Construction methods of three-dimensional surface wrinkled structures and three-dimensional structural materials

Abstract

This invention relates to the field of polymer materials technology, and more particularly to a method for constructing three-dimensional surface wrinkled structures and three-dimensional structural materials. The method for constructing three-dimensional surface wrinkled structures provided by this invention combines "top-down" 3D printing technology with "bottom-up" self-wrinkling structuring technology. During the 3D printing process, gradient cross-linking is induced through photocrosslinking curing, utilizing the material stress instability to form a self-wrinkled structure on the surface. This achieves the simultaneous construction of macroscopic structures and surface micro-patterns, extending surface wrinkled structures from two-dimensional planes to three-dimensional structures. This construction method can produce three-dimensional structural materials with wrinkled surfaces exhibiting near-infrared response characteristics, enabling in-situ dynamic control of the surface wrinkled structure, and demonstrating broad application prospects in fields such as smart devices and tunable structural materials.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a method for constructing three-dimensional surface wrinkled structures and three-dimensional structural materials. Background Technology

[0002] Wrinkled structures can endow material surfaces with a wealth of functional properties, finding wide applications in biomimetic materials, flexible devices, optical manipulation, wettability regulation, and enhanced mechanical properties. Traditional wrinkle construction primarily relies on surface mechanical instability strategies, such as thermal shrinkage, mechanical pre-stretching release, and solvent expansion. These strategies typically depend on two-dimensional planar substrates, forming wrinkles through surface stress release. However, with advancements in materials science and micro / nano manufacturing technologies, two-dimensional surface wrinkled structures are increasingly unable to meet the integration and functionality requirements of complex devices.

[0003] Extending wrinkled structures from two-dimensional planes to three-dimensional structures not only enhances the spatial structural freedom of materials but also endows them with richer physical and chemical responsive behaviors, showing broader application prospects in fields such as mechanical control, biomedical engineering, microelectronic devices, and micro-nano photonics. Currently, mainstream surface wrinkled structure fabrication technologies such as photolithography and nanoimprinting are based on planar processes, making them difficult to directly apply to the construction of three-dimensional surface wrinkled structures. Therefore, developing methods suitable for constructing three-dimensional surface wrinkled structures has significant scientific and practical value.

[0004] In recent years, various emerging technologies have been attempted to construct three-dimensional surface wrinkled structures, such as multilayer stacking, laser direct writing, and 3D printing. However, many challenges remain in constructing three-dimensional surface wrinkled structures. For example, Chinese patent application CN114750470 A discloses a composite film with isolated three-dimensional surface wrinkled microstructures and its preparation method. By designing the composite film structure, using a substrate as the support layer, a polymer substrate and a metal thin film with isolated three-dimensional wrinkled structures on the surface are sequentially set on one side of the substrate. Through a specific preparation method, a composite film with isolated three-dimensional wrinkled structures on the surface is finally obtained. However, this patent application is only applicable to the construction of surface wrinkled structures on specific two-dimensional planar substrates (metal thin films), and is still limited to two-dimensional planar substrates, making it difficult to achieve selective preparation of three-dimensional surface wrinkled structures. Chinese patent application CN 114683533 A discloses a 3D printing method, product, and application for preparing arbitrary nano-wrinkled structures. The method involves irradiating a precursor solution with a laser to induce wrinkles on the surface of voxel units. By continuously changing the laser irradiation area, multiple interconnected wrinkled voxel units are generated. After development and drying, nano-wrinkled structures are obtained, ranging from point-to-surface to surface-to-volume. Although this patent application represents progress in the preparation of three-dimensional surface wrinkled structures, its preparation process requires complex development steps, is complicated to operate, and makes it difficult to achieve dynamic control of micro- and nano-scale wrinkled structures.

[0005] Therefore, exploring construction strategies for novel three-dimensional surface wrinkled structures with simple processes is an urgent problem to be solved. Summary of the Invention

[0006] In order to solve the problems mentioned in the background art, the purpose of the present invention is to provide a method for constructing a three-dimensional surface wrinkled structure.

[0007] The present invention provides a method for constructing three-dimensional surface wrinkled structures by combining "top-down" 3D printing technology (photopolymerization 3D printing) with "bottom-up" self-wrinkling structuring technology. During the 3D printing process, gradient cross-linking is induced through photocrosslinking curing, utilizing the material stress instability to form a self-wrinkled structure on the surface. This achieves the simultaneous construction of macroscopic structures and surface micro-patterns, extending surface wrinkled structures from two-dimensional planes to three-dimensional solid structures. It is a universal strategy for constructing wrinkled structures on three-dimensional macroscopic surfaces. The construction process is simple, employing an integrated printing-wrinkled structure simultaneous construction method, simplifying the multi-step processing steps required for traditional three-dimensional surface micro-patterning, improving construction efficiency. Furthermore, the constructed wrinkled structures are stable and their dimensions are at the micro-nano scale, showing potential application value in fields such as flexible electronics, bio-interface engineering, and intelligent camouflage. Furthermore, the method for constructing three-dimensional surface wrinkled structures provided by this invention can also produce three-dimensional structural materials with surface wrinkled structures that have near-infrared response characteristics, realizing in-situ dynamic control of the surface wrinkled structure. It can be extended to the construction of intelligent responsive surface wrinkled structures and shows broad application prospects in fields such as intelligent devices and tunable structural materials.

[0008] The first aspect of the present invention provides a method for constructing a three-dimensional surface wrinkled structure, comprising the following steps:

[0009] (1) Dissolve a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent and an acrylate oligomer in an organic solvent to prepare a 3D printing resin solution, or mix a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent and an acrylate oligomer with a graphene solution to prepare a 3D printing resin solution.

[0010] (2) Photopolymerization 3D printing is used to crosslink and solidify the 3D printing resin solution under light irradiation during the printing process and deposit it onto the substrate to obtain a single-layer deposited material with a self-wrinkled structure on the surface.

[0011] (3) Repeat step (2) to finally obtain a three-dimensional structure material through layer-by-layer deposition;

[0012] (4) The three-dimensional structural material is subjected to heat treatment and photo-crosslinking curing treatment to obtain a three-dimensional structural material with a wrinkled surface.

[0013] The structure of the fluorine-containing macromolecular photoinitiator in the three-dimensional surface wrinkled structure described above is shown in formula (1) or formula (2):

[0014] Equation (1) Equation (2)

[0015] In equation (1) or equation (2), 0 <x≤ 100,0<y≤100,0<z≤100。

[0016] In the method for constructing the three-dimensional surface wrinkled structure as described above, in step (1), the mass fraction of the fluorine-containing macromolecular photoinitiator in the 3D printing resin solution is 4-15 wt%.

[0017] And / or, in step (1), the mass ratio of the fluorinated macromolecular photoinitiator, the multifunctional acrylate crosslinking agent and the acrylate oligomer is (2-10):(5-50):(5-50).

[0018] In the construction method of the three-dimensional surface wrinkled structure as described above, in step (1), the graphene solution is prepared by dissolving graphene in an organic solvent, and the mass fraction of the graphene solution is 0.2wt%-2wt%.

[0019] In the construction method of the three-dimensional surface wrinkled structure as described above, in step (1), the solid content of the 3D printing resin solution is 20%-80% by mass.

