The copolymer is connected to the surface of glass or silicon wafer by alkoxy hydrolysis, and the formed thin layer of zwitterion-containing polymer with a thickness of about 2 nm can effectively inhibit the non-specific adsorption and adhesion of proteins and cells.

Although atom transfer radical polymerization has been used in the production of polymers, and for the modification and modification of micro-nano surfaces, it has not been found that the atom transfer radical polymerization method is used in the in-situ polymerization of metals or inorganic non-metallic materials. The report on the preparation of zwitterionic polymer micro-nano patterns on the surface of solid substrates is novel.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies of the prior art, the present invention provides a method for preparing a zwitterionic polymer pattern on the surface of a solid substrate based on surface-initiated atom transfer radical polymerization technology. The zwitterionic polymer-modified solid surface prepared by the principle of transfer radical polymerization has the advantages of good uniformity of the zwitterionic polymer layer, and the layer has anti-organic pollution and anti-biological pollution properties, which can be used for anti-biological pollution and anti-biological pollution on the surface of the material. Resistant to biological corrosion.

The technical scheme of the present invention is as follows:

A method for preparing a zwitterionic polymer pattern on the surface of a solid substrate, which mainly comprises: cleaning the substrate, grafting an initiator to the substrate, and grafting the zwitterionic polymer to the surface of the substrate by atom transfer radical polymerization to obtain the zwitterionic polymer. Micro-nano patterned solid surface.

The preparation method of the above-mentioned solid substrate surface zwitterionic polymer pattern, the steps are as follows:

(1) Pretreatment of solid substrate surface: cleaning the substrate surface to remove impurities on the surface;

(2) Introducing the pattern of the initiator into the surface of the substrate by micro-contact printing: First, the patterned silicone stamp carries a solution of a specific structure initiator with an atom transfer radical polymerization initiating group at the end, and after volatilizing the solvent, a certain amount of The pressure transfers the pattern of the initiator to the surface of the substrate, and forms an initiator layer on the surface through relatively stable chemical adsorption bonds or covalent bonds;

(3) Polymerization reaction of zwitterionic polymer monomer on the surface of metal substrate: The solid substrate printed with initiator is placed in a polymerization reaction system containing zwitterionic polymer monomer, sacrificial initiator, catalyst, co-catalyst and solvent , the polymerization reaction occurs under certain conditions;

(4) Surface cleaning of the solid substrate carrying the pattern: after the reaction, the surface of the solid substrate is repeatedly cleaned with deionized water to remove the solvent, catalyst and co-catalyst, etc., and retain the polymer layer.

In this application, an initiator is used to immobilize a solid surface, and then the solid surface is placed in a solution containing zwitterionic monomers, and a polymer layer is formed on the surface by in-situ growth using atom transfer radical polymerization technology; Principle transfer radical polymerization technology for zwitterionic compounds The products obtained by the atom transfer radical polymerization principle have the characteristics of good molecular weight uniformity, and the obtained polymer layer should be more uniform.

Preferably, in step (1), a cleaning agent is used to clean the surface of the solid substrate to remove impurities and organic pollutants on the surface; the solids include metal solids or inorganic non-metallic solids.

Preferably, the metal solid refers to gold, silver, copper, iron, zinc, lead and other solids that can form relatively stable metal-sulfur bonds with thiols; the inorganic non-metal refers to solids containing or carrying hydroxyl groups on the surface or Inorganic non-metallic solids that can generate hydroxyl groups on the surface after acid-base treatment.

Preferably, the metal solids include metal hydroxides, mixed metal hydroxides or metal oxides; the inorganic non-metallic solids include metal hydroxides, mixed metal hydroxides or metal oxides, such as silicon wafers, Silica, glass, metal solid oxides or solid oxo acid salts.

Preferably, the silica is crystalline quartz and/or amorphous silica solid; the metal solid oxide is ferric oxide or alumina, etc.; the solid oxo acid salt is silicate, carbonate or Phosphate etc.

