Platinum diselenide-based electromagnetic shielding film and preparation method thereof

Abstract

The invention relates to a platinum diselenide-based electromagnetic shielding film and a preparation method thereof. The method comprises the following steps: 1, uniformly mixing platinum powder, selenium powder and potassium chloride powder according to a preset proportion, and placing the mixture at the bottom of a quartz tube with one sealed end; 2, putting the substrate slice into the quartz tube, arranging the substrate slice between the necking part and the opening part, and carrying out vacuum tube sealing on the quartz tube; 3, horizontally placing the quartz tube subjected to vacuum tube sealing in a single-temperature-zone tubular furnace, enabling the bottom of the quartz tube to directly face the center of the tubular furnace, and carrying out heating reaction to obtain platinum diselenide bulk crystals; 4, breaking the quartz tube, collecting the platinum diselenide bulk crystals, and grinding into powder; 5, platinum diselenide powder and carbon nanotubes are mixed and dispersed in deionized water to form turbid liquid, ultrasonic cleaning is carried out for multiple times, and the cleaned turbid liquid is obtained; and 6, carrying out suction filtration on the cleaned turbid liquid to form the platinum diselenide-based electromagnetic shielding film. The method is simple in process, and the prepared platinum diselenide-based electromagnetic shielding film can block 90% of electromagnetic waves.

Description

Technical Field

[0001] The invention relates to an electromagnetic interface (EMI) shielding material and a method for producing the electromagnetic interface (EMI) shielding material, and in particular to a platinum diselenide-based electromagnetic shielding film and a preparation method thereof. Background Art

[0002] With the rapid development of modern electronic technology, various electronic devices and wireless communication devices have been widely used in our daily lives. However, these devices generate electromagnetic radiation during operation, forming electromagnetic interference (EMI), which affects the normal operation of other electronic devices and even poses potential hazards to human health. Therefore, the research and development and application of electromagnetic shielding materials have become particularly important.

[0003] Traditional electromagnetic shielding materials are mainly metal materials, such as copper and aluminum. Although these metal materials have good shielding effects, they have disadvantages such as high density, poor flexibility, and difficult processing, which limit their use in certain applications. With the advancement of technology, the research on new electromagnetic shielding materials has gradually developed in the direction of light weight, high efficiency, flexibility and multifunctionality. Therefore, it is necessary to develop an electromagnetic shielding film that is easy to prepare, has stable performance and is lightweight, which is of great significance for improving the anti-interference ability of electronic equipment and reducing the interference of electronic equipment.

[0004] In recent years, two-dimensional materials have shown great potential in the field of electromagnetic shielding due to their unique physical and chemical properties. 2 ) As an emerging transition metal dichalcogenide, it has attracted widespread attention due to its excellent electrical, thermal and mechanical properties. Platinum diselenide is a two-dimensional material with a layered structure and excellent electrical conductivity and thermal stability. In addition, platinum diselenide film also has good flexibility and mechanical strength, and can maintain its electrical properties under complex conditions such as bending and stretching. Compared with traditional materials, platinum diselenide film is not only lighter and more flexible, but also can reduce electromagnetic pollution caused by electromagnetic wave reflection.

[0005] Although it has excellent electrical, thermal and mechanical properties, there are few reports on the application of platinum diselenide films in electromagnetic shielding. Therefore, the present invention selects platinum diselenide-based composite films as electromagnetic shielding film materials and provides a low-cost and simple preparation process, which is a problem that needs to be urgently solved in this field. Summary of the invention

[0006] The main purpose of the present invention is to propose a preparation process of platinum diselenide material and a preparation method of platinum diselenide-based electromagnetic shielding film, aiming to improve the process of semiconductor preparation and expand the research of platinum diselenide film in the field of electromagnetic shielding

[0007] To achieve the above object, the first aspect of the present invention provides a method for preparing a platinum diselenide-based electromagnetic shielding film, the preparation method comprising the following steps:

[0008] Step (1), platinum powder, selenium powder and potassium chloride powder are uniformly mixed according to a preset ratio to obtain a raw material mixture, and the raw material mixture is placed at the bottom of a quartz tube with one end sealed, wherein the quartz tube has a neck portion, and the neck portion is arranged between the bottom and the opening of the quartz tube;

