Photoresponsive multilayer self-assembled antifouling drag-reducing composite coating, its preparation and application

Abstract

The application discloses a kind of light-responsive multilayer self-assembled antifouling drag-reducing composite coatings and its preparation method and application.The light-responsive multilayer self-assembled antifouling drag-reducing composite coatings include substrate layer, multiple self-assembled functional unit layers and top functional unit layer formed on the surface of substrate in sequence;Wherein, the self-assembled functional unit layer is sequentially formed by elastic layer, connecting layer I, light-responsive antifouling layer, connecting layer II by self-assembly;The top functional unit layer is sequentially formed by elastic layer, connecting layer I, light-responsive antifouling layer by self-assembly.The light-responsive multilayer self-assembled antifouling drag-reducing composite coatings in the application has strong adhesion to substrate, also has antifouling drag-reducing performance, and the preparation method provided by the application has the advantages of wide application range, large-area coating, etc.

Description

Technical Field

[0001] This invention belongs to the field of marine coating protection technology, specifically relating to a photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating, its preparation method, and its application. Background Technology

[0002] With the development of the maritime transport industry and the increasing awareness of environmental protection, improving shipping speed, reducing energy consumption, and lowering greenhouse gas emissions have become urgent development needs. Currently, antifouling and drag reduction technologies are among the most effective measures to address these challenges. These technologies primarily rely on single antifouling techniques, reducing biofouling to decrease ship drag, rarely combining active drag reduction capabilities simultaneously. Combining antifouling materials with drag reduction technologies to simultaneously achieve both antifouling adhesion and frictional resistance reduction on ship surfaces has significant application value. Flexible drag reduction technology uses the flexibility of materials to suppress and absorb water pressure fluctuations, delaying the transition from laminar to turbulent flow, thereby achieving drag reduction. Organically combining antifouling technology with flexible drag reduction technology has significant application and economic value. Summary of the Invention

[0003] The main objective of this invention is to provide a photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating, its preparation method and application, in order to overcome the shortcomings of the prior art.

[0004] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0005] This invention provides a photoresponsive multilayer self-assembly anti-fouling and drag-reducing composite coating, which includes a base layer, a plurality of self-assembly functional unit layers and a top functional unit layer sequentially formed on the surface of a substrate.

[0006] The self-assembly functional unit layer is formed by self-assembly of an elastic layer, a connecting layer I, a photoresponsive antifouling layer, and a connecting layer II in sequence; the top functional unit layer is formed by self-assembly of an elastic layer, a connecting layer I, and a photoresponsive antifouling layer in sequence.

[0007] The elastic layer is formed by at least a mixture of flexible polymer resin and auxiliary antifouling agent; the connecting layer I and connecting layer II are both formed by at least a mixture of polydopamine and functional particles; the photoresponsive antifouling layer is formed by at least a mixture of tannic acid, alkane-based siloxane, and auxiliary antifouling agent; the functional particles are silane-modified micro / nano particles; wherein the silane includes one or more combinations of aminosilane, epoxysilane, methacryloxysilane, and isocyanate-based silane; the auxiliary antifouling agent includes any one or more combinations of titanium dioxide particles, silver nanoparticles, capsaicin, and chitosan.

[0008] This invention also provides a method for preparing the aforementioned photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating, comprising:

[0009] (1) A first base liquid comprising at least an adhesive resin, a filler, and a diluent is applied to the surface of a substrate and subjected to a first curing treatment to form a base layer;

[0010] (2) A second base liquid comprising at least a flexible polymer resin, an auxiliary antifouling agent, and solvent I is applied to the surface of the substrate layer and subjected to a second curing treatment to form an elastic layer; a third base liquid comprising at least polydopamine, functional particles, and solvent II is applied to the surface of the elastic layer and subjected to a third curing treatment to form a connecting layer I; a fourth base liquid comprising at least tannic acid, alkylsiloxane, an auxiliary antifouling agent, and solvent III is applied to the surface of the connecting layer I and subjected to a fourth curing treatment to form a photoresponsive antifouling layer; the third base liquid is applied to the surface of the photoresponsive antifouling layer and subjected to a third curing treatment to form a connecting layer II; thereby forming a self-assembled functional unit layer;

[0011] (3) Repeat step (2) until multiple self-assembled functional unit layers are formed;

[0012] (4) An elastic layer, a connecting layer I, and a photoresponsive antifouling layer are formed on the surface of a plurality of self-assembled functional unit layers by using a second base liquid, a third base liquid, and a fourth base liquid in sequence, to obtain a top functional unit layer, thereby obtaining a photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating.

