A UV-light-stimulus-responsive controllable wetting cross-linked molecular brush and its preparation method

Abstract

The present invention discloses a UV light-stimulus-responsive controllable wettability cross-linked molecular brush, which relates to the technical field of stimulus-responsive materials, and its structural formula is as follows: The present invention also discloses a preparation method of the above-mentioned molecular brush. The beneficial effects of the present invention are as follows: The surface of the UV light-stimulus-responsive controllable wettability material of the present invention can achieve controllable conversion of hydrophilicity and hydrophobicity only under light stimulation, and the surface of the polymer molecular brush in a cross-linked state has strong anti-protein adhesion performance.

Description

Technical Field

[0001] The present invention relates to the technical field of stimulus-responsive materials, and particularly relates to an ultraviolet light-stimulus-responsive controllable wetting crosslinked molecular brush and a preparation method thereof. Background Art

[0002] With the continuous development of social economy, people's requirements for the surface properties of materials are also changing rapidly. Surface modification can endow the material surface with various properties, including chemical inertness, adhesion, biocompatibility, hydrophilicity, hydrophobicity, etc. Modifying the material surface by grafting polymer molecular brushes has the characteristics of high efficiency and simplicity, and has become one of the important modification methods for regulating the physical and chemical properties of the interface.

[0003] Stimulus-responsive materials are a new type of intelligent materials that can respond to external conditions and exhibit corresponding properties. Introducing stimulus-responsive units into polymer molecular brushes will cause significant changes in the surface properties of the materials before and after the response. Controllable crosslinked / demulsified polymer molecular brushes are one type of stimulus-responsive materials. Currently, there are few research reports on controllable crosslinked molecular brushes, and the stimulus methods are mainly pH, temperature stimuli, etc. For example, the patent with the publication number CN101560062A discloses a preparation method of a stimulus-responsive polymer brush. The polymer brush prepared by this patent has temperature stimulus responsiveness. However, these stimulus methods not only have poor controllability, but also consume a large amount of heat energy or solvents, making them not in line with the concept of sustainable development. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a crosslinked molecular brush with ultraviolet light stimulus responsiveness and a preparation method thereof.

[0005] The present invention solves the above technical problems through the following technical means:

[0006] An ultraviolet light-stimulus-responsive controllable wetting crosslinked molecular brush has the following structural formula:

[0007]

[0008] Wherein R1 is selected from C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl; R2 is selected from Br, Cl; R3 is selected from C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl; R4 is selected from perfluorobutyl, perfluorohexyl, perfluorodecyl; R5 and R6 are the same or different and are independently selected from C 1-2 alkyl; R7 is selected from a hydrogen atom, C 1-12 alkyl, C 1-12 alkoxy, C 2-12Alkenyl; R8 and R9 are the same or different and are independently selected from a hydrogen atom, C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl, a halogen atom, a cyano group, C 6-10 aryl, C 6-10 aryloxy, C 6-10 aralkyloxy, C 8-12 arylalkenyl, C 3-8 cycloalkyl, carboxyl, carboxy C 1-12 alkyl ester group, carboxy poly(C 1-4 ) alkylene glycol ether ester group, C 2-7 carboxyalkoxy, C 1-12 alkyl ester group, C 2-7 carboxyalkoxy poly(C 1-4 ) alkylene glycol ether ester group;

[0009] A is selected from

[0010] m is an integer between 20 and 45;

[0011] n is an integer between 15 and 30;

[0012] is a polydopamine-modified solid matrix.

[0013] Advantageous effects: The ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush in the present invention can endow the surface with controllable hydrophilicity and hydrophobicity by using the cross-linking and de-cross-linking of coumarin groups.

[0014] After the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush in the present invention is irradiated with 365 nm ultraviolet light, the coumarin groups are cross-linked, endowing the material surface with good anti-protein adhesion properties.

