Wave-absorbing material packaging design based on electrostatic spinning and preparation method thereof

Abstract

The invention relates to a wave-absorbing material packaging design based on electrostatic spinning and a preparation method thereof, and belongs to the technical field of wave-absorbing material preparation. The wave-absorbing material packaging design based on electrostatic spinning and the preparation method of the wave-absorbing material packaging design comprise the following steps that firstly, a broadband graphene-based wave-absorbing composite material is prepared through an experiment, then the surface of the wave-absorbing composite material is packaged through electrostatic spinning, and after packaging is completed, a hot air negative pressure device is adopted, and the wave-absorbing composite material is obtained. And the spinning film on the surface is combined with the wave-absorbing composite material more tightly, so that the packaging effect is enhanced. According to the wave-absorbing material packaging design based on electrostatic spinning and the preparation method of the wave-absorbing material packaging design, a broadband graphene-based wave-absorbing composite material is prepared through simulation design, and then a layer of packaging film is spun on the surface of the wave-absorbing composite material through an electrostatic spinning technology to play a protection role. On the other hand, through the hot air negative pressure device, the combination between the spinning film and the wave-absorbing material is enhanced, and the packaging effect is enhanced.

Description

Technical Field

[0001] The invention relates to a wave-absorbing material packaging design based on electrostatic spinning and a preparation method thereof, belonging to the technical field of wave-absorbing material preparation. Background Art

[0002] With the increasing development of smart and wireless technologies, higher demands are being placed on absorbing materials. Graphene is a two-dimensional layered material. Due to its light weight and high conductivity, it also carries a large number of functional groups and intrinsic defects on its surface, which can increase dipole polarization, making graphene an excellent electromagnetic wave absorbing material. In addition, protective measures during the transportation of absorbing materials are also a major challenge affecting the application of absorbing materials. During transportation, absorbing materials are often damaged to varying degrees, affecting their absorbing performance. Therefore, the packaging of absorbing materials is also a major issue that needs to be solved urgently. By using a wave-transparent material as the spinning system and based on electrospinning technology, the absorbing material is encapsulated using an electrospinning membrane. The hot air negative pressure device is used to further strengthen the bond between the spinning membrane and the absorbing material matrix, thereby enhancing its packaging effect.

[0003] Therefore, the present invention provides an electrospinning-based absorbing material packaging design and preparation method to address the problem of existing absorbing materials being easily damaged during transportation. By using a wave-transparent material as the spinning system, the absorbing material is encapsulated and protected without adversely affecting its absorbing capacity. Summary of the Invention

[0004] The purpose of the present invention is to provide an electrospinning-based absorbing material packaging design and preparation method thereof, so as to encapsulate and protect the absorbing material, and the encapsulated graphene-based composite absorbing material maintains the original broadband electromagnetic wave absorption performance.

[0005] The present invention also provides a broadband graphene-based composite absorbing material prepared by the above-mentioned preparation method.

[0006] In order to achieve the above objectives, the technical solutions adopted by the electrospinning-based absorbing material packaging design and preparation method of the present invention are:

[0007] A design for an absorbing material package based on electrospinning and a preparation method thereof include the following steps: first, a broadband graphene-based absorbing composite material is obtained through experimental preparation, then electrospinning is used to encapsulate the surface of the absorbing composite material, and after encapsulation, a hot air negative pressure device is used to more tightly bond the surface spinning membrane to the absorbing composite material to enhance its encapsulation effect.

[0008] The present invention's electrospinning-based absorbing material packaging design and preparation method utilizes simulation design to produce a broadband graphene-based absorbing composite material. Subsequently, a protective encapsulation film is spun onto the surface of the absorbing composite material using electrospinning technology. Furthermore, a hot air negative pressure device strengthens the bond between the spinning film and the absorbing material, enhancing the encapsulation effect.

[0009] Preferably, the concentration of the graphene slurry is 1-18 mg / g, preferably 4-10 mg / g.

[0010] Preferably, the freeze-drying treatment time gradually increases with the increase of the thickness of the composite material, and the freeze-drying time is 3-6 days, preferably 6 days.

[0011] Preferably, the broadband graphene-based absorbing composite material is a multi-layer design, preferably three layers.

[0012] Preferably, the electrospinning precursor is a PCL and TPU system.

[0013] Preferably, the preparation of the electrospinning precursor includes the following steps: first, a mixed solution of tetrahydrofuran and DMF is prepared as a solvent, PCL or TPU is added to the mixed solvent according to a certain mass ratio, first ultrasonicated at 60°C for 2h, and then magnetically stirred at room temperature for 1h to obtain a spinning precursor solution.

[0014] Preferably, the mass ratio of tetrahydrofuran to DMF is 1:1-3:1, preferably 3:2.

[0015] Preferably, the mass ratio of the PCL or TPU to the solvent is 1:1-3:1, preferably 2:1.