[0013] This invention also provides the application of the aforementioned photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating in the surface protection of ship hulls, pipelines, offshore platforms, or underwater structures.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating provided by the present invention achieves comprehensive performance optimization by effectively coupling multiple functional layers; each functional layer retains its original function while achieving independent control through fine segmentation, and utilizes the strong adhesion of dopamine to establish a strong interface bond between the elastic layer and the antifouling layer containing tannic acid and photoresponsive particles, thereby achieving integrity; at the same time, the preparation method adopted by the present invention has the advantages of wide applicability and large-area coating. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating in a typical embodiment of the present invention. Detailed Implementation

[0017] In view of the deficiencies of existing technologies, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. This invention innovatively proposes a multi-layered structural design, organically integrating materials with flexibility, antifouling properties, and photoresponsiveness through layer-by-layer self-assembly, to achieve the synergistic enhancement of photoresponsive antifouling and drag-reducing materials. Through the design of the base layer, a strong bond is achieved between the functional coating and the substrate, significantly improving the product's service life. To enhance the connection between the elastic layer and the antifouling layer, polydopamine is introduced to tightly bond the elastic layer and the tannic acid antifouling layer. This bonding not only ensures structural stability, but the interaction between the phenolic hydroxyl groups in tannic acid and the amino groups in polydopamine also synergistically inhibits microbial growth, further enhancing the product's antifouling and antibacterial properties. Furthermore, the broad-spectrum light absorption of polydopamine, after being combined with tannic acid, greatly improves the product's photothermal efficiency through π-π stacking and hydrogen bonding interactions. As the temperature rises due to light exposure, tannic acid and auxiliary antifouling agents are gradually released, which not only triggers enhanced antifouling effects but also enables continuous regulation and optimization of product performance.

[0018] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Specifically, as one aspect of the technical solution of the present invention, the photoresponsive multilayer self-assembly anti-fouling and drag-reducing composite coating includes a base layer, a plurality of self-assembly functional unit layers and a top functional unit layer sequentially formed on the surface of the substrate.

[0020] The self-assembly functional unit layer is formed by self-assembly of an elastic layer, a connecting layer I, a photoresponsive antifouling layer, and a connecting layer II in sequence; the top functional unit layer is formed by self-assembly of an elastic layer, a connecting layer I, and a photoresponsive antifouling layer in sequence.

[0021] The elastic layer is formed by at least a mixture of flexible polymer resin and auxiliary antifouling agent; the connecting layer I and connecting layer II are both formed by at least a mixture of polydopamine and functional particles; the photoresponsive antifouling layer is formed by at least a mixture of tannic acid, alkane-based siloxane, and auxiliary antifouling agent; the functional particles are silane-modified micro / nano particles; wherein the silane includes one or more combinations of aminosilane, epoxysilane, methacryloxysilane, and isocyanate-based silane; the auxiliary antifouling agent includes any one or more combinations of titanium dioxide particles, silver nanoparticles, capsaicin, and chitosan.

[0022] In some preferred embodiments, the photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating comprises 2 to 10 self-assembly functional unit layers.

[0023] In some preferred embodiments, the base layer is in contact with an elastic layer in a self-assembling functional unit layer.

[0024] In some preferred embodiments, the thickness of the substrate layer is 10~20 μm.

[0025] In some preferred embodiments, the thickness of the plurality of self-assembled functional unit layers is 10~100μm.

[0026] In some preferred embodiments, within each self-assembly functional unit layer, the thickness of the elastic layer is 1~10μm, the thickness of the connecting layer I is 0.01~5μm, the thickness of the photoresponsive antifouling layer is 0.01~5μm, and the thickness of the connecting layer II is 0.01~5μm.

[0027] In some preferred embodiments, the thickness of the top functional unit layer is 1.02~20μm.

[0028] In some preferred embodiments, the thickness of the elastic layer in the top functional unit layer is 1~10μm, the thickness of the connecting layer I is 0.01~5μm, and the thickness of the photoresponsive antifouling layer is 0.01~5μm.

