CN113354973B

CN113354973B - Slow-release antifouling agent and preparation method and application thereof

Info

Publication number: CN113354973B
Application number: CN202110622420.3A
Authority: CN
Inventors: 李伟华; 谭旗清; 陈强
Original assignee: Sun Yat Sen University
Current assignee: Sun Yat Sen University
Priority date: 2021-06-03
Filing date: 2021-06-03
Publication date: 2022-06-03
Anticipated expiration: 2041-06-03
Also published as: CN113354973A

Abstract

The invention discloses a slow-release anti-fouling agent and a preparation method and application thereof. The antifouling agent encapsulated in the molecular sieve in situ can be slowly released from the pore canal of the molecular sieve, and once microorganisms attached to ships and various ocean engineering facilities are inhibited by the antifouling agent. The antifouling agent released from the carrier can inhibit microorganisms and can be automatically degraded in the marine environment, so that the adhesion of marine microorganisms on the surface of the metal matrix can be inhibited. The slow-release antifouling agent disclosed by the invention is efficient and durable, high in cost performance, non-toxic and environment-friendly, and has a wide application prospect.

Description

Slow-release antifouling agent and preparation method and application thereof

Technical Field

The invention relates to the field of marine organism fouling protection, and in particular relates to a slow-release antifouling agent and a preparation method and application thereof.

Background

Indole is also called benzopyrrole, indole and its derivatives widely exist in the natural world, and many natural plant structures contain indole rings, and due to the environment-friendly type and high-efficiency antifouling performance of indole compounds in marine environments, indole derivatives have attracted extensive attention as green antifouling agents in the field of marine antifouling in recent years.

Although the research of the indole antifouling agents has achieved a good result at present, efforts are still needed to replace antifouling coatings containing toxic substances, because the indole antifouling agents have two disadvantages, one is the self antifouling activity, the other is the release speed of the indole antifouling agents in seawater, in order to enable the indole antifouling agents to be applied to industry more quickly, the release speed of the indole antifouling agents can be stably controlled through a sustained-release technology, so that the indole antifouling agents can inhibit the attachment of fouling organisms for a long time, and the release speed of the indole antifouling agents is controlled through a micro-embedding method, a porous microparticle and a microtubule adsorption method which are commonly used at present. However, the porous micro-nano-tube and porous microcapsule materials loaded with the anti-indole stain agent belong to macroporous materials, and the structures of the materials are diverse and inhomogeneous, so that the anti-stain agent loaded in the materials are unevenly distributed, and an explosion release phenomenon occurs.

A Molecular sieve (Molecular sieve) is an aluminosilicate compound with a cubic lattice with a uniform pore structure, has the advantages of high adsorption capacity, strong thermal stability and the like which are not possessed by other adsorbents, so that the Molecular sieve can be widely applied, currently, beta Molecular sieves are mainly used in the fields of gas storage, gas separation, catalysis and the like, and Lijiang (2015) discloses a hydrophobic release type antifouling coating, wherein polystyrene-polybutadiene-polystyrene and vinyl fluorosilicone oil are used as reactants to prepare a low-surface-energy resin, an SBA-15 mesoporous Molecular sieve is synthesized and used as a carrier to carry nano silver to serve as an antifouling agent, and the organic low-surface-energy resin and an inorganic silver-carrying antifouling agent are mixed to form a hybrid antifouling coating. The silver-loaded antifouling agent of the molecular sieve adopts a silver-loading-after-loading method, namely, the SBA-15 mesoporous analysis sieve is prepared firstly, and then the Ag is impregnated and loaded, so that the antifouling agent cannot be released stably for a long time. (Lijiang. preparation of novel non-toxic release antifouling coating and study of its properties [ D ]. university of Hainan, 2015.). Therefore, it is desired to provide a sustained-release antifouling agent which can release an antifouling agent stably for a long period of time.

Disclosure of Invention

The invention aims to overcome the defects and shortcomings in the prior art and provide a slow-release antifouling agent.

The invention also aims to provide a preparation method of the slow-release antifouling agent.

The third purpose of the invention is to provide the application of the slow-release antifouling agent.

