Preparation method of nickel-coated pbo fiber with high conductivity and high electromagnetic shielding performance

Abstract

The application discloses a preparation method of nickel-coated PBO fibers with high conductivity and high electromagnetic shielding performance, and is specifically implemented according to the following steps: step 1, sequentially performing modification treatment, sensitization treatment and activation treatment on the PBO fibers; step 2, soaking the PBO fibers after the activation treatment in a sodium citrate solution; step 3, plating the PBO fibers after the step 2 treatment in a chemical nickel plating solution in a water bath environment, washing the PBO fibers after the plating with deionized water, and then drying the PBO fibers to obtain the chemical nickel-coated PBO fibers; and step 4, electroplating the chemical nickel-coated PBO fibers obtained in the step 3 by using a nickel rod as an anode and the chemical nickel-coated PBO fibers as a cathode, washing the PBO fibers after the electroplating with deionized water, and then drying the PBO fibers to obtain the nickel-coated PBO fibers with high conductivity and high electromagnetic shielding performance. The application has the advantages of simple process, short time consumption, and good conductivity and electromagnetic shielding performance of the prepared nickel-coated PBO fibers.

Description

Technical Field

[0001] The invention belongs to the technical field of PBO fiber preparation methods, and relates to a method for preparing nickel-coated PBO fibers with high electrical conductivity and high electromagnetic shielding performance. Background Art

[0002] PBO fibers not only possess high strength and modulus, but also excellent chemical stability, heat resistance, and flame retardancy. However, PBO fibers have poor surface activity, resulting in poor interfacial bonding with other materials. Traditional PBO fibers have relatively limited functionality, primarily used in aerospace, military protection, and sports equipment, primarily for their exceptional mechanical properties. Adding electrical conductivity and electromagnetic shielding properties to PBO fibers would significantly expand their applications.

[0003] Currently, most PBO fiber modification technologies focus on improving the reduced strength after UV irradiation. Relatively little research has been conducted on improving conductivity and electromagnetic shielding properties. Furthermore, most of these studies involve expensive equipment, complex processes, and long production times. Therefore, the present invention aims to address these issues by providing a simple, low-cost nickel-coated PBO fiber preparation technology. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing nickel-coated PBO fibers with high electrical conductivity and high electromagnetic shielding performance. The process is simple and time-saving, and the prepared nickel-coated PBO fibers have good electrical conductivity and electromagnetic shielding performance.

[0005] The technical solution adopted by the present invention is a method for preparing nickel-coated PBO fibers with high conductivity and high electromagnetic shielding performance, which is specifically implemented according to the following steps:

[0006] Step 1, modifying, sensitizing, and activating the PBO fiber in sequence;

[0007] Step 2, soaking the activated PBO fiber in a sodium citrate solution;

[0008] Step 3, placing the PBO fiber treated in step 2 in a chemical nickel plating solution in a water bath environment for plating, washing with deionized water after plating, and then drying to obtain chemical nickel-plated PBO fiber;

[0009] Step 4: Electroplating is performed using a nickel rod as an anode and the chemically nickel-plated PBO fiber obtained in step 3 as a cathode. After the electroplating is completed, the nickel-coated PBO fiber is washed with deionized water and then dried to obtain a nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance.

[0010] The present invention is also characterized in that:

[0011] The modification treatment in step 1 is specifically as follows:

[0012] The PBO fiber is immersed in acetone, and then the acetone-immersed PBO fiber is placed in a mixed solution of HNO3 and H2SO4 and subjected to ultrasonic vibration to obtain a modified PBO fiber;

[0013] The sensitization treatment in step 1 is specifically as follows: immersing the modified PBO fiber in a sensitizing solution in a water bath environment;

[0014] The activation treatment in step 1 is specifically as follows: the sensitized PBO fiber is immersed in an activation solution in a water bath environment.

[0015] In the modification treatment of step 1, the PBO fiber is immersed in acetone for 15 to 60 minutes; the concentration of HNO3 in the mixed solution of HNO3 and H2SO4 is 100 to 200 mL / L, the concentration of H2SO4 is 100 to 200 mL / L, and the ultrasonic oscillation time is 15 to 60 minutes.

