Biomimetic hierarchical porous nested structure with high spectral selectivity

Abstract

The utility model is applicable to the field of bionic functional materials, and provides a biomimetic graded porous nested structure with high spectral selectivity, which comprises an optical regulation and control layer, a functional composite layer and an interface enhancement layer which are sequentially arranged from outside to inside, the optical regulation and control layer comprises a multi-stage nested pore network, the pore network comprises first scale pores and second scale pores, the first scale pores and the second scale pores are of a honeycomb-shaped communicated structure, and pore walls are loaded with a light reflection enhancer and an infrared radiation agent; according to the utility model, the energy is saved, the consumption is reduced, the indoor temperature can be reduced by 5-8 DEG C and the energy consumption of an air conditioner can be reduced by 30-40% when the device is applied to a building external wall; the heat dissipation device is used for heat dissipation of electronic equipment, can reduce the surface temperature of the equipment by 8-12 DEG C, improves the energy efficiency of the equipment, reduces energy consumption, and is safe, reliable and wide in application.

Description

Technical Field

[0001] This invention belongs to the field of biomimetic functional materials, and particularly relates to a highly spectrally selective biomimetic hierarchical porous nested structure. Background Technology

[0002] In the field of thermal management technology, traditional materials and structures have significant drawbacks. Ordinary heat-dissipating coatings lack the ability to selectively modulate the spectrum of sunlight, failing to specifically reflect high-energy ultraviolet and near-infrared wavelengths. This results in objects absorbing large amounts of heat under sunlight, leading to poor heat dissipation. For example, conventional thermal insulation coatings used on building exteriors often fail to effectively reduce indoor temperatures during hot summer months, resulting in high air conditioning energy consumption. Furthermore, heat sinks in electronic devices are prone to performance degradation or even damage after prolonged operation due to insufficient heat dissipation.

[0003] While existing biomimetic structures have improved heat dissipation performance to some extent, their fabrication processes are complex, often relying on precision machining techniques such as electron beam lithography and photolithography, resulting in high costs and hindering large-scale industrial production. Furthermore, most heat dissipation materials have limited functionality and lack composite properties such as flame retardancy, self-cleaning, and strong adhesion. Their durability and safety in complex environments are insufficient, failing to meet the demands of modern multi-scenario applications.

[0004] Therefore, a highly spectrally selective, biomimetic hierarchical porous nested structure is needed to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a highly spectrally selective, biomimetic hierarchical porous nested structure to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A highly spectrally selective biomimetic hierarchical porous nested structure includes an optical control layer, a functional composite layer, and an interface enhancement layer, wherein the optical control layer, the functional composite layer, and the interface enhancement layer are arranged sequentially from the surface to the inside.

[0008] The optical control layer comprises a multi-level nested pore network, which includes first-scale pores (diameter 20-200nm) and second-scale pores (diameter 0.5-10μm), forming a honeycomb-like interconnected structure. The pore walls are loaded with light reflection enhancers and infrared radiants, enabling efficient reflection of electromagnetic waves in the 280-2500nm band and high emission of infrared radiation in the 5-15μm band, thereby achieving efficient passive heat dissipation.

[0009] The functional composite layer is a cross-linked polymer-based composite film with a thickness of 0.05-0.6 mm, containing flame-retardant functional groups (mass percentage ≥10%) and a thermally conductive reinforcing phase (volume percentage 3%-15%).

[0010] The interface reinforcement layer is a gradient coating composed of a first adhesive component and a second elastic component, with a thickness of 10-100 μm, to ensure a firm bond between the structure and the substrate.

[0011] By designing a hierarchical porous nested structure based on biomimetic principles, it achieves multifunctional integration of high reflectivity, high infrared emissivity, flame retardancy, and strong interface bonding, making it suitable for passive heat dissipation and safety protection in extreme environments.

[0012] In a further technical solution, the light reflection enhancer includes at least one of titanium dioxide, zinc oxide, or silicon dioxide nanoparticles, and the infrared radiant includes at least one of boron nitride, silicon carbide, or graphene derivatives.

[0013] In a further technical solution, the polymer matrix of the functional composite layer includes at least one of polyphosphate ester, polysiloxane or phenolic resin, the flame retardant functional group includes phosphorus-based, nitrogen-based or silicon-based flame retardant elements, and the thermally conductive reinforcing phase includes at least one of graphene, carbon nanotube or metal nanowire.

[0014] In a further technical solution, the first adhesive component of the interface reinforcement layer includes at least one of silane coupling agent, epoxy resin or polyurethane, and the second elastic component includes at least one of acrylate elastomer, silicone rubber or thermoplastic elastomer.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This utility model is energy-saving and consumption-reducing: when applied to building exterior walls, it can reduce indoor temperature by 5-8℃ and reduce air conditioning energy consumption by 30%-40%; when used for heat dissipation of electronic equipment, it can reduce the surface temperature of the equipment by 8-12℃, improve equipment energy efficiency, and reduce energy consumption.