The above purpose of the invention is realized by the following technical scheme:

a slow-release antifoulant is composed of molecular sieve material and antifoulant encapsulated in it, i.e. the compound of molecular sieve encapsulated antifoulant.

The slow-release antifouling agent adopts a molecular sieve with a plurality of pore passages with uniform pore diameters and a regularly arranged pore structure as a carrier, takes an antifouling agent as a load object, and is subjected to slow and controlled release to inhibit the attachment of microorganisms on ships and various marine engineering facilities in the field of marine environment after the molecular sieve material is combined with the antifouling agent to realize the in-situ encapsulation of the antifouling agent by the molecular sieve. The main action principle is as follows: the anti-fouling agent encapsulated in the molecular sieve in situ can be slowly released from the molecular sieve pore canal, and once microorganisms attached to ships and various ocean engineering facilities are inhibited by the anti-fouling agent. The antifouling agent released from the carrier can inhibit microorganisms and can be automatically degraded in the marine environment, so that the green antifouling performance of the antifouling agent composite system is realized.

Preferably, the molecular sieve material is a beta high-silicon molecular sieve. The beta high-silicon molecular sieve has thermal stability and three-dimensional pore channels, and the regular pore channels of the high-silicon molecular sieve enable the encapsulated antifouling agent to be uniformly distributed in the pore channels, so that the antifouling agent is slowly and uniformly released.

Preferably, the antifouling agent is an indole antifouling agent; because of low toxicity, the compound is widely used for herbicides, fungicides and plant growth regulators and conforms to the development trend of green antifouling agents.

Further preferably, the indole antifouling agent comprises one or more of indole, indole-3-ethanol, indole-3-sodium acetate or dihydroxyarundoin.

Preferably, the mass content of the molecular sieve material in-situ encapsulation antifouling agent is 1-10%

The invention also provides a preparation method of the slow-release antifouling agent, which is characterized in that an antifouling agent solution is added in the process of synthesizing the molecular sieve by a hydrothermal crystallization method, and a compound of the molecular sieve in-situ encapsulation antifouling agent, namely the slow-release antifouling agent, is synthesized.

Specifically, taking the beta high-silicon molecular sieve in-situ loaded antifouling agent as an example, the preparation method comprises the following steps:

s1, under the stirring state, NaAlO is added₂Dissolving NaOH and the mixed solution in deionized water to obtain a mixed solution A;

s2, stirring the mixed solution A obtained in the step S1 to be clear, then slowly adding a silicon source, and stirring for 1 hour to obtain a mixed solution B;

s3, adding beta crystal seeds into the mixed solution B, and stirring for 2-3 hours to obtain a mixed solution C;

s4, rapidly adding the antifouling agent solution into the mixed solution C to obtain a mixed solution D; heating and stirring for 1h, putting into a polytetrafluoroethylene reaction kettle, and carrying out hydrothermal crystallization for 72h in a homogeneous reactor at the temperature of 140 ℃; and filtering the product, washing the product with an ethanol solution for four times, drying the product at room temperature (24h) and grinding the product to obtain the beta molecular sieve in-situ encapsulated artificially synthesized indole natural product antifouling agent, namely the slow-release antifouling agent.

Generally, most zeolite molecular sieves are synthesized in the presence of organic templates, and the use of these templates often causes some disadvantages to a greater or lesser extent, including the high cost of the organic templates, and the removal of these organic templates by high-temperature calcination produces environmentally harmful gases, which have a great influence on their applications. Therefore, the invention adds the green antifouling agent into the beta molecular sieve synthesized by the crystal seed guiding method under the condition of no organic template. The environmental pollution is reduced by combining a low-cost and environment-friendly green synthetic crystal seed guiding method with a green antifouling agent which is easy to degrade in seawater.

Further preferably, the preparation of the beta molecular sieve in-situ encapsulation antifouling agent comprises the following steps:

(1) 0.6g NaAlO₂And 1.5-1.8 g of NaOH added to 45.5g H₂And (3) after stirring and dissolving in O, slowly adding 6.0g of Cab-O-Sil, stirring for 0.5-1 h, slowly adding 0.6-0.9 g of beta seed crystal (the seed amount is 10% -15% of the silicon source), and stirring for 2-3 h.