[0015] Preferably, the R1 is n-propyl; the R2 is Br; the R3 is ethyl; the R4 is perfluorobutyl; the R5 and R6 are the same and are methyl; the R7 is methyl; the R8 and R9 are the same and are hydrogen atoms; A is

[0016] Preferably, the surface cross-linking and de-cross-linking process of the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush is 365 nm ultraviolet light irradiation for 10 - 120 min and 254 nm ultraviolet light irradiation for 1 - 10 min.

[0017] The method for preparing the above-mentioned ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush includes the following steps:

[0018] (1) Preparation of polydopamine-modified solid matrix: After cleaning and drying the solid matrix, an ethanol solution and organic solvent 1 are loaded onto the surface of the solid matrix, and then dopamine hydrochloride is added. After the stirring reaction is completed, a solid matrix coated with a polydopamine coating is obtained;

[0019] (2) Grafting of substance C' onto the polydopamine-modified solid matrix: The polydopamine-modified solid matrix is placed in a container, organic solvent 2 is added, and after stirring at 60 °C, substance C' is added, and the stirring reaction is continued at 60 °C to obtain a polydopamine-modified solid matrix grafted with C';

[0020] The said substance C' is a compound of general formula IV:

[0021] wherein the definitions of R1, R2, R5, R6 and A are the same as those in the structural formula of the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush;

[0022] (3) Preparation of the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush: Substance G', substance F', catalyst A and developer B are weighed and added to a Schlenk flask, and then organic solvent 3 and deionized water are added thereto, and nitrogen is passed through the solution to remove dissolved oxygen; The polydopamine-modified solid matrix grafted with C' is added to another Schlenk flask, and the air in the system is replaced with a nitrogen atmosphere by evacuating and passing nitrogen; Then the mixed solution in the Schlenk flask after the above deoxygenation operation is transferred to the Schlenk flask filled with nitrogen atmosphere by a syringe. After the reaction under nitrogen protection, the ungrafted monomers are washed away, and then dried under nitrogen atmosphere to obtain the product;

[0023] The said substance F' is a compound of general formula VII: wherein the definitions of R7, R8, R9 are the same as those in the structural formula of the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush;

[0024] The said substance G' is a compound of general formula VIII: wherein the definitions of R3, R4 are the same as those in the structural formula of the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush.

[0025] Beneficial effects: In the present invention, polydopamine (PDA) is used as a secondary functionalization platform, and coumarin derivative monomers and fluorinated acrylate monomers are copolymerized onto the material surface by the SI-ATRP method. Through the cross-linking and de-cross-linking reactions of the coumarin groups under 365 nm and 254 nm ultraviolet light, the controllable conversion of the hydrophilicity and hydrophobicity of the material surface is realized, and the surface where the polymer molecular brush is in a cross-linked state has strong anti-protein adhesion performance.

[0026] Preferably, in the step (1), the organic solvent 1 is a basic substance, preferably ammonia water.

[0027] Preferably, the solid matrix is a glass slide, and the solid matrix is cleaned with deionized water and organic solvent 4.

[0028] Preferably, the organic solvent 4 can dissolve the reactants, and is preferably acetone.

[0029] Preferably, in the step (1), the organic solvent 2 can dissolve the substance C', and is preferably a 40% ethanol solution.

[0030] Preferably, after taking out the solid matrix coated with the polydopamine coating in the step (1), it is repeatedly rinsed with absolute ethanol and deionized water to remove the polydopamine particles non-specifically deposited on the material surface, and then dried in a nitrogen atmosphere for standby. The remaining reaction solution is rotary evaporated to remove absolute ethanol and deionized water.

[0031] Preferably, in the step (2), the substance C' is obtained by reacting the substance A' with the substance B';

[0032] The substance A' is a compound of general formula II:

[0033]

[0034] The substance B' is a compound of general formula III:

[0035] wherein R2, R5 and R6 are the same as defined in the structural formula of the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush; R 11 is Br or Cl, preferably Br.

