Graphene-polyimide composite yarn and preparation method and application thereof

Abstract

The application belongs to the technical field of composite materials, and particularly relates to a graphene-polyimide composite yarn as well as a preparation method and application thereof. The preparation method of the graphene-polyimide composite yarn comprises the following steps: preparing an oxidized graphene solution with a concentration of 1-10 mg / mL; pouring the oxidized graphene solution into a spinning groove; controlling a polyimide yarn by two motors, and immersing the polyimide yarn in the oxidized graphene solution in the spinning groove; after immersion, the polyimide yarn is guided out and directly dried under the action of hot air to obtain an oxidized graphene-coated polyimide yarn; after heat reduction, the oxidized graphene-coated polyimide yarn is subjected to hydroiodic acid reduction treatment, and then is repeatedly washed and dried with ethanol and deionized water to obtain a graphene-polyimide multi-dimensional sensing yarn. The traditional yarn is realized with conductivity and sensing property by the preparation method, and the traditional yarn is endowed with excellent conductivity and sensing functionality.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of composite materials, and particularly relates to a graphene-polyimide composite yarn as well as a preparation method and application thereof. BACKGROUND

[0002] With the rapid development of intelligent wearable technology and AI technology, flexible intelligent wearable sensors can be used to detect human motion. With the help of intelligent wearable technology, as a two-dimensional fabric in close contact with the human body, it will usher in tremendous development opportunities and challenges. Traditional yarns have the characteristics of one-dimensional materials such as light weight, bendability and flexibility, but do not have conductivity and recognition ability to external stimuli, which greatly weakens the development of traditional yarns in the field of wearable sensing. How to rely on traditional yarns and fabrics to build yarns and fabrics with conductivity and sensing is a new challenge faced by the traditional textile industry.

[0003] Nowadays, yarn or fabric sensing needs to be achieved by interweaving two or more conductive yarns, such as the patent documents with publication numbers CN109307565A and CN115597747A disclose achieving sensing by interweaving, and again such as the patent documents with publication numbers CN117127299A and CN117626490A disclose using two or more blended or wrapped yarns. However, how to achieve multi-dimensional sensing of a single yarn is a development difficulty, so it is necessary to develop a one-dimensional yarn with simple process flow, which can be mass-produced to have multi-dimensional sensing, to achieve multi-dimensional recognition and sensing of different forms of external stimuli, and to build a two-dimensional fabric with multi-dimensional sensing based on the one-dimensional yarn, to achieve multi-dimensional sensing from the one-dimensional yarn to the two-dimensional fabric. The above research will broaden the application of traditional yarns in the field of wearable sensing.

[0004] In addition, traditional yarns and fabrics do not have protection and use performance in harsh environments, and even less have conductivity. In the face of multiple harsh environments such as liquid nitrogen, super high temperature, strong acid, strong base, etc., traditional yarns and clothes do not have any protective effect, and the harsh environment will directly invade the human body, causing serious harm to the human body. In such harsh environments, yarns, fabrics and clothes with protective effects can maximize the resistance to the influence of harsh environments on the human body and maximize the protection and mitigation of harm to the human body. Under the protection of protective fabrics and clothes, special operation workers can successfully complete the necessary cleaning and obstacle removal work in harsh environments, avoiding further damage to the surrounding people and environment by harsh environments. Yarns and fabrics with protective properties should have basic properties such as super low temperature resistance, high temperature resistance, acid and alkali resistance, and also have good wearability. SUMMARY

[0005] Based on the above-mentioned shortcomings and deficiencies existing in the prior art, one of the purposes of the present application is to at least solve one or more of the above-mentioned problems existing in the prior art, in other words, one of the purposes of the present application is to provide a graphene-polyimide composite yarn and a preparation method and application thereof which meet one or more of the aforementioned needs.