[0020] In the method for constructing the three-dimensional surface wrinkled structure as described above, step (2) includes the following process parameters for photopolymerization 3D printing:

[0021] Control the extrusion speed of the peristaltic pump to 1 mL / hr-10 mL / hr;

[0022] Control the printing speed to 5mm / s-30mm / s;

[0023] The inner diameter of the printhead is controlled to be 0.4mm-0.8mm;

[0024] Control the thickness of each printing layer to 10μm-50μm;

[0025] Lighting conditions include: wavelength of 315nm-400nm and intensity of 10mW / cm². 2 -100mW / cm 2 Ultraviolet light.

[0026] In the method for constructing the three-dimensional surface wrinkled structure as described above, step (4) includes the photocrosslinking curing process: at a wavelength of 315nm-400nm and an intensity of 10mW / cm². 2 -100mW / cm 2 Irradiate under ultraviolet light for 5-20 minutes.

[0027] In the construction method of the three-dimensional surface wrinkled structure as described above, in step (4), the temperature of the heat treatment is 35℃-50℃ and the time is 30min-90min.

[0028] In the method for constructing the three-dimensional surface wrinkled structure as described above, the multifunctional acrylate crosslinking agent is at least one of 1,6-hexanediol diacrylate, trimethylolpropane trimethacrylate, glycerol trihydroxypropyl ether triacrylate, and pentaerythritol tetraacrylate.

[0029] And / or, the acrylate oligomer is at least one of polyether acrylate, aliphatic polyurethane triacrylate, and polyester acrylate.

[0030] A second aspect of the present invention provides a three-dimensional structural material with a wrinkled surface, which is prepared by the method for constructing the three-dimensional surface wrinkled structure.

[0031] The solution of the present invention has at least the following effects:

[0032] This invention provides a method for constructing three-dimensional surface wrinkled structures. It utilizes a top-down 3D printing technique (photopolymerization 3D printing) to construct macroscopic three-dimensional structural materials, and combines this with a bottom-up self-folding structuring technique to simultaneously generate micro- and nano-scale wrinkled structures on the surface of the three-dimensional structural material. This achieves the simultaneous construction of macroscopic structures and surface micro-patterns, extending surface wrinkled structures from two-dimensional planes to three-dimensional structures. It is a universal strategy for constructing wrinkled structures on three-dimensional macroscopic structural surfaces. This invention employs an integrated printing-wrinkled structure simultaneous construction method, simplifying the construction process and eliminating the multi-step processing steps required for traditional three-dimensional surface micro-patterning. This improves construction efficiency, and the constructed wrinkled structures are stable and have micro- and nano-scale dimensions, showing potential application value in flexible electronics, bio-interface engineering, and intelligent camouflage. Through the integrated design of the raw material formulation for the three-dimensional structural materials, this invention ensures the stability of the constructed wrinkled structures in terms of morphology and mechanical properties, significantly extending the service life of the wrinkled structures. This invention allows for precise control of the wavelength and amplitude of three-dimensional surface wrinkled structures by adjusting parameters such as light intensity and extrusion speed, thereby meeting the structural scale and functional response requirements of different application scenarios. The inventors' research demonstrates that by introducing functional units (graphene in this embodiment) that respond to external stimuli such as light / heat into the raw material formulation of three-dimensional structural materials, three-dimensional structural materials with near-infrared responsiveness and surface wrinkles can be prepared. This achieves in-situ dynamic control of the surface wrinkles, which can be extended to the construction of intelligent responsive surface wrinkled structures, showing broad application prospects in fields such as intelligent devices and tunable structural materials.

[0033] The present invention provides a three-dimensional structural material with a wrinkled surface, which is prepared by the aforementioned method for constructing a three-dimensional surface wrinkled structure. Compared with the problems of unadjustable surface wrinkles and difficulty in dynamic control in the preparation of traditional three-dimensional structural materials, the present invention introduces a collaborative construction mechanism of printing configuration and surface wrinkles, simultaneously completing the three-dimensional structural forming and the generation of surface micro-wrinkles in a one-step printing process, eliminating the need for additional development, washing, and drying processes, thus significantly reducing processing complexity and environmental burden. Furthermore, by introducing functional units (graphene in this embodiment) that respond to external stimuli such as light / heat into the raw material formulation of the three-dimensional structural material, the present invention endows the surface wrinkles of the three-dimensional structural material with in-situ reversible dynamic control capabilities, realizing dynamic control of the surface wrinkles of the three-dimensional structural material. This effectively solves the problem of the difficulty in achieving dynamic control of the surface of traditional three-dimensional structural materials, providing a new approach for constructing integrated intelligent structures with sensing, response, and reconfigurability functions. Attached Figure Description

[0034] 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 of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a synthetic route diagram of the fluorine-containing macromolecular photoinitiator I in Example 1 of the present invention;

[0036] Figure 2 The above is the 1H NMR spectrum of the random copolymer containing dimethylamino in Example 1 of this invention;

[0037] Figure 3 This is the 1H NMR spectrum of the fluorine-containing macromolecular photoinitiator I in Example 1 of the present invention;

[0038] Figure 4 This is a synthetic route diagram of the fluorine-containing macromolecular photoinitiator II in Example 2 of the present invention;

[0039] Figure 5 This is the 1H NMR spectrum of the fluorine-containing macromolecular photoinitiator II in Example 2 of the present invention;

[0040] Figure 6 The images shown are a preset path diagram for photopolymer 3D printing in Embodiment 3 of the present invention, and a physical image and surface morphology diagram of a three-dimensional structural material with a wrinkled surface. Figure 6 'a' represents the preset path diagram for photopolymer 3D printing. Figure 6Image b is a physical image of a three-dimensional material with a wrinkled surface. Figure 6 c is a surface morphology diagram of a three-dimensional material with a wrinkled surface.

[0041] Figure 7 The images shown are a preset path diagram for photopolymer 3D printing in Embodiment 4 of the present invention, and a physical image and surface morphology diagram of a three-dimensional structural material with a wrinkled surface. Figure 7 'a' represents the preset path diagram for photopolymer 3D printing. Figure 7 Image b is a physical image of a three-dimensional material with a wrinkled surface. Figure 7 c is a three-dimensional surface morphology diagram of a three-dimensional structural material with a wrinkled surface. Figure 7 d represents the two-dimensional surface morphology of a three-dimensional material with a wrinkled surface.

[0042] Figure 8 This is an in-situ dynamic control diagram of the surface wrinkle structure of the three-dimensional structural material with a wrinkled surface in Embodiment 5 of the present invention; wherein, Figure 8 'a' represents the surface wrinkle structure diagram of a three-dimensional material with a wrinkled surface. Figure 8 b is an enlarged view of the surface wrinkle structure of a three-dimensional material with a wrinkled surface. Figure 8 c represents the surface wrinkle structure of a three-dimensional material with a wrinkled surface after irradiation with 808nm near-infrared light. Figure 8 d is a magnified image of the surface wrinkle structure of a three-dimensional material with a wrinkled surface after being irradiated with 808nm near-infrared light.

[0043] Figure 9 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 1 of the present invention;

[0044] Figure 10 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 2 of the present invention;

[0045] Figure 11 This is a physical image of the three-dimensional structural material in Comparative Example 3 of the present invention;

[0046] Figure 12 This is a physical image of the three-dimensional structural material in Comparative Example 4 of the present invention;

[0047] Figure 13 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 5 of the present invention;

[0048] Figure 14 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 6 of the present invention;

[0049] Figure 15 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 7 of the present invention;

[0050] Figure 16 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 8 of the present invention;

[0051] Figure 17 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 9 of the present invention;

[0052] Figure 18 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 10 of the present invention;

[0053] Figure 19 This is an in-situ dynamic control diagram of the surface wrinkle structure of the three-dimensional structural material with a wrinkled surface in Comparative Example 11 of the present invention, wherein... Figure 19 'a' represents the surface wrinkle structure diagram of a three-dimensional material with a wrinkled surface. Figure 19 b is a diagram of the surface wrinkle structure of a three-dimensional material with a wrinkled surface after being irradiated with 808nm near-infrared light.

