Slow-release antifouling material, preparation method thereof and marine antifouling paint

Abstract

The invention relates to a slow-release antifouling material, a preparation method thereof and a marine antifouling coating. The preparation method of the slow-release antifouling material comprises the following steps: carrying out amination modification on porous silicon oxide to obtain aminated porous silicon oxide; loading a carboxylic acid natural antifouling agent on the aminated porous silicon oxide to obtain an aminated porous silicon oxide antifouling agent; blocking pore channels in the aminated porous silicon oxide-antifouling agent by adopting gelatin to obtain aminated porous silicon oxide-antifouling agent-gelatin, so as to obtain aminated porous silicon oxide-antifouling agent-gelatin; and mixing the aminated porous silicon oxide, antifouling agent and gelatin with a chitosan solution at 25-45 DEG C for at least 0.5 hour, collecting a product, and drying to obtain the slow-release antifouling material. According to the slow-release antifouling material, the release rate of the antifouling agent can be reduced, and the protection effect on marine equipment is improved.

Description

Technical Field

[0001] The invention relates to a slow-release antifouling material and a preparation method thereof and a marine antifouling coating, belonging to the field of marine biological fouling protection. Background Art

[0002] Microorganisms and macroscopic organisms usually attach and aggregate on marine facilities such as ships, buoys, marine pipelines and membrane tubes to form biofouling, which can accelerate the corrosion of marine facilities or cause pipeline blockage. Antifouling coatings containing antifouling agents are an effective measure to protect marine facilities. In particular, natural ingredients such as organic acids, inorganic acids, lactones, terpenes, phenols, sterols and indoles extracted from animals and plants in recent years have good antifouling properties and good ecological environmental friendliness. They are used as antifouling agents in antifouling coatings, which are green and environmentally friendly. Therefore, natural product antifouling coatings are receiving more and more attention.

[0003] The effectiveness of antifouling coatings depends mainly on the retention of antifouling agents in the coating. If the antifouling agent is kept relatively constant and released at a small dose, it is conducive to fully exerting its protective effect. However, the natural antifouling agents in current antifouling coatings are released at a fast rate in seawater, resulting in a short antifouling period of the antifouling coating. Therefore, there is an urgent need to provide a slow-release antifouling material and a marine antifouling coating. Summary of the invention

[0004] Based on the above situation, the present invention discloses a slow-release antifouling material and a preparation method thereof. The slow-release antifouling material obtained by the preparation method has a slow and stable release rate of the carboxylic acid-based natural antifouling agent in seawater, which can ensure the protective performance and extend the antifouling period. The present invention also provides a marine antifouling coating comprising the slow-release antifouling material.

[0005] To achieve the above object, the first aspect of the present invention provides a method for preparing a sustained-release antifouling material, comprising the following steps performed in sequence:

[0006] S1, performing amino modification on the porous silicon oxide to obtain amino-modified porous silicon oxide;

[0007] S2, loading a carboxylic acid-based natural antifouling agent on the aminated porous silica to obtain an aminated porous silica@antifouling agent;

[0008] S3, using gelatin to block the pores in the amino-modified porous silica@antifouling agent to obtain amino-modified porous silica@antifouling agent@gelatin;

[0009] S4. Mix the amino-modified porous silica@antifouling agent@gelatin and chitosan solution at 25-45° C. for at least 0.5 hour, wherein the mass ratio of the amino-modified porous silica@antifouling agent@gelatin to chitosan is (1-3):5, collect the product, and obtain a sustained-release antifouling material after drying.

[0010] Porous silica is a representative of porous materials, and according to its pore size, it can be further divided into micropores, mesopores and macroporous silica. Among them, mesoporous silica has the advantages of high load, slow release trend, easy surface modification, and high mechanical strength and thermal stability, and can be closely combined with antifouling agents, thereby reducing the release rate to extend the antifouling period. In the present invention, common mesoporous silica can be selected, such as silicon-based mesoporous molecular sieves such as MCM-41, SBA-15, and SBA-16, or a mixture of multiple mesoporous silicas. The present invention can achieve close combination with carboxylic acid natural antifouling agents by amino modification of the surface of porous silica such as mesoporous silica, thereby improving the loading capacity and slow release performance of carboxylic acid natural antifouling agents.

