CN111777909A

CN111777909A - Preparation method of universal functional polymer coating

Info

Publication number: CN111777909A
Application number: CN202010675136.8A
Authority: CN
Inventors: 杨晋涛; 毛世华; 何晓敏; 王晓宇; 钟明强; 陈枫; 范萍
Original assignee: Zhejiang University of Technology ZJUT
Current assignee: Zhejiang University of Technology ZJUT
Priority date: 2020-07-14
Filing date: 2020-07-14
Publication date: 2020-10-16

Abstract

The invention relates to the technical field of polymer coatings, and discloses a preparation method of a universal functional polymer coating, which comprises the following steps: (1) carrying out hydroxylation or amination treatment on the matrix; (2) polymerizing a functional monomer and GMA free radical to obtain a functional polymer; (3) and (2) placing the substrate treated in the step (1) in the solution of the functional polymer for reaction to realize surface functionalization of the substrate. The invention utilizes the epoxy ring-opening reaction to anchor the functional polymer on any substrate, does not need to consider the material or surface property of the substrate, can realize the surface functionalization of the substrate through a simple process and endows the substrate with various functions on the surface.

Description

Preparation method of universal functional polymer coating

Technical Field

The invention relates to the technical field of polymer coatings, in particular to a preparation method of a universal functional polymer coating.

Background

It is known that most stimuli-responsive polymers exhibit a transition from a disordered helical conformation to a more ordered conformation (e.g., arrangement and organization of the polymer chains, formation of secondary structures, further crystallization) is an intrinsic cause of property changes that achieve a wide variety of desired properties (e.g., physical, chemical, mechanical, electromagnetic, electronic, and biological properties) and at temperature, ionic strength, chemical or biological analytes, electric fields, light of different wavelengths, and other reversible or irreversible external stimuli. Intuitively, surface functionalization of reactive polymers is considered a common strategy for achieving reactive polymer films and coatings.

There are two types of surface functionalization strategies, namely chemical anchoring and physical adsorption. There are a variety of ways to anchor irritating polymers to surfaces and to embody their stimulus responsiveness, including surface Atom Transfer Radical Polymerization (ATRP), catechol derivative co-deposition, thiol-double bond click compounds and diels-alder reactions.

CN106833602A discloses an ATRP functional modified proppant and a preparation method thereof, wherein the method comprises the following steps: 1) selecting an initiator to perform surface modification on the proppant, 2) selecting a monomer with functional groups, and performing reaction grafting on the surface of the proppant by an Atom Transfer Radical Polymerization (ATRP) method by using a catalyst and a ligand at a certain temperature and under a proper condition for a certain time to obtain the functional polymer chain with the functionalized properties of hydrophobicity, temperature control, pH sensitivity, reactivity and the like.

Chemical anchoring strategies require pre-modification of the surface with an initiator to effect polymerization, but higher grafting densities and stronger surface adhesion are more easily achieved.

Physical adsorption is simple and easy to implement, such as host-guest interaction, layer-by-layer self-assembly, supramolecular interaction, metal coordination interaction and the like, but due to the inherent property of interfacial physical bonds, weaker and unstable polymer coatings often exist on the surface. Such as dopamine and its derivatives inspired by marine mussels, which researchers have conducted extensive research and use.

CN107629461A discloses a high-efficiency modification and functionalization means for an inert surface, and the method firstly realizes dopamine polymerization on the surface of a substance to be treated to generate a layer of compact polydopamine film. Then, silane coupling molecules or functional inorganic particles are introduced by taking the functional group of dopamine as a reaction site. The problems that surface treatment of surface inert substances such as novel two-dimensional materials (graphene and boron nitride), metals (stainless steel and copper plates), carbon fibers and the like is difficult, the mechanical strength of an interface after the surface inert substances are compounded and molded with polymers is low and the like are solved.

But the surface adhesion of the polymer coating is generally weak due to the physical adhesion properties of the dopamine inducing polymer on the surface. Even minor external environmental changes (e.g., ultrasound, acidic solutions) can cause the dopa-based coating to peel off the surface.

Thus, the development of a functional coating that is simple and efficient to produce and can be applied to any substrate would suggest a new versatile coating and functionalization process that can attach a variety of polymers to any surface without concern for the chemical nature or material characteristics of the surface, which provides a new range of impacts in a wide range of surface coating and engineering applications.

Disclosure of Invention

The invention aims to solve the problem that in the prior art, a functional polymer is anchored on any matrix by utilizing an epoxy ring-opening reaction to realize surface functionalization of the matrix.