[0006] In order to achieve the above-mentioned purposes of the application, the following technical solutions are adopted in the present application:

[0007] A preparation method of a graphene-polyimide composite yarn, comprising the following steps:

[0008] (1) preparing an oxidized graphene solution with a concentration of 1-10 mg / mL;

[0009] (2) pouring the oxidized graphene solution into a spinning tank, and immersing a polyimide yarn in the oxidized graphene solution in the spinning tank, the polyimide yarn being controlled by two motors, and then leading out the polyimide yarn after immersion and directly drying the polyimide yarn under the action of hot air to obtain an oxidized graphene-coated polyimide yarn;

[0010] (3) after the oxidized graphene-coated polyimide yarn is subjected to thermal reduction, the polyimide yarn is subjected to hydroiodic acid reduction treatment, and then the polyimide yarn is repeatedly washed and dried with ethanol and deionized water to obtain a graphene-polyimide composite yarn.

[0011] As a preferred solution, in the step (2), the fineness of the polyimide yarn is 10-50 s, and the number of yarn strands is 1-5 strands;

[0012] The rotation speeds of the two motors are the same, and the rotation speed is 5-50 rpm;

[0013] The number of layers of the oxidized graphene coating is 3-15 layers;

[0014] The temperature of the hot air is 120-300 DEG C.

[0015] As a preferred solution, in the step (3), the temperature of the thermal reduction is 280-320 DEG C, and the reduction duration is 3-8 h;

[0016] The temperature of the hydroiodic acid reduction is 60-100 DEG C, and the reduction duration is 20-60 min;

[0017] The temperature of the drying is 50-80 DEG C.

[0018] The present application also provides a graphene-polyimide composite yarn prepared by the preparation method according to any one of the above solutions, which is used for detecting multi-dimensional sensing yarns of different bending angles and different pressures, the bending angle detection range is 0-180 DEG, and the pressure detection range is 1-500 g;

[0019] It is also used for conductive yarns.

[0020] The application also provides a preparation method of the graphene-polyimide composite fabric, comprising the following steps:

[0021] The traditional yarn and the graphene-polyimide composite yarn described in the above scheme are used as the warp and weft respectively, and a fabric interwoven with each other is woven to obtain the graphene-polyimide composite fabric.

[0022] As a preferred scheme, the traditional yarn is one or more of cotton yarn, wool yarn, silk, hemp yarn, polyester, nylon, acrylic, polypropylene, vinylon, spandex, chlorofiber, polyimide yarn, rayon and blended yarn.

[0023] The fineness of the graphene-polyimide composite yarn is 20-50 s, and the yarn count is 1-5.

[0024] The fabric interwoven with each other is one or more of the combination of plain weave, twill, satin, changeable weave and complex weave.

[0025] The application also provides the graphene-polyimide composite fabric prepared by the preparation method described in any of the above schemes, which is used for sensing of bending strain and pressure, the sensing range of the bending strain is 0-180°, and the sensing range of the pressure is 0-500 g.

[0026] It is also used as a conductive fabric.

[0027] The application also provides a preparation method of a graphene-polyimide multi-dimensional sensor, which is based on the graphene-polyimide composite yarn described in the above scheme and is encapsulated by PDMS to construct a one-dimensional yarn-based wearable sensor.

[0028] The process of PDMS encapsulation comprises the following steps: the PDMS solution containing a curing agent is injected into a silicone hose, the graphene-polyimide composite yarn is fixed along the axial center line in the silicone hose, and the two ends of the graphene-polyimide composite yarn respectively extend out of the silicone hose, and a metal tape is arranged on the extended part as an electrode; after the PDMS is cured, the silicone hose is cut and removed to obtain a one-dimensional graphene-polyimide yarn multi-dimensional sensor with a flexible protective layer.

[0029] The application also provides a preparation method of a graphene-polyimide multi-dimensional sensor, which is based on the graphene-polyimide composite fabric described in the above scheme and is encapsulated by PDMS to construct a two-dimensional yarn-based wearable sensor.

[0030] The process of PDMS encapsulation comprises the following steps: the PDMS solution containing a curing agent is made into a flexible film as a flexible substrate, then the graphene-polyimide composite fabric is placed on the flexible substrate, and the PDMS solution is poured and cured to obtain a two-dimensional graphene-polyimide multi-dimensional sensor.

[0031] The application also provides the graphene-polyimide multi-dimensional sensor according to any one of the above solutions, which is used for multi-dimensional sensing of torsion, stretching and pressing.