[0009] Step (2), placing a substrate sheet into the quartz tube, and placing the substrate sheet between the neck portion and the opening portion, vacuum sealing the quartz tube, and converting the opening portion into a sealed portion;

[0010] Step (3), placing the vacuum-sealed quartz tube horizontally in a single-temperature zone tube furnace, with the bottom of the quartz tube facing the center of the tube furnace, and obtaining bulk platinum diselenide crystals after heating reaction;

[0011] Step (4), breaking the quartz tube to collect the platinum diselenide bulk crystals, and grinding the platinum diselenide bulk crystals into platinum diselenide powder;

[0012] Step (5), dispersing the platinum diselenide powder in deionized water to form a suspension, and performing ultrasonic cleaning on the platinum diselenide powder multiple times to obtain a cleaned suspension;

[0013] Step (6), filtering the cleaned suspension to form a platinum diselenide-based electromagnetic shielding film.

[0014] As a further preferred technical solution, the preset ratio in step (1) refers to the molar ratio of platinum powder, selenium powder and potassium chloride powder being 1:(2-5):(0.5-1.5).

[0015] As a further preferred technical solution, the molar ratio is 1:4:1.

[0016] As a further preferred technical solution, the distance between the edge of the substrate sheet close to the neck and the bottom of the quartz tube is L=10-20 cm;

[0017] As a further preferred technical solution, the substrate sheet is made of mica;

[0018] As a further preferred technical solution, the uniform mixing in step (1) is achieved by a degassing machine, and the specific steps are to put the zirconium oxide balls and the preset proportions of platinum powder, selenium powder and potassium chloride powder into a container, and the vibration frequency of the degassing machine is 800-1200r / min, and the time is 1-5min;

[0019] As a further preferred technical solution, in step (5), the ultrasonic time is 20-50 min, and the ultrasonic power is 650-800 W.

[0020] As a further preferred technical solution, the temperature curve of the heating reaction in step (3) is specifically:

[0021] ① Raise the temperature from room temperature to T at a heating rate of 4°C / min 1 ;

[0022] ②Heat at a rate of 5℃ / min from temperature T 1 Raised to temperature T 2 ;

[0023] ③At temperature T 2 Keep warm for 200-400 minutes;

[0024] ④ Stop heating and allow the quartz tube to cool naturally to room temperature;

[0025] Wherein T 1 =600-800°C, the T 2 =800-1000℃.

[0026] As a further preferred technical solution, the diameter of the filter membrane for vacuum filtration in step (6) is 50 mm and the pore size is 0.22±0.05 μm.

[0027] As a further preferred technical solution, the step (6) further includes filtering the ultrasonically cleaned platinum diselenide powder to form a platinum diselenide-based electromagnetic shielding film, and also includes mixing the ultrasonically cleaned platinum diselenide powder with carbon nanotubes in proportion, ultrasonically dispersing the mixture evenly, and then filtering to form a platinum diselenide-based electromagnetic shielding film.

[0028] As a further preferred technical solution, the mass ratio of the cleaned platinum diselenide powder to the carbon nanotubes is 1:(0-0.2).

[0029] The second aspect of the present invention provides a platinum diselenide-based electromagnetic shielding film, which is prepared by the above-mentioned preparation method.

[0030] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0031] 1. A large amount of platinum diselenide bulk crystals can be prepared at low cost through the CVT (vacuum chemical vapor transport) method.

[0032] 2. The vacuum-assisted filtration method can be used to quickly prepare electromagnetic shielding films over a large area, and the platinum diselenide-based electromagnetic shielding films prepared by the method of the present invention have good electromagnetic shielding performance.