(2) Adding 1-16% of indole antifouling agent into the mixed solution obtained in the step (1), stirring at normal temperature for 1 hour, heating and stirring for 1-2 hours, and then putting into a polytetrafluoroethylene reaction kettle for hydrothermal crystallization for 72 hours.

Preferably, the preparation method of the beta seed crystal comprises the following steps: according to the molar ratio of the molecular sieve as SiO₂：Al₂O₃：Na₂O：H₂O ═ 40.0: 1.0: 10.0: 570 and preparing the beta molecular sieve by a seed crystal method.

The slow-release antifouling agent can realize long-acting and stable release of the antifouling agent and is used for marine antifouling. Therefore, the invention also provides the application of any one of the slow-release antifouling agents in marine antifouling or preparation of marine antifouling paint; and the application of the molecular sieve material in the preparation of the slow-release antifouling agent.

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

the invention provides a slow-release anti-fouling agent, which consists of a molecular sieve material and an anti-fouling agent encapsulated in the molecular sieve material, wherein the anti-fouling agent encapsulated in situ in the molecular sieve can be slowly released from a molecular sieve pore passage, and is long-acting and stable, so that the adhesion of marine microorganisms on the surface of a metal matrix can be inhibited. The slow-release antifouling agent disclosed by the invention is efficient and durable, high in cost performance, non-toxic and environment-friendly, and has a wide application prospect.

Drawings

FIG. 1 is a molecular structure diagram of 4 indole antifouling agents provided in the embodiment of the present invention.

Fig. 2 is a synthesis route of the antifouling compound composite provided by the embodiment of the invention.

FIG. 3 is an XRD spectrum of beta molecular sieve encapsulated indoles provided by the embodiment of the present invention.

FIG. 4 is a nitrogen isothermal adsorption spectrum of beta molecular sieve encapsulated indole provided in the embodiments of the present invention.

FIG. 5 is a schematic diagram of a temperature programming process for encapsulating indole with beta molecular sieves according to an embodiment of the present invention. (A) A chromatogram representing beta molecular sieve encapsulated indole; (B) represents the mass spectrum of beta molecular sieve encapsulated indole.

FIG. 6 is a UV-Vis spectrum of a beta molecular sieve supported indole anti-fouling agent provided by an embodiment of the present invention.

Fig. 7 is an ultraviolet-visible spectrum of a beta molecular sieve encapsulated indole anti-fouling agent provided by an embodiment of the present invention.

Detailed Description

The invention is further described with reference to the drawings and the following detailed description, which are not intended to limit the invention in any way. The reagents, methods and apparatus employed in the present invention are conventional in the art, except as otherwise indicated.

Unless otherwise indicated, reagents and materials used in the following examples are commercially available.

The invention relates to a compound of an indole antifouling agent encapsulated by a specific molecular sieve, wherein the encapsulated indole antifouling agent is indole (I), indole-3-ethanol (I3E), indole-3-sodium acetate (I3SA) and Dihydroxy Arundoin (DAO), and the obtained compound of the molecular sieve encapsulated antifouling agent is I @ beta, I3E @ beta, I3SA @ beta and DAO @ beta respectively. The high-silicon beta molecular sieve with a hydrophobic surface is used as a carrier, and the artificially synthesized indole anti-fouling agent is used as the anti-fouling agent on the surface of the metal material loaded with an object, wherein the anti-fouling agent encapsulated in the molecular sieve can be slowly released from a molecular sieve pore passage to inhibit the attachment of microorganisms on a ship body. The antifouling system has the advantages of high efficiency, durability, high cost performance, obvious application value and wide market prospect.

Furthermore, based on the protective effect of the beta cavity on the indole antifouling agent guest activity and the property of slow release guest molecules of the beta molecular sieve, the antifouling performance of the indole is enhanced by constructing a core-shell structure system (I @ beta, I3E @ beta, I3SA @ beta, DAO @ beta) of the indole in the beta cavity.

The invention prepares liquid culture medium and solid culture medium and preserves and activates strains according to 4789.28-84 'food hygiene microbiological examination staining method, culture medium and reagent'. The adopted antifouling experimental test method is from the following national standards: microbiological experiments [ M ]. third edition Beijing, higher education Press.