[0016] The water bath temperature for the sensitization treatment in step 1 is 20-60° C., and the immersion time in the sensitizing solution is 10-40 min. The sensitizing solution is prepared as follows: hydrochloric acid is first diluted in deionized water to obtain a HCl solution with a concentration of 30-50 mL / L, and SnCl2·H2O is then added to the HCl solution to dissolve it to obtain a sensitizing solution, wherein the concentration of SnCl2·H2O is 5-15 g / L.

[0017] The activation solution in the activation treatment in step 1 is prepared by adding a 10% NH4OH solution to a 1-5 g / L AgNO3 solution until the solution becomes transparent to obtain the activation solution; the water bath temperature for the activation treatment is 20-60°C, and the soaking time for the PBO fiber is 10-40 min.

[0018] The concentration of the sodium citrate solution in step 2 is 5-10 g / L, and the soaking time is 5-30 min.

[0019] In step 3, the water bath temperature is 70-90° C., and the plating time is 5-60 min.

[0020] The preparation method of the chemical nickel plating solution in step 3 is:

[0021] Dissolving NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in deionized water to obtain a dissolving solution, wherein the concentrations of NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in the dissolving solution are 20-40 g / L, 20-40 g / L, and 20-35 mL / L, respectively;

[0022] The pH of the dissolving solution is then adjusted to 9-10 using 25% ammonia water to obtain a chemical nickel plating solution.

[0023] When electroplating in step 4, the electroplating solution is: NiCl2, C6H 11 NaO7 and (NH4)2SO4 are dissolved in deionized water to obtain an electroplating solution, wherein NiCl2, C6H 11 The concentrations of NaO7 and (NH4)2SO4 are: 80~150g / L, 10~50g / L, and 10~50g / L respectively;

[0024] Alternatively, NiSO4·6H2O, NaH2PO2·H2O, and lactic acid are dissolved in deionized water to obtain an electroplating solution, wherein the concentrations of NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in the electroplating solution are 20-40 g / L, 20-40 g / L, and 20-35 mL / L, respectively.

[0025] The electroplating process conditions are: the distance between the cathode and the anode is 2~6cm, the current density is 600~1500mA / dm 2 , the electroplating time is 5~30min, the electroplating temperature is 50~80℃, and the pH value is 3~6.

[0026] The beneficial effects of the present invention are:

[0027] The process of the present invention is simple and time-saving. A dense and continuous layer of nickel is completely coated on the surface of the PBO fiber, thereby improving the surface activity of the PBO, making it easy to composite with other materials and increasing the interface bonding and stability of the composite material; the conductivity function is added to the PBO fiber, the PBO fiber has an electromagnetic shielding function, and the mechanical properties of the PBO fiber are still well maintained after the modification. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a scanning electron microscope image of the original PBO fiber used in Example 2 of the present invention;

[0029] Figure 2 is a scanning electron microscope image of the chemical nickel-plated PBO fiber obtained in Example 2 of the present invention;

[0030] Figure 3 is a scanning electron microscope image of the nickel-coated PBO fiber with high strength, high conductivity, and high electromagnetic shielding performance obtained in Example 2 of the present invention;

[0031] Figure 4 is a scanning electron microscope image of the nickel-coated PBO fiber with high strength, high conductivity, and high electromagnetic shielding performance obtained in Example 3 of the present invention;

[0032] Figure 5Graphs showing tensile properties of the PBO fiber of Example 2 of the present invention, the PBO fiber treated with a mixed solution of 100-200 mL / L HNO3 and 100-200 mL / L H2SO4, and the resulting nickel-coated PBO fiber having high strength, high conductivity, and high electromagnetic shielding performance;

[0033] Figure 6 This is a resistance data graph of the nickel-coated PBO fiber with high strength, high conductivity, and high electromagnetic shielding performance obtained in Example 2 of the present invention;

[0034] Figure 7 This is a graph showing the electromagnetic shielding effectiveness of the nickel-coated PBO fiber with high strength, high conductivity, and high electromagnetic shielding performance obtained in Example 2 of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] The preparation method of nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is specifically implemented according to the following steps:

[0038] Step 1: Modification treatment, sensitization treatment, and activation treatment are performed on the PBO fiber in sequence; wherein the modification treatment is specifically as follows:

[0039] The PBO fiber is immersed in acetone for 15 to 60 minutes, and then the PBO fiber soaked in acetone is placed in a mixed solution of HNO3 and H2SO4 and ultrasonically shaken at the same time. The concentration of HNO3 in the mixed solution of HNO3 and H2SO4 is 100 to 200 mL / L, the concentration of H2SO4 is 100 to 200 mL / L, and the ultrasonic shaking time is 15 to 60 minutes to obtain the modified PBO fiber;