Preferably, in step (2), the initiator refers to an initiator with a specific structure at the end with an atom transfer radical polymerization initiating group and a group connected to the solid surface; wherein, the atom transfer radical polymerization initiates The group is bromoisobutyramide or bromoisobutyryloxy, etc.; the group connected to the surface of the metal substrate is a sulfhydryl group, which can react with the metal substrate to form a metal-sulfur bond to realize the connection; and the surface of an inorganic non-metallic solid The connecting group is an alkoxysilane, which can condense the Si-OH formed by the hydrolysis of the alkoxy group with the hydroxyl group on the solid surface to form a covalent bond between the initiator and the surface of the inorganic non-metallic solid substrate; two functional groups Linked by alkyl chains of different lengths, the number of carbon atoms in the alkyl chain varies from 2 to 18.

Preferably, the alkoxysilane includes trimethoxysilane or triethoxysilane.

Preferably, in step (2), the shape and size of the pattern are determined by the pattern of the silicone seal, including long strips, squares, circles, etc., as well as full coverage; the imprinting induces The optimized conditions of the agent pattern are that the concentration of the initiator is 0.1-2.5 mmol/L, the applied pressure is 0.1-1 kPa, and the imprinting time is 0.5-10 h.

Preferably, in step (3), the zwitterionic polymer monomer, including the part containing double bonds in the structure, includes acrylates, methacrylates or acrylamides, etc., and the zwitterionic part in the structure is Betaines, including sulfobetaine, carboxybetaine and phosphobetaine, etc.

Preferably, in step (3), the polymerization reaction conditions are as follows: the solvent is a mixture of water and alcohol with a volume ratio of 0.05-0.5, the monomer concentration is 1-3 mol/L, the reaction temperature is 10-50 °C, and the reaction time is 5-24 h ; Wherein, the sacrificial initiator concentration is 0.08-0.15mol/L, the catalyst concentration is 0.08-0.12mol/L, and the co-catalyst concentration is 0.3-0.9mol/L; wherein, the sacrificial initiator involved is 2-bromo-2 - Ethyl methylpropionate, etc., the catalyst is CuBr, etc., the co-catalyst is pentamethyldiethylenetriamine, etc., and the alcohol in the mixed solvent is methanol, ethanol or isopropanol, etc.

Compared with the prior art, the beneficial effects of the present invention are:

The biofouling resistance of zwitterionic polymers makes them widely used in related fields such as biomedical materials. The invention prepares micro-scale or nano-scale zwitterionic polymer patterns with specific design on the surface of solid substrate, which can change the adsorption behavior of the substrate surface and adjust the surface properties of the metal substrate, such as wettability, anti-pollution, corrosion resistance and Thermal stability, etc., can be used for anti-pollution, anti-corrosion, etc. In addition, zwitterionic polymer patterns can be used for laboratory studies on biofouling, corrosion resistance, etc.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. In other words, other drawings can also be obtained based on these drawings without creative labor.

FIG. 1 is a schematic diagram of the preparation process of the zwitterionic polymer pattern on the surface of the gold sheet.

FIG. 2 is a schematic diagram of the preparation process of the zwitterionic polymer pattern on the surface of the glass sheet.

Figure 3 is a 1H NMR spectrum (A) of a zwitterionic polymer.

Figure 4 is an infrared spectrum (B) of the zwitterionic polymer.

FIG. 5 is an optical microscope photograph of the gold flakes modified by initiator (A).

FIG. 6 is an optical microscope photograph of the zwitterionic polymer (B) modified gold sheet.

Fig. 7 is an optical microscope photograph of the initiator (A) modified glass sheet.

FIG. 8 is an optical microscope photograph of a glass sheet modified with zwitterionic polymer (B).

FIG. 9 is two-dimensional (A) and three-dimensional (B) atomic force microscope photographs of zwitterionic polymer-modified gold flakes and thickness analysis images (C, D) of surface polymer patterns.