The preparation method of the beta seed crystal described in the following examples is as follows: according to the molar ratio of the molecular sieve as SiO₂：Al₂O₃：Na₂O：H₂O ═ 40.0: 1.0: 10.0: 570 and preparing the beta molecular sieve by a seed crystal method.

Example 1

The preparation of the Beta molecular sieve in-situ encapsulation artificially synthesized indole natural product antifouling agent comprises the following steps:

the first step is as follows: preparation of indole natural product antifouling agents at different concentrations:

firstly, 0.0359g of indole is added into 3mL of deionized water, and then the mixture is stirred for 10min at 40-60 ℃ to obtain 1% indole aqueous solution with the solubility of 100%.

The second step is that: in the process of synthesizing the beta molecular sieve by using a hydrothermal crystallization method, 1% indole aqueous solution is packaged in situ, wherein the beta synthesis reaction formula is shown in figure 2:

firstly, 0.6g of sodium metaaluminate and 1.8g of sodium hydroxide are added into 25.5g of deionized water; and obtaining a solution A, after uniformly stirring, slowly adding 6g of white carbon black, stirring for 1h to obtain a solution B, slowly adding 0.6g of beta crystal seed into the solution B, and stirring for 2-3 h to obtain a solution C.

And then, quickly adding the 1% indole aqueous solution obtained in the first step into the solution C, and stirring for 0.5-1 h at 50-60 ℃.

Then, the obtained gel is transferred to a polytetrafluoroethylene high-pressure reaction kettle to react for 72 hours, and the reaction temperature is 140 ℃.

And finally, filtering the product, washing the product with an ethanol solution for four times, drying the product at room temperature (24h) and grinding the product to obtain the beta molecular sieve in-situ encapsulated artificially synthesized indole natural product antifouling agent, wherein the loading content of the encapsulated antifouling agent is 1%.

And the third step is that the preparation process of 2%, 4%, 8% and 15% indole natural product antifouling agents is the same as the synthesis step, and 2%, 4%, 8% and 10% indole natural product antifouling agent compounds can be prepared by respectively replacing 0.0359g of indole with 0.0719g, 0.1439g, 0.2878g and 0.5396 g.

Example 2

the first step is as follows: preparation of indole-3-ethanol natural product antifouling agents with different concentrations:

firstly, 0.0359g of indole and indole-3-ethanol are added into 3mL of deionized water, and then the mixture is stirred for 14min at 40-60 ℃ to obtain 1% indole-3-ethanol aqueous solution with the solubility of 100%.

The second step is that: in the process of synthesizing the beta molecular sieve by using a hydrothermal crystallization method, 1% indole-3-ethanol aqueous solution is packaged in situ, wherein the beta synthesis reaction formula is shown in figure 2:

firstly, 0.6g of sodium metaaluminate and 1.8g of sodium hydroxide are added into 25.5g of deionized water; and (3) obtaining a solution A, after uniformly stirring, slowly adding 6g of white carbon black, stirring for 1 hour to obtain a solution B, slowly adding 0.6g of beta crystal seed into the solution B, and stirring for 2-3 hours to obtain a solution C.

And then, quickly adding the 1% indole-3-ethanol aqueous solution obtained in the first step into the solution C, and stirring for 0.5-1 h at 50-60 ℃.

And finally, filtering the product, washing the product with an ethanol solution for four times, drying the product at room temperature (24h) and grinding the product to obtain the beta molecular sieve in-situ encapsulated artificially synthesized indole-3-ethanol natural product antifouling agent, wherein the load content of the antifouling agent after encapsulation is 1%.

And the third step is that the preparation process of 2%, 4%, 8% and 15% indole natural product antifouling agent is the same as the synthesis step, and 2%, 4%, 8% and 10% indole-3-ethanol indole natural product antifouling agent compound can be prepared by respectively replacing 0.0359g of indole-3-ethanol with 0.0719g, 0.1439g, 0.2878g and 0.5396 g.

Example 3

the first step is as follows: preparation of indole-3-sodium acetate natural product antifouling agents with different concentrations:

firstly, 0.0359g of indole 3-sodium acetate is added into 3mL of deionized water, and then the mixture is stirred for 16min at 40-60 ℃ to obtain 1% indole 3-sodium acetate aqueous solution with the solubility of 100%.