[0054] Figure 20 This is the surface wrinkle structure morphology of the three-dimensional structural material with a wrinkled surface in Comparative Example 12 of the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this art or in accordance with the product instructions. Reagents or instruments used without specified manufacturers are all conventional products that can be obtained commercially.

[0056] It should be noted that the descriptions involving "first," "second," "third," etc. in this invention are used to distinguish similar objects and are not used to describe a specific order or sequence, and therefore should not be construed as limiting the invention.

[0057] Those skilled in the art will understand that the numerical ranges in the embodiments of the present invention should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0058] Unless otherwise stated, the technical / scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0059] The first aspect of the present invention provides a method for constructing a three-dimensional surface wrinkled structure, comprising the following steps:

[0060] (1) Dissolve a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent and an acrylate oligomer in an organic solvent to prepare a 3D printing resin solution, or mix a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent and an acrylate oligomer with a graphene solution to prepare a 3D printing resin solution.

[0061] (2) Photopolymerization 3D printing is used to crosslink and solidify the 3D printing resin solution under light irradiation during the printing process and deposit it onto the substrate to obtain a single-layer deposited material with a self-wrinkled structure on the surface.

[0062] (3) Repeat step (2) to finally obtain a three-dimensional structure material through layer-by-layer deposition;

[0063] (4) The three-dimensional structural material is subjected to heat treatment and photo-crosslinking curing treatment to obtain a three-dimensional structural material with a wrinkled surface.

[0064] In step (1), the 3D printing resin solution can be composed of a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent, acrylate oligomers and an organic solvent, or it can be composed of a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent, acrylate oligomers and a graphene solution.

[0065] In step (2), photopolymerization 3D printing is used to cross-link and solidify the 3D printing resin solution under light conditions and deposit it onto the substrate. During the cross-linking and solidification process, due to the low surface energy characteristics of the fluorinated macromolecular photoinitiator, the fluorinated macromolecular photoinitiator can be enriched on the surface of the 3D printing resin solution, thereby causing gradient cross-linking on the surface of the 3D printing resin solution. This results in a mismatch between the thermal expansion and contraction rates of the surface and inner layers of the 3D printing resin solution. During the evaporation of organic solvents and the cooling of the material, the inner layer shrinks more than the surface layer, thus forming a self-wrinkled structure on the surface, resulting in a single-layer deposited material with a self-wrinkled surface.

[0066] In step (4), heat treatment is to evaporate the organic solvent remaining in the three-dimensional structure material; photocrosslinking curing treatment is to further crosslink and cure the three-dimensional structure material as a whole, forming a stable wrinkled structure, and finally obtaining a three-dimensional structure material with a wrinkled surface.

[0067] In this invention, the organic solvent in step (1) is of a conventional type. For example, the organic solvent is at least one of chloroform, 1,4-dioxane, N,N-dimethylformamide (DMF), N,N-dimethylacetamide, tetrahydrofuran, acetone, and trifluorotoluene.

[0068] The present invention does not impose any particular limitation on the specific shape of the above-mentioned three-dimensional structural material, and the shape can be selected according to actual needs. For example, three-dimensional structural materials with different shapes can be prepared by changing the printing path.

[0069] The present invention does not impose any particular limitation on the specific thickness of the above-mentioned three-dimensional structural material, which can be selected according to actual needs.

[0070] In this invention, the substrate is a conventional substrate, such as plastic (e.g., polyethylene terephthalate (PET), polymethyl methacrylate (PMMA)), metal (e.g., copper, iron, aluminum), glass, etc.

[0071] The present invention does not limit the shape, size, or thickness of the substrate; it can be selected according to actual needs.

[0072] This invention provides a method for constructing three-dimensional surface wrinkled structures. It utilizes a top-down 3D printing technique (this invention employs photopolymerization 3D printing) to construct macroscopic three-dimensional structural materials, and combines this with a bottom-up self-folding structuring technique to simultaneously generate micro- and nano-scale wrinkled structures on the surface of the three-dimensional structural material. This achieves the simultaneous construction of macroscopic structures and surface micro-patterns, extending surface wrinkled structures from two-dimensional planes to three-dimensional structures. It is a universal strategy for constructing wrinkled structures on three-dimensional macroscopic structural surfaces. This invention employs an integrated printing-wrinkled structure simultaneous construction method, simplifying the construction process and eliminating the multi-step processing steps required for traditional three-dimensional surface micro-patterning, thus improving construction efficiency. Furthermore, the constructed wrinkled structures are at the micro- and nano-scale, possessing potential application value in fields such as flexible electronics, bio-interface engineering, and intelligent camouflage. Through the integrated design of the raw material formulation for the three-dimensional structural materials, this invention ensures the stability of the constructed wrinkled structures in terms of morphology retention and mechanical properties, significantly extending the service life of the wrinkled structures. This invention allows for precise control of the wavelength and amplitude of three-dimensional surface wrinkled structures by adjusting parameters such as light intensity and extrusion speed, thereby meeting the requirements of different application scenarios for structural scale and functional response.

[0073] When step (1) involves mixing a fluorine-containing macromolecular photoinitiator, a multifunctional acrylate crosslinking agent, an acrylate oligomer, and a graphene solution to prepare a 3D printing resin solution, the resulting three-dimensional structural material with a wrinkled surface exhibits near-infrared response characteristics. This enables in-situ dynamic control of the three-dimensional surface wrinkled structure, which can be extended to the construction of intelligent responsive surface wrinkled structures, demonstrating broad application prospects in fields such as intelligent devices and tunable structural materials.

[0074] In one specific embodiment, the structure of the above-mentioned fluorine-containing macromolecular photoinitiator is shown in formula (1) or formula (2):

[0075] Equation (1) Equation (2)

[0076] In equation (1) or equation (2), 0 <x≤ 100,0<y≤100,0<z≤100。

[0077] In this invention, the fluorinated macromolecular photoinitiator contains fluorinated functional monomers. Its inherent ultra-low surface energy characteristics enable the 3D printing resin solution to form a gradient self-assembled layer during photocrosslinking and curing, resulting in a surface self-wrinkled structure. Compared to traditional small-molecule photoinitiators, the fluorinated macromolecular photoinitiator of this invention exhibits lower migration and higher structural stability, avoiding the precipitation or degradation problems that may occur after photocrosslinking and curing of small-molecule photoinitiators, thus improving the durability of the formed wrinkled structure. Simultaneously, the fluorinated macromolecular photoinitiator possesses better dispersibility and controllable reaction rate, enabling more precise control of photocrosslinking and curing during printing, which helps to construct a stable wrinkled structure.

[0078] The present invention can prepare a fluorine-containing macromolecular photoinitiator with the structure shown in formula (1) by a preparation method including the following process:

[0079] Dimethylaminoethyl methacrylate (DMAEMA), perfluorooctyl ethyl acrylate and the first catalyst were dissolved in the first solvent and stirred at 70℃-90℃ for 12h-18h. After post-treatment, a random copolymer containing dimethylamino was obtained. The random copolymer containing dimethylamino and 4-(bromomethyl)benzophenone were dissolved in the second solvent and stirred at 60℃-80℃ for 12h-24h to obtain a fluorine-containing macromolecular photoinitiator with the structure shown in formula (1).

