Glass-copper composite foam as well as preparation method and application thereof
Through the composite foam structure of glass hollow microspheres and copper, the problem of functional network formation in the open and closed pore structure of metal foam materials was solved, efficient conductivity and lightweight were achieved, the preparation process was simplified and the cost was reduced.
Patent Information
- Application Number
- CN202410321541.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-20
- Publication Date
- 2025-09-23
AI Technical Summary
Existing metal foam materials are difficult to achieve efficient formation of functional networks through open and closed pore structures, and the preparation process is complex and costly, making it difficult to achieve both lightweight and electrical conductivity.
A composite foam structure of glass hollow microspheres connected with copper is adopted. By depositing copper on the surface of the glass hollow microspheres and forming connections, the conductivity of copper and the cavity structure of the glass microspheres are utilized to form an open-closed cell composite foam. The preparation process is simplified by combining the room temperature reduction process.
It achieves efficient formation of a conductive network, improves microwave shielding performance, reduces preparation energy consumption, simplifies the process flow, reduces costs, and has a lightweight effect.
Smart Images
Figure CN120683483A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of composite materials, and more particularly to a glass-copper composite foam and a preparation method and application thereof. Background Art
[0002] With the development of society and the advancement of science and technology, the lightweighting of advanced materials and structures has become an important focus of scientific research, technology development and product design personnel. Because various types of materials (functional materials and structural materials) are the basis of equipment and devices, their lightweighting is the source of equipment weight reduction. As for the lightweighting of materials, the chemical composition of the material can be designed at the atomic and molecular scale, and it can also be achieved to a greater extent by introducing micro-nanoscale cavities into the material. The former is limited by the natural characteristics of the material and it is difficult to significantly reduce the density (lightweighting) while meeting the functional requirements; the latter can achieve a significant reduction in density by finely controlling factors such as the size, distribution state, and volume ratio of the cavity inside the material.
[0003] There are numerous lightweight foam materials, with metal foams being a key category. Unlike polymer foams like sponges, the metal skeleton within metal foams provides the material with functional properties such as conductivity and magnetism. In particular, for electrical conductivity and electromagnetic shielding, the metal skeleton effectively constructs a conductive network and ensures the material's functionality, while the presence of cavities significantly reduces density. Furthermore, designing metal into a foam structure not only reduces density and achieves lightweighting, but also reduces metal usage, improving cost efficiency. However, on the one hand, the cavity walls of metal foams can become stress concentration areas, resulting in a decrease in the mechanical stability of the foam material; on the other hand, the template removal required to create the cavities increases process complexity and costs; and thirdly, the conventional large-scale open-cell cavity structure is not conducive to the efficient formation of the conductive network. Therefore, while current metal foam materials and their preparation methods can achieve good structural uniformity and functionality, they are not conducive to the efficient formation of functional networks through the synergistic combination of open and closed pore structures. Furthermore, factors such as the process conditions and template removal of the template method also increase process complexity and cost. Summary of the Invention
[0004] Based on the above facts, the purpose of the present invention is to provide a glass-copper composite foam and its preparation method and application, so as to improve the problems of conventional metal foam materials such as difficulty in achieving efficient formation of functional networks through the synergy of open and closed pore structures and high energy consumption in preparation.
[0005] In order to achieve the above object, the present invention adopts the following technical solutions:
[0006] A glass-copper composite foam comprises a plurality of glass hollow microspheres and a connecting material for connecting the glass hollow microspheres, wherein the connecting material is copper.
[0007] In the technical solution of the present invention, metallic copper is deposited on the surface of the glass hollow microspheres and between the glass hollow microspheres, thereby realizing mutual connection between the glass hollow microspheres.
[0008] Furthermore, there are through holes in the connecting material.
[0009] Furthermore, the apparent density of the composite foam is 0.2-0.5 g / cm 3 , the porosity is 88-96%; the open porosity is 47-53%.
[0010] Furthermore, the composite foam comprises 30-68% glass hollow microspheres and 32-70% copper, calculated by weight. In this technical solution, the glass hollow microspheres provide cavities and low density, while the presence of copper enables surface deposition and inter-sphere connection (welding). If the content of the glass hollow microspheres is too low, the resulting composite foam has a high density, and excessive copper deposition complicates and increases processing costs due to the time-consuming process. Conversely, if the content of the glass hollow microspheres is too low, the composite foam has poor conductivity, and inter-sphere connection may not even be effectively achieved.