The second step: in the process of synthesizing the beta molecular sieve by using a hydrothermal crystallization method, 1% indole 3-sodium acetate aqueous solution is packaged in situ, wherein the beta synthesis reaction formula is shown in figure 2:

And then, quickly adding the 2% indole 3-sodium acetate aqueous solution obtained in the first step into the solution C, and stirring for 0.5-1 h at 50-60 ℃.

And the third step is that the preparation process of 2%, 4%, 8% and 15% indole natural product antifouling agents is the same as the synthesis step, and 2%, 4%, 8% and 10% indole 3-sodium acetate natural product antifouling agent compounds can be prepared by respectively replacing 0.0359g of indole 3-sodium acetate with 0.0719g, 0.1439g, 0.2878g and 0.5396 g.

Example 4

the first step is as follows: preparation of different concentrations of dihydroxy arundoin natural product antifouling agent:

firstly, 0.0359g of dihydroxyl arundoin is added into 3mL of deionized water, and then stirred for 30min at 40-60 ℃ to obtain 1% dihydroxyl arundoin aqueous solution, wherein the solubility of the aqueous solution is 100%.

And then, quickly adding the 1% dihydroxyl arundo donax aqueous solution obtained in the first step into the solution C, and stirring for 0.5-1 h at the temperature of 50-60 ℃.

And the third step is that the preparation process of 2%, 4%, 8% and 15% indole natural product antifouling agents is the same as the synthesis step, and 0.0719g, 0.1439g, 0.2878g and 0.5396g of dihydroxyarundoin 0.0359g are respectively replaced, so that 2%, 4%, 8% and 10% dihydroxyarundoin natural product antifouling agent compounds can be prepared.

Test example 1 analysis of physical Properties of beta molecular Sieve-Encapsulated indole composite Material

(1) XRD analysis

The composite material of the beta molecular sieve-encapsulated indole antifouling agent is prepared by combining an in-situ encapsulation technology with a crystal seed guiding method, XRD shows that in figure 3, the encapsulation of guest organic molecules (indole, 3-indole-sodium acetate, indole-3 ethanol and dihydroxy arundoin) does not influence the processes of nucleation, crystallization and the like of the beta molecular sieve. Compared with a pure beta molecular sieve, the diffraction peak of the beta molecular sieve for in-situ encapsulation of the indole organic compounds is basically kept unchanged, and the introduction of the indole organic compounds can not damage the framework structure of the beta molecular sieve.

(2)N₂Adsorption desorption analysis

Using the example of 2beta molecular sieves encapsulated 4% indole (I @ beta), N was performed₂Adsorption and desorption, elemental analysis, and TPD, among others. From the N2-adsorption and desorption characteristics of FIG. 4, the isothermal adsorption lines of the beta molecular sieve before and after encapsulation are consistent with IUPAC type IV isothermal line and relative pressure (P/P)_o) Within the range of 0.43-1.0, the pure beta molecular sieve has an obvious H4 hysteresis loop, which indicates that the beta molecular sieve also has a mesoporous structure. The beta molecular sieve encapsulated with indole has the advantages that the micropore volume is reduced by 51.50%, and the H4 hysteresis loop is reduced, so that the number of mesopores is reduced, presumably caused by the fact that the encapsulated indole occupies mesopores and part of micropores, and the result also indicates that the molecular sieve should successfully encapsulate the indole.

(3) Temperature Programmed Desorption (TPD) analysis

The temperature programmed desorption experiment shows that after the I @ beta composite material is subjected to a high-temperature desorption experiment, indole is gradually volatilized along with the increase of the temperature, and the gas chromatography coupled with TPD can detect the indole within 15min of retention time, as shown in figure 5(A), the indole molecule is shown to be located in a molecular sieve. In the mass spectrum of fig. 5(B), the abscissa shows the fragment peaks of three

organic substances

63, 90 and 117, where 117 is the mass-to-charge ratio of the indole organic substance, which indicates that the volatilized indole gradually decomposes acetylene and butyne with the increase of the desorption temperature.