In order to achieve the purpose, the invention adopts the technical scheme that:

a method for preparing a versatile functional polymer coating, comprising the steps of:

(1) carrying out hydroxylation or amination treatment on the matrix;

(2) polymerizing a functional monomer and (methyl methacrylate) GMA free radical to obtain a functional polymer;

(3) and (2) placing the substrate treated in the step (1) in the solution of the functional polymer for reaction to realize surface functionalization of the substrate.

The invention utilizes simple epoxy ring-opening reaction, firstly carries out hydroxylation or amination treatment on the matrix, leads the surface of the matrix to be provided with hydroxyl functional groups or amino functional groups and increases the surface activity; and polymerizing a functional monomer to be functionalized with GMA free radicals to enable the functional polymer to have an epoxy functional group, and finally reacting with hydroxyl or amino on the surface of the substrate to anchor the functional polymer on the surface of the substrate, thereby realizing the functionalization of the surface of the substrate.

The greatest advantage of the invention is that the surface functionalization can be realized without limiting the type of the substrate and without concern for the chemical nature or the type of the material of the substrate surface, including but not limited to ceramic materials, metallic materials or plastics.

The hydroxylation treatment in the step (1) is to carry out plasma treatment on the substrate; the treatment time is 1-5 min, and the purpose is to hydroxylate the surface.

Before plasma treatment, Piranha solution (Piranha) can be used for treating the matrix, for example, ultrasonic treatment is carried out for 10-60 min at 100-140 ℃, and the surface treatment effect is improved.

The amination treatment is to soak the substrate in a dilute solution of an amino alkyl silane coupling agent.

The aminoalkyl silane coupling agent comprises one or more of amino n-propyl trimethoxy siloxane, gamma-aminopropyl trimethoxy silane, gamma- (B-aminoethyl) aminopropyl trimethoxy silane and the like.

The volume concentration of the aminoalkyl silane coupling agent in the dilute solution is 10-20 mL/mL. The concentration of the silane coupling agent is not easy to be too high or too high, the silane coupling agent is condensed when the concentration is too high, and the surface amino group is too small to be connected with the functional polymer when the concentration is too low.

The functional monomer comprises a monomer with a sterilization function, a pH response function, a fluorescence function, a temperature response function, a salt response function or a functional double bond;

specifically, the monomer may include methacryloyloxyethyltrimethyl ammonium chloride (METAC) having a bactericidal function, dimethylaminoethyl methacrylate (DMAEMA) having a pH response function, methacrylic acid (MAA), fluorescent monomers PyMA, NDBCB, SPMA and the like, N-isopropylacrylamide (NIPAM) having a temperature response function, dimethyl- (4-vinylphenyl) ammonio propanesulfonate inner salt (DVBAPS) having a salt response function, and monomers having a functional double bond such as hydroxyethyl methacrylate (HEMA), N-Hydroxyethylacrylamide (HEAA), sulfobetaine methacrylate (SBMA), carboxybetaine methyl methacrylate (CBMA), polyethylene glycol methacrylate (POEGMA) and the like.

Preferably, the functional monomer is any one or more of METAC, DMAEMA, SPMA, NIPAM, DVBAPS, SBMA, POEGMA.

The reaction temperature of the free radical polymerization in the step (2) is between 50 and 70 ℃, and the reaction time is 5 to 7 hours; the molar ratio of the functional monomer to GMA is 2-6: 1, preferably, the molar ratio of the functional monomer to the GMA is 4: 1. If the content of GMA is too much, the functional performance of the functional polymer is reduced, and the required requirements cannot be met; if the GMA content is too low, a small amount of polymer anchoring will result, and the functional properties will also be reduced, so that controlling the ratio of the two has a very important effect on the functional effect of the coating.

The radical polymerization in step (2) is carried out by using a common initiator, such as Azobisisobutyronitrile (AIBN), and the addition amount of the initiator is the common amount for the radical polymerization by a person skilled in the art.

In the step (3), the reaction temperature is 60-80 ℃, and the reaction time is 6-24 hours; the concentration of the functional polymer in the solution of the functional polymer is 5-10 mg/mL. Too high a temperature or too high a concentration can lead to a implosion of the reaction, and too low a temperature or too low a concentration can lead to too slow or even no reaction.

In the step (3), triethylamine is included in the reaction process, and the volume ratio of the triethylamine to the functional polymer solution is 0.5-1.5: 10. The triethylamine is used as a catalyst for the reaction of the functional polymer and the amino or hydroxyl on the surface of the matrix, so that the reaction efficiency is improved, and the functionalization effect of the surface of the matrix is improved.