[0011] In another aspect, the present invention provides a method for preparing the glass-copper composite foam as described above, the method comprising the following steps:
[0012] The glass hollow microspheres are pre-treated for activation to obtain activated glass hollow microspheres;
[0013] Copper is deposited on the surface of the activated glass hollow microspheres and connected to obtain the glass-copper composite foam.
[0014] Furthermore, the preparation of the activated glass hollow microspheres comprises the following steps:
[0015] The glass hollow microspheres are treated in treatment solutions A and B in sequence to obtain the activated glass hollow microspheres.
[0016] Furthermore, the solvent of the treatment liquid A is anhydrous ethanol and / or distilled water, more preferably anhydrous ethanol and distilled water in a volume ratio of 1:1-3:1.
[0017] Furthermore, the density of the glass hollow microspheres is 0.1-0.90 g / cm 3 , for example, 0.2-0.30 g / cm 3 .
[0018] Furthermore, the solute of the treatment solution A is a coupling agent, such as KH550.
[0019] Furthermore, in the treatment liquid A, the concentration of the solute is 10-15 g / L.
[0020] Furthermore, the treatment liquid B contains a noble metal salt, an acid and water, wherein the concentration of the noble metal salt in the treatment liquid B is 0.002-0.2 mol / L, preferably 0.005-0.05 mol / L, more preferably 0.005-0.015 mol / L, more preferably 0.01 mol / L, etc.
[0021] Furthermore, the treatment process temperature is 10-50° C., the treatment time in treatment liquid A is 10-60 minutes, and the treatment time in treatment liquid B is 10-40 minutes.
[0022] Furthermore, in the treatment solution B, the noble metal salt includes but is not limited to palladium chloride.
[0023] Furthermore, in the treatment liquid B, the acid includes but is not limited to hydrochloric acid. In the treatment liquid B, the concentration of the acid includes but is not limited to 0.3-0.6 mol / L, preferably 0.5 mol / L.
[0024] Furthermore, the method of sequentially treating the glass hollow microspheres with treatment liquids A and B includes: sequentially dispersing the glass hollow microspheres in treatment liquids A and B, stirring, and drying to obtain the activated glass hollow microspheres.
[0025] Furthermore, the stirring temperature is 40-50°C, preferably 50°C, and the stirring time is 30-60 min, preferably 40 min.
[0026] Furthermore, the drying temperature is preferably 60°C.
[0027] The activation pretreatment mentioned above allows the subsequent reduction reaction of copper ions to occur. Compared with other activation pretreatment methods (such as silver activation), this method is simple and easy to implement, and has good effects.
[0028] Furthermore, the method of depositing copper on the surface of activated glass hollow microspheres and performing connection treatment comprises the following steps:
[0029] The activated glass hollow microspheres are dispersed in water and filtered, and the treatment liquid C is added to the obtained filter cake to perform copper deposition and connection treatment, and the mixture is dried to obtain a glass-copper composite foam;
[0030] Furthermore, the dispersion ratio of the activated glass hollow microspheres in water is 0.03-0.1 g / mL, preferably 0.03-0.05 g / mL.
[0031] Furthermore, the treatment solution C is an aqueous solution containing 0.1-0.2 mol / L copper sulfate, 0.08-0.12 mol / L potassium sodium tartrate, 0.06-0.09 mol / L EDTA, 0.5-0.7 mol / L sodium hydroxide, and 5-8 ml / L formaldehyde solution. By further controlling the formulation of treatment solution C, the composite foam achieves both high porosity and open cell ratio and electromagnetic shielding effect.
[0032] Furthermore, the ratio of the activated glass hollow microspheres to the treatment liquid C is 0.003-0.016 g / mL, preferably 0.003-0.009 g / mL. In this case, the obtained composite foam has high porosity, open porosity and higher electromagnetic shielding effectiveness.
[0033] Furthermore, the copper deposition and connection process is performed at room temperature.
[0034] Furthermore, the treatment liquid C can be used once or recycled, and the number of recycling times is not more than 5 times.
[0035] In the preparation method of the present invention, under the above conditions, glass hollow microspheres are used as a scaffold, and copper is deposited on the surface of the microspheres and in the contact areas between the microspheres to achieve copper coating on the surface of the glass microspheres and connection (welding) between the microspheres through copper; through a specific activation pretreatment on the surface of the glass microspheres, the copper ions in the reaction solution undergo a reduction reaction under the action of the active sites on the surface of the microspheres to generate copper.