[0011] In the specific implementation process, in step S1, the process of aminated modification of porous silica includes: mixing porous silica and an amino silane coupling agent in a solvent, reacting at 70-90° C. for at least 6 hours, such as 12 hours, and drying the solid product portion to obtain aminated porous silica.

[0012] The above-mentioned amino silane coupling agent can be, for example, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane. The amount of the amino silane coupling agent can be 20-60% of the mass of the porous silicon oxide. The above-mentioned solvent can be an organic solvent such as toluene and ethanol.

[0013] Subsequently, the carboxylic acid-based natural antifoulant is loaded onto the aminated porous silica to obtain an aminated porous silica @ indole antifoulant. Specifically, a commonly used loading process can be used. One of the loading processes is: the aminated porous silica is contacted with the carboxylic acid-based natural antifoulant in a solvent, so that the carboxylic acid-based natural antifoulant is loaded onto the aminated porous silica, and after the loading is completed, the solvent is removed and the product is washed and dried to obtain the aminated porous silica @ antifoulant. Through the above-mentioned loading process, the carboxylic acid-based natural antifoulant such as indoleacetic acid can form an electrostatic bond with the amino-modified silicon-based mesoporous molecular sieve.

[0014] In a specific implementation process, the loading process in step S2 includes: mixing the amino-modified porous silica with a solvent, and then adding a carboxylic acid-based natural antifouling agent, and mixing at a temperature of 25 to 35° C. for at least 1 hour.

[0015] The above-mentioned carboxylic acid-based natural antifouling agent can specifically be indoleacetic acid; the solvent used can be, for example, an organic solvent with a low boiling point and easily soluble in water, such as acetone or ethanol.

[0016] Studies have shown that reasonable control of the mass ratio of aminated porous silica to carboxylic acid natural antifouling agents is beneficial to improving the antibacterial properties of sustained-release antifouling materials. In the specific implementation process, the mass ratio of the two is generally controlled to be (1-2): (1-2), such as the mass ratio of aminated porous silica to carboxylic acid natural antifouling agents is 1:1, 1:2, 2:1. Moreover, within the above ratio range, the amount of carboxylic acid natural antifouling agents is relatively large, which is more conducive to improving the antibacterial properties of sustained-release antifouling materials. Therefore, the mass ratio of aminated porous silica to carboxylic acid natural antifouling agents is generally controlled to be 1: (1-2).

[0017] The purpose of step S3 is to temporarily block the pores of the product material produced in step S2, specifically the porous silica, to prevent the carboxylic acid-based natural antifouling agent from penetrating from the porous silica into the chitosan when step S4 is implemented later, thereby affecting the sustained release effect. Specifically, step S3 may include the following process: mixing the amino porous silica @ antifouling agent with the gelatin solution at 25-35°C for at least 1 hour, wherein the mass ratio of the amino porous silica @ antifouling agent to the gelatin is (0.8-1.0): 1, collecting the product, washing and drying it, and obtaining the amino porous silica @ antifouling agent @ gelatin;

[0018] In the specific implementation process, the process of step S3 can be specifically: put the amino porous silica @ antifouling agent into a gelatin aqueous solution, then put it into a constant temperature shaker at 25-45°C for 5 hours, add 4°C deionized water and centrifuge and wash twice, filter and dry at a low temperature such as 30°C to obtain the amino porous silica @ antifouling agent @ gelatin.

[0019] Finally, the target product is synthesized, and the specific process can be: chitosan is added to the acetic acid solution and dispersed evenly to obtain a chitosan solution, and then amino-modified porous silica@antifouling agent@gelatin is added thereto, and the mass ratio of chitosan to amino-modified porous silica@antifouling agent@gelatin is controlled to be 2:5, and then poured into a culture dish after stirring evenly, and placed in a vacuum drying oven at 35°C, and dried to obtain a sustained-release antifouling material. Through the above step S4, chitosan can be used as a substrate to cooperate with the modified antifouling agent carrier to improve the antibacterial performance, and at the same time, the pores of the molecular sieve carrier are blocked to reduce the release rate of natural antifouling agents such as indoleacetic acid, so as to achieve the purpose of long-term antifouling.

[0020] The second aspect of the present invention provides a sustained-release antifouling material, which is prepared by the preparation method described in the first aspect.