[0017] This utility model is safe and reliable: its flame retardant performance reaches a high standard, and it can effectively delay the spread of fire in dangerous situations such as fires, ensuring the safety of people and property; its superhydrophobic or self-cleaning function reduces the impact of external factors on structural performance and extends service life.

[0018] This utility model has a wide range of applications: it can be adapted to the needs of multiple fields such as construction, electronics, and aerospace, and can be firmly bonded to different substrates. It provides innovative solutions for thermal management and protection in various fields and has significant practical value and market potential.

[0019] To more clearly illustrate the structural features and effects of this utility model, the following detailed description of this utility model is provided in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention from the front view;

[0021] Figure 2 This is a three-dimensional structural diagram of the present invention viewed from below;

[0022] Figure 3 This utility model Figure 2 Enlarged structural diagram at point A in the middle.

[0023] In the figure: 1. Optical control layer; 11. Pore network; 111. First-scale pores; 112. Second-scale pores; 113. Reflection enhancer; 114. Infrared radiant; 2. Functional composite layer; 21. Composite film; 22. Flame retardant functional group; 23. Thermally conductive enhancement phase; 3. Interface enhancement layer; 31. First binder component; 32. Second elastic group. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0025] The specific implementation of this utility model will be described in detail below with reference to specific embodiments.

[0026] Example 1

[0027] like Figure 1 , Figure 2 and Figure 3 As shown, this utility model embodiment provides a highly spectrally selective biomimetic hierarchical porous nested structure, including an optical control layer 1: a first-scale pore 111 with a diameter of 80 nm, a second-scale pore 112 with a diameter of 3 μm, a porosity of 55%, and titanium dioxide nanoparticles and boron nitride nanosheets loaded on the pore walls. The outer surface is modified with fluorosilane, and the contact angle reaches 118°.

[0028] Functional composite layer 2: Polyphosphate ester is selected as the matrix, and 15% by mass of phosphorus flame retardant groups and 10% by volume of graphene are added. The composite film 21 with a thickness of 0.3 mm is made by in-situ polymerization crosslinking process.

[0029] Interface reinforcement layer 3: The bottom layer is a 10% concentration silane coupling agent anchoring layer, and the top layer is a 70% concentration acrylate elastomer buffer layer with a total thickness of 60μm. The peel strength with the building exterior wall tiles reaches 9N / cm.

[0030] In this embodiment, the embodiment is applied to the exterior wall of a building;

[0031] During the high-temperature period in summer, with a light intensity of 1000W / m², the surface temperature of the exterior wall is reduced by 15℃ compared to traditional coatings, the indoor temperature is reduced by 6℃, and the average daily operating time of air conditioning is reduced by 4 hours, resulting in significant energy-saving effects. After being subjected to simulated acid rain (pH=3) erosion for 1000 hours, the structural performance retention rate is ≥95%, and the hydrophobic performance is stable.

[0032] Example 2:

[0033] The difference between this embodiment and Embodiment 1 is as follows: Optical control layer 1: formed by 3D printing technology, with a first-scale pore 111 diameter of 120nm, a second-scale pore 112 diameter of 5μm, a porosity of 60%, and loaded with zinc oxide nanoparticles and silicon carbide nanosheets to achieve efficient radiative heat dissipation of heat generated by electronic devices; Functional composite layer 2: with phenolic resin as the matrix, 12% by mass of nitrogen-based flame retardant and 8% by volume of carbon nanotubes are added, with a thickness of 0.25mm, which improves flame retardant performance while ensuring heat dissipation;

[0034] Interface reinforcement layer 3: It adopts a polyurethane-silicone rubber gradient coating with a thickness of 40μm, which forms a strong chemical bond with the aluminum alloy shell and has a peel strength of 8.5N / cm;

[0035] In this embodiment, this embodiment is applied to heat dissipation of electronic devices;

[0036] After the electronic equipment has been running at full load for 4 hours, the casing temperature is only 42℃, which is 10℃ lower than the traditional heat dissipation structure, greatly improving the stability of the equipment operation. In the vertical combustion test, the flame is extinguished within 5 seconds, which meets the UL94V-0 standard and ensures the safe operation of the equipment.

[0037] Example 3:

[0038] The difference between this embodiment and Embodiment 1 is that: Optical control layer 1: the first-scale pore 111 has a diameter of 50nm, the second-scale pore 112 has a diameter of 2μm, the porosity is 45%, the pore walls are loaded with silica nanoparticles and graphene derivatives, and the solar radiation reflectivity is ≥98.5%;

[0039] Functional composite layer 2: 18% by mass of silicon-based flame retardant and 12% by volume of metal nanowires are added to polysiloxane to form a high-strength, high-thermal-conductivity protective layer with a thickness of 0.4 mm.