[0036] Compared with other metals, copper can be efficiently reduced at room temperature with low cost and good effect. The prepared composite foam can better form an open-pore interconnected structure.
[0037] In another aspect, the present invention provides a microwave shielding material or a conductive material, which is prepared from the glass-copper composite foam as described above.
[0038] In another aspect, the present invention provides use of the glass-copper composite foam described above in the preparation of microwave shielding or conductive devices.
[0039] Furthermore, the glass-copper composite foam is used in the preparation of microwave shielding or conductive devices in military stealth, broadcasting, television transmission, microwave darkrooms, buildings or radio communication equipment.
[0040] The beneficial effects of the present invention are as follows:
[0041] The composite foam provided by this invention utilizes a designed composition and structure of a metallic copper foam, incorporating hollow glass microspheres into a composite with metallic copper to create an open-cell / closed-cell composite metallic copper foam. The presence of the microspheres and surface copper deposition create a closed-cell structure, while the copper interconnects the microspheres to form an open-cell interconnected structure. This conductive network enhances the composite foam's microwave shielding performance.
[0042] Furthermore, the composite foam used in this invention is prepared through a room-temperature reduction process induced by surface active sites, avoiding the high-temperature treatment required in traditional metal foam preparation. This method is both convenient and efficient, while also reducing energy consumption. Specifically, this method utilizes a novel metal foam formation mechanism, introducing cavities using preformed hollow microspheres. The catalytic action of the preformed hollow microspheres allows for the in-situ formation and deposition of metallic copper, resulting in a convenient and efficient process. BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0044] Figure 1 The following is a flow chart of the preparation of the glass-copper composite foam according to the present invention.
[0045] Figure 2 A schematic structural diagram of the glass-copper composite foam of the present invention is shown.
[0046] Figure 3 The scanning electron microscope (SEM) image of the glass-copper composite foam obtained in Example 1 of the present invention is shown. DETAILED DESCRIPTION
[0047] In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the following detailed description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.
[0048] Example 1
[0049] A preparation process of glass-copper composite foam is shown in the following flow chart: Figure 1 The specific plan is as follows:
[0050] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.30g / cm 3) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0051] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered; then, treatment liquid C (the solvent of treatment liquid C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was added to the filter cake at a ratio of 1 g / 140 mL of the initial activated glass hollow microspheres under filtration, and the reaction was carried out at room temperature. The filtrate was repeatedly added to the filter cake and the reaction was repeated for 4 rounds. The filter cake was then taken out and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure. The structural diagram thereof is shown in FIG. Figure 2 As shown in the SEM images Figure 3 shown.
[0052] The apparent density of the glass-copper composite foam obtained in this example is 0.31 g / cm 3 ; Porosity 92.6%; Open porosity 50.4%; The mass fractions of glass hollow microspheres and copper are 48.8% and 51.2% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 58-70dB.
[0053] Example 2
[0054] A preparation method of glass-copper composite foam is as follows:
[0055] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.30g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0056] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 115 mL of the initial activated glass hollow microspheres under filtration. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0057] The apparent density of the glass-copper composite foam obtained in this example is 0.31 g / cm 3 ; Porosity 92.9%; Open porosity 51.2%; The mass fractions of glass hollow microspheres and copper are 52.6% and 47.4% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 63-69dB.
[0058] Example 3
[0059] A preparation method of glass-copper composite foam is as follows:
[0060] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.30g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0061] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 190 mL of the initial activated glass hollow microspheres under filtration. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0062] The apparent density of the glass-copper composite foam obtained in this example is 0.38 g / cm 3; Porosity 91.7%; Open porosity 48.7%; The mass fractions of glass hollow microspheres and copper are 40.8% and 59.2% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 66-74dB.
[0063] Example 4
[0064] A preparation method of glass-copper composite foam is as follows:
[0065] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.50g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0066] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 65 mL of the initial activated glass hollow microspheres under filtration. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0067] The apparent density of the glass-copper composite foam obtained in this example is 0.37 g / cm 3 ; Porosity 89.2%; Open porosity 50.5%; The mass fractions of glass hollow microspheres and copper are 66.7% and 33.3% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 35-42dB.