[0033] 3. The film prepared by the present invention can block most electromagnetic waves and broaden new ideas for the research on electromagnetic wave shielding of two-dimensional material films. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0035] Figure 1 A picture of a quartz tube used to prepare bulk platinum diselenide crystals in the present invention;

[0036] Figure 2 This is the XRD pattern of the platinum diselenide material prepared by the present invention;

[0037] Figure 3 This is a Raman graph of the platinum diselenide material prepared by the present invention;

[0038] Figure 4 This is an XPS graph of Pt in the platinum diselenide material prepared by the present invention;

[0039] Figure 5 This is an XPS graph of Se in the platinum diselenide material prepared in the present invention;

[0040] Figure 6 This is a picture of the platinum diselenide-based electromagnetic shielding film prepared in Example 1 of the present invention;

[0041] Figure 7 This is a graph showing the electromagnetic shielding performance of the platinum diselenide-based electromagnetic shielding film prepared in Example 1 of the present invention;

[0042] Figure 8 This is a picture of the platinum diselenide and carbon nanotube electromagnetic shielding film prepared in Example 7 of the present invention;

[0043] Fig. 9 This is a diagram of the electromagnetic shielding performance of the platinum diselenide and carbon nanotube electromagnetic shielding films prepared in Examples 1 and 7 of the present invention.

[0044] In the figure: 1, quartz tube; 2, bottom; 3, neck portion; 4, substrate sheet; 5, opening. DETAILED DESCRIPTION

[0045] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention are further described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0046] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0047] As used in this disclosure, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0048] The terms used in the present disclosure are only used to describe specific embodiments and are not intended to limit the present disclosure.As used in the present disclosure, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0049] When the terms “comprising” and / or “made of…” are used in the present disclosure, it specifies the existence of the stated features, integers, steps, operations, elements and / or components, but does not exclude the existence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0050] Unless otherwise defined, all terms (including technical and scientific terms) used in this disclosure have the same meaning as those commonly understood by those of ordinary skill in the art. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and this disclosure, and will not be interpreted as having an idealized or overly formal meaning unless explicitly defined in this disclosure.

[0051] In order to better understand the platinum diselenide-based electromagnetic shielding film and the preparation method thereof provided in the embodiments of the present application, the platinum diselenide-based electromagnetic shielding film and the preparation method thereof are described in detail below through multiple specific embodiments.

[0052] The embodiment of the present invention provides a method for preparing a platinum diselenide-based electromagnetic shielding film, wherein the Figure 1 This is a picture of a quartz tube for preparing bulk platinum diselenide crystals according to the present invention, which comprises a bottom 1, a neck 2 and an opening 3, wherein a raw material mixture is placed at the bottom 1, and a substrate sheet 4 is placed near the opening 3.

[0053] The method comprises the following steps:

[0054] Step (1), uniformly mixing platinum powder, selenium powder and potassium chloride powder according to a preset ratio, that is, the molar ratio of platinum powder, selenium powder and potassium chloride powder is 1: (2-5): (0.5-1.5) to obtain a raw material mixture; wherein the molar ratio is 1:2:0.5, 1:2:1, 1:3:1, 1:4:1, 1:4:1.5, 1:5:1.5, etc.

[0055] The raw material mixture is placed at the bottom of a quartz tube 1 sealed at one end, wherein the quartz tube 1 has a neck portion 3, and the neck portion 3 is arranged between the bottom 2 and the opening 5 of the quartz tube 1; the distance L between the edge of the substrate sheet 4 close to the neck portion 3 and the bottom 2 of the quartz tube 1 is 10-20 cm; wherein L is 10 cm, 12 cm, 15 cm, 18 cm, 20 cm, etc.

[0056] The substrate sheet 4 is made of mica.

[0057] The uniform mixing is achieved by a degassing machine, and the specific steps are to put the zirconium oxide balls and the preset proportion of platinum powder, selenium powder and potassium chloride powder into a container, and the vibration frequency of the degassing machine is 800-1200r / min, and the time is 1-5min.

[0058] Step (2), placing the substrate sheet 4 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening portion 5, and then vacuum sealing the quartz tube 1, and converting the opening portion 5 into a sealed portion.

[0059] Step (3), placing the vacuum-sealed quartz tube 1 horizontally in a single-temperature zone tubular furnace, with the bottom of the quartz tube 1 facing the center of the tubular furnace, and obtaining bulk platinum diselenide crystals after heating reaction.