[0040] Interface reinforcement layer 3: A gradient coating composed of silane coupling agent and thermoplastic elastomer, with a thickness of 80μm, a peel strength of 10N / cm, and no significant decrease in bonding strength after 500 cycles at temperatures ranging from -180℃ to 250℃.

[0041] In this embodiment, the application is in aerospace thermal protection;

[0042] Under the intense solar radiation environment at high altitudes, the surface temperature of aerospace equipment is stably controlled within the allowable range, effectively protecting the internal precision instruments; under extreme temperature environments, the thermal expansion coefficient of the structure matches the substrate well, and no cracking or peeling occurs, ensuring long-term reliable operation of the equipment.

[0043] The working principle of this utility model:

[0044] Principle of Spectral Selectivity Control: The multi-level nested pore network 11 of the optical control layer 1 exerts a synergistic effect on electromagnetic waves of different wavelengths. The first-scale nanoscale pores produce Mie scattering of ultraviolet-visible light in the 280-760nm range, while the second-scale micrometer-scale pores produce Bragg reflection of near-infrared light in the 760-2500nm range. The two work together to reflect more than 98% of sunlight back to the environment, reducing heat absorption by the structure. At the same time, the loaded infrared radiants 114, such as boron nitride and silicon carbide, have high emission characteristics in the 5-15μm atmospheric window band, which can directly dissipate the heat inside the structure into space in the form of infrared radiation, achieving zero-energy passive cooling.

[0045] The principle of synergistic flame retardancy and thermal conductivity: Under high temperature or flame, the polymer matrix of the functional composite layer 2 decomposes the flame retardant functional groups 22, such as phosphorus and nitrogen elements, to produce substances such as phosphoric acid and polyphosphoric acid. Together with the thermally conductive reinforcing phase 23, such as graphene and carbon nanotubes, a dense carbonized layer is formed. This carbonized layer isolates oxygen and heat transfer, and has a thermal conductivity ≤0.5W / (m・K), thus inhibiting the combustion reaction. At the same time, the three-dimensional network constructed by the thermally conductive reinforcing phase 23 quickly conducts local hot spot heat to the optical control layer 1, which dissipates the heat through infrared radiation, avoiding heat accumulation and achieving the dual effects of flame retardancy and heat dissipation.

[0046] Interface bonding and protection principle: The gradient coating of the interface reinforcement layer 3 is firmly bonded to the substrate through a dual mechanism of chemical anchoring, such as silane coupling agent forming Si-O bonds with the substrate, and physical interlocking, such as elastomer mechanical entanglement with the substrate surface; the bottom anchoring layer provides high-strength adhesion, and the top elastic buffer layer can absorb external stress such as thermal stress and mechanical vibration, protecting the structural integrity. In addition, the gradient coating can also block the intrusion of external moisture and corrosive gases, improving the durability and stability of the structure in complex environments.

[0047] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A highly spectrally selective, biomimetic hierarchical porous nested structure, comprising an optical control layer (1), a functional composite layer (2), and an interface enhancement layer (3), characterized in that: The optical control layer (1), the functional composite layer (2), and the interface enhancement layer (3) are arranged sequentially from the outside to the inside; The optical control layer (1) includes a multi-level nested pore network (11), which includes a first-scale pore (111) and a second-scale pore (112), which are connected in a honeycomb structure. The pore walls are loaded with a light reflection enhancer (113) and an infrared radiant (114). The functional composite layer (2) is a cross-linked polymer-based composite film (21) with a thickness of 0.05-0.6 mm, containing flame-retardant functional groups (22) and a thermally conductive reinforcing phase (23). The interface reinforcement layer (3) is a gradient coating composed of a first adhesive component (31) and a second elastic component (32), with a thickness of 10-100 μm.

2. The highly spectrally selective biomimetic hierarchical porous nested structure according to claim 1, characterized in that: The light reflection enhancer (113) includes at least one of titanium dioxide, zinc oxide or silicon dioxide nanoparticles, and the infrared radiant (114) includes at least one of boron nitride, silicon carbide or graphene derivative.

3. The highly spectrally selective biomimetic hierarchical porous nested structure according to claim 1, characterized in that: The polymer matrix of the functional composite layer (2) includes at least one of polyphosphate, polysiloxane or phenolic resin, the flame retardant functional group (22) includes phosphorus-based, nitrogen-based or silicon-based flame retardant elements, and the thermally conductive reinforcing phase (23) includes at least one of graphene, carbon nanotube or metal nanowire.

4. The highly spectrally selective biomimetic hierarchical porous nested structure according to claim 1, characterized in that: The first adhesive component (31) of the interface reinforcement layer (3) includes at least one of silane coupling agent, epoxy resin or polyurethane, and the second elastic component (32) includes at least one of acrylate elastomer, silicone rubber or thermoplastic elastomer.

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