[0068] Example 5
[0069] A preparation method of glass-copper composite foam is as follows:
[0070] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.20g / cm 3) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0071] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 260 mL of the initial activated glass hollow microspheres under filtration. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0072] The apparent density of the glass-copper composite foam obtained in this example is 0.29 g / cm 3 ; Porosity 94.3%; Open porosity 52.3%; The mass fractions of glass hollow microspheres and copper are 33.4% and 66.6% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 67-78dB.
[0073] Example 6
[0074] A preparation method of glass-copper composite foam is as follows:
[0075] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.15g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0076] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 250 mL of the initial activated glass hollow microspheres under filtration. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0077] The apparent density of the glass-copper composite foam obtained in this example is 0.22 g / cm 3 ; Porosity 95.5%; Open porosity 49.1%; The mass fractions of glass hollow microspheres and copper are 34.5% and 65.5% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 66-73dB.
[0078] Example 7
[0079] A preparation method of glass-copper composite foam is as follows:
[0080] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.22g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0081] 2) Activated hollow glass microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 170 mL of the initial activated hollow glass microspheres. The mixture was reacted at room temperature. The filtrate was then added to the filter cake and the reaction was repeated four times. The filter cake was removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0082] The apparent density of the glass-copper composite foam obtained in this example is 0.27 g / cm 3; Porosity 93.9%; Open porosity 47.5%; The mass fractions of glass hollow microspheres and copper are 43.5% and 56.5% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 64-72dB.
[0083] Example 8
[0084] A preparation method of glass-copper composite foam is as follows:
[0085] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.38g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0086] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 143 mL of the initial activated glass hollow microspheres under filtration. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0087] The apparent density of the glass-copper composite foam obtained in this example is 0.39 g / cm 3 ; Porosity 90.7%; Open porosity 51.3%; The mass fractions of glass hollow microspheres and copper are 47.6% and 52.4% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 61-73dB.
[0088] Example 9
[0089] A preparation method of glass-copper composite foam is as follows:
[0090] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.38g / cm 3) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0091] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered; then, under filtration, treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was added to the filter cake at a ratio of 1 g / 160 mL of the initial activated glass hollow microspheres. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0092] The apparent density of the glass-copper composite foam obtained in this example is 0.41 g / cm 3 ; Porosity 90.4%; Open porosity 50.7%; The mass fractions of glass hollow microspheres and copper are 45.5% and 54.5% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 61-75dB.
[0093] Example 10
[0094] A preparation method of glass-copper composite foam is as follows:
[0095] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.46g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0096] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered; then, under filtration, treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was added to the filter cake at a ratio of 1 g / 105 mL of the initial activated glass hollow microspheres, and the mixture was reacted at room temperature. The filtered filtrate was repeatedly added to the filter cake, and the reaction was repeated for 4 rounds. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0097] The apparent density of the glass-copper composite foam obtained in this example is 0.42 g / cm 3 ; Porosity 89.0%; Open porosity 49.2%; The mass fractions of glass hollow microspheres and copper are 55.6% and 44.4% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 52-61dB.
[0098] Comparative Example 1
[0099] A preparation method of glass-copper composite foam is as follows:
[0100] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.50g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent was a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L copper chloride, solvent was water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0101] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered; then, treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was added to the filter cake at a ratio of 1 g / 65 mL of the initial activated glass hollow microspheres under filtration, and the reaction was carried out at room temperature. The filtered filtrate was repeatedly added to the filter cake and the reaction was repeated for 4 rounds. The filter cake was then removed and dried.
[0102] In this comparative example, due to poor activation effect, reduction and deposition of copper could not be achieved, and a glass-copper composite foam with a conductive hollow microsphere welded structure was not obtained.
[0103] Comparative Example 2
[0104] A preparation method of glass-copper composite foam is as follows:
[0105] 1) Preparation of activated glass hollow microspheres: 40g of glass hollow microspheres (density 0.50g / cm 3 ) was dispersed in 1000 ml of treatment solution A (12 g / L silane coupling agent KH550, solvent is a mixture of anhydrous ethanol and distilled water in a volume ratio of 2:1); then dispersed in 800 ml of treatment solution B (0.5 mol / L hydrochloric acid, 0.01 mol / L palladium chloride, solvent is water), stirred at 50° C. for 40 min, filtered, dried at 60° C., and sieved to remove agglomerated particles to obtain activated glass hollow microspheres;
[0106] 2) The activated glass hollow microspheres were dispersed in water at a ratio of 1 g / 30 mL, stirred for 10 minutes, and then filtered. Treatment solution C (the solvent of treatment solution C is water, containing 0.15 mol / L copper sulfate, 0.08 mol / L potassium sodium tartrate, 0.06 mol / L EDTA, 0.5 mol / L sodium hydroxide, and 5 ml / L formaldehyde) was then added to the filter cake at a ratio of 1 g / 40 mL of the initial activated glass hollow microspheres under filtration. The mixture was reacted at room temperature, and the filtered filtrate was repeatedly added to the filter cake for four rounds of reaction. The filter cake was then removed and dried to obtain a glass-copper composite foam with a conductive hollow microsphere welded structure.