[0060] The temperature curve of the heating reaction is as follows: ① The temperature is raised from room temperature to temperature T at a heating rate of 4°C / min 1 ; ② Increase the temperature from T1 to T at a heating rate of 5℃ / min 2 ; ③ At temperature T 2 Keep warm for 200-400min; ④ stop heating, and allow the quartz tube to cool naturally to room temperature; wherein the T 1 =600-800°C, the T 2 =800-1000℃; specifically, T 1 The options are 600℃, 620℃, 650℃, 680℃, 700℃, 720℃, 750℃, 780℃, and 800℃.

[0061] Step (4), breaking the quartz tube 1 to collect the platinum diselenide bulk crystals, and grinding the platinum diselenide bulk crystals into platinum diselenide powder.

[0062] The powder was tested using X-ray diffraction (XRD). Figure 2 The XRD pattern of the platinum diselenide material prepared by the method of the present invention is shown in the attached Figure 2 It can be seen that the prepared material is consistent with the XRD standard peak of platinum diselenide. A small amount of powder was taken and Raman spectroscopy was performed after silicon wafer sample preparation. The measurement results are shown in the attached figure. Figure 3As shown, the prepared material is consistent with the standard Raman peak of platinum diselenide material. Then, a portion of the powder was taken for X-ray photoelectron spectroscopy (XPS) test, where the binding energy peak of platinum and selenium in the grown material is consistent with the platinum and selenium peaks corresponding to the binding energy of platinum diselenide. The test results are shown in the attached Figure 4-5 The above test results show that platinum diselenide is successfully generated.

[0063] Step (5), dispersing the platinum diselenide powder in deionized water to form a suspension, performing ultrasonic cleaning, filtering after cleaning, adding deionized water to form a dispersion, and performing a second ultrasonic cleaning; each ultrasonic time is 20-50 minutes, and the ultrasonic power is 650-800W.

[0064] Step (6), filtering the cleaned suspension to form a platinum diselenide-based electromagnetic shielding film; the vacuum filtration filter membrane has a diameter of 50 mm and a pore size of 0.22±0.05 μm; filtering the ultrasonically cleaned platinum diselenide powder to form a platinum diselenide-based electromagnetic shielding film; as another option, the ultrasonically cleaned platinum diselenide powder can be mixed with carbon nanotubes in proportion, and then ultrasonically dispersed evenly after mixing, and then filtered to form a platinum diselenide-based electromagnetic shielding film; the mass ratio of the cleaned platinum diselenide powder to the carbon nanotubes is 7:(0-1.5), and further, the mass ratio of the platinum diselenide powder to the carbon nanotubes can also be 7:0.5, 7:1, 7:1.5.

[0065] In order to better understand the platinum diselenide-based electromagnetic shielding film and the preparation method thereof provided in the embodiments of the present application, the platinum diselenide-based electromagnetic shielding film and the preparation method thereof are described in detail below through multiple specific embodiments.

[0066] Example 1

[0067] Step (1), weigh 0.3960 g of platinum powder, 0.6320 g of selenium powder and 0.1490 g of potassium chloride powder in a molar ratio of 1:4:1, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0068] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0069] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 800°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2= 1000°C. Keep at 1000°C for 300 min and then cool naturally to room temperature.

[0070] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0071] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and disperse it in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30min at a power of 720W; add deionized water after filtering to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30min; and obtain a cleaned suspension.

[0072] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0073] Example 2

[0074] Step (1), weigh 0.3960 g of platinum powder, 0.3160 ​​g of selenium powder and 0.0745 g of potassium chloride powder in a molar ratio of 1:2:0.5, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0075] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0076] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 800°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2 = 1000°C. Keep at 1000°C for 300 min and then cool naturally to room temperature.

[0077] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0078] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and disperse it in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30min at a power of 720W; add deionized water after filtering to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30min; and obtain a cleaned suspension.

[0079] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0080] Example 3

[0081] Step (1), weigh 0.3960 g of platinum powder, 0.7900 g of selenium powder and 0.2235 g of potassium chloride powder in a molar ratio of 1:5:1.5, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0082] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0083] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 800°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2 = 1000°C. Keep at 1000°C for 300 min and then cool naturally to room temperature.