[0040] The sensitization treatment is specifically as follows: the modified PBO fiber is placed in a sensitizing solution and immersed for 10 to 40 minutes in a water bath environment with a water bath temperature of 20 to 60°C. The sensitizing solution is prepared as follows: hydrochloric acid is first diluted in deionized water to obtain a HCl solution with a concentration of 30 to 50 mL / L, and then SnCl2·H2O is added to the HCl solution to dissolve it to obtain a sensitizing solution, wherein the concentration of SnCl2·H2O is 5 to 15 g / L.

[0041] The activation treatment is specifically as follows: the sensitized PBO fiber is immersed in an activation solution in a water bath at a temperature of 20-60°C for 10-40 minutes; the activation solution is prepared by adding a 10% NH4OH solution to a 1-5g / L AgNO3 solution until the solution becomes transparent to obtain the activation solution;

[0042] Step 2: soaking the activated PBO fiber in a sodium citrate solution with a concentration of 5-10 g / L for 5-30 minutes;

[0043] Step 3: Plating the PBO fiber treated in step 2 in a chemical nickel plating solution at a water bath temperature of 70-90° C. for 5-60 min. After plating, washing with deionized water and drying to obtain chemical nickel-plated PBO fiber; wherein the preparation method of the chemical nickel plating solution is as follows:

[0044] Dissolving NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in deionized water to obtain a dissolving solution, wherein the concentrations of NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in the dissolving solution are 20-40 g / L, 20-40 g / L, and 20-35 mL / L, respectively;

[0045] The pH of the solution is then adjusted to 9-10 using 25% ammonia water to obtain a chemical nickel plating solution;

[0046] Step 4, electroplating using a nickel rod as an anode and the chemically nickel-plated PBO fiber obtained in step 3 as a cathode, washing with deionized water after the electroplating and then drying to obtain a nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance;

[0047] Among them, when electroplating, the electroplating solution is: NiCl2, C6H 11 NaO7 and (NH4)2SO4 are dissolved in deionized water to obtain an electroplating solution, wherein NiCl2, C6H 11 The concentrations of NaO7 and (NH4)2SO4 are: 80~150g / L, 10~50g / L, and 10~50g / L respectively;

[0048] Alternatively, NiSO4·6H2O, NaH2PO2·H2O, and lactic acid are dissolved in deionized water to obtain an electroplating solution, wherein the concentrations of NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in the electroplating solution are 20-40 g / L, 20-40 g / L, and 20-35 mL / L, respectively;

[0049] The electroplating process conditions are: the distance between the cathode and the anode is 2~6cm, the current density is 600~1500mA / dm 2 , the electroplating time is 5~30min, the electroplating temperature is 50~80℃, and the pH value is 3~6.

[0050] The scanning electron microscope images of the original PBO fibers used in Examples 2-3 of the present invention are as follows: Figure 1 shown.

[0051] Example 2

[0052] The preparation method of nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is specifically implemented according to the following steps:

[0053] Step 1, soak the PBO fiber in acetone for 30 minutes;

[0054] Step 2: placing the PBO fiber treated in step 1 in solution A and ultrasonically vibrating for 60 minutes to obtain modified PBO fiber, wherein solution A is a mixed solution of HNO3 with a concentration of 100 mL / L and H2SO4 with a concentration of 100 mL / L;

[0055] Step 3: soaking the modified PBO fiber obtained in step 2 in a sensitizing solution for 30 minutes in a water bath at a temperature of 40° C.; wherein the sensitizing solution is prepared as follows: first, diluting hydrochloric acid in deionized water to obtain a 40 mL / L HCl solution, then adding SnCl2·H2O to the HCl solution to dissolve it, wherein the concentration of SnCl2·H2O is 10 g / L, to obtain a sensitizing solution;

[0056] Step 4: preparing an activation solution, and then soaking the PBO fiber soaked in step 3 in the activation solution in a water bath at a temperature of 40° C. for 30 minutes; wherein the activation solution is prepared by adding a 10% NH 4 OH solution to a 5 g / L AgNO 3 solution until the solution becomes transparent to obtain the activation solution;

[0057] Step 5, placing the PBO fiber soaked in step 4 in a sodium citrate solution with a concentration of 8 g / L for 15 minutes;