[0036] Preferably, the preparation method of the substance C' specifically includes the following steps: adding the organic solvent 5, the substance A', and the organic solvent 6 into a flask filled with nitrogen, stirring and mixing in an ice-water bath; then slowly dropping the substance B' into it, reacting for 1 hour, and then raising the temperature to room temperature and reacting for 24 hours to end; filtering to remove the white precipitate, rotary evaporating to remove the organic solvent, and then performing vacuum distillation to remove the remaining solvent and unreacted raw materials to obtain a brown liquid, which is the product C'.

[0037] Preferably, the organic solvent 5 can dissolve the substance A' and the substance B', and is preferably toluene; preferably, the organic solvent 6 can dissolve the substance A' and the substance B', and is preferably triethylamine.

[0038] Preferably, the molar ratio of the substance A' to B' is 1:(0.5 - 2.0), preferably 1:(1.2 - 1.8), and the molar ratio of the substance A' to the organic solvent 5 is 1:(0.5 - 2.0), preferably 1:(1.2 - 1.8).

[0039] Preferably, in the step (3), the catalyst A is N,N,N′,N″,N″-pentamethyldiethylenetriamine, and the amount of substance of the catalyst A is 0.3 mmol.

[0040] Preferably, in the step (3), the color developer B can be used to indicate whether the reaction is completed, and is preferably cuprous bromide.

[0041] Preferably, in the step (3), deionized water and an organic solvent 9 are used to wash away the ungrafted monomers.

[0042] Preferably, in the step (3), the substance F’ is obtained by reacting the substance D’ with the substance E’;

[0043] The substance D’ is a compound of general formula V:

[0044] wherein the definition of R7 is the same as that in the ultraviolet light-stimulated responsive controllable wetting crosslinked molecular brush structural formula, and R 10 is a hydroxyl group, an amino group, a mercapto group, preferably a hydroxyl group;

[0045] The substance E’ is a compound of general formula VI:

[0046] wherein the definitions of R8 and R9 are the same as those in the ultraviolet light-stimulated responsive controllable wetting crosslinked molecular brush structural formula.

[0047] Preferably, the preparation method of the substance F’ specifically includes the following steps: Add the substance D’ and triethylamine to a three-necked flask, then add an organic solvent 7, cool to 0 °C in an ice-water bath, and then stir for 30 minutes to fully dissolve it; then dissolve the substance E’ in an organic solvent 8, slowly add it dropwise to the system, stir for 1 hour, and continue to react at 25 °C for 2 hours to end; wash three times with saturated brine and let stand, dry the organic phase with a drying agent A, evaporate the solvent by rotary evaporation, and after purification, obtain a white solid, which is the substance F’.

[0048] Preferably, the organic solvent 7 can dissolve the substance D’, and is preferably N,N-dimethylformamide; the organic solvent 8 can dissolve the substance E’, and is preferably ethyl acetate.

[0049] Preferably, the drying agent A is used to dry the organic phase, and is preferably anhydrous magnesium sulfate.

[0050] Preferably, in the step (3), the molar ratio of the substance G’ to F’ is 1:(0 - 10), preferably 1:(0 - 4).

[0051] Preferably, in the step (3), the substance F’ is purified by column chromatography, and the preferred eluent ratio is PE:EA = 6:1.

[0052] The advantages of the present invention are as follows: The ultraviolet light-stimulated responsive controllable wettability cross-linked molecular brush in the present invention can endow the surface with controllable hydrophilicity and hydrophobicity by utilizing the cross-linking and de-cross-linking of coumarin groups.

[0053] After the ultraviolet light-stimulated responsive controllable wettability cross-linked molecular brush in the present invention is irradiated with 365 nm ultraviolet light, the coumarin groups are cross-linked, endowing the surface of the material with good anti-protein adhesion properties.