[0084] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0085] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and disperse it in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30min at a power of 720W; add deionized water after filtering to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30min; and obtain a cleaned suspension.

[0086] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0087] Example 4

[0088] Step (1), weigh 0.3960 g of platinum powder, 0.6320 g of selenium powder and 0.1490 g of potassium chloride powder in a molar ratio of 1:4:1, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0089] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0090] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 750°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2 = 950° C. After being kept at 950° C. for 300 min, the mixture was naturally cooled to room temperature.

[0091] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0092] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and disperse it in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30min at a power of 720W; add deionized water after filtering to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30min; and obtain a cleaned suspension.

[0093] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0094] Example 5

[0095] Step (1), weigh 0.3960 g of platinum powder, 0.6320 g of selenium powder and 0.1490 g of potassium chloride powder in a molar ratio of 1:4:1, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0096] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0097] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 600°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2= 800°C. After being kept at 800°C for 300 min, the mixture was naturally cooled to room temperature.

[0098] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0099] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and disperse it in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30min at a power of 720W; add deionized water after filtering to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30min; and obtain a cleaned suspension.

[0100] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0101] Example 6

[0102] Step (1), weigh 0.3960 g of platinum powder, 0.6320 g of selenium powder and 0.1490 g of potassium chloride powder in a molar ratio of 1:4:1, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0103] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0104] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 800°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2 = 1000°C. Keep at 1000°C for 300 min and then cool naturally to room temperature.

[0105] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0106] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and 0.025g of carbon nanotubes (CNT) and disperse them in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30 minutes at a power of 720W; after filtering, add deionized water to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30 minutes; obtain a cleaned suspension.

[0107] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0108] Example 7

[0109] Step (1), weigh 0.3960 g of platinum powder, 0.6320 g of selenium powder and 0.1490 g of potassium chloride powder in a molar ratio of 1:4:1, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0110] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0111] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 800°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2 = 1000°C. Keep at 1000°C for 300 min and then cool naturally to room temperature.

[0112] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0113] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and 0.05g of carbon nanotubes (CNT) and disperse them in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30 minutes at a power of 720W; after filtering, add deionized water to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30 minutes; obtain a cleaned suspension.

[0114] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0115] Example 8

[0116] Step (1), weigh 0.3960 g of platinum powder, 0.6320 g of selenium powder and 0.1490 g of potassium chloride powder in a molar ratio of 1:4:1, mix the raw materials thoroughly to obtain a raw material mixture, and place the raw material mixture at the bottom 2 of the quartz tube 1.

[0117] Step (2), placing a substrate sheet 4 having at least one side length smaller than the diameter of the quartz tube 1 into the quartz tube 1, and placing the substrate sheet 4 between the neck portion 3 and the opening 5, and vacuum sealing the quartz tube 1;

[0118] Step (3), place the vacuum sealed quartz tube 1 horizontally in a single temperature zone tube furnace, align the bottom 2 of the quartz tube 1 with the center of the tube furnace, and place the substrate 4 close to the end of the quartz column. After heating to 800°C at a rate of 4°C / min, change the heating rate to 5°C / min and heat to T 2 = 1000°C. Keep at 1000°C for 300 min and then cool naturally to room temperature.

[0119] Step (4), taking out the quartz tube 1 and breaking it in a fume hood, and collecting the platinum diselenide bulk crystals produced by the reaction;

[0120] Step (5), after using a ball mill to make platinum diselenide bulk crystals into powder, weigh 0.35g of platinum diselenide and 0.075g of carbon nanotubes (CNTs) and disperse them in 50ml of deionized water to form a suspension; keep the suspension in an ultrasonic cleaning machine for 30 minutes at a power of 720W; after filtering, add deionized water to form a new suspension, perform secondary ultrasonic cleaning at a power of 720W for 30 minutes; obtain a cleaned suspension.

[0121] Step (6), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a platinum diselenide-based electromagnetic shielding film.