[0016] Preferably, the electrospinning package comprises the following steps: first, transferring the spinning precursor into a syringe, setting the parameters of the electrospinning machine to a spinning voltage of 20 kV, a spinning distance of 7 cm, and a propulsion rate of 20 μl / min, and then performing electrospinning.

[0017] Preferably, the hot air negative pressure device includes the following steps: first, the above-mentioned electrospun encapsulated graphene absorbing composite material is placed for 1 hour, and the electrospun membrane on the surface is dried. Then, the hot air negative pressure device is preheated to the operating temperature, the composite material and the negative pressure device are adjusted to a fixed distance, and then the negative pressure is turned on to make the bonding between the electrospun membrane and the composite material tighter.

[0018] Preferably, the temperature of the hot air negative pressure device is set to 50-600°C, preferably 300°C.

[0019] Preferably, the distance between the hot air negative pressure device and the wave-absorbing material is set to 5-10 cm, preferably 6 cm.

[0020] The technical solutions adopted by the electrospinning-based absorbing material packaging design and preparation method of the present invention are:

[0021] A broadband graphene-based composite absorbing material is produced by adopting the above-mentioned electrospinning-based absorbing material packaging design and preparation method.

[0022] The present invention's electrospinning-based absorbing material packaging design and preparation method utilizes simulation to produce a broadband graphene-based absorbing composite material. Subsequently, a protective encapsulation film is spun onto the surface of the absorbing composite material using electrospinning technology. Furthermore, a hot air negative pressure device enhances the bonding between the spun film and the absorbing material, further enhancing the encapsulation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the absorbing material after electrospinning and encapsulation in Example 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of the absorbing material after being treated by the hot air negative pressure device in Example 1 of the present invention;

[0025] Figure 3 This is a SEM image of the electrospinning encapsulation membrane prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention is further described below in conjunction with specific implementation methods.

[0027] Example 1

[0028] The electrospinning-based absorbing material packaging design and preparation method of this embodiment include the following steps:

[0029] 1) Graphene slurries of different concentrations are prepared and freeze-dried respectively, and the obtained graphene absorbing materials are combined according to the results of the simulation optimization design to obtain a broadband graphene-based absorbing composite material.

[0030] 2) First, tetrahydrofuran and DMF were mixed in a mass ratio of 3:2 to obtain a mixed solvent. Subsequently, PCL was mixed in a mass ratio of 2:1 to the mixed solvent. The mixture was ultrasonicated at 60°C for 2 hours and then mechanically stirred for 1 hour to obtain a spinning precursor solution.

[0031] 3) The prepared spinning precursor solution was transferred to a syringe and spun using electrospinning technology. The electrospinning machine parameters were set to 20 kV spinning voltage, 7 cm spinning distance, and 20 μl / min propulsion rate. Electrospinning was then continued.

[0032] 4) After the spun and packaged graphene-based absorbing composite material is placed for 1 hour, the hot air negative pressure device is heated to the set temperature and maintained at this temperature. The distance between the hot air negative pressure device and the packaged absorbing material is adjusted to 6 cm. Then, the negative pressure is turned on and the negative pressure time is controlled to make the bond between the electrospun membrane and the composite material closer.

[0033] Example 2

[0034] The electrospinning-based absorbing material packaging design and preparation method of this embodiment include the following steps:

[0035] 1) Graphene slurries of different concentrations are prepared and freeze-dried respectively, and the obtained graphene absorbing materials are combined according to the results of the simulation optimization design to obtain a broadband graphene-based absorbing composite material.

[0036] 2) Tetrahydrofuran and DMF were first mixed in a mass ratio of 3:2 to obtain a mixed solvent. Subsequently, TPU was mixed with the mixed solvent in a mass ratio of 2:1. The mixture was ultrasonicated at 60°C for 2 hours and then mechanically stirred for 1 hour to obtain a spinning precursor solution.

[0037] 3) The prepared spinning precursor solution was transferred to a syringe and spun using electrospinning technology. The electrospinning machine parameters were set to 20 kV spinning voltage, 7 cm spinning distance, and 20 μl / min propulsion rate. Electrospinning was then continued.

[0038] 4) After the spun and packaged graphene-based absorbing composite material is placed for 1 hour, the hot air negative pressure device is heated to the set temperature and maintained at this temperature. The distance between the hot air negative pressure device and the packaged absorbing material is adjusted to 6 cm. Then, the negative pressure is turned on and the negative pressure time is controlled to make the bond between the electrospun membrane and the composite material closer.

[0039] Example 3

[0040] The electrospinning-based absorbing material packaging design and preparation method of this embodiment include the following steps:

[0041] 1) Graphene slurries of different concentrations are prepared and freeze-dried respectively, and the obtained graphene absorbing materials are combined according to the results of the simulation optimization design to obtain a broadband graphene-based absorbing composite material.