[0054] In the present invention, poly(dopamine) (PDA) is used as a secondary functionalization platform, and the coumarin derivative monomer and the fluorinated acrylate monomer are copolymerized onto the material surface by surface-initiated atom transfer radical polymerization (SI-ATRP). The cross-linking and de-cross-linking reactions of the coumarin groups under 365 nm and 254 nm ultraviolet light are used to realize the controllable conversion of the hydrophilicity and hydrophobicity of the material surface, and the surface in the cross-linked state of the polymer molecular brush has strong anti-protein adhesion performance. Brief Description of the Drawings

[0055] Figure 1 It is the reaction flow chart of the surface coated with poly(dopamine) in Example 1 of the present invention;

[0056] Figure 2 It is for 1 1H NMR spectrum of BRMPA in Example 2 of the present invention;

[0057] Figure 3 It is for 1 1H NMR spectrum of AMYCM in Example 4 of the present invention;

[0058] Figure 4 It is the XPS spectrum of the CUM-F-G surface prepared in Example 5 of the present invention;

[0059] Figure 5 It is the XPS spectrum of the CUM-F-G surface prepared in Example 6 of the present invention;

[0060] Figure 6 It is the XPS spectrum of the CUM-F-G surface prepared in Example 7 of the present invention;

[0061] Figure 7 It is the XPS spectrum of the CUM-F-G surface prepared in Example 8 of the present invention;

[0062] Figure 8 It is the light-responsive controllable wettability cycle test chart of the surface CUM8-F2-G prepared in Example 5 of the present invention;

[0063] Figure 9 It is the anti-protein adhesion diagram of the surfaces prepared in Example 5, Example 6, Example 7, and Example 8 of the present invention. Detailed Description of the Invention

[0064] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0065] Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources.

[0066] If no specific techniques or conditions are specified in the examples, they can be carried out according to the techniques or conditions described in the literature in the field or according to the product instructions.

[0067] Among them, aminopropyltrimethoxysilane (AR): Tianjin Xiensi Aopude Technology Co., Ltd.; 2-bromoisobutyryl bromide (AR): Shanghai Bid Pharmaceutical Technology Co., Ltd.; triethylamine (TEA, AR): Tianjin Xiensi Aopude Technology Co., Ltd.; 7-hydroxy-4-methylcoumarin (HMCM, AR): Beijing Yinuokai Technology Co., Ltd.; acryloyl chloride (AR): Tianjin Xiensi Aopude Technology Co., Ltd.; dopamine hydrochloride (PDA·HCl, AR): Tianjin Xiensi Aopude Technology Co., Ltd.; 2-(perfluorobutyl)ethyl acrylate (PFBEA, AR) : Beijing Mairida Technology Co., Ltd.; N,N,N′,N",N"-pentamethyldiethylenetriamine (PMDETA, AR): Shanghai Bid Pharmaceutical Technology Co., Ltd.; anhydrous magnesium sulfate (MgSO4, AR): Beijing Chemical Plant; sodium chloride (AR): Beijing Chemical Plant; toluene (AR): Tianjin Damao Chemical Reagent Factory; anhydrous ethanol (AR): Tianjin Damao Chemical Reagent Factory; acetonitrile (AR): Tianjin Guangfu Science and Technology Development Co., Ltd.; ethyl acetate (EA, AR): Tianjin Damao Chemical Reagent Factory; petroleum ether (PE, AR): Tianjin Damao Chemical Reagent Factory.

[0068] Example 1

[0069] Preparation of polydopamine-modified solid matrix

[0070] Laboratory slides were cut into 8 mm × 8 mm pieces using a glass cutter, washed repeatedly with deionized water and acetone, and dried in a nitrogen atmosphere for later use.