Figure 10 is two-dimensional (A) and three-dimensional (B) atomic force microscope photographs of zwitterionic polymer-modified glass sheets and thickness analysis images (C, D) of surface polymer patterns.

Detailed ways

In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

1, 3, 4, 5, 6 and 9, this embodiment is described in detail; in this embodiment, a gold-plated silicon wafer is selected as the gold wafer substrate, and 2-(2-bromoisobutyryl is selected Oxy) undecyl mercaptan is an initiator with special structure, and [3-(methacrylamido)propyl]dimethyl-(3-propylsulfonic acid) ammonium monomer was selected to prepare polymer on gold surface. The pattern of [3-(methacrylamido)propyl]dimethyl-(3-propylsulfonic acid)ammonium zwitterionic polymer was characterized, and the schematic diagram of the preparation process is shown in Figure 1.

(1) Pretreatment of metal substrates

Soak a 10mm×8mm gold-plated silicon wafer in a lotion prepared with concentrated sulfuric acid and hydrogen peroxide with a volume ratio of 3:1, soak it for 1 hour, take it out, rinse it with deionized water, and blow dry;

(2) Microcontact printing of metal substrate surface to obtain initiator pattern

Initiator solution: The specific configuration process is to take 353.36 mg of 2-(2-bromoisobutyryloxy)undecyl mercaptan and dissolve in 500 mL of dichloromethane solution to obtain a solution with a concentration of 2 mmol/L.

Take 20 μL of the above-mentioned initiator solution and drop it on the stamp (the size of the stamp is 5mm×4mm) printed with the pattern. After the solvent is evaporated, the stamp is covered on the substrate processed in step (1), and the load is about 1.5g. Heavy objects, stamped for 6h;

(3) Polymerization of zwitterionic monomers

Put 57.2 mg of CuBr and 1.46 g of [3-(methacrylamido)propyl] dimethyl-(3-propylsulfonic acid) ammonium monomer into a 50 mL Schlenk bottle, and place the one obtained in step (2) printed with The gold-plated silicon wafer with the initiator pattern is put into the reaction system, vacuumized, and nitrogen is passed through, and the operation is repeated 4 times to remove oxygen in the reaction system;

Take 1mL of ultrapure water, 2mL of isopropanol, and 0.5mL of pentamethyldiethylenetriamine into a sample bottle of about 10mL, bubble with nitrogen for 20 minutes (discharge the oxygen in the solution), and use a syringe to take the sample bottle The liquid in the reaction system was injected into the reaction system in the Schlenk bottle, and the monomer was dissolved under stirring; then, 60 μL of the initiator 2-(2-bromoisobutyryloxy)undecyl mercaptan and 1 mL of isopropanol were added to the sample bottle In the process, the reaction system in the Schlenk bottle was also injected into the Schlenk bottle with a syringe after bubbling with nitrogen for 20 minutes; finally, the reaction temperature was set at 50 ° C, and the reaction was stirred for 24 h;

(4) Post-processing and characterization

After the reaction, open the Schlenk reaction flask, take out the gold piece, rinse it with deionized water, and use it for subsequent testing; the remaining reaction solution is dialyzed with a dialysis bag (Mw3500) to remove the solvent, catalyst, co-catalyst, etc., and collect the dialysis bag. The polymer obtained by the polymerization initiated by the sacrificial initiator was characterized by nuclear magnetic resonance and infrared spectroscopy. The results are shown in Figures 3 and 4.

Example 2

2, 3, 4, 7, 8 and 10, this embodiment will be described in detail; in this embodiment, a glass sheet is selected as the inorganic non-metallic solid substrate, and 3-(2-bromoiso Butyamido)propyl-triethoxysilane was used as initiator, and [3-(methacrylamido)propyl]dimethyl-(3-propylsulfonic acid) ammonium monomer was selected to prepare on the surface of glass sheet The poly[3-(methacrylamido)propyl]dimethyl-(3-propylsulfonic acid)ammonium zwitterionic polymer pattern was patterned and characterized; the schematic diagram of the preparation process is shown in Figure 2.

