A moisture-resistant layered biomimetic composite material and its 3D printing preparation method

Abstract

This invention provides a moisture-resistant layered biomimetic composite material and its 3D printing preparation method, relating to the fields of polymer composite materials and additive manufacturing technology. The invention comprises a vinylsilane-grafted graphene inorganic reinforcing phase and a polydimethylsiloxane nonpolar polymer matrix. The graphene is obtained by vinylsilane modification and hydrothermal reduction, while the polydimethylsiloxane is formed by crosslinking vinyl silicone oil, hydrogen-containing silicone oil, and a platinum catalyst. The two are stacked in a mass ratio of 95:5 to 60:40 to construct a layered structure along the thickness direction, achieving strong, tough, hydrophobic, and moisture-resistant properties. This synergistic interface structure maintains stable mechanical and interlayer interactions in humid environments, overcoming the defect of existing biomimetic composite materials that are prone to moisture absorption and failure.

Description

Technical Field

[0001] This invention relates to the fields of polymer composite materials and additive manufacturing technology, and in particular to a moisture-resistant layered biomimetic composite material and its 3D printing preparation method. Background Technology

[0002] Layered biomimetic composite materials designed and fabricated using the nacreous layer of seashells as a biomimetic model exhibit ultra-high strength while maintaining good toughness, achieving a combination of strength and toughness. Therefore, they hold great promise for applications in aerospace, mechanical, and biomedical engineering. Furthermore, layered biomimetic composite materials with conductive properties have demonstrated significant application value in emerging fields such as flexible electronics.

[0003] To construct high-strength and tough layered biomimetic composites, the current strategy is to use easily peelable and disperseable inorganic nanosheets (such as nanoclay and graphene oxide) as "bricks" to facilitate precise layered assembly. Simultaneously, polymeric materials with polar side groups (such as polyvinyl alcohol and thermoplastic polyurethane) are used as "mortar" to allow their molecular chains to diffuse and coat the surface of the inorganic nanosheets, and the interfacial interactions are enhanced by hydrogen bonds or chemical bonds formed between the polar side groups and the inorganic nanosheet surface. A strong and tough layered biomimetic composite can be prepared by using graphene oxide and molybdenum disulfide nanosheets as "bricks" and thermoplastic polyurethane as "mortar" to form a homogeneous suspension, followed by vacuum filtration to aid the self-assembly between the "bricks" and "mortar." Similarly, a layered biomimetic composite prepared using hydrated calcium silicate nanosheets as "bricks" and polyvinyl alcohol as "mortar" using vacuum filtration also exhibits excellent comprehensive mechanical properties.

[0004] However, using polar polymers as the "mud" makes current layered biomimetic composites prone to moisture absorption. In high humidity environments, the polar groups of the "brick" and "mud" freely complex with water molecules, disrupting the original interlayer hydrogen bonds and severely reducing the mechanical properties of the composite. Simultaneously, the disruption of strong interfacial interactions and the presence of water molecules affect the effective conduction of phonons and electrons at the composite interface, causing fluctuations in the thermal and electrical conductivity of the composite with changes in humidity, significantly reducing its stability in use. Furthermore, the vacuum filtration method is inefficient; obtaining a single layered biomimetic composite film typically requires several days. Therefore, there is an urgent need to develop methods using non-polar (non-hygroscopic) polymers as the "mud" to prepare moisture-resistant layered biomimetic composites, and to develop suitable processing technologies to improve their preparation efficiency. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a moisture-resistant layered biomimetic composite material and its 3D printing preparation method. Through the synergistic construction of a non-polar matrix and hydrophobic modified graphene, the layered structure can maintain stable interface and strong toughness in a humid environment, thereby overcoming the defect of existing biomimetic composite materials that are prone to moisture absorption and failure.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] A moisture-resistant layered biomimetic composite material is composed of a layered structure made of vinylsilane-grafted graphene and polydimethylsiloxane. Vinylsilane-grafted graphene serves as an inorganic reinforcing phase, and polydimethylsiloxane serves as a non-polar polymer matrix. The vinylsilane-grafted graphene is obtained by surface chemical modification of graphene oxide with vinylsilane followed by hydrothermal reduction. The polydimethylsiloxane is formed by crosslinking and curing vinyl silicone oil, hydrogen-containing silicone oil, and a platinum catalyst. In the composite material, the total mass ratio of vinylsilane-grafted graphene to vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst is 95:5 to 60:40. A layered structure of stacked vinylsilane-grafted graphene is formed along the thickness direction of the composite material, thereby obtaining a layered biomimetic composite film with strong, tough, integrated, hydrophobic, and moisture-resistant properties.