(4) Ultraviolet visible spectrophotometer

Referring to fig. 6, after the beta molecular sieve loaded with the indole anti-fouling agent by the impregnation method is washed with the absolute ethyl alcohol solvent, no indole ultraviolet absorption peak can be detected, which indicates that indole loaded on the surface of the beta molecular sieve is easy to be washed, and after the compounds I @ beta, I3E @ beta, I3SA @ beta, and DAO @ beta prepared by the in-situ encapsulation technology are washed with the absolute ethyl alcohol, as shown in fig. 7, the absorption peak of the indole anti-fouling agent can still be detected at 288nm, which indicates that the indole anti-fouling agent is successfully encapsulated in the indole anti-fouling agent. In the process of preparing the composite antifouling material by using the crystal seed guiding method, no organic template is introduced, and an effective basis is provided for analyzing the distribution condition of the indole compound in the beta molecular sieve.

Test 2 composite sustained Release Performance test

The difference between the compound for in-situ encapsulation of the indole antifouling agent and the compound for loading the indole antifouling agent by an impregnation method is compared. Soaking indole anti-fouling agents with different concentrations in absolute ethyl alcohol solution by adopting a dipping method, and stirring overnight until the absolute ethyl alcohol solution is completely volatilized, so that the indole anti-fouling agents are loaded on the outer surface of the beta molecular sieve. The encapsulation rate, loading rate, release rate and release amount of the compound are tested by ultraviolet visible absorption spectrum before testing. 0.3g of the composite and 0.3g of the indole antifouling agent-loaded beta molecular sieve by an impregnation method are soaked in a 3.5% NaCl solution and stirred for 180 days, washed by an ethanol solution, and the composite is filtered and stirred for 5 days in 20mL of 75% ethanol to test the release rate.

Table 1 table comparing sustained release performance of example 1 with that of indole loaded by immersion

TABLE 2 comparison of the sustained Release Performance of example 2 with Indol-3-ethanol loaded by immersion

TABLE 3 comparison of the sustained Release Performance of example 3 with Indole-3-sodium acetate loaded by immersion

Table 4 comparative table of sustained release performance of example 4 versus impregnation supported dihydroxyarundoin

Through the data analysis, the indole anti-fouling agent can be stably and long-term released by encapsulating the indole anti-fouling agent into the pore channel of the beta molecular sieve in situ. And when the indole anti-fouling agent is loaded on the outer surface of the beta molecular sieve by adopting an immersion method, the indole anti-fouling agent is completely released after 180 days. Therefore, the composite of the invention which adopts the molecular sieve to encapsulate the anti-fouling agent in situ can stably release the anti-fouling agent.

Test example 3 antifouling property test

(1) Minimum Inhibitory Concentration (MIC)

MIC measurement was carried out by the two-fold dilution method in a bactericide test tube on the antifouling systems of examples 1 to 4. The antifouling systems of examples 1 to 4 were dissolved in dimethyl sulfoxide to prepare a solution of 2 mg/mL. Taking 10 sterilized small test tubes, respectively injecting 2mL of sterilized liquid culture medium into the small test tubes, after changing a gun head, injecting 2mL of the 2mg/mL bactericide into the first test tube, after uniformly oscillating, transferring 2mL of mixed solution from the first test tube into the second test tube, uniformly mixing, changing the gun head, transferring 2mL of mixed solution from the second test tube into the third test tube, uniformly mixing, diluting test tubes by test tubes until reaching a ninth test tube, and finally taking 2mL of mixed solution from the ninth test tube and pouring into a waste liquid tank. The tenth tube is a reference without added bactericide.

And (3) injecting 200 mu L of diluted bacterial suspension into the ten large test tubes, culturing for 24 hours at 37 ℃ in a shaking incubator, observing the growth condition of bacteria in each test tube, generally considering that the mass concentration of the compound which obviously grows aseptically in the test tube is the minimum inhibitory concentration, measuring the ultraviolet visible absorption value of the bacterial liquid in each test tube, and determining the antibacterial performance of the antifouling system of the embodiment 1-4.