[0029] In some preferred embodiments, the method for preparing the functional particles includes: mixing silane with micro / nano particles and reacting at 20-60°C for 4-24 hours to obtain functional particles; wherein the micro / nano particles include one or more combinations of micro / nano SiO2 particles, micro / nano TiO2 particles, carbon nanotubes, and diatomaceous earth; and the mass ratio of silane to micro / nano particles is 0.1-1:0.5-2.

[0030] In some preferred embodiments, the base layer is formed by mixing and reacting at least adhesive resin, filler, and diluent.

[0031] Another aspect of the present invention provides a method for preparing the aforementioned photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating, comprising:

[0032] (1) A first base liquid comprising at least an adhesive resin, a filler, and a diluent is applied to the surface of a substrate and subjected to a first curing treatment to form a base layer;

[0033] (2) A second base liquid comprising at least a flexible polymer resin, an auxiliary antifouling agent, and solvent I is applied to the surface of the substrate layer and subjected to a second curing treatment to form an elastic layer; a third base liquid comprising at least polydopamine, functional particles, and solvent II is applied to the surface of the elastic layer and subjected to a third curing treatment to form a connecting layer I; a fourth base liquid comprising at least tannic acid, alkylsiloxane, an auxiliary antifouling agent, and solvent III is applied to the surface of the connecting layer I and subjected to a fourth curing treatment to form a photoresponsive antifouling layer; the third base liquid is applied to the surface of the photoresponsive antifouling layer and subjected to a third curing treatment to form a connecting layer II; thereby forming a self-assembled functional unit layer;

[0034] (3) Repeat step (2) until multiple self-assembled functional unit layers are formed;

[0035] (4) An elastic layer, a connecting layer I, and a photoresponsive antifouling layer are formed on the surface of a plurality of self-assembled functional unit layers by using a second base liquid, a third base liquid, and a fourth base liquid in sequence to obtain a top functional unit layer, which is then cured at room temperature to obtain a photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating.

[0036] In some preferred embodiments, the first curing treatment is performed at room temperature for 6 to 24 hours.

[0037] In some preferred embodiments, the second curing treatment is performed at room temperature for 4 to 12 hours.

[0038] In some preferred embodiments, the third curing treatment is performed at room temperature for 0.1 to 2 hours.

[0039] In some preferred embodiments, the fourth curing treatment is performed at room temperature for 0.1 to 2 hours.

[0040] In some preferred embodiments, the room temperature curing time is 6 to 30 hours.

[0041] In some preferred embodiments, the first base liquid comprises the following components by mass percentage: 20-50 wt% adhesive resin, 1-10 wt% filler and 0-40 wt% diluent.

[0042] In some preferred embodiments, the second base liquid comprises the following components by mass ratio: 20-50 wt% flexible polymer resin, 1-10 wt% auxiliary antifouling agent, and 0-60 wt% solvent I.

[0043] In some preferred embodiments, the third base liquid comprises the following components by mass ratio: 10-50 wt% polydopamine, 1-10 wt% functional particles, and 0-60 wt% solvent II.

[0044] In some preferred embodiments, the fourth base liquid comprises the following components by mass ratio: 10-50 wt% tannic acid, 1-10 wt% alkane-based siloxane, 1-10 wt% auxiliary antifouling agent, and 0-60 wt% solvent III.

[0045] In some preferred embodiments, the adhesive resin includes any one or more combinations of modified epoxy resin, epoxy zinc-rich primer, acrylic polyurethane varnish, amino silicone resin, and polyurethane modified epoxy resin, and is not limited thereto.

[0046] In some preferred embodiments, the filler includes any one or a combination of two or more of bentonite, talc, zinc oxide, titanium dioxide, silica, glass microspheres, and diatomaceous earth, and is not limited thereto.

[0047] In some preferred embodiments, the particle size of the filler is 0.01~30 μm.

[0048] In some preferred embodiments, the diluent includes any one or more combinations of toluene, xylene, ethanol, ethyl acetate, butyl acetate, and propylene glycol methyl ether, and is not limited thereto.

[0049] In some preferred embodiments, the flexible polymer resin includes any one or more combinations of silicone resin, polyurethane modified resin, acrylic modified silicone resin, and polyurea, and is not limited thereto.

[0050] In some preferred embodiments, the alkane-based siloxane includes any one or more combinations of aminopropyltriethoxysilane, aminopropyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, and 3-mercaptopropyltrimethoxysilane, and is not limited thereto.