[0008] Preferably, the graphene oxide used to prepare the vinylsilane-grafted graphene is a graphene oxide aqueous slurry with a mass concentration of 2 mg / mL or 10 mg / mL, wherein the graphene oxide aqueous slurry is composed of graphene oxide and water.

[0009] Preferably, the vinylsilane is at least one of vinyltrimethoxysilane or vinyltriethoxysilane, and a mixture of water and methanol or a mixture of water and ethanol is used as a solvent when preparing the vinylsilane solution, wherein the volume ratio of water to methanol or water to ethanol is 95:5 to 30:70.

[0010] Preferably, the mass ratio of vinyl silicone oil to hydrogen-containing silicone oil in the polydimethylsiloxane is 20:1 to 1:10, and the amount of platinum catalyst used is 1‰ to 20‰ of the total mass of vinyl silicone oil and hydrogen-containing silicone oil.

[0011] Preferably, the composite material is prepared by using a mixed suspension of vinylsilane-grafted graphene, vinyl silicone oil, hydrogen-containing silicone oil and platinum catalyst in a total mass ratio of 95:5 to 60:40. The suspension is extruded layer by layer using a direct-write three-dimensional printing process, and each printed layer is rolled after it is formed to obtain a layered structure of vinylsilane-grafted graphene stacks.

[0012] A method for three-dimensional printing of a moisture-resistant layered biomimetic composite material includes:

[0013] Prepare a vinylsilane solution to hydrolyze the vinylsilane into vinylsilanol;

[0014] The graphene oxide slurry was added to the vinyl silane solution and stirred until homogeneous to obtain a vinyl silane-grafted graphene oxide suspension.

[0015] The vinylsilane-grafted graphene oxide suspension was poured into a high-pressure reactor and subjected to a hydrothermal reduction reaction at 150°C for 3 hours. After cooling and drying, vinylsilane-grafted graphene was obtained.

[0016] Vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst were added to tetrahydrofuran and stirred until homogeneous to obtain a dilute solution of polydimethylsiloxane precursor; wherein the total mass of vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst was 0.2% to 2% of the mass of tetrahydrofuran;

[0017] A measured amount of vinylsilane-grafted graphene was added to the dilute solution of the polydimethylsiloxane precursor and stirred to form a stable mixed suspension, such that the mass ratio of vinylsilane-grafted graphene to vinyl silicone oil, hydrogen-containing silicone oil and platinum catalyst was 95:5 to 60:40.

[0018] The mixed suspension is loaded into a syringe, and the direct-write three-dimensional printing process is used to extrude and stack the layers one by one according to the predetermined line pattern under the set base plate temperature. After each layer is printed, the current layer is flattened by a pressure roller before printing the next layer, until a layered biomimetic composite film is obtained.

[0019] The printed film was fixed and cured in a 90°C oven for 12 hours to obtain a moisture-resistant layered biomimetic composite material.

[0020] Preferably, the graphene oxide aqueous slurry has a mass concentration of 2 mg / mL or 10 mg / mL, and the vinylsilane is at least one of vinyltrimethoxysilane or vinyltriethoxysilane.

[0021] Preferably, when preparing the vinylsilane solution, a mixture of water and methanol or a mixture of water and ethanol is used as the solvent, wherein the volume ratio of water to methanol or water to ethanol is 95:5 to 30:70, and the mass ratio of vinylsilane to graphene oxide is 2:1 or 4:1.

[0022] Preferably, the mass ratio of vinyl silicone oil to hydrogen-containing silicone oil is 20:1 to 1:10, and the amount of platinum catalyst is 1‰ to 20‰ of the total mass of vinyl silicone oil and hydrogen-containing silicone oil.

[0023] Preferably, the routing pattern of the direct-write 3D printing process is 0°, ±45° or ±90°, the base plate temperature is set to 60°C, and the printing speed is 50 mm per second.