[0071] Put the above-treated glass slides into a 100 mL three-necked flask, then add 65 mL of 30% ethanol solution thereto, and use a pipette to add 0.8 mL of ammonia water to the system. Stir at room temperature for half an hour to mix well, then weigh 0.6 g of DA·HCl and add it to the reaction system. Under air oxidation conditions, stir and react at room temperature for 24 hours to end the reaction. The reaction process is as shown in Figure 1 shown. Take out the glass slides coated with polydopamine coating, and rinse them repeatedly with anhydrous ethanol and deionized water to remove the polydopamine particles non-specifically deposited on the material surface, and then dry them in a nitrogen atmosphere for standby. The remaining reaction solution is rotary evaporated to remove anhydrous ethanol and deionized water to obtain a polydopamine-coated surface PDA-Glass.

[0072] Example 2

[0073] Synthesis of SI-ATRP initiator BRMPA (substance C’)

[0074] Add 50 mL of anhydrous toluene, 0.90 g (5 mmol) of APS, and 0.81 g (8 mmol) of anhydrous TEA to a flask filled with nitrogen, and stir in an ice-water bath for 30 minutes to mix evenly. Then slowly drop 1.84 g (8 mmol) of BIBB into it. After reacting for 1 hour, raise the temperature to room temperature and react for 24 hours to end. Filter to remove the white precipitate, then rotary evaporate to remove toluene, and then distill under reduced pressure to remove the remaining solvent and unreacted raw materials to obtain a brown liquid, which is BRMPA.

[0075]

[0076] The NMR spectrum of SI-ATRP initiator BRMPA is shown in Figure 2 , and its NMR data are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 6.89 (s, 1H), 3.58 (d, J = 5.7 Hz, 9H), 3.27 (td, J = 7.1, 5.9 Hz, 2H), 1.95 (s, 6H), 1.66 (dddd, J = 9.4, 5.3, 2.5, 1.4 Hz, 2H), 0.70–0.64 (m, 2H).

[0077] Example 3

[0078] Grafting BRMPA on the surface of PDA-Glass

[0079] The prepared PDA-Glass was placed into a 100 mL flask, and then 25 mL of 40% ethanol solution was added. It was stirred at 60 °C for thirty minutes. Then, 0.04 g of BRMPA prepared in Example 2 was weighed and quickly added to the reaction system. Stirring was continued at 60 °C for three hours. The PDA-Glass was taken out to obtain a glass slide grafted with BRMPA on the surface, namely Br-Glass.

[0080]

[0081] Example 4

[0082] Synthesis of 7-acryloyl-4-methylcoumarin (AMYCM, Substance F')

[0083] 0.90 g of HMCM (Substance D') and 0.51 g of TEA were added to a 100 mL three-necked round-bottom flask. Then, 4 mL of DMF was added and cooled to 0 °C in an ice-water bath, followed by stirring for 30 minutes to fully dissolve it. Then, 0.46 g of acryloyl chloride (Substance E') was dissolved in 15 mL of EA and slowly added dropwise to the system. After stirring for 1 hour, the reaction continued at 25 °C for 2 hours to completion. It was washed three times with saturated brine and allowed to stand. The organic phase was dried over anhydrous magnesium sulfate, and EA was removed by rotary evaporation. It was purified by column chromatography (PE:EA = 6:1) to obtain a white solid, which was AMYCM.

[0084]

[0085] The NMR spectrum of the coumarin derivative monomer AMYCM is shown in Figure 3 , and its NMR data are as follows: 1 H NMR (400 MHz, Chloroform-d) δ 7.63 (d, J = 8.7 Hz, 1H), 7.20–7.10 (m, 2H), 6.66 (dd, J = 17.3, 1.2 Hz, 1H), 6.35 (dd, J = 17.3, 10.6 Hz, 1H), 6.28 (q, J = 1.3 Hz, 1H), 6.10 (dd, J = 10.4, 1.1 Hz, 1H), 2.45 (d, J = 1.3 Hz, 3H).