(1) Pretreatment of solid substrates

Soak a 10mm×8mm glass piece in a lotion prepared with concentrated sulfuric acid and hydrogen peroxide with a volume ratio of 3:1, soak it for 1 hour, take it out, rinse it with deionized water, and blow dry; then put the glass piece in 10mmol Soak in sulfuric acid for 30min/L for acidification treatment, take out and blow dry;

(2) Grafting of substrate surface initiators

Initiator solution: the specific configuration process is to take 370.4mg of 3-(2-bromoisobutyrylamido)propyl-triethoxysilane and add it to 500ml of absolute ethanol to obtain (2mmol/L) initiator solution .

Take 20 μL of the above initiator solution and drop it on the stamp (5mm×4mm) printed with the pattern. After the solvent has evaporated, cover the stamp on the treated glass sheet, load about 1.5g of weight, and imprint for 6h;

(3) Polymerization of zwitterionic monomers

Put 57.2mg CuBr, 1.46g [3-(methacrylamido)propyl]dimethyl-(3-propylsulfonic acid) ammonium monomer into a 50ml Schlenk bottle, and place the obtained in step (2) printed with The glass sheet of the initiator pattern is put into the reaction system, and the operation is repeated 3 times by vacuuming and passing nitrogen to remove the oxygen in the reaction system;

Take 1mL of ultrapure water, 2mL of isopropanol, and 0.5mL of pentamethyldiethylenetriamine into a 10mL sample bottle, and bubble with nitrogen for 20 minutes (to discharge the oxygen in the solution); take the sample bottle with a syringe The liquid was injected into the reaction system in the Schlenk bottle, and the monomer was dissolved under stirring; then, 60 μL of 2-(2-bromoisobutyryloxy)undecylthiol (sacrificial initiator) and 1 mL of isopropanol were added into the sample bottle, bubbling with nitrogen for 20 minutes, and then injecting it into the reaction system in the Schlenk bottle with a syringe; then, set the reaction temperature at 50 °C, and stir the reaction for 24 hours;

(4) Post-processing and characterization

After the reaction, open the Schlenk reaction flask, take out the glass piece, rinse it with deionized water, and use it for characterization; the remaining reaction solution is dialyzed with a dialysis bag (Mw3500) to remove the solvent, catalyst, co-catalyst, etc. The polymer obtained by sacrificing the initiator to initiate polymerization was characterized by nuclear magnetic resonance and infrared spectroscopy, and the results were consistent with the data in Example 1.

Although the present invention has been described in detail with reference to the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, those of ordinary skill in the art can make various equivalent modifications or replacements to the embodiments of the present invention, and these modifications or replacements should be included within the protection scope of the present invention . Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. A method for preparing a zwitterionic polymer pattern on the surface of a solid substrate is characterized by mainly comprising the following steps: substrate cleaning, substrate grafting initiator, and grafting the zwitterionic polymer to the surface of the substrate through atom transfer radical polymerization to obtain a solid surface with the zwitterionic polymer micro-nano pattern.

2. The method for preparing the zwitterionic polymer pattern on the surface of the solid substrate according to claim 1, characterized by comprising the following specific steps:

(1) pretreatment of the surface of the solid substrate: cleaning the surface of the substrate to remove impurities on the surface;

(2) introducing a pattern of initiator to the substrate surface by microcontact printing: firstly, carrying a solution of an initiator with a specific structure and an end of which is an atom transfer radical polymerization initiation group on an organic silicon seal with a pattern, volatilizing a solvent, transferring the pattern of the initiator to the surface of a substrate at a certain pressure, and forming an initiator layer on the surface by combining a relatively stable chemical adsorption bond or a covalent bond;

(3) polymerization of zwitterionic polymer monomer on the surface of a metal substrate: placing the solid substrate printed with the initiator in a polymerization reaction system containing a zwitterionic polymer monomer, a sacrificial initiator, a catalyst, a cocatalyst and a solvent, and carrying out polymerization reaction under certain conditions;

(4) surface cleaning of solid substrates carrying patterns: after the reaction is finished, the surface of the solid substrate is repeatedly cleaned by deionized water, the solvent, the catalyst, the cocatalyst and the like are removed, and the polymer layer is reserved.