[0024] The present invention discloses the following technical effects:

[0025] The moisture-resistant layered biomimetic composite material of this invention utilizes vinylsilane-grafted graphene as an inorganic reinforcing phase and polydimethylsiloxane as a nonpolar polymer matrix to construct a stable layered interface structure. This fundamentally solves the problem of hydrogen bond breakage, weakened interfacial forces, and significant decline in mechanical and conductive properties caused by moisture absorption by the polar matrix in high-humidity environments in existing layered biomimetic materials. Vinylsilane grafting gives the graphene surface stable hydrophobic properties and enhances interfacial compatibility with the nonpolar polymer matrix, thus maintaining the integrity of the layered interface and efficient energy transfer capability even under continuous moisture conditions. The nonpolar nature of polydimethylsiloxane further prevents water molecules from intruding into the interlayer structure, giving the composite material high strength, high toughness, and long-term moisture resistance. Furthermore, this invention uses direct-write 3D printing to achieve rapid construction of the layered structure, significantly improving preparation efficiency and overcoming the bottlenecks of low forming efficiency and limited structural design in traditional vacuum filtration methods. Therefore, this invention can simultaneously achieve a comprehensive improvement in mechanical property stability, environmental humidity stability, and preparation efficiency, overcoming the core defects of existing technologies. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram illustrating the 3D printing and roll forming process of graphene / polysiloxane biomimetic layered composite film provided in an embodiment of the present invention;

[0028] Figure 2 Thin film photographs and mechanism diagrams provided for embodiments of the present invention;

[0029] Figure 3 A schematic diagram of a scanning electron microscope image provided in an embodiment of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0031] The purpose of this invention is to provide a moisture-resistant layered biomimetic composite material and its 3D printing preparation method. By constructing a nonpolar layered interface structure of vinylsilane-grafted graphene and polydimethylsiloxane, a moisture-resistant biomimetic composite material that maintains stable mechanical properties and interfacial interaction under high humidity environment is achieved, and the 3D printing preparation efficiency is significantly improved.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] This invention discloses a moisture-resistant layered biomimetic composite material and its 3D printing preparation method, including: (1) surface chemical modification of graphene oxide and hydrothermal reduction of modified graphene oxide; (2) preparation of dilute solution of nonpolar polymer material and preparation of mixed suspension of modified graphene and nonpolar polymer; (3) 3D printing preparation of layered biomimetic composite material.

[0034] Example 1

[0035] 1. Prepare an aqueous solution of trimethoxyvinylsilane and pour it into graphene oxide slurry and stir evenly. The mass ratio of silane to graphene oxide is 2:1. Raise the temperature to 60 ℃ and continue stirring for 2 h. Filter and wash to obtain vinylsilane-grafted graphene oxide. Perform hydrothermal reduction at 150 ℃, remove and dry to obtain vinylsilane-grafted graphene.

[0036] 2. Vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst are added to tetrahydrofuran to prepare a solution, wherein the total content of vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst in the solvent is 1%, and the mass ratio of vinyl silicone oil to hydrogen-containing silicone oil is 5 / 1; vinylsilane-grafted graphene is added to the solution, and its mass ratio with vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst is 85 / 15; after stirring evenly at room temperature, it is loaded into an injection unit for later use.

[0037] 3. The aforementioned solution was stacked layer by layer and rolled into a thin film using a direct-write 3D printing process. The substrate temperature was set to 60℃, the printing speed was 50 mm / s, and the ribbing pattern was ±45°. After printing, the film was fixed and cured in a 90℃ oven for 12 h. The mechanical and hydrophobic properties of the film were then tested.

[0038] Example 2

[0039] 1. Prepare an aqueous solution of trimethoxyvinylsilane and pour it into graphene oxide slurry and stir evenly. The mass ratio of silane to graphene oxide is 4:1. Raise the temperature to 60 ℃ and continue stirring for 2 h. Filter and wash to obtain vinylsilane-grafted graphene oxide. Perform hydrothermal reduction at 150 ℃, remove and dry to obtain vinylsilane-grafted graphene oxide.

[0040] 2. Vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst are added to tetrahydrofuran to prepare a solution, wherein the total content of vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst in the solvent is 1%, and the mass ratio of vinyl silicone oil to hydrogen-containing silicone oil is 5 / 1; vinylsilane-grafted graphene is added to the solution, and its mass ratio with vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst is 80 / 20; after stirring evenly at room temperature, it is loaded into an injection unit for later use.

[0041] 3. The aforementioned solution was stacked layer by layer and rolled into a thin film using a direct-write 3D printing process. The substrate temperature was set to 60℃, the printing speed was 50 mm / s, and the ribbing pattern was ±45°. After printing, the film was fixed and cured in a 90℃ oven for 12 h. The mechanical and hydrophobic properties of the film were then tested.