[0051] In some preferred embodiments, solvent I, solvent II, and solvent III each include any one or a combination of two or more of anhydrous ethanol, methanol, dimethyl sulfoxide, dimethylformamide, acetone, diethyl ether, xylene, and ethyl acetate, and are not limited thereto.

[0052] Another aspect of the present invention provides the application of the aforementioned photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating in the surface protection of ship hulls, pipelines, offshore platforms, or underwater structures.

[0053] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0054] Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0055] Example 1

[0056] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0057] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure at room temperature for 12 hours to form an elastic layer;

[0058] (3) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0059] (4) Dissolve 20 wt.% tannic acid, 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above-mentioned connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0060] (5) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0061] (6) Repeat steps (2) to (5) once to obtain two self-assembly functional unit layers;

[0062] (7) Repeat steps (2) to (4) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain a photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating.

[0063] Example 2

[0064] (1) Dissolve 65 wt.% acrylic polyurethane paint, 2.5 wt.% titanium dioxide and 2.5 wt.% zinc oxide in a 1:1 mixture of xylene and ethyl acetate, stir mechanically until uniform, and obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0065] (2) Dissolve 70 wt.% of single-component polyurethane modified silicone resin and 5 wt.% of chitosan in a 1:1 mixture of xylene and ethyl acetate, and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ, and cure at room temperature for 8 hours to form an elastic layer;

[0066] (3) Dissolve 20 wt.% polydopamine and 5 wt.% methacryloyloxysilane modified SiO2 particles in anhydrous ethanol solvent and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0067] (4) Dissolve 20 wt.% tannic acid, 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in anhydrous ethanol and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above-mentioned connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0068] (5) Dissolve 20 wt.% polydopamine and 5 wt.% methacryloyloxysilane modified SiO2 particles in anhydrous ethanol and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the above photoresponsive antifouling layer in situ and dry it at room temperature for 2 hours to form the connecting layer II;

[0069] (6) Repeat steps (2) to (5) once to obtain two self-assembly functional unit layers;

[0070] (7) Repeat steps (2) to (4) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain a photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating.

[0071] Example 3

[0072] (1) Dissolve 70 wt.% epoxy zinc-rich primer, 2.5 wt.% silica and 2.5 wt.% diatomaceous earth in a 1:1 mixture of xylene and butyl acetate, and stir mechanically until homogeneous to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0073] (2) Dissolve 70 wt.% acrylic modified silicone resin and 5 wt.% capsaicin in a 1:1 mixture of xylene and butyl acetate, and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ, and cure at room temperature for 10 h to form an elastic layer;

[0074] (3) Dissolve 20 wt.% polydopamine and 5 wt.% octadecyltrimethoxysilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0075] (4) Dissolve 20 wt.% tannic acid, 5 wt.% 3-mercaptopropyltrimethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% chitosan in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0076] (5) Dissolve 20 wt.% polydopamine and 5 wt.% octadecyltrimethoxysilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0077] (6) Repeat steps (2) to (5) once to obtain two self-assembly functional unit layers;

[0078] (7) Repeat steps (2) to (4) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain a photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating.

[0079] Comparative Example 1 (lacking a basal layer compared to Example 1)

[0080] (1) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above substrate in situ and cure at room temperature for 12 hours to form an elastic layer;

[0081] (2) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0082] (3) Dissolve 20 wt.% tannic acid, 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt.% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above-mentioned connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0083] (4) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0084] (5) Repeat steps (1) to (4) once to obtain two self-assembly functional unit layers;

[0085] (6) Repeat steps (1) to (3) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain a multi-layer self-assembled composite coating.

[0086] Performance characterization: The prepared composite coating has poor film-substrate adhesion and is easy to peel off.

[0087] Comparative Example 2 (lacking an elastic layer compared to Example 1)

[0088] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0089] (2) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above base layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0090] (3) Dissolve 20 wt.% tannic acid, 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above-mentioned connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0091] (4) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0092] (5) Repeat steps (2) to (4) once, and then repeat steps (2) to (3) to cure the prepared material at room temperature for 12 hours to obtain a multi-layer self-assembled composite coating.

[0093] Performance characterization: The prepared composite coating lacks flexibility and has poor drag reduction performance.

[0094] Comparative Example 3 (lacking a connecting layer compared to Example 1)

[0095] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0096] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure at room temperature for 12 hours to form an elastic layer;

[0097] (3) Dissolve 20 wt.% tannic acid, 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above elastic layer in situ and cure at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0098] (4) Repeat steps (2) to (3) twice to cure the prepared material at room temperature for 12 hours to obtain a multi-layer self-assembled composite coating.