[0021] The third aspect of the present invention provides a marine antifouling coating, comprising the above-mentioned slow-release antifouling material. In addition to the above-mentioned slow-release antifouling material, the marine antifouling coating may also contain components such as solvents, pigments and fillers, and specific components and proportions may be selected according to actual needs, which will not be described in detail here.

[0022] The sustained-release antifouling material and preparation method thereof provided by the present invention utilize an adsorption equilibrium solvent evaporation method to synthesize the sustained-release antifouling material. Specifically, by performing amino modification on the surface of porous silicon oxide such as silicon-based mesoporous molecular sieves, the binding with carboxylic acid-based natural antifouling agents can be enhanced, thereby increasing the drug loading and sustained-release performance; chitosan can be used as a substrate to coordinate with the modified antifouling agent carrier to improve its antibacterial performance, and chitosan can also block the pores of the molecular sieve carrier to reduce the release rate of carboxylic acid-based natural antifouling agents such as indoleacetic acid, thereby achieving the purpose of long-term antifouling.

[0023] The marine antifouling paint provided by the present invention, because it includes the above-mentioned slow-release antifouling material, has good antifouling performance and a long antifouling period, thereby providing effective protection for marine facilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The infrared spectra of the intermediate product and the final product obtained in Example 1 of the present invention;

[0025] Figure 2 The XRD patterns of the intermediate product and the final product obtained in Example 1 of the present invention;

[0026] Figure 3 This is a graph showing the cumulative release of indoleacetic acid in the sustained-release antifouling material prepared in Example 1 of the present invention;

[0027] Figure 4 The antibacterial effect diagram of chitosan and the sustained-release antifouling material prepared in Examples 1-3. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Example 1

[0030] This embodiment provides a sustained-release antifouling material, and the preparation method thereof is as follows:

[0031] S1. Preparation of amino-SBA-16: 1 g of SBA-16 and 0.6 g of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (silane coupling agent KH-792) were mixed in 70 mL of toluene, heated to 80±5° C. and stirred for 12 hours, then filtered, and then placed in a vacuum drying oven at about 70° C. for about 5 hours to obtain amino-SBA-16, which is a white powder;

[0032] S2. Preparation of amino-SBA-16@indoleacetic acid: 1 g of amino-SBA-16 was dissolved in 30 mL of acetone solvent, and indoleacetic acid was added under heating and stirring at 30°C for 10 hours, wherein the mass ratio of amino-SBA-16 to indoleacetic acid was 2:1; after the reaction was completed, the solution was rotary evaporated, washed with a corresponding solvent, and placed in a vacuum drying oven at 30±1°C for about 5 hours, and then taken out to obtain amino-SBA-16@indoleacetic acid, which was a reddish brown powder;

[0033] S3. Preparation of amino-SBA-16@indoleacetic acid@gelatin: 1 g of amino-SBA-16@indoleacetic acid was placed in a gelatin solution with a concentration of 50 mg / mL and a volume of 20 mL (i.e., the mass ratio of gelatin to amino-SBA-16@indoleacetic acid was 1:1), and then placed in a constant temperature shaker at 30±1°C for about 5 hours, then centrifuged and washed twice with deionized water at 4°C, filtered, and dried at 30°C±1°C for about 12 hours to obtain amino-SBA-16@indoleacetic acid@gelatin;

[0034] S4. Preparation of amino-SBA-16@indoleacetic acid@chitosan: add 1 g of chitosan into 100 mL (1%, vol%) of acetic acid solution and disperse evenly to obtain 10 mg / mL chitosan solution, add amino-SBA-16@indoleacetic acid@gelatin to the above chitosan solution, and control the mass ratio of chitosan to amino-SBA-16@indoleacetic acid@gelatin to be 2:5. After stirring for about 1 hour, pour into a culture dish, put it in a vacuum drying oven at 35±1°C and dry it for about 12 hours to obtain an amino-SBA-16@indoleacetic acid@chitosan coating.

[0035] Example 2

[0036] This embodiment provides a sustained-release antifouling material, and its preparation method is basically the same as that of Embodiment 1, except that in step S2, the mass ratio of the amino-SBA-16 to the indoleacetic acid is 1:1.