[0042] Example 3

[0043] 1. Prepare an aqueous solution of trimethoxyvinylsilane and pour it into graphene oxide slurry and stir evenly. The mass ratio of silane to graphene oxide is 2:1. Raise the temperature to 60 ℃ and continue stirring for 2 h. Filter and wash to obtain vinylsilane-grafted graphene oxide. Perform hydrothermal reduction at 150 ℃, remove and dry to obtain vinylsilane-grafted graphene.

[0044] 2. Vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst are added to tetrahydrofuran to prepare a solution, wherein the total content of vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst in the solvent is 1%, and the mass ratio of vinyl silicone oil to hydrogen-containing silicone oil is 5 / 1; vinylsilane-grafted graphene is added to the solution, and its mass ratio with vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst is 70 / 30; after stirring evenly at room temperature, it is loaded into an injection unit for later use.

[0045] 3. The aforementioned solution was stacked layer by layer and rolled into a thin film using a direct-write 3D printing process. The substrate temperature was set to 60℃, the printing speed was 50 mm / s, and the ribbing pattern was ±45°. After printing, the film was fixed and cured in a 90℃ oven for 12 h. The mechanical and hydrophobic properties of the film were then tested.

[0046] Example 4

[0047] 1. Prepare an aqueous solution of triethoxyvinylsilane and pour it into graphene oxide slurry and stir evenly. The mass ratio of silane to graphene oxide is 4:1. Raise the temperature to 60 ℃ and continue stirring for 2 h. Filter and wash to obtain vinylsilane-grafted graphene oxide. Perform hydrothermal reduction at 150 ℃, remove and dry to obtain vinylsilane-grafted graphene oxide.

[0048] 2. Vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst are added to tetrahydrofuran to prepare a solution, wherein the total content of vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst in the solvent is 1%, and the mass ratio of vinyl silicone oil to hydrogen-containing silicone oil is 5 / 1; vinylsilane-grafted graphene is added to the solution, and its mass ratio with vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst is 85 / 15; after stirring evenly at room temperature, it is loaded into an injection unit for later use.

[0049] 3. The aforementioned solution was stacked layer by layer and rolled into a thin film using a direct-write 3D printing process. The substrate temperature was set to 60℃, the printing speed was 50 mm / s, and the ribbing pattern was ±45°. After printing, the film was fixed and cured in a 90℃ oven for 12 h. The mechanical and hydrophobic properties of the film were then tested.

[0050] Example 5

[0051] 1. Prepare an aqueous solution of triethoxyvinylsilane and pour it into graphene oxide slurry and stir evenly. The mass ratio of silane to graphene oxide is 4:1. Raise the temperature to 60 ℃ and continue stirring for 2 h. Filter and wash to obtain vinylsilane-grafted graphene oxide. Perform hydrothermal reduction at 150 ℃, remove and dry to obtain vinylsilane-grafted graphene oxide.

[0052] 2. Vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst are added to tetrahydrofuran to prepare a solution, wherein the total content of vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst in the solvent is 1%, and the mass ratio of vinyl silicone oil to hydrogen-containing silicone oil is 10 / 1; vinylsilane-grafted graphene is added to the solution, and its mass ratio with vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst is 60 / 40; after stirring evenly at room temperature, it is loaded into an injection unit for later use.

[0053] 3. The aforementioned solution was stacked layer by layer and rolled into a thin film using a direct-write 3D printing process. The substrate temperature was set to 60℃, the printing speed was 50 mm / s, and the ribbing pattern was ±45°. After printing, the film was fixed and cured in a 90℃ oven for 12 h. The mechanical and hydrophobic properties of the film were then tested.

[0054] Comparative Example 1

[0055] The only difference from Example 1 is that the hydrothermal reduction step of vinyl-grafted graphene oxide is not performed.

[0056] Comparative Example 2

[0057] The only difference from Example 2 is that the 3D printing wiring pattern is 0°.

[0058] Comparative Example 3

[0059] The only difference from Example 3 is that the 3D printing wiring pattern is ±90°.

[0060] Comparative Example 4

[0061] The only difference from Example 4 is the removal of the platinum catalyst component.

[0062] Comparative Example 5

[0063] The only difference from Example 5 is that the 3D printed film does not undergo a heating and curing step.

[0064] The mechanical properties and water contact angle of the 3D printed film were tested, and the results are shown in Table 1:

[0065] Table 1. Mechanical properties and water contact angles of the 3D printed thin film composites prepared in Examples 1-5 and Comparative Examples 1-5

[0066]

[0067] As shown in Table 1, the time required for 3D printing to prepare layered biomimetic composite materials is significantly shorter than that of the filtration method. The printed layered biomimetic composite materials possess both strong and tough integrated properties and hydrophobic characteristics.