[0032] Compared with the prior art, the application has the following beneficial effects:

[0033] (1) The traditional yarn can realize sensing, ultra-low temperature resistance, high temperature resistance, acid and alkali resistance and conductivity by the preparation method of the application, so that the traditional yarn is endowed with excellent functionality;

[0034] (2) The graphene oxide can be prepared by the Hummers method, and the common polyimide yarn is widely available, and is more widely available as the source of the interwoven traditional yarn;

[0035] (3) The process flow adopted by the application is simple, and the yarn with multi-dimensional sensing performance and the conductivity of ultra-low temperature resistance, high temperature resistance and acid and alkali resistance can be prepared on a large scale and in batches, the two-dimensional multi-functional fabric can be prepared on a large scale, and the entire process can be automated to a certain extent and is easy to operate;

[0036] (4) The application can realize the multi-dimensional sensing performance of the one-dimensional yarn, the multi-dimensional sensing of the two-dimensional fabric, and the complete system preparation from the preparation of the single yarn to the two-dimensional fabric and the packaged sensor;

[0037] (5) The application can realize the conductivity of ultra-low temperature resistance, high temperature resistance and acid and alkali resistance of the one-dimensional yarn, and realize the preparation system from the preparation of the one-dimensional functional yarn to the two-dimensional functional fabric. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 It is an electron photo of the graphene-polyimide yarn of the embodiment 1 of the application;

[0039] Figure 2 It is a signal change graph of the graphene-polyimide yarn of the embodiment 1 of the application as a bending strain sensor;

[0040] Figure 3 It is an electron photo of the PDMS packaged graphene-polyimide yarn sensor of the embodiment 2 of the application;

[0041] Figure 4 It is a signal change graph of the graphene-polyimide yarn multi-dimensional sensor of the embodiment 2 of the application for detecting the multi-dimensional sensing of torsion, stretching and pressing;

[0042] Figure 5 It is a scanning electron microscope photo of the graphene-polyimide multi-dimensional sensing fabric of the embodiment 3 of the application;

[0043] Figure 6Signal change diagram for detecting and identifying bending strain of the graphene-polyimide multi-dimensional sensing fabric of Example 3 of the present application;

[0044] Figure 7 Electronic photo of the graphene-polyimide composite fabric of Example 7 of the present application. DETAILED DESCRIPTION

[0045] In order to more clearly illustrate the embodiments of the present application, the specific embodiments of the present application will be described below with reference to the accompanying drawings. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings and other embodiments can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0046] The preparation method of the graphene-polyimide multi-dimensional sensing yarn of the present application comprises the following steps:

[0047] (1) Prepare a graphene oxide solution with a concentration of 1-10 mg / mL as a coating solution at 25°C;

[0048] (2) Pour the above-mentioned graphene oxide solution into a spinning tank, and control the polyimide yarn by two motors, so that the polyimide yarn is immersed in the graphene oxide solution in the spinning tank, dried directly under the action of hot air, and a tight coating layer is formed on the surface of the polyimide yarn;

[0049] (3) After the obtained graphene oxide coated polyimide yarn is pre-thermally reduced, it is further reduced by using hydriodic acid, and after washing and drying with ethanol and deionized water repeatedly, the graphene-polyimide yarn is obtained.

[0050] The typical values of the concentration of the graphene oxide solution prepared in the above-mentioned step (1) are 5, 8 and 10 mg / mL, respectively.

[0051] The fineness of the polyimide yarn used in the above-mentioned step (1) is 10-50 s, and the number of yarn strands is 1-5 strands.

[0052] The temperature of the hot air in the above-mentioned step (2) is 120-300°C.

[0053] In the above-mentioned step (2), the moving speed and stable tension of the polyimide yarn during the coating process are controlled, and the rotating speeds of the two motors used are the same, and the range is 5-50 rpm.

[0054] In the above-mentioned step (2), the coating times of the polyimide in the graphene oxide, i.e. the number of layers of the coating layer formed, is 3-15 layers.