Compared with the prior art, the invention has the following beneficial effects:

(1) the method of the invention does not need to consider the material or surface property of the substrate, and can be generally used on any substrate, including the surfaces of materials such as ceramics, plastics, metals and the like;

(2) the method has simple process, adopts simple epoxy ring-opening reaction to anchor on the matrix, can modify polymers with various functions on the surface of the material, endows the surface of the matrix with various functions, including antibacterial property, temperature responsiveness, pH responsiveness, hydrophilicity and the like, and has wide application range.

Drawings

FIG. 1 is a schematic diagram of a process for preparing a functional polymer coating according to the present invention.

FIG. 2 is a graph of the bactericidal properties of the polymer matrix of example 1 anchored Poly (GMA-co-METAC).

FIG. 3 is a graph of the temperature response performance of the polymer matrix of the anchored poly (GMA-co-NIPAM) of example 2.

FIG. 4 is a graph of pH response performance of the anchoring poly (GMA-co-DMAEMA) polymer matrix of example 3.

FIG. 5 is a graph of the salt response performance of the anchored poly (GMA-co-DVBAPS) polymer matrix of example 4.

FIG. 6 is the release rate of E.coli and S.aureus in response from the matrices of examples 2, 3, 4.

FIG. 7 is a graph showing the antifouling property of the surface of the substrate of the anchoring polymer in example 5 in 24 to 120 hours.

FIG. 8 is a graph of the surface anti-fouling performance of a substrate without any surface functionalization at 24 h.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Those skilled in the art should understand that they can make modifications and equivalents without departing from the spirit and scope of the present invention, and all such modifications and equivalents are intended to be included within the scope of the present invention.

As shown in fig. 1, the preparation process of the functional polymer coating of the present invention is schematically illustrated, and the functionalization of the substrate surface is achieved by hydroxylation or amination of the substrate surface and then reaction with the functional polymer. In the following embodiments, a silicon wafer is used as a base material, and surface hydroxylation or surface amination treatment is firstly carried out on the surface of the silicon wafer, so that the subsequent reaction with a functional polymer is facilitated;

surface hydroxylation: the silicon wafers were subjected to a reaction in a Piranha solution (H)₂SO₄/H₂O₂Cleaning the silicon wafer at 120 ℃ for 0.5h in a (V/V) ═ 3:1) manner, cleaning the silicon wafer with deionized water, drying the silicon wafer with nitrogen, and treating the cleaned silicon wafer with plasma for 2 min.

Surface amination: the silicon chip is placed in an ethanol solution (15mL/1mL) dissolved with amino n-propyl trimethoxy siloxane, and after shaking reaction for 2 hours at room temperature, the silicon chip is washed by ethanol and deionized water respectively and dried.

EXAMPLE 1 preparation of antimicrobial surfaces

Dissolving 4.2g of monomer methacryloyloxyethyl trimethyl ammonium chloride and 0.7g of glycidyl methacrylate in 5mL of mixed solvent (methanol/deionized water (V/V) ═ 1:1), stirring and blowing nitrogen for 30 minutes after 0.008g of initiator AIBN, reacting for 5 hours at 65 ℃, introducing air into the reaction and placing the reaction in ice water to terminate the reaction after the reaction is finished, and finally performing ether precipitation, centrifugal separation and vacuum oven drying to obtain a white powdery product poly (GMA-co-METAC).

Dissolving 0.1g of poly (GMA-co-METAC) in 10mL of deionized water to prepare a reaction solution of 10mg/mL, then placing the substrate subjected to surface amination treatment in the reaction solution, adding 1mL of triethylamine solution, uniformly mixing, placing the mixture in an oil bath kettle, reacting for 12 hours at 80 ℃, and after the reaction is finished, cleaning the surface of the material with deionized water and drying the material by blowing.

Example 2: preparation of temperature responsive surface

4.5g of monomer N-isopropylacrylamide and 1.4g of glycidyl methacrylate are dissolved in 10mL of dimethyl sulfoxide, 0.008g of initiator AIBN is added, stirring and nitrogen blowing are carried out for 30 minutes, the reaction is carried out for 6 hours at the temperature of 60 ℃, after the reaction is finished, a dialysis bag with the molecular weight of 3500 is used for dialysis for 3 days, and then freeze drying is carried out, so as to obtain poly (GMA-co-NIPAM) polymer.

Dissolving 0.1g of poly (GMA-co-NIPAM) in 10mL of dimethyl sulfoxide to prepare a reaction solution of 10mg/mL, then placing a substrate with hydroxylated surface into the reaction solution, adding 1mL of triethylamine solution, mixing uniformly, placing the mixture into an oil bath kettle, reacting for 12 hours at 80 ℃, and after the reaction is finished, cleaning the surface of the material with deionized water and drying the material by blowing.