[0068] Figure 1 This is a schematic diagram of the three-dimensional printing and roll forming process of the graphene / polysiloxane biomimetic layered composite film in this invention. Figure 1 The system includes a hopper for storing a mixed suspension of vinylsilane-grafted graphene and polydimethylsiloxane precursor. Below the hopper is a nozzle, which moves controllably along the X, Y, and Z directions under the drive of a three-dimensional motion assembly, continuously extruding the mixed suspension in a direct-write manner. Below the nozzle is a worktable to support the film structure during the printing process. Above the worktable are pressure rollers that compact each printed layer, ensuring the vinylsilane-grafted graphene sheets are aligned along the planar direction to form a regular layered structure. Through the layer-by-layer extrusion from the hopper and nozzle, and the synchronous compaction by the pressure rollers, a biomimetic composite film with a multi-layered stacked interface structure is ultimately constructed on the worktable.

[0069] Figure 2 Part a shows a photograph of the graphene / polysiloxane layered biomimetic composite film prepared in the example. It can be seen that the film is flat and has a uniform structure, indicating that continuous, macroscopic film construction can be achieved through three-dimensional printing and rolling steps. Figure 2 Part b is a schematic diagram of the internal interlayer structure of the film. It can be observed that the vinylsilane-grafted graphene sheets are arranged in a stacked manner along the planar direction, with polydimethylsiloxane segments distributed in between. Together, they form a stable layered interface structure. This structure not only ensures high strength and high toughness in the loading direction, but also avoids the interface damage caused by moisture absorption in traditional polar polymer matrices. Figure 2 Part C illustrates the chemical mechanism of the curing reaction between vinyl silicone oil and hydrogen-containing silicone oil and vinyl silane-grafted graphene under the action of platinum catalyst: After being modified by vinyl silane, graphene oxide acquires vinyl functional groups on its surface, which can form a stable chemical bond with polysiloxane segments through addition reaction, thereby improving the interfacial bonding strength between the inorganic reinforcing phase and the polymer matrix in the composite material, and providing key support for the material's moisture resistance and mechanical stability.

[0070] Figure 3 Part a and Figure 3 Part b shows cross-sectional scanning electron microscope (SEM) images of the graphene / polysiloxane layered biomimetic composite films prepared in Examples 2 and 4, respectively. Figure 3 As can be seen, the film exhibits a distinct multi-layered, sheet-like stacked structure. The graphene sheets are continuously arranged along a direction parallel to the film surface, forming a typical biomimetic layered interface morphology. The layers are tightly bonded together, with no obvious pores or delamination, indicating that the three-dimensional printing layer-by-layer extrusion and roll compaction steps proposed in this invention can effectively orient vinylsilane-grafted graphene and form a dense, continuous layered structure. (Cross-section of Example 4) Figure 3 The layered interfaces in section b are clearer, indicating that with a higher proportion of inorganic reinforcing phase or improved printing conditions, the stacking regularity of the layers can be further improved, thereby enhancing the mechanical properties and moisture resistance of the composite material. Figure 3 This provides direct verification that the preparation method of the present invention can construct a stable and continuous graphene stacked layer structure, which is the key basis for achieving the excellent performance of composite materials.

[0071] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0072] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A moisture-resistant layered biomimetic composite material, characterized in that, The composite material comprises a layered structure of vinylsilane-grafted graphene and polydimethylsiloxane. Vinylsilane-grafted graphene serves as the inorganic reinforcing phase, while polydimethylsiloxane acts as the nonpolar polymer matrix. The vinylsilane-grafted graphene is obtained by surface chemical modification of graphene oxide with vinylsilane followed by hydrothermal reduction. The polydimethylsiloxane is formed by crosslinking and curing vinyl silicone oil, hydrogen-containing silicone oil, and a platinum catalyst. In the composite material, the total mass ratio of vinylsilane-grafted graphene to vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst is 85:15 to 60:40, forming a stacked layered structure of vinylsilane-grafted graphene along the thickness direction of the composite material. This results in a layered biomimetic composite film with strong, tough, integrated, hydrophobic, and moisture-resistant properties. The mass ratio of vinyl silicone oil to hydrogen-containing silicone oil in the polydimethylsiloxane is 20:1 to 5:1, and the amount of platinum catalyst is not zero.