3. The method for preparing the zwitterionic polymer pattern on the surface of the solid substrate according to claim 2, wherein in the step (1), the surface of the solid substrate is cleaned by a cleaning agent, and the solid comprises metal solid or inorganic non-metal solid.

4. The method for preparing the zwitterionic polymer pattern on the surface of the solid substrate according to claim 3, wherein the metal solid is gold, silver, copper, iron, zinc, lead and other solids capable of forming relatively stable metal sulfur bonds with thiol; the inorganic nonmetal refers to solid with or carrying hydroxyl on the surface or inorganic nonmetal solid with hydroxyl on the surface after acid and alkali treatment.

5. The method of preparing the zwitterionic polymer pattern according to claim 4, wherein the metal solid comprises a metal hydroxide, mixed metal hydroxide or metal oxide; the inorganic non-metallic solid comprises a metal hydroxide, a mixed metal hydroxide or a metal oxide, such as silicon wafer, silica, glass, a metal solid oxide or a solid oxysalt.

6. The method of claim 5, wherein the silica is crystalline quartz and/or amorphous silica solid; the metal solid oxide is ferric oxide or aluminum oxide; the solid oxysalt is silicate, carbonate or phosphate, etc.

7. The method for preparing zwitterionic polymer patterns on the surface of a solid substrate according to any one of claims 2-6, characterized in that in step (2), the initiator refers to an initiator having a specific structure with atom transfer radical polymerization initiating groups at the ends and groups attached to the solid surface; wherein, the atom transfer free radical polymerization initiating group is bromo-isobutanoylamino or bromo-isobutanoyloxy, etc.; the group connected with the surface of the metal substrate is sulfydryl; the group connected with the surface of the inorganic nonmetallic solid is alkoxy silane; the two functional groups are connected by alkyl chains of different lengths, the number of carbon atoms in the alkyl chain varying from 2 to 18.

8. The method of claim 7, wherein the alkoxysilane comprises trimethoxysilane or triethoxysilane.

9. The method for preparing zwitterionic polymer patterns on surface of solid substrate according to claim 8, characterized in that in step (2), said patterns, the shape and size of which are determined by the pattern style of silicone stamp, including stripes, squares, circles, etc., and also including full-face coverage; the optimized condition of the imprinting initiator pattern is that the concentration of the initiator is 0.1-2.5mmol/L, the applied pressure is 0.1-1kPa, and the imprinting time is 0.5-10 h.

10. The method for preparing the zwitterionic polymer pattern on the surface of the solid substrate according to claim 9, wherein in the step (3), the zwitterionic polymer monomer comprises a part containing double bonds in the structure, such as acrylate, methacrylate or acrylamide, and the like, and the zwitterionic part in the structure is betaine, such as sulfobetaine, carboxylic betaine, phosphoric betaine, and the like; polymerization conditions: the solvent is a mixture of water and alcohol with the volume ratio of 0.05-0.5, the monomer concentration is 1-3mol/L, the reaction temperature is 10-50 ℃, and the reaction time is 5-24 h; wherein, the concentration of the sacrificial initiator is 0.08-0.15mol/L, the concentration of the catalyst is 0.08-0.12mol/L, and the concentration of the cocatalyst is 0.3-0.9 mol/L; the sacrificial initiator is ethyl 2-bromo-2-methylpropionate, the catalyst is CuBr, the cocatalyst is pentamethyldiethylenetriamine, and the alcohol in the mixed solvent is methanol, ethanol or isopropanol.

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