[0099] Performance characterization: The antifouling layer and elastic layer of the prepared composite coating have poor adhesion and are easy to fall off.

[0100] Comparative Example 4 (lacking a light-responsive antifouling layer compared to Example 1)

[0101] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0102] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure at room temperature for 12 hours to form an elastic layer;

[0103] (3) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0104] (4) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above-mentioned connecting layer I and dry it at room temperature for 2 hours to form connecting layer II;

[0105] (6) Repeat steps (2) to (4) once, and then repeat steps (2) to (3) to cure the prepared material at room temperature for 12 hours to obtain a multi-layer self-assembled composite coating.

[0106] Performance characterization: The prepared composite coating has no photoresponsiveness and poor antifouling performance.

[0107] Comparative Example 5 (lacking auxiliary antifouling agent compared to Example 1)

[0108] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0109] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin in xylene and stir it evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure it at room temperature for 12 hours to form an elastic layer;

[0110] (3) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in xylene and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0111] (4) Dissolve 20 wt.% tannic acid and 5 wt.% aminopropyltriethoxysilane in xylene and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above-mentioned connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0112] (5) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in xylene and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0113] (6) Repeat steps (2) to (5) once, and then repeat steps (2) to (4) to cure the prepared material at room temperature for 12 hours to obtain a multi-layer self-assembled composite coating.

[0114] Performance characterization: The prepared composite coating has poor anti-fouling performance.

[0115] Comparative Example 6 (lacking polydopamine compared to Example 1)

[0116] The method is the same as in Example 1, except that polydopamine is missing when preparing connecting layer I and connecting layer II.

[0117] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0118] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure at room temperature for 12 hours to form an elastic layer;

[0119] (3) Dissolve 5 wt.% aminosilane-modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0120] (4) Dissolve 20 wt.% tannic acid, 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above-mentioned connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0121] (5) Dissolve 5 wt.% aminosilane-modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0122] (6) Repeat steps (2) to (5) once to obtain two self-assembly functional unit layers;

[0123] (7) Repeat steps (2) to (4) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain the composite coating.

[0124] Performance characterization: The prepared composite coating has poor adhesion and is easy to fall off.

[0125] Comparative Example 7 (The method is the same as in Example 1, except that the aminosilane-modified SiO2 particles are replaced by SiO2 particles.)

[0126] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0127] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure at room temperature for 12 hours to form an elastic layer;

[0128] (3) Dissolve 20 wt.% polydopamine and 5 wt.% SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 hour to form the connecting layer I;

[0129] (4) Dissolve 20 wt.% tannic acid, 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above-mentioned connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0130] (5) Dissolve 20 wt.% polydopamine and 5 wt.% SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above photoresponsive antifouling layer in situ and dry it at room temperature for 2 hours to form the connecting layer II;

[0131] (6) Repeat steps (2) to (5) once to obtain two self-assembly functional unit layers;

[0132] (7) Repeat steps (2) to (4) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain the composite coating.

[0133] Performance characterization: The prepared composite coating showed a decrease in contact angle, a deterioration in hydrophobicity, and a reduction in antifouling properties.

[0134] Comparative Example 8 (The method is the same as in Example 1, except that the photoresponsive antifouling layer lacks tannins.)

[0135] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0136] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure at room temperature for 12 hours to form an elastic layer;

[0137] (3) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0138] (4) Dissolve 5 wt.% aminopropyltriethoxysilane, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above connecting layer I in situ and cure it at room temperature for 1 h to form a photoresponsive antifouling layer;

[0139] (5) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0140] (6) Repeat steps (2) to (5) once to obtain two self-assembly functional unit layers;

[0141] (7) Repeat steps (2) to (4) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain the composite coating.

[0142] Performance characterization: The bonding force between the antifouling layer and the bonding layer of the prepared composite coating deteriorates.

[0143] Comparative Example 9 (lacking alkane-based siloxanes compared to Example 1)

[0144] The method is the same as in Example 1, except that the photoresponsive antifouling layer lacks aminopropyltriethoxysilane.