[0058] Step 6: The PBO fiber treated in step 5 is placed in a chemical nickel plating solution in a water bath environment with a water bath temperature of 70° C. for 30 minutes. The composition of the chemical nickel plating solution is NiSO4·6H2O 30 g / L, NaH2PO2·H2O 30 g / L, and lactic acid 30 mL / L. The solvent is deionized water. After the chemical nickel plating solution is prepared, the pH of the chemical nickel plating solution is adjusted to 4.5 using a 25% ammonia solution to obtain a final chemical nickel plating solution. After the plating is completed, the fiber is washed with deionized water and dried to obtain a nickel-plated PBO fiber. The scanning electron microscope image thereof is shown in FIG. Figure 2 As shown;

[0059] Step 7: The PBO fiber treated in step 6 is used as the cathode of the electroplating equipment, and the nickel rod is used as the anode. The electroplating is carried out for 30 minutes. The distance between the cathode and the anode is 2.5 cm, and the current density is 1000 mA / dm 2, the plating temperature is 80℃, and the pH value is 4. The plating solution composition is NiCl2120g / L, C6H 11 NaO730g / L, (NH4)2SO430g / L. After the electroplating is completed, the nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance can be obtained by washing and drying. The scanning electron microscope image is as follows Figure 3 shown.

[0060] The tensile properties of the original PBO fiber, the PBO fiber treated with a mixed solution of 100-200 mL / L HNO3 and 100-200 mL / L H2SO4, and the obtained nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance were tested. The test results are shown in FIG. Figure 5 As shown in the figure, the tensile strength of the original PBO fiber is 5.18GPa. After acid treatment, the tensile strength decreases to 4.29GPa. However, this step is indispensable because the acid treatment can introduce active groups to the fiber surface and etch grooves on the fiber surface, providing chemical bonding and physical meshing between the coating and the fiber matrix, which is beneficial to improving the bonding strength of the coating. After the surface is plated with Ni, the tensile strength of the fiber is increased to 5.15GPa, returning to the original level and still showing high strength characteristics.

[0061] The resistance data of the nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance prepared in this embodiment was tested, and the test results are as follows: Figure 6 As shown in the figure, it can be seen that the resistance of a bundle of PBO fibers is reduced from non-conductive to 0.6Ω after chemical plating and electroplating, and the resistance change is also small after water washing and hot and cold shock, and the conductivity is better.

[0062] The nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance prepared in this embodiment was tested for electromagnetic shielding effectiveness, and the results are as follows: Figure 7 As shown in the figure, it can be seen that the electromagnetic shielding capability of the nickel-plated fiber in the X-band can reach more than 64dB, and can shield more than 99.9999% of electromagnetic waves.

[0063] Example 3

[0064] The preparation method of nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is specifically implemented according to the following steps:

[0065] Step 1, soaking the PBO fiber in acetone for 40 minutes;

[0066] Step 2: placing the PBO fiber treated in step 1 in solution A and ultrasonically vibrating for 30 minutes to obtain modified PBO fiber, wherein solution A is a mixed solution of HNO3 with a concentration of 150 mL / L and H2SO4 with a concentration of 150 mL / L;

[0067] Step 3: soaking the modified PBO fiber obtained in step 2 in a sensitizing solution at a water bath temperature of 50° C. for 40 minutes; wherein the sensitizing solution is prepared as follows: first, diluting hydrochloric acid in deionized water to obtain a 30 mL / L HCl solution, then adding SnCl2·H2O to the HCl solution to dissolve it, wherein the concentration of SnCl2·H2O is 12 g / L, to obtain a sensitizing solution;

[0068] Step 4: preparing an activation solution, and then soaking the PBO fiber soaked in step 3 in the activation solution in a water bath at a temperature of 50° C. for 40 minutes; wherein the activation solution is prepared by adding a 10% NH 4 OH solution to a 3 g / L AgNO 3 solution until the solution becomes transparent to obtain the activation solution;

[0069] Step 5, placing the PBO fiber soaked in step 4 in a 10 g / L sodium citrate solution for 10 minutes;

[0070] Step 6: Place the PBO fiber treated in step 5 in a chemical nickel plating solution in a water bath environment with a water bath temperature of 70° C. for 20 minutes. The components of the chemical nickel plating solution are 35 g / L NiSO4·6H2O, 35 g / L NaH2PO2·H2O, and 30 mL / L lactic acid. The solvent is deionized water. After the chemical nickel plating solution is prepared, the pH of the chemical nickel plating solution is adjusted to 9 using a 25% concentration of ammonia solution to obtain a final chemical nickel plating solution. After the plating is completed, wash with deionized water and obtain the nickel-plated PBO fiber after drying.