[0037] Example 3

[0038] This embodiment provides a sustained-release antifouling material, and its preparation method is basically the same as that of Embodiment 1, except that in step S2, the mass ratio of amino-SBA-16 to indoleacetic acid is 1:2.

[0039] Figure 1 The infrared spectra of the intermediate product and the final product obtained in Example 1 of the present invention are shown in FIG. Figure 1 As shown, in the infrared spectrum of the product (amino-SBA-16@indoleacetic acid) in step S2, at 3400 cm -1 There are sharp peaks around the left and right sides, which are characteristic peaks of indoleacetic acid, confirming that the porous silicon SBA-16 after indoleacetic acid is successfully loaded; in the infrared spectrum of the product of step S4 (aminated-SBA-16@indoleacetic acid@chitosan), at 3400cm -1 The steamed bread peak appears around 1450-1600cm due to the addition of chitosan. -1 The characteristic absorption peak of the benzene ring was weakened, which indirectly verified that the amino-SBA-16@indoleacetic acid was successfully encapsulated by chitosan.

[0040] Figure 2 The X-ray diffraction (XRD) patterns of the intermediate product and the final product obtained in Example 1 of the present invention are shown in FIG. Figure 2 As shown in the figure, the product of step S2, amination-SBA-16@indoleacetic acid, shows a diffraction peak of indoleacetic acid, indicating that the amination-porous silicon SBA-16 successfully loaded with indoleacetic acid; while the product of step S4, amination-SBA-16@indoleacetic acid@chitosan, does not have a diffraction peak of indoleacetic acid, which is speculated to be because the indoleacetic acid loaded in the amination-porous silicon SBA-16 is blocked inside the pores by chitosan.

[0041] Evaluation Example 1

[0042] Sustained release performance evaluation: 50 mg each of the amino-SBA-16@indoleacetic acid and amino-SBA-16@indoleacetic acid@chitosan in Example 2 and 50 mg of SBA-16@indoleacetic acid were placed in 100 mL of seawater, and the concentration of indoleacetic acid in the seawater was continuously measured using an ultraviolet spectrophotometer. The results are as follows: Figure 4 shown.

[0043] The preparation process of the above-mentioned SBA-16@indoleacetic acid is similar to step S2 in Example 2, except that the raw material is changed from amino-SBA-16 to SBA-16. The specific process is: 1 g of SBA-16 is dissolved in 30 mL of acetone solvent, and indoleacetic acid is added under heating and stirring conditions at 30°C for 10 hours, wherein the mass ratio of SBA-16 to indoleacetic acid is 1:1; after the reaction is completed, the solution is rotary evaporated, washed with a corresponding solvent, and placed in a vacuum drying oven at 30±1°C for about 5 hours and then taken out to obtain SBA-16@indoleacetic acid.

[0044] The results show that in a short period of time, the indoleacetic acid in SBA-16@indoleacetic acid and amino-SBA-16@indoleacetic acid is quickly released in seawater: after about 3 days, the release rate of indoleacetic acid is more than 80%; after about 4 days, the release rate of indoleacetic acid is 90%. It is also noted that although the indoleacetic acid in both is quickly released in a short period of time, the release rate of indoleacetic acid in amino-SBA-16@indoleacetic acid is slower in comparison, indicating that the amination treatment of SBA-16 can help improve the binding force between indoleacetic acid and SBA-16.

[0045] Compared with SBA-16@indoleacetic acid and amino-SBA-16@indoleacetic acid, the release rate of indoleacetic acid in amino-SBA-16@indoleacetic acid@chitosan is greatly reduced. Even when the release rate of indoleacetic acid in the first two reaches 90%, the release amount of indoleacetic acid in amino-SBA-16@indoleacetic acid@chitosan material is less than 20%. Moreover, after further verification, the release amount of indoleacetic acid in amino-SBA-16@indoleacetic acid@chitosan reaches 90% after about 40 days, indicating that the use of the sustained-release antifouling material in the embodiment of the present invention greatly prolongs the release time of the indoleacetic acid antifouling agent and ensures the protective effect of the marine antifouling coating on marine facilities. This also confirms that chitosan blocks the pores of the molecular sieve carrier, so that the indoleacetic acid therein can be released at a relatively stable and small dose rate.