[0080] The molar ratio of the above-mentioned dimethylaminoethyl methacrylate, perfluorooctyl ethyl acrylate and the first catalyst is (30-50):10:(1-2); the molar ratio of the above-mentioned random copolymer containing dimethylamino and 4-(bromomethyl)benzophenone is (30-60):(20-40).

[0081] The first solvent is selected from at least one of 1,4-dioxane, N,N-dimethylformamide (DMF), N,N-dimethylacetamide, tetrahydrofuran, acetone, and trifluorotoluene.

[0082] The second solvent is selected from at least one of N,N-dimethylformamide (DMF), N,N-dimethylacetamide, tetrahydrofuran, acetone, and toluene.

[0083] The first catalyst mentioned above includes azobisisobutyronitrile (AIBN).

[0084] The present invention can prepare a fluorine-containing macromolecular photoinitiator with the structure shown in formula (2) by a preparation method including the following process:

[0085] Dimethylaminoethyl methacrylate (DMAEMA), 4-acryloylhydroxybenzoate benzophenone, perfluorooctyl ethyl acrylate and the second catalyst were dissolved in a third solvent and stirred at 70℃-90℃ for 12h-18h. After post-treatment, a fluorine-containing macromolecular photoinitiator with the structure shown in formula (2) was obtained.

[0086] The molar ratio of the above-mentioned dimethylaminoethyl methacrylate, 4-acryloylhydroxybenzoate benzophenone, perfluorooctyl ethyl acrylate and the second catalyst is (20-40):(40-70):(10-20):(1-2).

[0087] The third solvent mentioned above is selected from at least one of 1,4-dioxane, N,N-dimethylformamide (DMF), N,N-dimethylacetamide, tetrahydrofuran, acetone, and trifluorotoluene.

[0088] The second catalyst mentioned above includes azobisisobutyronitrile (AIBN).

[0089] In one specific embodiment, the mass fraction of the above-mentioned fluorine-containing macromolecular photoinitiator in the 3D printing resin solution is 4-15 wt%.

[0090] When the mass fraction of fluorinated macromolecular photoinitiator in the 3D printing resin solution is within the above range, a three-dimensional structural material with disordered micron-level wrinkles on the surface can be obtained. If the content of fluorinated macromolecular photoinitiator is too low (e.g., the mass fraction of fluorinated macromolecular photoinitiator in the 3D printing resin solution is 2wt%), the three-dimensional structural material will not cure completely, and the wrinkled structure will not be formed on the material surface. If the content of fluorinated macromolecular photoinitiator is too high (e.g., the mass fraction of fluorinated macromolecular photoinitiator in the 3D printing resin solution is 20wt%), the three-dimensional structural material will experience severe phase separation, and the disordered micron-level wrinkled structure will not be able to be constructed on the material surface.

[0091] In one specific embodiment, in step (1), the mass ratio of the above-mentioned fluorinated macromolecular photoinitiator, the above-mentioned multifunctional acrylate crosslinking agent and the above-mentioned acrylate oligomer is (2-10):(5-50):(5-50).

[0092] When the mass ratio of the above-mentioned fluorinated macromolecular photoinitiator, the above-mentioned multifunctional acrylate crosslinking agent and the above-mentioned acrylate oligomer is within the above range in step (1), the fluorinated macromolecular photoinitiator rapidly absorbs ultraviolet light under illumination, undergoes electronic transition, and captures hydrogen atoms from hydrogen donors to form active free radicals, preferentially initiating the opening of double bonds in acrylate oligomers and forming chain growth; the multifunctional acrylate crosslinking agent rapidly connects linear polymer chains into a network through multiple reaction sites, increases the crosslinking density of the system, accelerates the curing speed of the material, and forms a gradient system while the material is photocured and crosslinked, thereby forming a wrinkled structure on the surface of the material.

[0093] In one specific embodiment, in step (1), the graphene solution is prepared by dissolving graphene in an organic solvent, and the mass fraction of the graphene solution is 0.2wt%-2wt%.

[0094] This invention does not specifically limit the type of organic solvent used in preparing the graphene solution. In some embodiments, the organic solvent in the graphene solution is at least one selected from chloroform, 1,4-dioxane, N,N-dimethylformamide (DMF), N,N-dimethylacetamide, tetrahydrofuran, acetone, and trifluorotoluene.

[0095] Graphene exhibits excellent photothermal conversion effects. This invention mixes graphene with a fluorine-containing macromolecular photoinitiator, a multifunctional acrylate crosslinking agent, and acrylate oligomers to prepare a three-dimensional structural material with a wrinkled surface, exhibiting near-infrared response characteristics. Research by the inventors has shown (e.g.) Figure 8 As shown, under 808 nm near-infrared light irradiation, the temperature of the three-dimensional structural material with a wrinkled surface will rise rapidly and thermal expansion will occur, and the wrinkled surface structure will be erased. After the 808 nm near-infrared light irradiation is removed, the temperature of the system will decrease and the volume will shrink, resulting in the recovery of the wrinkled surface structure. This indicates that the method of the present invention achieves in-situ dynamic control of the wrinkled surface structure of the three-dimensional structural material.

[0096] When the mass fraction of the graphene solution is within the above range, a three-dimensional structural material with a wrinkled surface and near-infrared response characteristics can be obtained. If the mass fraction of the graphene solution is too low (e.g., 0.05 wt%), the wrinkled surface of the three-dimensional structural material cannot be completely erased under 808 nm near-infrared light irradiation, making in-situ dynamic control of the wrinkled surface impossible. If the mass fraction of the graphene solution is too high (e.g., 4 wt%), it will not only affect the uniformity of the 3D printing resin solution but also the overall mechanical properties of the material. Uneven mixing of the 3D printing resin solution will directly affect the formation of the wrinkled surface, resulting in an uneven wrinkled surface structure in the obtained three-dimensional structural material.

[0097] For example, the mass fraction of the graphene solution can be any one or any combination of 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, and 2wt%.

[0098] In one specific embodiment, in step (1), the solid content of the 3D printing resin solution is 20%-80% by mass.

[0099] When the solid content percentage of the 3D printing resin solution is within the above range, the printing accuracy and the curing and forming of the three-dimensional structure can be well controlled. If the solid content percentage of the 3D printing resin solution is too low (e.g., 10%), its high fluidity during extrusion makes it difficult to cure quickly and thus difficult to construct a three-dimensional structure. If the solid content percentage of the 3D printing resin solution is too high (e.g., 100%), its resin fluidity is too low and it cannot be extruded well, resulting in low precision in the layer-by-layer printing process and producing uneven and inconsistent three-dimensional structural materials.

[0100] For example, in step (1), the solid content of the 3D printing resin solution can be any one or any combination of 20%, 30%, 40%, 50%, 60%, 70%, 80%.

[0101] In one specific embodiment, in step (2), the process parameters for the photopolymerization 3D printing include: controlling the extrusion speed of the peristaltic pump to be 1 mL / hr-10 mL / hr, for example, 1 mL / hr, 2 mL / hr, 3 mL / hr, 4 mL / hr, 5 mL / hr, 6 mL / hr, 7 mL / hr, 8 mL / hr, 9 mL / hr, 10 mL / hr, etc.; and controlling the printing speed to be 5 mm / s-30 mm / s, for example, 5 mm / s, 10 mm / s, etc. The printing speeds are controlled as follows: m / s, 15mm / s, 20mm / s, 25mm / s, 30mm / s, etc.; the inner diameter of the printhead is controlled to be 0.4mm-0.8mm, for example, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, etc.; the thickness of each printing layer is controlled to be 10μm-50μm, for example, 10μm, 20μm, 30μm, 40μm, 50μm, etc.; the illumination conditions include: wavelength of 315nm-400nm and intensity of 10mW / cm². 2 -100mW / cm 2 Ultraviolet light.