[0071] Step 7: The PBO fiber treated in step 6 is used as the cathode of the electroplating equipment, and the nickel rod is used as the anode. The electroplating is carried out for 30 minutes. The distance between the cathode and the anode is 2.5 cm, and the current density is 600 mA / dm 2 The electroplating temperature is 80°C and the pH value is 4.5. The electroplating solution composition is NiSO4·6H2O 30g / L, NaH2PO2·H2O 30g / L, and lactic acid 30mL / L. After the electroplating is completed, the nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is obtained by washing and drying. The scanning electron microscope image is shown below. Figure 4 shown.

[0072] The nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance prepared in this embodiment was subjected to resistance test, electromagnetic shielding test and tensile strength test, and the test results showed that the resistance was 0.8Ω, the electromagnetic shielding effectiveness was 60dB, and the tensile strength was 5.07GPa.

[0073] Example 4

[0074] The preparation method of nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is specifically implemented according to the following steps:

[0075] Step 1, soak the PBO fiber in acetone for 20 minutes;

[0076] Step 2: placing the PBO fiber treated in step 1 in solution A and ultrasonically vibrating for 15 minutes to obtain modified PBO fiber, wherein solution A is a mixed solution of HNO3 with a concentration of 200 mL / L and H2SO4 with a concentration of 200 mL / L;

[0077] Step 3: soaking the modified PBO fiber obtained in step 2 in a sensitizing solution for 15 minutes in a water bath at 60° C.; wherein the sensitizing solution is prepared as follows: first, diluting hydrochloric acid in deionized water to obtain a 30 mL / L HCl solution, then adding SnCl2·H2O to the HCl solution to dissolve it, wherein the concentration of SnCl2·H2O is 10 g / L, to obtain a sensitizing solution;

[0078] Step 4: preparing an activation solution, and then soaking the PBO fiber soaked in step 3 in the activation solution for 15 minutes in a water bath at a temperature of 60° C.; wherein the activation solution is prepared by adding a 10% NH 4 OH solution to a 3 g / L AgNO 3 solution until the solution becomes transparent to obtain the activation solution;

[0079] Step 5, placing the PBO fiber soaked in step 4 in a sodium citrate solution with a concentration of 5 g / L for 30 minutes;

[0080] Step 6: Plating the PBO fiber treated in step 5 in a chemical nickel plating solution at a water bath temperature of 80° C. for 15 minutes, wherein the chemical nickel plating solution comprises 35 g / L NiSO4·6H2O, 35 g / L NaH2PO2·H2O, and 35 mL / L lactic acid, and the solvent is deionized water. After the chemical nickel plating solution is prepared, the pH value of the chemical nickel plating solution is adjusted to 9.5 using a 25% ammonia solution to obtain a final chemical nickel plating solution. After the plating is completed, the fiber is washed with deionized water and dried to obtain the nickel-plated PBO fiber.

[0081] Step 7: The PBO fiber treated in step 6 is used as the cathode of the electroplating equipment, and the nickel rod is used as the anode. The electroplating is carried out for 30 minutes. The distance between the cathode and the anode is 4 cm, and the current density is 1200 mA / dm 2 , the plating temperature is 70℃, and the pH value is 4. The plating solution composition is NiCl2100g / L, C6H 11NaO740g / L, (NH4)2SO440g / L. After the electroplating is completed, the nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance can be obtained by washing and drying.

[0082] The nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance prepared in this embodiment was subjected to resistance test, electromagnetic shielding test and tensile strength test, and the test results showed that the resistance was 0.6Ω, the electromagnetic shielding effectiveness was 62dB, and the tensile strength was 5.09GPa.