[0145] (1) Dissolve 70 wt.% high solids content epoxy resin, 2.5 wt.% talc powder and 2.5 wt.% zinc oxide in xylene and mix evenly to obtain the first base liquid; brush the base liquid onto the surface of the substrate and cure at room temperature for 8 hours to form a base layer;

[0146] (2) Dissolve 70 wt.% of single-component high-elasticity silicone resin and 5 wt.% of silver nanoparticles in xylene and stir evenly by mechanical stirring to obtain a second base liquid; brush the base liquid onto the surface of the above base layer in situ and cure at room temperature for 12 hours to form an elastic layer;

[0147] (3) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid onto the surface of the above elastic layer in situ and dry it at room temperature for 1 h to form the connecting layer I;

[0148] (4) Dissolve 20 wt.% tannic acid, 2.5 wt.% silver nanoparticles and 2.5 wt% TiO2 particles in dimethylformamide and stir evenly by mechanical stirring to obtain the fourth base liquid; brush the base liquid onto the surface of the above connecting layer I in situ and cure it at room temperature for 1 hour to form a photoresponsive antifouling layer;

[0149] (5) Dissolve 20 wt.% polydopamine and 5 wt.% aminosilane modified SiO2 particles in dimethyl sulfoxide and stir evenly by mechanical stirring to obtain the third base liquid; brush the base liquid in situ onto the surface of the above photoresponsive antifouling layer and dry it at room temperature for 2 hours to form the connecting layer II;

[0150] (6) Repeat steps (2) to (5) once to obtain two self-assembly functional unit layers;

[0151] (7) Repeat steps (2) to (4) to prepare the elastic layer, the connecting layer I, and the photoresponsive antifouling layer in sequence to form the top functional unit layer. The prepared material is cured at room temperature for 12 hours to obtain the composite coating.

[0152] Performance characterization: The bonding force between the prepared antifouling layer and the bonding layer decreased, the contact angle decreased, the hydrophobicity deteriorated, and the antifouling performance decreased.

[0153] The composite materials provided in the proportions and examples of this invention were subjected to performance tests, and the specific test results are shown in Table 1 below:

[0154] Table 1. Properties of the materials prepared in Examples 1-3 and Comparative Examples 1-9

[0155]

[0156] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0157] It should be understood that the technical solutions of the present invention are not limited to the specific embodiments described above. Any technical modifications made to the technical solutions of the present invention without departing from the spirit and scope of the claims are within the scope of protection of the present invention.

Claims

1. A photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating, characterized in that, It includes a base layer, a plurality of self-assembly functional unit layers and a top functional unit layer formed sequentially on the surface of the substrate; The self-assembly functional unit layer is formed by self-assembly of an elastic layer, a connecting layer I, a photoresponsive antifouling layer, and a connecting layer II in sequence; the top functional unit layer is formed by self-assembly of an elastic layer, a connecting layer I, and a photoresponsive antifouling layer in sequence. The elastic layer is formed by at least a mixture of flexible polymer resin and auxiliary antifouling agent; the connecting layer I and connecting layer II are both formed by at least a mixture of polydopamine and functional particles; the photoresponsive antifouling layer is formed by at least a mixture of tannic acid, alkane-based siloxane, and auxiliary antifouling agent; the functional particles are silane-modified micro / nano particles; wherein the silane includes one or more combinations of aminosilane, epoxysilane, methacryloxysilane, and isocyanate-based silane; the auxiliary antifouling agent includes any one or more combinations of titanium dioxide particles, silver nanoparticles, capsaicin, and chitosan.

2. The photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating according to claim 1, characterized in that: The photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating comprises 2 to 10 self-assembly functional unit layers. And / or, the base layer is in contact with an elastic layer in a self-assembling functional unit layer.

3. The photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating according to claim 1, characterized in that: The thickness of the substrate layer is 10~20μm; And / or, the thickness of the plurality of self-assembly functional unit layers is 10~100μm; and / or, within each self-assembly functional unit layer, the thickness of the elastic layer is 1~10μm, the thickness of the connecting layer I is 0.01~5μm, the thickness of the photoresponsive antifouling layer is 0.01~5μm, and the thickness of the connecting layer II is 0.01~5μm; And / or, the thickness of the top functional unit layer is 1.02~20μm; and / or, the thickness of the elastic layer in the top functional unit layer is 1~10μm, the thickness of the connecting layer I is 0.01~5μm, and the thickness of the photoresponsive antifouling layer is 0.01~5μm.