[0102] In this invention, controlling the extrusion speed of the peristaltic pump within the aforementioned range enables the production of a three-dimensional structural material with a uniformly wrinkled surface. Extrusion speeds that are too fast or too slow directly affect printing quality, structural integrity, and mechanical properties. If the extrusion speed is too fast (e.g., 15 mL / hr for the peristaltic pump), too much 3D printing resin solution is extruded, leading to material accumulation and uneven curing. If the extrusion speed is too slow (e.g., 0.5 mL / hr for the peristaltic pump), the 3D printing resin solution cannot continuously cover the preset path, resulting in surface defects. Furthermore, because the extrusion process is accompanied by light, it can cause clogging of the printhead.

[0103] In this invention, controlling the inner diameter of the printhead within the aforementioned range results in higher printing efficiency. If the inner diameter of the printhead is too small (e.g., 0.2 mm), the printing speed is slow, the interlayer bonding force may be insufficient, the surface wrinkle structure may become oriented, and there is a risk of clogging the printhead. If the inner diameter of the printhead is too small (e.g., 1 mm), the fineness of the surface wrinkle structure will be sacrificed, leading to loss of detail and over-extrusion problems.

[0104] In this invention, the intensity of ultraviolet light is controlled to be 10 mW / cm. 2 -100mW / cm 2 This ensures that the three-dimensional structural material solidifies while simultaneously constructing a uniform, disordered surface wrinkled structure. However, if the intensity of the ultraviolet light is too low (e.g., 5 mW / cm²),... 2The low degree of surface curing of three-dimensional structural materials results in low structural precision and makes it impossible to obtain three-dimensional structural materials with wrinkled surfaces; if the intensity of ultraviolet light is too high (e.g., ultraviolet light intensity of 150mW / cm²), it will also lead to problems. 2 The poor interlayer adhesion results in obvious delamination of the three-dimensional structure material, affecting the printing accuracy of the overall structure. Furthermore, the excessive intensity of ultraviolet light leads to a rapid cross-linking speed, which affects the gradient self-assembly of the fluorine-containing macromolecular photoinitiator on the material surface, making it difficult to produce wrinkled structures.

[0105] In one specific embodiment, step (4) includes the following photocrosslinking curing process: at a wavelength of 315nm-400nm and an intensity of 10mW / cm². 2 -100mW / cm 2 Irradiate under ultraviolet light for 5-20 minutes.

[0106] In one specific embodiment, in step (4), the temperature of the heat treatment is 35℃-50℃ and the time is 30min-90min.

[0107] In one specific embodiment, the aforementioned multifunctional acrylate crosslinking agent is at least one selected from 1,6-hexanediol diacrylate, trimethylolpropane trimethacrylate, glyceryl trihydroxypropyl ether triacrylate, and pentaerythritol tetraacrylate.

[0108] In one specific embodiment, the aforementioned acrylate oligomer is at least one of polyether acrylate, aliphatic polyurethane triacrylate, and polyester acrylate.

[0109] A third aspect of this invention provides a three-dimensional structural material with a wrinkled surface, prepared by the aforementioned method for constructing a three-dimensional surface wrinkled structure. Compared with the problems of unadjustable surface wrinkles and difficulty in dynamic control in the preparation of traditional three-dimensional structural materials, this invention introduces a collaborative construction mechanism between the printing configuration and the surface wrinkle structure, simultaneously completing the three-dimensional structural forming and the generation of surface micro-wrinkles in a one-step printing process. This eliminates the need for additional developing, washing, and drying processes, significantly reducing processing complexity and environmental burden. Furthermore, by introducing functional units (graphene in this embodiment) that respond to external stimuli such as light / heat into the raw material formulation of the three-dimensional structural material, this invention endows the surface wrinkle structure of the three-dimensional structural material with in-situ reversible dynamic control capabilities, realizing dynamic control of the surface wrinkle structure of the three-dimensional structural material. This effectively solves the problem of difficulty in achieving dynamic control of the surface of traditional three-dimensional structural materials, providing a new approach for constructing integrated intelligent structures with sensing, responsive, and reconfigurable functions.

[0110] The present invention will be further described below through specific embodiments.

[0111] In the following examples, S5 polyether acrylate was purchased from Jiaxing Sudi Polymer Materials Co., Ltd., aliphatic polyurethane triacrylate was purchased from Jiaxing Sudi Polymer Materials Co., Ltd., 811 polyester acrylate was purchased from Zhanxin Resin Co., Ltd., and graphene was purchased from Aladdin Biochemical Technology Co., Ltd.

[0112] Example 1

[0113] This embodiment provides a fluorine-containing macromolecular photoinitiator I, the structural formula of which is as follows:

[0114]

[0115] Where x=10, y=30, z=10.

[0116] Figure 1 This is a synthetic route diagram of the fluorine-containing macromolecular photoinitiator I in Example 1 of the present invention, as shown below. Figure 1 As shown, the preparation method of the above-mentioned fluorine-containing macromolecular photoinitiator I provided in this embodiment includes the following steps:

[0117] (1) 40 mmol of dimethylaminoethyl methacrylate (DMAEMA), 10 mmol of perfluorooctyl ethyl acrylate, and 1 mmol of azobisisobutyronitrile (AIBN) were dissolved in 80 mL of 1,4-dioxane. The mixture was stirred at 80 °C for 18 h under a nitrogen atmosphere. The resulting mixture was precipitated in n-hexane, filtered, and a white precipitate was obtained. The white precipitate was then vacuum dried in a vacuum drying oven at 60 °C to obtain a white powdery random copolymer containing dimethylamino. The 1H NMR spectrum of this random copolymer containing dimethylamino is shown below. Figure 2 As shown.

[0118] (2) 40 mmol of the dimethylamino-containing random copolymer from step (1) and 20 mmol of 4-(bromomethyl)benzophenone were dissolved in 50 mL of N,N-dimethylformamide (DMF) and reacted at 70 °C for 24 h to prepare fluorinated macromolecular photoinitiator I. The proton NMR spectrum of this fluorinated macromolecular photoinitiator I is shown below. Figure 3 As shown.

[0119] Example 2

[0120] This embodiment provides a fluorine-containing macromolecular photoinitiator II, the structural formula of which is as follows:

[0121]

[0122] Where x=30, y=60, z=10.

[0123] Figure 4 This is a synthetic route diagram of the fluorine-containing macromolecular photoinitiator II in Example 2 of the present invention, as shown below. Figure 4 As shown, the preparation method of the above-mentioned fluorine-containing macromolecular photoinitiator II provided in this embodiment includes the following steps:

[0124] 30 mmol of dimethylaminoethyl methacrylate (DMAEMA), 60 mmol of 4-acryloylhydroxybenzoate benzophenone, 10 mmol of perfluorooctyl ethyl acrylate, and 1 mmol of azobisisobutyronitrile (AIBN) were dissolved in 80 mL of 1,4-dioxane. The mixture was stirred at 80 °C for 18 h under a nitrogen atmosphere. The resulting mixture was precipitated in n-hexane, filtered, and a white precipitate was obtained. The white precipitate was then vacuum dried in a vacuum drying oven at 60 °C to obtain a white powdery fluorinated macromolecular photoinitiator II. The 1H NMR spectrum of this fluorinated macromolecular photoinitiator II is shown below. Figure 5 As shown.