[0086] Example 5

[0087] Preparation of a cross-linked molecular brush with ultraviolet light-stimulated responsive controllable wettability

[0088] Weigh 0.13 g of 2-(perfluorobutyl)ethyl acrylate (PFBEA), 0.37 g of AMYCM in Example 4, 0.05 g (0.3 mmol) of pentamethyldiethylenetriamine (PMDETA), and 0.0143 g (0.1 mmol) of CuBr, and add them to a 100 mL Schlenk flask. Then add 22.5 mL of acetone and 2.5 mL of deionized water thereto, and purge nitrogen into the solution for thirty minutes to remove dissolved oxygen. Transfer the material grafted with the above ATRP initiator to another Schlenk flask, and perform the evacuation and nitrogen purging operations three times to replace the air in the system with a nitrogen atmosphere. Then transfer the mixed solution in the Schlenk flask after the above deoxygenation operation to the Schlenk flask filled with a nitrogen atmosphere, and react at 50 °C for 6 hours under nitrogen protection. Wash away the ungrafted monomers, etc. with deionized water and acetone, and then dry under a nitrogen atmosphere to obtain the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush CUM8-F2-G.

[0089]

[0090] The XPS spectrum of the CUM8-F2-G surface is as Figure 4 shown. The water contact angle of the CUM8-F2-G surface without ultraviolet light irradiation is 80°. After the surface is irradiated with 365 nm ultraviolet light for 2 h, the coumarin groups are cross-linked, and the water contact angle of the CUM8-F2-G surface rises to 107.9°. Then, after irradiation with 254 nm ultraviolet light for 10 min, the coumarin groups are de-cross-linked, and the water contact angle of the CUM8-F2-G surface drops to 79.1°.

[0091] Example 6

[0092] Repeat the steps of Example 5 to prepare the ultraviolet light-stimulated responsive controllable wetting cross-linked molecular brush CUM10-F0-G. The difference lies in that 0.46 g of AMYCM and 0 g of PFBEA are added.

[0093] The XPS spectrum of the CUM10-F0-G surface is as Figure 5 shown. The water contact angle of the CUM10-F0-G surface without ultraviolet light irradiation is 73.6°. After the surface is irradiated with 365 nm ultraviolet light for 2 h, the coumarin groups are cross-linked, and the water contact angle of the CUM10-F0-G surface rises to 102.3°. Then, after irradiation with 254 nm ultraviolet light for 10 min, the coumarin groups are de-cross-linked, and the water contact angle of the CUM10-F0-G surface drops to 73.5°.

[0094] Example 7

[0095] Repeat the steps of Example 5 to prepare the controllable wettability surface material CUM5-F5-G. The difference is that the added AMYCM is 0.23 g and the PFBEA is 0.32 g.

[0096] The XPS spectrum of the CUM5-F5-G surface is as Figure 6 shown. The water contact angle of the CUM5-F5-G surface without ultraviolet light irradiation is 87.2°. After the surface is irradiated with 365 nm ultraviolet light for 2 h, the coumarin groups are crosslinked, and the water contact angle of the CUM5-F5-G surface rises to 114.0°. Then, after irradiation with 254 nm ultraviolet light for 10 min, the coumarin groups are de-crosslinked, and the water contact angle of the CUM5-F5-G surface drops to 88.3°.

[0097] Example 8

[0098] Repeat the steps of Example 5 to prepare the controllable wettability surface material CUM2-F8-G. The difference is that the added AMYCM is 0.10 g and the PFBEA is 0.52 g.

[0099] The XPS spectrum of the CUM2-F8-G surface is as Figure 7 shown. The water contact angle of the CUM2-F8-G surface without ultraviolet light irradiation is 91.0°. After the surface is irradiated with 365 nm ultraviolet light for 2 h, the coumarin groups are crosslinked, and the water contact angle of the CUM2-F8-G surface rises to 128.0°. Then, after irradiation with 254 nm ultraviolet light for 10 min, the coumarin groups are de-crosslinked, and the water contact angle of the CUM2-F8-G surface drops to 92.6°.