[0083] Example 5

[0084] The preparation method of nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is specifically implemented according to the following steps:

[0085] Step 1, soak the PBO fiber in acetone for 10 minutes;

[0086] Step 2: placing the PBO fiber treated in step 1 in solution A and ultrasonically vibrating for 50 minutes to obtain modified PBO fiber, wherein solution A is a mixed solution of HNO3 with a concentration of 120 mL / L and H2SO4 with a concentration of 120 mL / L;

[0087] Step 3: soaking the modified PBO fiber obtained in step 2 in a sensitizing solution for 40 minutes in a water bath at 60° C.; wherein the sensitizing solution is prepared as follows: first, diluting hydrochloric acid in deionized water to obtain a 30 mL / L HCl solution, then adding SnCl2·H2O to the HCl solution to dissolve it, wherein the concentration of SnCl2·H2O is 5 g / L, to obtain a sensitizing solution;

[0088] Step 4: preparing an activation solution, and then soaking the PBO fiber soaked in step 3 in the activation solution in a water bath at a temperature of 50° C. for 40 minutes; wherein the activation solution is prepared by adding a 10% NH 4 OH solution to a 2 g / L AgNO 3 solution until the solution becomes transparent to obtain the activation solution;

[0089] Step 5, placing the PBO fiber soaked in step 4 in a sodium citrate solution with a concentration of 10 g / L for 5 minutes;

[0090] Step 6: Plating the PBO fiber treated in step 5 in a chemical nickel plating solution at a water bath temperature of 90° C. for 10 minutes, wherein the chemical nickel plating solution comprises 40 g / L NiSO4·6H2O, 40 g / L NaH2PO2·H2O, and 35 mL / L lactic acid, and the solvent is deionized water. After the chemical nickel plating solution is prepared, the pH value of the chemical nickel plating solution is adjusted to 10 using a 25% ammonia solution to obtain a final chemical nickel plating solution. After the plating is completed, the fiber is washed with deionized water and dried to obtain the nickel-plated PBO fiber.

[0091] Step 7: The PBO fiber treated in step 6 is used as the cathode of the electroplating equipment, and the nickel rod is used as the anode. The electroplating is carried out for 20 minutes. The distance between the cathode and the anode is 3 cm, and the current density is 1300 mA / dm 2 , the plating temperature is 80℃, and the pH value is 4. The plating solution composition is NiCl2150g / L, C6H 11 NaO 750g / L, (NH4)2SO4 50g / L. After the electroplating is completed, the nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance can be obtained by washing and drying.

[0092] The nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance prepared in this embodiment was subjected to resistance test, electromagnetic shielding test and tensile strength test, and the test results showed that the resistance was 0.7Ω, the electromagnetic shielding effectiveness was 62dB, and the tensile strength was 5.18GPa.

[0093] Example 6

[0094] The preparation method of nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is specifically implemented according to the following steps:

[0095] Step 1, soaking the PBO fiber in acetone for 60 minutes;

[0096] Step 2: placing the PBO fiber treated in step 1 in solution A and ultrasonically vibrating for 15 minutes to obtain modified PBO fiber, wherein solution A is a mixed solution of HNO3 with a concentration of 200 mL / L and H2SO4 with a concentration of 200 mL / L;

[0097] Step 3: soaking the modified PBO fiber obtained in step 2 in a sensitizing solution at a water bath temperature of 30° C. for 10 minutes; wherein the sensitizing solution is prepared as follows: first, diluting hydrochloric acid in deionized water to obtain a 50 mL / L HCl solution, then adding SnCl2·H2O to the HCl solution to dissolve it, wherein the concentration of SnCl2·H2O is 15 g / L, to obtain a sensitizing solution;

[0098] Step 4: preparing an activation solution, and then soaking the PBO fiber soaked in step 3 in the activation solution in a water bath at a temperature of 50° C. for 10 minutes; wherein the activation solution is prepared by adding a 10% NH 4 OH solution to a 5 g / L AgNO 3 solution until the solution becomes transparent to obtain the activation solution;

[0099] Step 5, placing the PBO fiber soaked in step 4 in a sodium citrate solution with a concentration of 8 g / L for 15 minutes;

[0100] Step 6: Plating the PBO fiber treated in step 5 in a chemical nickel plating solution at a water bath temperature of 90° C. for 5 minutes, wherein the chemical nickel plating solution comprises 40 g / L NiSO4·6H2O, 40 g / L NaH2PO2·H2O, and 35 mL / L lactic acid, and the solvent is deionized water. After the chemical nickel plating solution is prepared, the pH value of the chemical nickel plating solution is adjusted to 10 using a 25% ammonia solution to obtain a final chemical nickel plating solution. After the plating is completed, the fiber is washed with deionized water and dried to obtain the nickel-plated PBO fiber.