TABLE 6 MIC (g/L) of antifouling systems of examples 1 to 4 for Escherichia coli

Concentration of Complex	l@beta	I3E@beta	I3SA@beta	DAO@beta
						1％	1.00	1.00	1.00	1.00
2％	0.630	0.660	0.700	0.690
					4％	0.600	0.610	0.620	0.640
8％	0.054	0.055	0.057	0.056
					10％	0.050	0.060	0.056	0.065

The test results show that the compound for encapsulating the antifouling agent by the molecular sieve frame has low consumption and high antifouling efficiency, and has obvious application value and wide market prospect.

(2) Sterilization Rate testing

3% of the antifouling system of examples 1 to 4 was added to the epoxy coating, the coating preparation ratio was epoxy: curing agent: diluent agent: compound 1: 1: 0.9: 0.03. soaking the prepared coating in 3.6% NaCl solution, stirring for 120 days, putting the coating into 50mL of Escherichia coli liquid with OD 1, culturing at 37 ℃ for 10h, taking out supernatant, diluting ten times, inoculating the strain into solid culture medium, performing 5 parallel experiments, detecting the viable count in a sample plate, and calculating the antibacterial rate of the coating, wherein the results are shown in Table 7

TABLE 7 Sterilization percentage (%) of Escherichia coli in the antifouling systems of examples 1 to 4

Concentration of Complex	l@beta	I3E@beta	I3SA@beta	DAO@beta
					Blank space	10.3％	11.20％	9.12％	9.14％
Epoxy varnish	35.10％	45.10％	43.10％	41.30％
					1％	88.10％	88.10％	87.32％	88.78％
2％	89.2％	86.20％	86.20％	89.30％
					4％	90.3％	90.60％	90.30％	90.20％
8％	91.80％	93.20％	94.14％	92.20％
					10％	96.50％	97.5％	96.20％	9887％

As can be seen from the table above, the compound of the invention is applied to the antifouling coating, and the sterilization rate is greater than 88.10%, which shows that the compound has better antifouling performance.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. The slow release type anti-fouling agent is characterized by consisting of a Beta molecular sieve material and an indole anti-fouling agent encapsulated in the Beta molecular sieve material in situ; the preparation method of the slow-release antifouling agent comprises the following steps:

s1, under the stirring state, NaAlO is added₂Dissolving NaOH in deionized water to obtain a mixed solution A;

s2, after dissolving the mixed solution A in the step S1, slowly adding a silicon source, and stirring for 0.5-1 h to obtain a mixed solution B;

s4, rapidly adding the indole anti-fouling agent solution into the mixed solution C to obtain a mixed solution D; heating to 40-60 ℃, stirring for 1-2 h, and carrying out hydrothermal crystallization for 72h in a homogeneous reactor at the temperature of 140 ℃; and filtering the product, washing the product by using an ethanol solution, drying the product at room temperature, and grinding the product to obtain the beta molecular sieve in-situ encapsulated artificially synthesized indole natural product antifouling agent, namely the slow-release antifouling agent.

2. The sustained-release antifouling agent according to claim 1, wherein the indole antifouling agent is one or more of indole, indole-3-ethanol, indole-3-sodium acetate, or dihydroxyarundoin.

3. The slow-release antifouling agent according to claim 1, wherein the mass content of the molecular sieve material-encapsulated antifouling agent is 1-10%.

4. The method for preparing the slow-release antifouling agent according to any one of claims 1 to 3, wherein an antifouling agent solution is added during the synthesis of the molecular sieve by a hydrothermal crystallization method to synthesize a compound of the molecular sieve in-situ encapsulated antifouling agent, namely the slow-release antifouling agent; the method specifically comprises the following steps:

s4, rapidly adding the indole antifoulant solution into the mixed solution C to obtain a mixed solution D; heating to 40-60 ℃, stirring for 1-2 h, and carrying out hydrothermal crystallization in a homogeneous reactor at the temperature of 140 ℃ for 72 h; filtering the product, washing the product with an ethanol solution, drying the product at room temperature, and grinding the product to obtain a beta molecular sieve in-situ encapsulated artificially synthesized indole natural product antifouling agent, namely the slow-release antifouling agent;

the antifouling agent is an indole antifouling agent.

5. The use of the slow-release antifouling agent as claimed in any one of claims 1 to 3 in marine antifouling or in the preparation of marine antifouling paints.

6. A marine antifouling paint comprising the slow-release antifouling agent according to any one of claims 1 to 3.