Example 3: preparation of pH responsive surfaces

6.28g of monomer dimethylaminoethyl methacrylate and 1.4g of monomer glycidyl methacrylate are dissolved in 10mL of dimethyl sulfoxide, 0.008g of initiator AIBN is added, stirring and nitrogen blowing are carried out for 30 minutes, the reaction is carried out for 6 hours at the temperature of 60 ℃, after the reaction is finished, a dialysis bag with the molecular weight of 3500 is used for dialysis for 3 days, and then freeze drying is carried out, so as to obtain poly (GMA-co-DMAEMA) polymer.

0.1g of poly (GMA-co-DMAEMA) is dissolved in 10mL of dimethyl sulfoxide to prepare a reaction solution of 10mg/mL, then the substrate with aminated surface is placed in the reaction solution, 1mL of triethylamine solution is added to be mixed uniformly, the mixture is placed in an oil bath pot to react for 12 hours at 80 ℃, and after the reaction is finished, the surface of the material is cleaned by deionized water and dried by blowing.

Example 4: preparation of salt-responsive surfaces

DVBAPS monomer (1.425g, 5mmol) and GMA monomer (glycidyl methacrylate) (0.175g, 2.5mmol) were dissolved in a round bottom flask (50mL ca.) with 10mL mixed solution (TFE (trifluoroethanol)/deionized water (V/V) ═ 1:1) and mixed well with stirring for 10 min. The mixed solution was then sealed with nitrogen bubbling for 15 minutes, and the initiator potassium persulfate (0.008g) was added to the mixed solution and dissolved with stirring for another 15 minutes. (may be added together and then directly sparged with nitrogen for 15min) the reaction flask was placed in a water bath and heated to 60 ℃ for 6 hours. After the reaction was complete, the reaction flask was vented and placed in an ice-water bath to terminate the reaction. The reaction product was then added to an ethanol solution (volume ratio 1:1, i.e., 15mL:15mL) to obtain a viscous solid precipitate, and the polymer was purified by centrifugation (8000r/min 5 min). Finally, the mixture is put into a vacuum oven to be dried to obtain transparent polymer poly (GMA-co-DVBAPS).

0.1g of poly (GMA-co-DVBAPS) is dissolved in 10mL of mixed solution of water and trifluoroethanol (V: V is 1:1) to prepare 10mg/mL of reaction solution, then the substrate with the hydroxylated or aminated surface is placed in the reaction solution, 1mL of triethylamine solution is added and mixed uniformly, the mixture is placed in an oil bath pot to react for 12 hours at the temperature of 80 ℃, and after the reaction is finished, the surface of the material is cleaned by deionized water and dried by blowing.

Example 5: preparation of an antifouling surface

Dissolving 4.56g of monomer methacrylic acid sulfobetaine and 0.52g of monomer glycidyl methacrylate in 10mL of dimethyl sulfoxide, adding 0.008g of initiator AIBN, stirring and blowing nitrogen for 30 minutes, reacting for 6 hours at 60 ℃, dialyzing for 3 days by using a dialysis bag with 3500 molecular weight after the reaction is finished, and then freeze-drying to obtain poly (GMA-co-SBMA) polymer.

Dissolving 0.1g of poly (GMA-co-SBMA) in 10mL of dimethyl sulfoxide to prepare a reaction solution of 10mg/mL, then placing the matrix with the hydroxylated surface into the reaction solution, adding 1mL of triethylamine solution, uniformly mixing, placing the mixture into an oil bath kettle, reacting for 12 hours at 80 ℃, and after the reaction is finished, cleaning the surface of the material with deionized water and drying the material by blowing.

Performance testing

Coli (gram negative bacteria) and staphylococcus aureus (gram positive bacteria) are used for testing the antifouling, bactericidal and regeneration performances of the polymer surface. Both bacteria were first incubated overnight on Luria-Bertani (LB) agar medium at 37 ℃ and bacterial colonies on the plates were inoculated into 40mL of LB medium and shaken for 10h at 37 ℃. The bacterial solution was diluted with pure LB to a diluted bacterial solution with OD values of 0.1 for E.coli and 0.05 for S.aureus, respectively. For antimicrobial assays, the polymer brush was sterilized with a 75% ethanol solution and rinsed with PBS before being placed in a 12-well sterile plate. Subsequently, 3mL of the bacterial suspension was added to the wells and incubated at 37 ℃ for a predetermined time (24 h for E.coli and 12h for S.aureus) at 100 rpm. After the incubation was completed, the sample was divided into two parts. The samples for testing release characteristics were placed in 1M NaCl solution and shaken gently for 10 minutes, then all samples were washed 3 times with sterile PBS and placed in the dark using LIVE/DEAD Back light visualization Kit (Thermo Fisher Scientific Inc.) for 15 minutes, rinsed with sterile PBS, and then viewed using an Axio Observer model A1 inverted fluorescence microscope.