[0125] Example 3

[0126] This embodiment provides a method for constructing a three-dimensional surface wrinkled structure, including the following steps:

[0127] (1) 200 mg of the fluorinated macromolecular photoinitiator I from Example 1, 0.2 g of 1,6-hexanediol diacrylate, 0.2 g of pentaerythritol tetraacrylate and 0.5 g of S5 polyether acrylate were dissolved in 2 mL of chloroform solvent to prepare a 3D printing resin solution; the solid content of the 3D printing resin solution was 27.1% by mass; the mass fraction of the fluorinated macromolecular photoinitiator I in the 3D printing resin solution was 4.9 wt%.

[0128] (2) Place the 3D printing resin solution according to the preset printing path (e.g., Figure 6 a) Perform photopolymerization 3D printing, specifically including: Step S1, extrude the 3D printing resin solution through a printing nozzle with an inner diameter of 0.6 mm (the extrusion speed of the peristaltic pump is 5 mL / hr), and after reaching a stable extrusion state, control the movement of the printing nozzle at a printing speed of 10 mm / s and deposit it on a polyethylene terephthalate (PET) substrate, while combining a 365 nm light source (ultraviolet light intensity of 60 mW / cm²). 2The extruded 3D printing resin solution is photocrosslinked and cured. Due to the funnel effect of light, gradient crosslinking occurs on the surface of the 3D printing resin solution, leading to a mismatch in the thermal expansion and contraction rates between the surface and inner layers. During the evaporation of organic solvents and material cooling, the inner layer shrinks more than the surface layer, thus forming a self-wrinkled structure on the surface, resulting in a single-layer deposited material with a self-wrinkled surface (each layer is 30 μm thick). Step S2 is repeated with step S1, and through layer-by-layer deposition, a three-dimensional structure material (1.2 cm thick) is finally obtained. The deposition system is computer-controlled, with the printing nozzle moving along the x, y, and z directions.

[0129] (3) The three-dimensional structure material was heat-treated at 40°C for 1 hour, followed by photocrosslinking curing treatment (at a wavelength of 365 nm and an intensity of 60 mW / cm). 2 After irradiating with ultraviolet light for 10 minutes, a three-dimensional structure material with a wrinkled surface was finally obtained, and the wrinkled structure was disordered and micron-sized (e.g., Figure 6 (b and c).

[0130] Example 4

[0131] This embodiment provides a method for constructing a three-dimensional surface wrinkled structure, including the following steps:

[0132] (1) 200 mg of fluorinated macromolecular photoinitiator II, 0.2 g of trimethylolpropane trimethacrylate, 0.3 g of glycerol trihydroxypropyl ether triacrylate, 0.2 g of aliphatic polyurethane triacrylate and 0.3 g of 811 polyester acrylate were dissolved in 2 mL of chloroform solvent to prepare a 3D printing resin solution; the solid content of the 3D printing resin solution was 28.8% by mass; the mass fraction of fluorinated macromolecular photoinitiator II in the 3D printing resin solution was 4.8 wt%.

[0133] (2) Place the 3D printing resin solution according to the preset printing path (e.g., Figure 7 a) Perform photopolymerization 3D printing, specifically including: Step S1, extrude the 3D printing resin solution through a printing nozzle with an inner diameter of 0.6 mm (the extrusion speed of the peristaltic pump is 5 mL / hr), and after reaching a stable extrusion state, control the movement of the printing nozzle at a printing speed of 10 mm / s and deposit it on a polyethylene terephthalate (PET) substrate, while combining a 365 nm light source (ultraviolet light intensity of 60 mW / cm²). 2The process involves photocrosslinking and curing. Due to the funnel effect of light, gradient crosslinking occurs on the surface of the 3D printing resin solution, leading to a mismatch in thermal expansion and contraction rates between the surface and inner layers. During the evaporation of organic solvents and material cooling, the inner layer shrinks more than the surface layer, thus forming a self-wrinkled structure on the surface, resulting in a single-layer deposited material with a self-wrinkled surface (each layer is 30 μm thick). Step S2 is repeated with step S1, and through layer-by-layer deposition, a three-dimensional structure material (1.2 cm thick) is finally obtained. The deposition system is computer-controlled, with the printing nozzle moving along the x, y, and z directions.

[0134] (3) The three-dimensional structure material was heat-treated at 40°C for 1 hour, followed by photocrosslinking curing treatment (at a wavelength of 365 nm and an intensity of 60 mW / cm). 2 After irradiating with ultraviolet light for 10 minutes, a three-dimensional structure material with a wrinkled surface was finally obtained, and the wrinkled structure was disordered and micron-sized (e.g., Figure 7 (bd).

[0135] Example 5

[0136] This embodiment provides a method for constructing a three-dimensional surface wrinkled structure, including the following steps:

[0137] (1) 300 mg of graphene was added to 10 mL of chloroform and ultrasonically dispersed for 36 h to prepare a graphene solution with a mass fraction of 2 wt%. 200 mg of the fluorine-containing macromolecular photoinitiator II from Example 2, 0.2 g of trimethylolpropane trimethacrylate, 0.3 g of glycerol trihydroxypropyl ether triacrylate, 0.2 g of aliphatic polyurethane triacrylate and 0.3 g of 811 polyester acrylate were mixed with 2 mL of graphene solution to prepare a 3D printing resin solution. The solid content of the 3D printing resin solution was 29.9% by mass.

[0138] (2) The 3D printing resin solution is photocured and 3D printed according to the preset printing path, specifically including: Step S1, the 3D printing resin solution is extruded through a printing nozzle with an inner diameter of 0.6 mm (the extrusion speed of the peristaltic pump is 5 mL / hr), and after reaching the extrusion stabilization state, the printing nozzle is moved at a printing speed of 10 mm / s and deposited on the polyethylene terephthalate (PET) substrate, while combined with a 365 nm light source (ultraviolet light intensity of 60 mW / cm). 2The process involves photocrosslinking and curing. Due to the funnel effect of light, gradient crosslinking occurs on the surface of the 3D printing resin solution, leading to a mismatch in thermal expansion and contraction rates between the surface and inner layers. During the evaporation of organic solvents and material cooling, the inner layer shrinks more than the surface layer, thus forming a self-wrinkled structure on the surface, resulting in a single-layer deposited material with a self-wrinkled surface (each layer is 30 μm thick). Step S2 is repeated with step S1, and through layer-by-layer deposition, a three-dimensional structure material (1.2 cm thick) is finally obtained. The deposition system is computer-controlled, with the printing nozzle moving along the x, y, and z directions.

[0139] (3) The three-dimensional structure material was heat-treated at 40°C for 1 hour, followed by photocrosslinking curing treatment (at a wavelength of 365 nm and an intensity of 60 mW / cm). 2 After irradiating with ultraviolet light for 10 minutes, a three-dimensional structure material with a wrinkled surface was finally obtained, and the wrinkled structure was disordered and micron-sized (e.g., Figure 8 (a).

[0140] Figure 8 This is an in-situ dynamic control diagram of the surface wrinkle structure of the three-dimensional structural material with a wrinkled surface in Embodiment 5 of the present invention; wherein, Figure 8 'a' represents the surface wrinkle structure diagram of a three-dimensional material with a wrinkled surface. Figure 8 b is an enlarged view of the surface wrinkle structure of a three-dimensional material with a wrinkled surface. Figure 8 c represents the surface wrinkle structure of a three-dimensional material with a wrinkled surface after irradiation with 808nm near-infrared light. Figure 8 d is a magnified image of the surface wrinkle structure of a three-dimensional material with a wrinkled surface after being irradiated with 808nm near-infrared light.