[0107] The apparent density of the glass-copper composite foam obtained in this comparative example is 0.33 g / cm 3 ; Porosity 91.1%; Open porosity 52.4%; The mass fractions of glass and copper are 76.7% and 23.3% respectively; The electromagnetic shielding effectiveness at 3mm thickness is 11-17dB.
[0108] Performance testing:
[0109] The electromagnetic properties of the products prepared in the above embodiments were tested. The testing method is as follows:
[0110] Apparent density is obtained by measuring size and weight;
[0111] Porosity is obtained by measuring true density;
[0112] The transmission parameters are tested (test frequency 8-12GHz) using a vector network analyzer to analyze its shielding performance.
[0113] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.
Claims
1. A glass-copper composite foam, characterized in that: The composite foam structure comprises a plurality of glass hollow microspheres and a connecting material for connecting the glass hollow microspheres, wherein the connecting material is copper.
2. The glass-copper composite foam according to claim 1, characterized in that There are through holes in the connecting material.
3. The glass-copper composite foam according to claim 1, characterized in that The apparent density of the composite foam is 0.2-0.5 g / cm 3 , the porosity is 88-96%; the open porosity is 47-53%.
4. The glass-copper composite foam according to claim 1, characterized in that Calculated by mass percentage, the composite foam contains 30-68% of glass hollow microspheres and 32-70% of copper.
5. The method for preparing the glass-copper composite foam according to any one of claims 1 to 4, characterized in that: The steps include: The glass hollow microspheres are pre-treated for activation to obtain activated glass hollow microspheres; Copper is deposited on the surface of the activated glass hollow microspheres and connected to obtain the glass-copper composite foam.
6. The preparation method according to claim 5, characterized in that The preparation of the activated glass hollow microspheres comprises the following steps: treating the glass hollow microspheres in treatment solutions A and B in sequence to obtain the activated glass hollow microspheres; Preferably, the solvent of the treatment liquid A is anhydrous ethanol and / or distilled water, more preferably anhydrous ethanol and distilled water in a volume ratio of 1:1-3:1; Preferably, the solute of the treatment solution A is a coupling agent; Preferably, the treatment solution B comprises a noble metal salt, an acid and water, wherein the concentration of the noble metal salt is 0.002-0.2 mol / L; Preferably, the treatment process temperature is 10-50° C., the treatment time in treatment liquid A is 10-60 min, and the treatment time in treatment liquid B is 10-40 min.
7. The preparation method according to claim 5, characterized in that The method for depositing copper on the surface of activated glass hollow microspheres and performing a connection process comprises the following steps: The activated glass hollow microspheres are dispersed in water and filtered, and the treatment liquid C is added to the obtained filter cake to perform copper deposition and connection treatment, and the mixture is dried to obtain a glass-copper composite foam; Preferably, the dispersion ratio of the activated glass hollow microspheres in water is 0.03-0.1 g / mL; Preferably, the treatment solution C is an aqueous solution containing 0.1-0.2 mol / L copper sulfate, 0.08-0.12 mol / L potassium sodium tartrate, 0.06-0.09 mol / L EDTA, 0.5-0.7 mol / L sodium hydroxide and 5-8 ml / L formaldehyde solution; Preferably, the ratio of the activated glass hollow microspheres to the treatment solution C is 0.003-0.016 g / mL; Preferably, the copper deposition and connection process is performed at room temperature.
8. A microwave shielding material or a conductive material, characterized in that: The invention is prepared from the glass-copper composite foam according to any one of claims 1 to 4.
9. Use of the glass-copper composite foam according to any one of claims 1 to 4 in the preparation of microwave shielding or conductive devices.
10. The use according to claim 9, characterized in that The glass-copper composite foam is used in the preparation of microwave shielding or conductive devices in military stealth, broadcasting, television transmission, microwave darkrooms, buildings or radio communication equipment.