[0101] Step 7: The PBO fiber treated in step 6 is used as the cathode of the electroplating equipment, and the nickel rod is used as the anode. The electroplating is carried out for 5 minutes. The distance between the cathode and the anode is 3 cm, and the current density is 1500 mA / dm 2 The electroplating temperature is 80°C and the pH is 4. The plating solution consists of 40g / L NiSO4·6H2O, 40g / L NaH2PO2·H2O, and 35mL / L lactic acid. After electroplating, the product is washed and dried to produce nickel-coated PBO fibers with high electrical conductivity and excellent electromagnetic shielding properties.

[0102] The nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance prepared in this embodiment was subjected to resistance test, electromagnetic shielding test and tensile strength test, and the test results showed that the resistance was 0.6Ω, the electromagnetic shielding effectiveness was 60dB, and the tensile strength was 5.02GPa.

[0103] Example 7

[0104] The preparation method of nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance is specifically implemented according to the following steps:

[0105] Step 1, soaking the PBO fiber in acetone for 45 minutes;

[0106] Step 2: placing the PBO fiber treated in step 1 in solution A and ultrasonically vibrating for 20 minutes to obtain modified PBO fiber, wherein solution A is a mixed solution of HNO3 with a concentration of 170 mL / L and H2SO4 with a concentration of 170 mL / L;

[0107] Step 3: soaking the modified PBO fiber obtained in step 2 in a sensitizing solution at a water bath temperature of 45° C. for 20 minutes; wherein the sensitizing solution is prepared as follows: first, diluting hydrochloric acid in deionized water to obtain a 35 mL / L HCl solution, then adding SnCl2·H2O to the HCl solution to dissolve it, wherein the concentration of SnCl2·H2O is 10 g / L, to obtain a sensitizing solution;

[0108] Step 4: preparing an activation solution, and then soaking the PBO fiber soaked in step 3 in the activation solution in a water bath at a temperature of 45° C. for 20 minutes; wherein the activation solution is prepared by adding a 10% NH 4 OH solution to a 3 g / L AgNO 3 solution until the solution becomes transparent to obtain the activation solution;

[0109] Step 5, placing the PBO fiber soaked in step 4 in a sodium citrate solution with a concentration of 7 g / L for 20 minutes;

[0110] Step 6: Plating the PBO fiber treated in step 5 in a chemical nickel plating solution at a water bath temperature of 85° C. for 40 minutes, wherein the chemical nickel plating solution comprises 20 g / L NiSO4·6H2O, 20 g / L NaH2PO2·H2O, and 20 mL / L lactic acid, and the solvent is deionized water. After the chemical nickel plating solution is prepared, the pH value of the chemical nickel plating solution is adjusted to 9.5 using a 25% ammonia solution to obtain a final chemical nickel plating solution. After the plating is completed, the fiber is washed with deionized water and dried to obtain the nickel-plated PBO fiber.

[0111] Step 7: The PBO fiber treated in step 6 is used as the cathode of the electroplating equipment, and the nickel rod is used as the anode. The electroplating is carried out for 40 minutes. The distance between the cathode and the anode is 6 cm, and the current density is 1500 mA / dm 2 The electroplating temperature is 85°C and the pH is 5. The electroplating solution consists of 20g / L NiSO4·6H2O, 20g / L NaH2PO2·H2O, and 20mL / L lactic acid. After electroplating, the product is washed and dried to produce nickel-coated PBO fibers with high electrical conductivity and excellent electromagnetic shielding properties.

[0112] The nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance prepared in this embodiment was subjected to resistance test, electromagnetic shielding test and tensile strength test, and the test results showed that the resistance was 0.5Ω, the electromagnetic shielding effectiveness was 59dB, and the tensile strength was 5.05GPa.

Claims

1. A method for preparing nickel-coated PBO fibers with high electrical conductivity and high electromagnetic shielding performance, characterized in that: The specific implementation steps are as follows: Step 1, modifying, sensitizing, and activating the PBO fiber in sequence; The modification treatment is specifically as follows: The PBO fiber is immersed in acetone, and then the acetone-immersed PBO fiber is placed in a mixed solution of HNO3 and H2SO4 and subjected to ultrasonic vibration to obtain a modified PBO fiber; Step 2, soaking the activated PBO fiber in a sodium citrate solution; Step 3, placing the PBO fiber treated in step 2 in a chemical nickel plating solution in a water bath environment for plating, washing with deionized water after plating, and then drying to obtain chemical nickel-plated PBO fiber; Step 4: Electroplating is performed using a nickel rod as an anode and the chemically nickel-plated PBO fiber obtained in step 3 as a cathode. After the electroplating is completed, the nickel-coated PBO fiber is washed with deionized water and then dried to obtain a nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance.