[0100] Example 9

[0101] Measure the water contact angle of the surface CUM8-F2-G prepared in Example 5. At the same time, use a water contact angle measuring instrument to characterize the ultraviolet light-responsive controllable wettability of the material surface. Wrap half of the CUM8-F2-G surface with tin foil paper and place it under 365 nm ultraviolet light irradiation for 2 hours. Then measure the water contact angles of the irradiated area and the non-irradiated area respectively. Then place the CUM8-F2-G surface under 254 nm light source irradiation for 10 minutes and measure its water contact angle. Repeat this operation three times to verify the repeatability of the controllable wettability. The results are as Figure 8 shown. After repeating the light irradiation three times, there is no obvious difference in the water contact angles in the same state, indicating that the repeatability of the controllable wettability is good.

[0102] Example 10

[0103] Immerse the surfaces (before and after ultraviolet light stimulation) obtained in Example 5, Example 6, Example 7, and Example 8 in 2 mL of phosphate buffer solution (PBS solution) for 2 hours, and then immerse them in 1 mL of bovine serum albumin standard solution (BSA solution) (4.5 mg·mL -1 -1) for 2 hours, and then take them out after culturing in a constant temperature oven at 37 °C. After rinsing three times with PBS solution, place the samples in 1 wt% sodium dodecyl sulfate solution (SDS solution) and ultrasonicate for 20 minutes to completely detach the adhered proteins. The SDS solution is to be tested. Use the Bicinchonininc Acid (BCA) method to determine the protein content in the desorption solution. After diluting the above SDS solution containing BSA by 10 times, prepare a working solution using a total protein quantification test kit to obtain the sample to be tested. Measure the absorbance of all samples at 562 nm to characterize the anti-protein adhesion property.

[0104] The results are as Figure 9 shown. It can be seen from the figure that when the material surface is irradiated with 365 nm light for 120 min, its anti-protein adsorption ability on the surface is enhanced compared with that before crosslinking. This is because after irradiation with 365 nm ultraviolet light, a cycloaddition reaction occurs on the surface of the coumarin derivative of the material, and the degree of crosslinking between the molecular brushes increases, restricting the adhesion of proteins on the surface.

[0105] The present invention can also directly graft BRMPA with polydopamine particles, and then continue to prepare the product and coat it on the surface of the solid matrix.

[0106] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A UV light-stimulus-responsive controllable wetting cross-linked molecular brush, characterized in that: Its structural formula is as follows: wherein R1 is selected from C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl; R2 is selected from Br, Cl; R3 is selected from C 1-12 alkyl, C 1-12 alkoxy, C 2-12 alkenyl; R4 is selected from perfluorobutyl, perfluorohexyl, perfluorodecyl; R5 and R6 are the same or different and are independently selected from C 1-2 alkyl; R7 is selected from a hydrogen atom, C 1-12 alkyl; R8 and R9 are the same and are a hydrogen atom; A is m is an integer between 20 and 45; n is an integer between 15 and 30; It is a polydopamine-modified solid matrix.

2. The ultraviolet light-stimulus-responsive controllable wetting cross-linked molecular brush according to claim 1, characterized in that: The R1 is n-propyl; the R2 is Br; the R3 is ethyl; the R4 is perfluorobutyl; the R5 and R6 are the same and are methyl; the R7 is methyl; the R8 and R9 are the same and are hydrogen atoms; A is 3. The ultraviolet light-stimulus-responsive controllable wetting cross-linked molecular brush according to claim 1, wherein: The surface crosslinking and de-crosslinking processes of the ultraviolet light-stimulated responsive controllable wetting crosslinked molecular brush are 10 - 120 min of 365 nm ultraviolet light irradiation and 1 - 10 min of 254 nm ultraviolet light irradiation.