[0046] Evaluation Example 2

[0047] Evaluation of antibacterial performance: After preparing fresh culture of Bacillus subtilis, grow the bacterial culture at 37°C for 24 hours. Divide 12 panels (1 cm×1 cm) into four groups, 3 panels in each group, and coat each group of panels with chitosan and the sustained-release antifouling materials in Examples 1 to 3, respectively, and use the chitosan coating as a negative control. 3 mL of sterile marine broth was mixed with a concentration of approximately 10 CFU (colony forming units) / mL of Bacillus subtilis bacterial culture and added to each well. The number of CFU in all treatments was measured after 0 hours and 24 hours. The results are as follows: Figure 4As shown in the figure, 2:1, 1:1, and 1:2 respectively represent the mass ratios of the amino-SBA-16 and the indoleacetic acid in step S2, that is, Examples 1 to 3.

[0048] The results show that: under the same initial concentration (about 10 CFU / mL), after 24 hours, compared with pure chitosan, coating the sustained-release antifouling materials in Examples 1 to 3 on the panel will increase the bacterial inactivation rate, indicating that the amino-SBA-16@indoleacetic acid@chitosan prepared in different examples have a certain antibacterial effect on Bacillus subtilis, and the amino-SBA-16@indoleacetic acid@chitosan with a mass ratio of amino-SBA-16 to indoleacetic acid of 1:2 has the best effect.

[0049] From the above results, it can be seen that the slow-release antifouling material prepared by the present invention has a good effect on prolonging marine antifouling. Therefore, it can be used to solve the phenomenon of sudden release of marine antifouling agents and has good application prospects.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a sustained-release antifouling material, characterized in that: The steps include: Aminated porous silicon oxide is modified to obtain aminated porous silicon oxide; Carboxylic acid-based natural antifouling agent is loaded on the aminated porous silica to obtain aminated porous silica@antifouling agent; The pores in the amino-modified porous silica@antifouling agent are blocked with gelatin to obtain the amino-modified porous silica@antifouling agent@gelatin; The aminated porous silica@antifouling agent@gelatin and chitosan solution are mixed at 25-45°C for at least 0.5 hours, wherein the mass ratio of the aminated porous silica@antifouling agent@gelatin to chitosan is (1-3):5, and the product is collected and dried to obtain a sustained-release antifouling material.

2. The preparation method according to claim 1, characterized in that: The porous silicon oxide is mesoporous silicon oxide.

3. The preparation method according to claim 1 or 2, characterized in that: The process of amino modification of porous silica includes: The porous silicon oxide and the amino silane coupling agent are mixed in a solvent, reacted at 70-90° C. for at least 6 hours, and the solid product is taken and dried to obtain the amino porous silicon oxide; The amino silane coupling agent accounts for 20-60% of the mass of the porous silicon oxide.

4. The preparation method according to claim 1, characterized in that: The carboxylic acid-based natural antifouling agent is indoleacetic acid.

5. The preparation method according to claim 1 or 4, characterized in that: The process of obtaining the amino porous silica@antifouling agent includes: contacting the amino porous silica with a carboxylic acid natural antifouling agent in a solvent, so that the carboxylic acid natural antifouling agent is loaded onto the amino porous silica, wherein the mass ratio of the amino porous silica to the carboxylic acid natural antifouling agent is (1-2): (1-2), and after the loading is completed, the solvent is removed and the product is washed and dried.

6. The preparation method according to claim 5, characterized in that: The loading process comprises: adding the carboxylic acid-based natural antifouling agent into a mixture of amino-modified porous silica and a solvent, and mixing the mixture at a temperature of 25 to 35° C. for at least 1 hour.

7. The preparation method according to claim 1, characterized in that: The use of gelatin to block the pores in amino-modified porous silica@antifouling agents includes: The aminated porous silica @ antifouling agent and gelatin solution are mixed at 25-35° C. for at least 1 hour, wherein the mass ratio of the aminated porous silica @ antifouling agent to the gelatin is (0.8-1.0):1, the product is collected, washed and dried to obtain the aminated porous silica @ antifouling agent @ gelatin.

8. A sustained-release antifouling material, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 7.

9. A marine antifouling coating, characterized in that: The invention comprises the sustained-release antifouling material as claimed in claim 8.

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