2. The method for preparing nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance according to claim 1, characterized in that: The sensitization treatment in step 1 is specifically as follows: immersing the modified PBO fiber in a sensitizing solution in a water bath environment; The activation treatment in step 1 is specifically as follows: the sensitized PBO fiber is immersed in an activation solution in a water bath environment.

3. The method for preparing nickel-coated PBO fiber with high electrical conductivity and high electromagnetic shielding performance according to claim 2, characterized in that: In the modification treatment of step 1, the PBO fiber is immersed in acetone for 15 to 60 minutes; the concentration of HNO3 in the mixed solution of HNO3 and H2SO4 is 100 to 200 mL / L, the concentration of H2SO4 is 100 to 200 mL / L, and the ultrasonic oscillation time is 15 to 60 minutes.

4. The method for preparing nickel-coated PBO fiber with high electrical conductivity and high electromagnetic shielding performance according to claim 3, characterized in that: The water bath temperature for the sensitization treatment in step 1 is 20-60° C., and the immersion time in the sensitizing solution is 10-40 min. The sensitizing solution is prepared as follows: hydrochloric acid is first diluted in deionized water to obtain an HCl solution with a concentration of 30-50 mL / L, and SnCl2·H2O is added to the HCl solution to dissolve it to obtain the sensitizing solution, wherein the concentration of SnCl2·H2O is 5-15 g / L.

5. The method for preparing nickel-coated PBO fiber with high conductivity and high electromagnetic shielding performance according to claim 4, characterized in that: The activation solution in the activation treatment in step 1 is prepared by adding a 10% NH4OH solution to a 1-5 g / L AgNO3 solution until the solution becomes transparent to obtain the activation solution; the water bath temperature for the activation treatment is 20-60°C, and the soaking time for the PBO fiber is 10-40 min.

6. The method for preparing nickel-coated PBO fiber with high electrical conductivity and high electromagnetic shielding performance according to claim 5, characterized in that: The concentration of the sodium citrate solution in step 2 is 5-10 g / L, and the soaking time is 5-30 min.

7. The method for preparing nickel-coated PBO fiber with high electrical conductivity and high electromagnetic shielding performance according to claim 6, characterized in that: In step 3, the water bath temperature is 70-90° C., and the plating time is 5-60 min.

8. The method for preparing nickel-coated PBO fiber with high electrical conductivity and high electromagnetic shielding performance according to claim 7, characterized in that: The preparation method of the chemical nickel plating solution in step 3 is: Dissolving NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in deionized water to obtain a dissolving solution, wherein the concentrations of NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in the dissolving solution are 20-40 g / L, 20-40 g / L, and 20-35 mL / L, respectively; The pH of the dissolving solution is then adjusted to 9-10 using 25% ammonia water to obtain a chemical nickel plating solution.

9. The method for preparing nickel-coated PBO fiber with high electrical conductivity and high electromagnetic shielding performance according to claim 8, characterized in that: When the electroplating is performed in step 4, the electroplating solution is: NiCl2, C6H 11 NaO7 and (NH4)2SO4 are dissolved in deionized water to obtain an electroplating solution, wherein NiCl2, C6H 11 The concentrations of NaO7 and (NH4)2SO4 are: 80~150g / L, 10~50g / L, and 10~50g / L respectively; Alternatively, NiSO4·6H2O, NaH2PO2·H2O, and lactic acid are dissolved in deionized water to obtain an electroplating solution, wherein the concentrations of NiSO4·6H2O, NaH2PO2·H2O, and lactic acid in the electroplating solution are 20-40 g / L, 20-40 g / L, and 20-35 mL / L, respectively.

10. The method for preparing nickel-coated PBO fiber with high electrical conductivity and high electromagnetic shielding performance according to claim 9, characterized in that: The electroplating process conditions are: the distance between the cathode and the anode is 2-6 cm, the current density is 600-1500 mA / dm 2 , the electroplating time is 5~30min, the electroplating temperature is 50~80℃, and the pH value is 3~6.

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