[0141] Depend on Figure 8It is evident that when the three-dimensional structural material with a wrinkled surface in this embodiment is irradiated with 808 nm near-infrared light, the wrinkled surface structure is erased. After the 808 nm near-infrared light irradiation is removed and the material is cooled to room temperature, the surface morphology spontaneously recovers to its initial shape, achieving in-situ restoration of the macroscopic structure and microscopic pattern. The inventors analyzed this and believe the reason is that, due to the excellent photothermal conversion effect of graphene, when the three-dimensional structural material with a wrinkled surface is irradiated with 808 nm near-infrared light, the system temperature of the three-dimensional structural material with a wrinkled surface rapidly increases, causing thermal expansion and erasing the wrinkled surface structure. After the 808 nm near-infrared light irradiation is removed, the system temperature decreases, causing volume contraction and leading to the restoration of the wrinkled surface structure. The above results indicate that the three-dimensional structural material with a wrinkled surface prepared in this embodiment has near-infrared response characteristics, achieving in-situ dynamic control of the three-dimensional surface wrinkled structure.

[0142] Comparative Example 1 (2 wt% of fluorine-containing macromolecular photoinitiator II in 3D printing resin solution)

[0143] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0144] (1) Dissolve 80 mg of the fluorinated macromolecular photoinitiator II from Example 2, 0.2 g of trimethylolpropane trimethacrylate, 0.3 g of glycerol trihydroxypropyl ether triacrylate, 0.2 g of aliphatic polyurethane triacrylate and 0.3 g of 811 polyester acrylate in 2 mL of chloroform solvent to prepare a 3D printing resin solution; the solid content of the 3D printing resin solution is 26.7% by mass; the mass fraction of the fluorinated macromolecular photoinitiator II in the 3D printing resin solution is 2 wt%.

[0145] Figure 9 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 1 of the present invention.

[0146] Depend on Figure 9 It can be seen that the surface of the three-dimensional structural material in this comparative example does not have disordered micron-level wrinkles. The inventors analyzed this and believe that the reason is that insufficient content of fluorine-containing macromolecular photoinitiator II leads to incomplete curing of the three-dimensional structural material, resulting in the inability to form wrinkles on the material surface.

[0147] Comparative Example 2 (20 wt% of fluorine-containing macromolecular photoinitiator II in 3D printing resin solution)

[0148] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0149] (1) Dissolve 1g of fluorinated macromolecular photoinitiator II from Example 2, 0.2g of trimethylolpropane trimethacrylate, 0.3g of glycerol trihydroxypropyl ether triacrylate, 0.2g of aliphatic polyurethane triacrylate and 0.3g of 811 polyester acrylate in 2mL of chloroform solvent to prepare a 3D printing resin solution; the solid content of the 3D printing resin solution is 40.3% by mass; the mass fraction of fluorinated macromolecular photoinitiator II in the 3D printing resin solution is 20wt%.

[0150] Figure 10 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 2 of the present invention.

[0151] Depend on Figure 10 It can be seen that the surface of the three-dimensional structural material in this comparative example does not have disordered micron-level wrinkles. The inventors analyzed this and believe that the reason is that excessive fluorine-containing macromolecular photoinitiator II will cause severe phase separation in the three-dimensional structural material, making it impossible to construct disordered micron-level wrinkles on the material surface.

[0152] Comparative Example 3 (3D printing resin solution with a solid content of 10% by mass)

[0153] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0154] (1) Dissolve 200 mg of fluorine-containing macromolecular photoinitiator II, 0.2 g of trimethylolpropane trimethacrylate, 0.3 g of glycerol trihydroxypropyl ether triacrylate, 0.2 g of aliphatic polyurethane triacrylate and 0.3 g of 811 polyester acrylate in 7.3 mL of chloroform solvent to prepare a 3D printing resin solution; the solid content of the 3D printing resin solution is 10% by mass.

[0155] Figure 11 This is a physical image of the three-dimensional structural material in Comparative Example 3 of the present invention.

[0156] Depend on Figure 11 It is evident that the three-dimensional structural material in this comparative example was not fully cured. The inventors analyzed this and believe the reason is that the solid content of the 3D printing resin solution is too low. Due to its high fluidity during extrusion, it cannot cure quickly and is difficult to construct a three-dimensional structure.

[0157] Comparative Example 4 (the solid content of the 3D printing resin solution is 100% by mass).

[0158] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0159] (1) 200 mg of fluorine-containing macromolecular photoinitiator II, 0.2 g of trimethylolpropane trimethacrylate, 0.3 g of glycerol trihydroxypropyl ether triacrylate, 0.2 g of aliphatic polyurethane triacrylate and 0.3 g of 811 polyester acrylate were thoroughly mixed to prepare a 3D printing resin solution; the solid content of the 3D printing resin solution was 100% by mass.

[0160] Figure 12 This is a physical image of the three-dimensional structural material in Comparative Example 4 of the present invention.

[0161] Depend on Figure 12 It is evident that the three-dimensional structural material in this comparative example was not completely cured. The inventors analyzed this and believe the reason is that the solid content of the 3D printing resin solution is too high, and its resin fluidity is too low to be extruded well, resulting in low precision in the layer-by-layer printing process and producing a three-dimensional structural material with unevenness and texture.

[0162] Comparative Example 5 (extrusion speed 0.5 mL / hr)

[0163] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0164] (2) Replace the extrusion speed of the peristaltic pump of 5 mL / hr with the extrusion speed of the peristaltic pump of 0.5 mL / hr.

[0165] Figure 13 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 5 of the present invention.

[0166] Depend on Figure 13 It can be seen that the surface of the three-dimensional structural material in this comparative example does not have disordered micron-level wrinkles.

[0167] Comparative Example 6 (extrusion speed 15 mL / hr)

[0168] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0169] (2) Replace the extrusion speed of the peristaltic pump of 5 mL / hr with the extrusion speed of the peristaltic pump of 15 mL / hr.

[0170] Figure 14 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 6 of the present invention.

[0171] Depend on Figure 14 It can be seen that the surface of the three-dimensional structural material in this comparative example does not have disordered micron-level wrinkles.

[0172] Comparative Example 7 (printer nozzle inner diameter is 0.2mm)

[0173] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0174] (2) Replace the 0.6mm inner diameter printhead with a 0.2mm inner diameter printhead.

[0175] Figure 15 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 7 of the present invention.

[0176] Depend on Figure 15 It can be seen that the surface of the three-dimensional structural material in this comparative example has some uneven wrinkles oriented along the printing direction, which is not conducive to the subsequent application and mechanism research of disordered wrinkle structures.

[0177] Comparative Example 8 (printer nozzle inner diameter is 1mm)

[0178] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0179] (2) Replace the 0.6mm inner diameter printhead with a 1mm inner diameter printhead.

[0180] Figure 16 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 8 of the present invention.

[0181] Depend on Figure 16 It can be seen that the fineness of the wrinkled structure on the surface of the three-dimensional material in this comparative example is poor, with obvious wavelength inconsistencies and uneven orientation of the wrinkled structure, which is not conducive to the subsequent application and mechanism research of disordered wrinkled structures.

[0182] Comparative Example 9 (UV light intensity of 5 mW / cm²) 2 )

[0183] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0184] (2) The intensity of ultraviolet light is 60mW / cm 2 Replace with ultraviolet light intensity of 5mW / cm 2 .