2. The moisture-resistant layered biomimetic composite material according to claim 1, characterized in that, The graphene oxide used to prepare the vinylsilane-grafted graphene is a graphene oxide aqueous slurry with a mass concentration of 2 mg / mL or 10 mg / mL, wherein the graphene oxide aqueous slurry is composed of graphene oxide and water.

3. The moisture-resistant layered biomimetic composite material according to claim 1, characterized in that, The vinylsilane is at least one of vinyltrimethoxysilane or vinyltriethoxysilane. When preparing the vinylsilane solution, a mixture of water and methanol or a mixture of water and ethanol is used as the solvent, and the volume ratio of water to methanol or water to ethanol is 85:15 to 30:

70.

4. The moisture-resistant layered biomimetic composite material according to claim 1, characterized in that, The amount of platinum catalyst used is 1‰ to 20‰ of the total mass of vinyl silicone oil and hydrogen-containing silicone oil.

5. The moisture-resistant layered biomimetic composite material according to claim 1, characterized in that, The composite material is prepared by using a mixed suspension of vinyl silane-grafted graphene, vinyl silicone oil, hydrogen-containing silicone oil and platinum catalyst in a total mass ratio of 85:15 to 60:

40. The suspension is extruded layer by layer through a direct-write three-dimensional printing process. After each printed layer is formed, the current layer is rolled to obtain a layered structure of vinyl silane-grafted graphene stacks.

6. A method for three-dimensional printing preparation of a moisture-resistant layered biomimetic composite material according to any one of claims 1 to 5, characterized in that, include: Prepare a vinylsilane solution to hydrolyze the vinylsilane into vinylsilanol; The graphene oxide slurry was added to the vinyl silane solution and stirred until homogeneous to obtain a vinyl silane-grafted graphene oxide suspension. The vinylsilane-grafted graphene oxide suspension was poured into a high-pressure reactor and subjected to a hydrothermal reduction reaction at 150°C for 3 hours. After cooling and drying, vinylsilane-grafted graphene was obtained. Vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst were added to tetrahydrofuran and stirred until homogeneous to obtain a dilute solution of polydimethylsiloxane precursor; wherein the total mass of vinyl silicone oil, hydrogen-containing silicone oil, and platinum catalyst was 0.2% to 2% of the mass of tetrahydrofuran; A measured amount of vinylsilane-grafted graphene was added to the dilute solution of the polydimethylsiloxane precursor and stirred to form a stable mixed suspension, such that the mass ratio of vinylsilane-grafted graphene to vinyl silicone oil, hydrogen-containing silicone oil and platinum catalyst was 85:15 to 60:

40. The mixed suspension is loaded into a syringe, and the direct-write three-dimensional printing process is used to extrude and stack the layers one by one according to the predetermined line pattern under the set base plate temperature. After each layer is printed, the current layer is flattened by a pressure roller before printing the next layer, until a layered biomimetic composite film is obtained. The printed film was fixed and cured in a 90°C oven for 12 hours to obtain a moisture-resistant layered biomimetic composite material.

7. The method for three-dimensional printing of the moisture-resistant layered biomimetic composite material according to claim 6, characterized in that, The graphene oxide aqueous slurry has a mass concentration of 2 mg / mL or 10 mg / mL, and the vinyl silane is at least one of vinyltrimethoxysilane or vinyltriethoxysilane.

8. The method for three-dimensional printing preparation of the moisture-resistant layered biomimetic composite material according to claim 6, characterized in that, When preparing the vinylsilane solution, a mixture of water and methanol or a mixture of water and ethanol is used as the solvent, wherein the volume ratio of water to methanol or water to ethanol is 85:15 to 30:70, and the mass ratio of vinylsilane to graphene oxide is 2:1 or 4:

1.

9. The method for three-dimensional printing preparation of the moisture-resistant layered biomimetic composite material according to claim 6, characterized in that, The mass ratio of vinyl silicone oil to hydrogen-containing silicone oil is 20:1 to 5:1, and the amount of platinum catalyst used is 1‰ to 20‰ of the total mass of vinyl silicone oil and hydrogen-containing silicone oil.

10. The method for three-dimensional printing preparation of the moisture-resistant layered biomimetic composite material according to claim 6, characterized in that, The direct-write 3D printing process uses a trace pattern of 0°, ±45°, or ±90°, with the base plate temperature set to 60°C and the printing speed at 50 mm per second.

Images