[0122] Comparative Example 1

[0123] Step (1), weighing 0.05g of carbon nanotubes (CNT) and dispersing them in 50ml of deionized water to form a suspension; keeping the suspension in an ultrasonic cleaning machine for 30min at a power of 720W; adding deionized water to form a new suspension after filtering, and performing a second ultrasonic cleaning at a power of 720W for 30min; obtaining a cleaned suspension.

[0124] Step (2), filtering the washed suspension completely using a vacuum-assisted filtration device, wherein the filter membrane used has a diameter of 50 mm and a pore size of 0.22 μm; and naturally drying the obtained film to obtain a carbon nanotube electromagnetic shielding film.

[0125] Test Method

[0126] The electromagnetic shielding performance of the platinum diselenide-based electromagnetic shielding film of the synthetic materials of Examples 1 to 9 and Comparative Example 1 was tested using a waveguide fixture and a vector network analyzer, with the frequency band set to 8-12 GHz; the performance is shown in Table 1.

[0127] Table 1 Electromagnetic shielding properties of platinum diselenide-based electromagnetic shielding films of Examples 1 to 8 and Comparative Example 1

[0128] Pt:Se:KCl molar ratio <![CDATA[T 1 / ℃]]> <![CDATA[T 2 / ℃]]> Mass ratio of platinum diselenide powder to carbon nanotubes Electromagnetic shielding performance / dB Example 1 1：4：1 800 1000 7：0 10 Example 2 1：2：0.5 800 1000 7：0 6 Example 3 1：5：1.5 800 1000 7：0 9 Example 4 1：4：1 750 950 7：0 9 Example 5 1：4：1 600 800 7：0 5 Example 6 1：4：1 800 1000 7：0.5 16 Example 7 1：4：1 800 1000 7：1 25 Example 8 1：4：1 800 1000 7：1.5 25 Comparative Example 1 —— —— —— 0：1 20

[0129] From the test results in Table 1, it can be seen that, compared with Examples 1-3, the platinum diselenide crystals produced only according to the stoichiometric ratio of selenium in the raw material have a great influence on the electromagnetic shielding performance, resulting in a decrease in the electromagnetic shielding performance. Compared with Examples 1, 4-5, it can be seen that the electromagnetic shielding performance of the electromagnetic shielding film prepared from the platinum diselenide bulk crystals prepared at too low a sintering temperature is reduced. The reason is that T 1 or T 2 The decrease in T 2 The reduction of T is particularly significant, significantly reducing the electromagnetic shielding performance. It can be seen that among Examples 1-5, the electromagnetic shielding performance of the platinum diselenide electromagnetic shielding film prepared in Example 1 is the best, that is, the molar ratio of platinum: selenium: potassium chloride in the raw material mixture is 1:4:1, T 1 =800℃, T 2 =1000°C is the best embodiment among embodiments 1-5. Figure 1-7 , are the performance parameters of the platinum diselenide powder and the platinum diselenide-based electromagnetic shielding film prepared in the corresponding Example 1.

[0130] Comparing Examples 1, 6-8, it can be seen that the addition of carbon nanotubes greatly improves the electromagnetic shielding performance of platinum diselenide. Figure 8-9 , especially with Fig. 9In Example 7, when the mass ratio of platinum diselenide to carbon nanotubes is 7:1, an electromagnetic shielding film with the best performance compared to the electromagnetic shielding film of the composite of platinum diselenide and carbon nanotubes is obtained. The electromagnetic shielding performance at this time is higher than that of the single carbon nanotube film or platinum diselenide film. Referring to Example 8, the degree of improvement in the electromagnetic shielding performance by increasing the amount of carbon nanotubes relative to Example 7 is limited. Referring to Comparative Example 1, the electromagnetic shielding performance of the single carbon nanotube film is better than that of the platinum diselenide-based electromagnetic shielding film, but the strength of the carbon nanotube film is lower than that of the platinum diselenide-based electromagnetic shielding film, and adding an appropriate amount of carbon nanotubes to the raw material of the pure platinum diselenide electromagnetic shielding film can obtain an electromagnetic shielding performance that is better than that of the single carbon nanotube film and the single platinum diselenide electromagnetic shielding film. Therefore, considering the electromagnetic shielding performance and the strength and toughness of the film comprehensively, it is preferred that the mass ratio of the washed platinum diselenide powder to the carbon nanotubes is 1: (0-0.2).