4. A method for preparing the ultraviolet light-stimulus responsive controllable wetting cross-linked molecular brush according to any one of claims 1-3, characterized in that: It includes the following steps: (1) Prepare a polydopamine-modified solid matrix: After cleaning and drying the solid matrix, load an ethanol solution and organic solvent 1 onto the surface of the solid matrix, then add dopamine hydrochloride, and obtain a solid matrix coated with a polydopamine coating after the stirring reaction ends; (2) Graft substance C' onto the polydopamine-modified solid matrix: Put the polydopamine-modified solid matrix into a container, add organic solvent 2, stir at 60 °C, then add substance C', and continue to stir and react at 60 °C to obtain a polydopamine-modified solid matrix grafted with C'; The substance C' is a compound of general formula IV: (3) Preparation of the ultraviolet light-stimulated responsive controllable wetting crosslinked molecular brush: Weigh substance G', substance F', catalyst A, and developer B and add them to a Schlenk flask, then add organic solvent 3 and deionized water to it, and pass nitrogen through the solution to remove dissolved oxygen; Add the polydopamine-modified solid matrix grafted with C' to another Schlenk flask, evacuate and pass nitrogen to replace the air in the system with a nitrogen atmosphere; Then transfer the mixed solution in the Schlenk flask after the above deoxygenation operation to the Schlenk flask filled with a nitrogen atmosphere. Under nitrogen protection, after the reaction, wash away the ungrafted monomers, and then dry under a nitrogen atmosphere to obtain the product; The substance F' is a compound of general formula VII: The substance G’ is a compound of general formula VIII:

5. The method for preparing an ultraviolet light-stimulus responsive controllable wetting cross-linked molecular brush according to claim 4, characterized in that: In the step (2), the substance C' is obtained by the reaction of substance A' and substance B'; The substance A' is a compound of general formula II: The substance B' is a compound of general formula III: wherein R 11 is Br or Cl.

6. The method for preparing an ultraviolet light-stimulus responsive controllable wetting crosslinked molecular brush according to claim 5, characterized in that: The preparation method of the substance C' specifically includes the following steps: Add organic solvent 5, substance A', and organic solvent 6 to a flask filled with nitrogen, stir and mix in an ice-water bath; Then slowly drop substance B' into it, react for 1 hour, then raise the temperature to room temperature and react for 24 hours to end; Filter to remove the white precipitate, then rotary evaporate to remove the organic solvent, and then distill under reduced pressure to remove the remaining solvent and unreacted raw materials to obtain a brown liquid, which is the product C'.

7. The method for preparing an ultraviolet light-stimulus-responsive controllable wetting cross-linked molecular brush according to claim 6, characterized in that: The organic solvent 5 is toluene, and the organic solvent 6 is triethylamine.

8. The method for preparing a cross-linked molecular brush with controllable wettability responsive to ultraviolet light stimulation according to claim 4, characterized in that: In the step (3), the substance F' is obtained by the reaction of substance D' and substance E'; The substance D' is a compound of general formula V: wherein R 10 is hydroxy, amino, or mercapto; The substance E' is a compound of general formula VI:

9. The method for preparing a cross-linked molecular brush with ultraviolet light-stimulated responsive controllable wettability according to claim 8, characterized in that: The preparation method of the substance F' specifically includes the following steps: Add substance D' and triethylamine to a three-necked flask, then add organic solvent 7, cool to 0 °C in an ice-water bath, and then stir for 30 minutes to fully dissolve it; Then dissolve substance E' in organic solvent 8, slowly drop it into the system, stir for 1 hour, and continue to react at 25 °C for 2 hours to end; Wash three times with saturated brine and let it stand, dry the organic phase with desiccant A, rotary evaporate to remove the solvent, and after purification, obtain a white solid, which is the substance F'.

10. The method for preparing an ultraviolet light-stimulus responsive controllable wetting crosslinked molecular brush according to claim 9, characterized in that: The organic solvent 7 is N,N-dimethylformamide, and the organic solvent 8 is ethyl acetate.

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