4. The photoresponsive multilayer self-assembly anti-fouling and drag-reducing composite coating according to claim 1, characterized in that, The method for preparing the functional particles includes: mixing silane with micro / nano particles and reacting at 20-60°C for 4-24 hours to obtain functional particles; wherein the micro / nano particles include one or more combinations of micro / nano SiO2 particles, micro / nano TiO2 particles, carbon nanotubes, and diatomaceous earth; and the mass ratio of silane to micro / nano particles is 0.1-1:0.5-2.

5. The photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating according to claim 1, characterized in that: The base layer is formed by the reaction of at least adhesive resin, filler and diluent.

6. The method for preparing the photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating as described in any one of claims 1-5, characterized in that, include: (1) A first base liquid comprising at least an adhesive resin, a filler, and a diluent is applied to the surface of a substrate and subjected to a first curing treatment to form a base layer; (2) A second base liquid comprising at least a flexible polymer resin, an auxiliary antifouling agent, and solvent I is applied to the surface of the substrate layer and subjected to a second curing treatment to form an elastic layer; a third base liquid comprising at least polydopamine, functional particles, and solvent II is applied to the surface of the elastic layer and subjected to a third curing treatment to form a connecting layer I; a fourth base liquid comprising at least tannic acid, alkane-based siloxane, an auxiliary antifouling agent, and solvent III is applied to the surface of the connecting layer I and subjected to a fourth curing treatment to form a photoresponsive antifouling layer; the third base liquid is applied to the surface of the photoresponsive antifouling layer and subjected to a third curing treatment to form a connecting layer II; thereby forming a self-assembled functional unit layer; (3) Repeat step (2) until multiple self-assembled functional unit layers are formed; (4) An elastic layer, a connecting layer I, and a photoresponsive antifouling layer are formed on the surface of a plurality of self-assembled functional unit layers by using a second base liquid, a third base liquid, and a fourth base liquid in sequence to obtain a top functional unit layer, which is then cured at room temperature to obtain a photoresponsive multilayer self-assembled antifouling and drag-reducing composite coating.

7. The preparation method according to claim 6, characterized in that: The first curing treatment is performed at room temperature for 6 to 24 hours. And / or, the second curing treatment is performed at room temperature for 4 to 12 hours; And / or, the third curing treatment is performed at room temperature for 0.1 to 2 hours; And / or, the fourth curing treatment is performed at room temperature for 0.1 to 2 hours.

8. The preparation method according to claim 6, characterized in that: The first base liquid comprises the following components by mass percentage: 20-50 wt% adhesive resin, 1-10 wt% filler and 0-40 wt% diluent; And / or, the second base liquid comprises the following components calculated by mass ratio: 20-50 wt% flexible polymer resin, 1-10 wt% auxiliary antifouling agent and 0-60 wt% solvent I; And / or, the third base liquid comprises the following components by mass ratio: 10-50 wt% polydopamine, 1-10 wt% functional particles and 0-60 wt% solvent II; And / or, the fourth base liquid comprises the following components by mass ratio: 10-50 wt% tannic acid, 1-10 wt% alkane-based siloxane, 1-10 wt% auxiliary antifouling agent, and 0-60 wt% solvent III.

9. The preparation method according to claim 6, characterized in that: The adhesive resin includes any one or more combinations of modified epoxy resin, epoxy zinc-rich primer, acrylic polyurethane paint, amino silicone resin, and polyurethane modified epoxy resin. And / or, the filler comprises any one or a combination of two or more of bentonite, talc, zinc oxide, titanium dioxide, silica, glass microspheres, and diatomaceous earth; and / or, the particle size of the filler is 0.01~30 μm; And / or, the diluent comprises any one or more combinations of toluene, xylene, ethanol, ethyl acetate, butyl acetate, and propylene glycol methyl ether; And / or, the flexible polymer resin includes any one or more combinations of silicone resin, polyurethane modified resin, acrylic modified silicone resin, and polyurea. And / or, the alkane-based siloxane comprises any one or more combinations of aminopropyltriethoxysilane, aminopropyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, and 3-mercaptopropyltrimethoxysilane; And / or, Solvent I, Solvent II, and Solvent III each include any one or a combination of two or more of anhydrous ethanol, methanol, dimethyl sulfoxide, dimethylformamide, acetone, diethyl ether, xylene, and ethyl acetate.

10. The application of the photoresponsive multilayer self-assembly antifouling and drag-reducing composite coating according to any one of claims 1-5 in the surface protection of ship hulls, pipelines, offshore platforms or underwater structures.

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