[0042] 2) First, tetrahydrofuran and DMF were mixed in a mass ratio of 3:2 to obtain a mixed solvent. Subsequently, PCL and TPU were mixed in a mass ratio of 1:1. The solute and solvent were then mixed with the mixed solvent in a mass ratio of 2:1. The mixture was ultrasonicated at 60°C for 2 hours and then mechanically stirred for 1 hour to obtain a spinning precursor solution.

[0043] 3) The prepared spinning precursor solution was transferred to a syringe and spun using electrospinning technology. The electrospinning machine parameters were set to 20 kV spinning voltage, 7 cm spinning distance, and 20 μl / min propulsion rate. Electrospinning was then continued.

[0044] 4) After the spun and packaged graphene-based absorbing composite material is placed for 1 hour, the hot air negative pressure device is heated to the set temperature and maintained at this temperature. The distance between the hot air negative pressure device and the packaged absorbing material is adjusted to 6 cm. Then, the negative pressure is turned on and the negative pressure time is controlled to make the bond between the electrospun membrane and the composite material closer.

[0045] The graphene absorbing composite material after electrospinning and encapsulation in step 3) of Example 1 is shown in FIG. Figure 1 ,Depend on Figure 1 It can be seen that the spinning membrane obtained by electrospinning is relatively uniform and can completely cover the absorbing material; the graphene absorbing composite material treated by the hot air negative pressure device in step 4) of Example 1 is shown in FIG. Figure 2 , SEM test was performed on the surface of the absorbing material after hot air negative pressure treatment in Example 1. The results are as follows Figure 3 It can be seen that the electrospun membrane after hot air negative pressure treatment still retains the fiber structure, which has a protective effect on the absorbing material.

[0046] Experimental example

[0047] The electromagnetic wave absorption performance of the broadband graphene-based composite absorbing material before and after treatment by the hot air negative pressure device in Example 1 was tested.

[0048] The test method is to use an Agilent N5244A vector network analyzer to test the reflection loss of the broadband graphene composite absorber before and after hot air negative pressure treatment using a bow frame test method. The electromagnetic wave band is 2-18 GHz.

[0049] As can be seen from the above examples, the present invention provides a broadband graphene-based composite absorbing material produced using the aforementioned electrospinning-based absorbing material packaging design and preparation method. The present invention utilizes simulation design to produce a broadband graphene-based absorbing composite material. Subsequently, a protective encapsulation film is spun onto the surface of the absorbing composite material using electrospinning technology. Furthermore, a hot air negative pressure device enhances the bonding between the spun film and the absorbing material, further enhancing the encapsulation effect.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A design for an electrospinning-based microwave absorbing material package and a method for preparing the same, characterized in that: The following steps are involved: First, a broadband graphene-based absorbing composite material was obtained through experimental preparation, and then electrostatic spinning was used to encapsulate the surface of the absorbing composite material. After encapsulation, a hot air negative pressure device was used to make the surface spinning membrane more tightly combined with the absorbing composite material, thereby enhancing its encapsulation effect.

2. The electrospinning absorbing material packaging design and preparation method thereof according to claim 1, characterized in that: The preparation of the wave-absorbing composite material comprises the following steps: firstly preparing graphene slurries of different concentrations, freeze-drying them respectively, and preparing a broadband graphene-based wave-absorbing composite material based on simulation design optimization.

3. The electrospinning absorbing material packaging design and preparation method thereof according to claim 1, characterized in that: The system adopted for the electrospinning encapsulation is a polycaprolactone (PCL) system or a polyurethane (TPU) system.

4. The electrospun absorbing material packaging design and preparation method according to claim 1, characterized in that: The preparation of electrospinning precursor includes the following steps: first, a mixed solution of tetrahydrofuran and DMF is prepared as a solvent, PCL or TPU is added to the above mixed solvent according to a certain mass ratio, first ultrasonicated at 60°C for 2h, and then magnetically stirred at room temperature for 1h to obtain the spinning precursor solution.

5. The electrospun absorbing material packaging design and preparation method according to any one of claims 1 to 4, characterized in that: The electrospinning process involves transferring the spinning precursor into a syringe and setting the electrospinning machine parameters to 20 kV spinning voltage, 7 cm spinning distance, and 20 μl / min propulsion rate. Electrospinning is then performed.

6. The electrospinning absorbing material packaging design and preparation method thereof according to claim 1, characterized in that: The hot air negative pressure device includes the following steps: first, the above-mentioned electrospun encapsulated graphene absorbing composite material is placed for 1 hour to wait for the electrospun membrane on the surface to dry, then the hot air negative pressure device is preheated to the operating temperature, the composite material and the negative pressure device are adjusted to a fixed distance, and then the negative pressure is turned on to make the bond between the electrospun membrane and the composite material tighter.

7. The electrospinning absorbing material packaging design and preparation method thereof according to claim 1, characterized in that: The encapsulation is not just surface encapsulation, but all surfaces of the sample are covered with a layer of spinning membrane for encapsulation.

8. A broadband graphene-based absorbing composite material produced by using the electrospinning absorbing material packaging design and preparation method according to any one of claims 1 to 7.

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