The sterilization performance is as follows: the substrate anchored with Poly (GMA-co-METAC) polymer prepared in example 1 was tested for sterilization performance, and as a result, as shown in fig. 2, it was found that the surface of the substrate had good sterilization performance with a sterilization rate of about 95%.

Temperature response performance: temperature response tests were performed on the substrate of example 2, which was anchored with poly (GMA-co-NIPAM) polymer, and the substrate of example 2 was tested for bacterial density at different temperatures (4 ℃ and 40 ℃), and as a result, as shown in FIG. 3, it was found that the substrate had good temperature response to both E.coli and S.aureus.

pH response performance: the pH response test was performed on the poly (GMA-co-DMAEMA) anchored polymer matrix of example 3. The bacterial densities of the matrix at different pH (pH 1.0 and pH 12.0) were tested, and the results are shown in fig. 4, where the matrix surface was seen to have distinct pH response properties, and at different pH, the densities of escherichia coli and staphylococcus aureus on the matrix surface were distinct.

Salt response performance: salt response test is carried out on the substrate of the polymer anchoring poly (GMA-co-DVBAPS) in example 4, and the bacterial densities of the substrate under water and under salt are respectively tested, and the result is shown in FIG. 5.

Fig. 6 shows that the release rates of escherichia coli (e.coli) and staphylococcus aureus (s.aureus) in the response of examples 2, 3 and 4 are both substantially above 80%, and the response effect is very good.

Long-term antifouling property: the surface of the substrate of example 5, which was anchored with poly (GMA-co-SBMA) polymer, was tested for long-term antifouling performance, with incubation times of 120h and 72h for E.coli (OD value: 0.1) and S.aureus (OD value: 0.05) as one cycle, respectively. Thereafter, the surface of the substrate prepared in example 5 was stained according to the above staining procedure, and the antibacterial assay thereof was examined, and the result is shown in fig. 7. The antifouling performance was tested by using a substrate without any surface functionalization as a control, and at 24h, the surface bacteria condition is shown in fig. 8, and the substrate prepared in example 5 is very excellent in long-term antifouling performance, and the bacterial species density on the inner surface is very low in 72h, which is much better than that in fig. 8 without any surface functionalization.

Claims

1. A method for preparing a universal functional polymer coating, comprising the steps of:

(1) carrying out hydroxylation or amination treatment on the matrix;

(2) polymerizing a functional monomer and GMA free radical to obtain a functional polymer;

2. The method as claimed in claim 1, wherein the substrate is made of a ceramic material, a metallic material or a plastic material.

3. The method of claim 1, wherein the hydroxylation is plasma treating the substrate.

4. The method of claim 1, wherein the amination step comprises immersing the substrate in a dilute solution of an aminoalkyl silane coupling agent.

5. The method for preparing a functional polymer coating as claimed in claim 4, wherein the aminoalkyl silane coupling agent comprises one or more selected from amino n-propyl trimethoxy siloxane, y-aminopropyl trimethoxy silane, and y- (B-aminoethyl) aminopropyl trimethoxy silane.

6. The method for preparing the universal functional polymer coating according to claim 4, wherein the volume concentration of the aminoalkyl silane coupling agent in the dilute solution is 10-20 mL/mL.

7. The method of claim 1, wherein the functional monomer comprises: any one or more of METAC, DMAEMA, PyMA, NDBCB, SPMA, NIPAM, MAA, DVBAPS, HEMA, HEAA, SBMA, CBMA, POEGMA.

8. The method for preparing a universal functional polymer coating according to claim 1, wherein the temperature of the radical polymerization reaction in the step (2) is 50-70 ℃ and the reaction time is 5-7 hours; the molar ratio of the functional monomer to GMA is 2-6: 1.

9. the method for preparing a universal functional polymer coating according to claim 1, wherein the reaction temperature in the step (3) is 60 ℃ to 80 ℃ and the reaction time is 6 to 24 hours; the concentration of the functional polymer in the solution of the functional polymer is 5-10 mg/mL.

10. The method for preparing a universal functional polymer coating according to claim 1, wherein in the step (3), triethylamine is included in the reaction process, and the volume ratio of the triethylamine to the functional polymer solution is 0.5-1.5: 10.