[0131] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing a platinum diselenide-based electromagnetic shielding film, characterized in that: The following steps are involved: Step (1), platinum powder, selenium powder and potassium chloride powder are uniformly mixed according to a preset ratio to obtain a raw material mixture, and the raw material mixture is placed at the bottom of a quartz tube with one end sealed, wherein the quartz tube has a neck portion, and the neck portion is arranged between the bottom and the opening of the quartz tube; Step (2), placing a substrate sheet into the quartz tube, and placing the substrate sheet between the neck portion and the opening portion, vacuum sealing the quartz tube, and converting the opening portion into a sealed portion; Step (3), placing the vacuum-sealed quartz tube horizontally in a single-temperature zone tube furnace, with the bottom of the quartz tube facing the center of the tube furnace, and obtaining bulk platinum diselenide crystals after heating reaction; Step (4), breaking the quartz tube to collect the platinum diselenide bulk crystals, and grinding the platinum diselenide bulk crystals into platinum diselenide powder; Step (5), dispersing the platinum diselenide powder in deionized water to form a suspension, and performing ultrasonic cleaning on the platinum diselenide powder multiple times to obtain a cleaned suspension; Step (6), filtering the cleaned suspension to form a platinum diselenide-based electromagnetic shielding film.

2. The method for preparing the platinum diselenide-based electromagnetic shielding film according to claim 1, characterized in that: The preset ratio in step (1) refers to the molar ratio of platinum powder, selenium powder and potassium chloride powder being 1:(2-5):(0.5-1.5).

3. The method for preparing the platinum diselenide-based electromagnetic shielding film according to claim 2, characterized in that: The molar ratio is 1:4:

1.

4. The method for preparing a platinum diselenide-based electromagnetic shielding film according to any one of claims 1 to 3, characterized in that: Include at least one of the following features: a) the distance between the edge of the substrate sheet close to the neck and the bottom of the quartz tube is L=10-20 cm; b) the substrate sheet is made of mica; c) The uniform mixing in step (1) is achieved by a degassing machine, specifically comprising placing zirconium oxide balls together with a preset proportion of platinum powder, selenium powder and potassium chloride powder into a container, and the degassing machine vibrates at a frequency of 800-1200 r / min for a time of 1-5 min; d) In step (5), the ultrasonic time is 20-50 min and the ultrasonic power is 650-800 W.

5. The method for preparing a platinum diselenide-based electromagnetic shielding film according to claim 4, characterized in that: The temperature curve of the heating reaction in step (3) is specifically: ① Raise the temperature from room temperature to T1 at a heating rate of 4℃ / min; ② Raise the temperature from T1 to T2 at a heating rate of 5°C / min; ③ Keep at temperature T2 for 200-400 minutes; ④ Stop heating and allow the quartz tube to cool naturally to room temperature; Wherein said T1=600-800°C, said T2=800-1000°C.

6. The method for preparing a platinum diselenide-based electromagnetic shielding film according to claim 4, characterized in that: The diameter of the filter membrane for vacuum filtration in step (6) is 50 mm and the pore size is 0.22±0.05 μm.

7. The method for preparing a platinum diselenide-based electromagnetic shielding film according to claim 4, characterized in that: The step (6) further comprises filtering the ultrasonically cleaned platinum diselenide powder to form a platinum diselenide-based electromagnetic shielding film, and also comprises mixing the ultrasonically cleaned platinum diselenide powder with carbon nanotubes in proportion, and then filtering after ultrasonic dispersion to form a platinum diselenide-based electromagnetic shielding film.

8. The method for preparing a platinum diselenide-based electromagnetic shielding film according to claim 7, characterized in that: The mass ratio of the cleaned platinum diselenide powder to the carbon nanotubes is 1:(0-0.2).

9. A platinum diselenide-based electromagnetic shielding film, characterized in that: The method is prepared by the method according to any one of claims 1 to 8.

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