[0185] (3) At a wavelength of 365nm and an intensity of 60mW / cm 2 The 10-minute irradiation under ultraviolet light was replaced with irradiation at a wavelength of 365 nm and an intensity of 5 mW / cm. 2 Irradiate under ultraviolet light for 10 minutes.

[0186] Figure 17 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 9 of the present invention.

[0187] Depend on Figure 17 It can be seen that no obvious wrinkles appeared on the surface of the three-dimensional structural material in this comparative example.

[0188] Comparative Example 10 (UV light intensity of 150 mW / cm²) 2 )

[0189] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 4, except that:

[0190] (2) The intensity of ultraviolet light is 60mW / cm 2 Replace with ultraviolet light intensity of 150mW / cm 2 .

[0191] (3) At a wavelength of 365nm and an intensity of 60mW / cm 2 The 10-minute irradiation under ultraviolet light was replaced with irradiation at a wavelength of 365 nm and an intensity of 150 mW / cm. 2 Irradiate under ultraviolet light for 10 minutes.

[0192] Figure 18 This is a surface morphology diagram of the three-dimensional structural material in Comparative Example 10 of the present invention.

[0193] Depend on Figure 18 It can be seen that the surface of the three-dimensional material in this comparative example exhibits obvious layering and no wrinkled structure.

[0194] Comparative Example 11 (graphene solution with a mass fraction of 0.05 wt%)

[0195] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 5, except that:

[0196] (1) 7.5 mg of graphene was added to 10 mL of chloroform and ultrasonically dispersed for 36 h to prepare a graphene solution with a mass fraction of 0.05 wt%. 200 mg of fluorine-containing macromolecular photoinitiator II from Example 2, 0.2 g of trimethylolpropane trimethacrylate, 0.3 g of glycerol trihydroxypropyl ether triacrylate, 0.2 g of aliphatic polyurethane triacrylate and 0.3 g of 811 polyester acrylate were mixed with 2 mL of graphene solution to prepare a 3D printing resin solution. The solid content of the 3D printing resin solution was 28.8% by mass.

[0197] Figure 19 This is an in-situ dynamic control diagram of the surface wrinkle structure of the three-dimensional structural material with a wrinkled surface in Comparative Example 11 of the present invention, wherein... Figure 19 Figure a is a surface wrinkle structure diagram of the three-dimensional structural material with a wrinkled surface in Comparative Example 11 of the present invention. Figure 19 b is a diagram of the surface wrinkle structure of the three-dimensional structural material with a wrinkled surface in Comparative Example 11 of the present invention after being irradiated with 808nm near-infrared light.

[0198] Depend on Figure 19 It can be seen that when the three-dimensional structural material with a wrinkled surface in this comparative example is irradiated with 808nm near-infrared light, the wrinkled surface structure cannot be completely erased, and the in-situ dynamic control of the wrinkled surface structure cannot be achieved.

[0199] Comparative Example 12 (graphene solution with a mass fraction of 4 wt%)

[0200] The method for constructing the three-dimensional surface wrinkled structure provided in this comparative example is basically the same as that in Example 5, except that:

[0201] (1) 620 mg of graphene was added to 10 mL of chloroform and ultrasonically dispersed for 36 h to prepare a graphene solution with a mass fraction of 4 wt%. 200 mg of the fluorine-containing macromolecular photoinitiator II from Example 2, 0.2 g of trimethylolpropane trimethacrylate, 0.3 g of glycerol trihydroxypropyl ether triacrylate, 0.2 g of aliphatic polyurethane triacrylate and 0.3 g of 811 polyester acrylate were mixed with 2 mL of graphene solution to prepare a 3D printing resin solution. The solid content of the 3D printing resin solution was 38.1% by mass.

[0202] Figure 20 The image shows the surface wrinkle structure morphology of the three-dimensional structural material with a wrinkled surface in Comparative Example 12 of this invention.

[0203] Depend on Figure 20 It can be seen that the wrinkle structure on the surface of the three-dimensional material in this comparative example is not uniform.

[0204] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a three-dimensional surface wrinkled structure, characterized in that, Includes the following steps: (1) A 3D printing resin solution is prepared by dissolving a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent, and an acrylate oligomer in an organic solvent, or by mixing a fluorinated macromolecular photoinitiator, a multifunctional acrylate crosslinking agent, and an acrylate oligomer with a graphene solution; wherein the mass fraction of the fluorinated macromolecular photoinitiator in the 3D printing resin solution is 4-15 wt%. (2) Photopolymerization 3D printing is used to crosslink and solidify the 3D printing resin solution under light irradiation during the printing process and deposit it onto the substrate to obtain a single-layer deposited material with a self-wrinkled structure on the surface. (3) Repeat step (2) to finally obtain a three-dimensional structure material through layer-by-layer deposition; (4) The three-dimensional structural material is subjected to heat treatment and photo-crosslinking curing treatment to obtain a three-dimensional structural material with a wrinkled surface. The structure of the fluorine-containing macromolecular photoinitiator is shown in formula (1) or formula (2): ； Equation (1) Equation (2) In equation (1) or equation (2), 0 <x≤100,0<y≤100,0<z≤100。 2. The method for constructing a three-dimensional surface wrinkled structure according to claim 1, characterized in that, In step (1), the mass ratio of the fluorinated macromolecular photoinitiator, the multifunctional acrylate crosslinking agent and the acrylate oligomer is (2-10):(5-50):(5-50).

3. The method for constructing a three-dimensional surface wrinkled structure according to claim 1, characterized in that, In step (1), the graphene solution is prepared by dissolving graphene in an organic solvent, and the mass fraction of the graphene solution is 0.2wt%-2wt%.

4. The method for constructing a three-dimensional surface wrinkled structure according to claim 1, characterized in that, In step (1), the solid content of the 3D printing resin solution is 20%-80% by mass.

5. The method for constructing a three-dimensional surface wrinkled structure according to claim 1, characterized in that, In step (2), the process parameters for photopolymerization 3D printing include: Control the extrusion speed of the peristaltic pump to 1 mL / hr-10 mL / hr; Control the printing speed to 5mm / s-30mm / s; The inner diameter of the printhead is controlled to be 0.4mm-0.8mm; Control the thickness of each printing layer to 10μm-50μm; Lighting conditions include: wavelength of 315nm-400nm and intensity of 10mW / cm². 2 -100mW / cm 2 Ultraviolet light.

6. The method for constructing a three-dimensional surface wrinkled structure according to claim 1, characterized in that, In step (4), the photocrosslinking curing process includes: at a wavelength of 315nm-400nm and an intensity of 10mW / cm². 2 -100mW / cm 2 Irradiate under ultraviolet light for 5-20 minutes.

7. The method for constructing a three-dimensional surface wrinkled structure according to claim 1, characterized in that, In step (4), the temperature of the heat treatment is 35℃-50℃ and the time is 30min-90min.

8. The method for constructing a three-dimensional surface wrinkled structure according to claim 1, characterized in that, The multifunctional acrylate crosslinking agent is at least one of 1,6-hexanediol diacrylate, trimethylolpropane trimethacrylate, glyceryl trihydroxypropyl ether triacrylate, and pentaerythritol tetraacrylate. And / or, the acrylate oligomer is at least one of polyether acrylate, aliphatic polyurethane triacrylate, and polyester acrylate.

9. A three-dimensional structural material with a wrinkled surface, characterized in that, It is prepared by the method for constructing a three-dimensional surface wrinkled structure as described in any one of claims 1-8.

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