[0055] The temperature of the pre-thermal reduction in step (3) is 280-320℃, and the reduction time is 3-8h. The reagent for further chemical reduction is hydroiodic acid, and the reduction temperature is 60-100℃, and the reduction time is 20-60min.

[0056] The reagent for removing the residual hydroiodic acid in step (3) is anhydrous ethanol and deionized water in turn, and the number of repeated washing is 6-10 times, and the drying temperature after washing is 50-80℃.

[0057] The graphene-polyimide multi-dimensional sensing yarn can be directly used as a multi-dimensional sensing yarn for detecting different bending angles and different pressures. The graphene-polyimide multi-dimensional sensing yarn can realize the detection of bending angles and pressures, and the bending angle detection is 0-180°, and the pressure detection range is 1-500g.

[0058] Further, the graphene-polyimide multi-dimensional sensing fabric is constructed based on the multi-dimensional sensing yarn, and the preparation method comprises the following steps:

[0059] The conventional yarn is used as the weft yarn, and the graphene-polyimide multi-dimensional sensing yarn is used as the warp yarn to weave the interwoven fabric; or the conventional yarn is used as the warp yarn, and the graphene-polyimide multi-dimensional sensing yarn is used as the weft yarn to weave the graphene-polyimide multi-dimensional sensing fabric.

[0060] The conventional yarn is one yarn or a plurality of yarns selected from the group consisting of cotton yarn, wool yarn, silk yarn, hemp yarn, polyester yarn, nylon yarn, acrylic yarn, polypropylene yarn, vinylon yarn, spandex yarn, chlorofiber yarn and rayon, and a blended yarn prepared by blending the yarns.

[0061] The number of the graphene-polyimide multi-dimensional sensing yarn can be adjusted as required, and is preferably 20-50s, and the number of yarn strands is 1-5 strands. The number and thickness of the conventional yarn can be adjusted as required.

[0062] The interwoven manner is one of weaving, knitting and braiding, and the warp yarn and the weft yarn are interwoven into a two-dimensional fabric. In addition, the fabric organization of the interwoven fabric is one or more organizations selected from the group consisting of plain weave, twill weave, satin weave, changeable weave and complex weave.

[0063] The graphene-polyimide multi-dimensional sensing fabric can realize the sensing of bending strain and pressure, and the sensing range of the bending strain is 0-180°, and the sensing range of the pressure is 0-500g.

[0064] The application also constructs a one-dimensional yarn-based wearable sensor based on the prepared graphene-polyimide multi-dimensional sensing yarn; in addition, a two-dimensional fabric-based wearable sensor can also be prepared based on the prepared graphene-polyimide multi-dimensional sensing fabric.

[0065] (a) based on the graphene-polyimide multi-dimensional sensing yarn, encapsulating with PDMS to construct a one-dimensional yarn-based wearable sensor; wherein the number of strands of the graphene-polyimide multi-dimensional sensing yarn is one or several twisted multi-strand yarns, and the number of strands of the yarn can be controlled according to needs; specifically, the PDMS is encapsulated by preparing a solution with a solution mass:solidifying agent mass ratio of 10:1, stirring uniformly, and then injecting into a silicone hose. The prepared conductive graphene-polyimide yarn is fixed along the axial center line in the silicone hose, and the conductive yarn is longer than the silicone tube, and a metal tape is attached to the excess part as an electrode. After the PDMS is cured at a temperature of 60°C for 2h, the silicone hose mold is cut open and removed, and a one-dimensional graphene-polyimide yarn multi-dimensional sensor with a flexible protective layer is obtained.

[0066] (b) based on the graphene-polyimide multi-dimensional sensing fabric, encapsulating with PDMS to prepare a fabric-based wearable sensor. Specifically, the PDMS is encapsulated by preparing a solution with a solution mass:solidifying agent mass ratio of 10:1 to prepare a flexible film as a flexible substrate; then the graphene-polyimide multi-dimensional sensing fabric is placed on the flexible substrate, and then poured with the PDMS solution, and cured at a temperature of 60°C for 2h to obtain a two-dimensional fabric-based wearable sensor.

[0067] Example 1:

[0068] The preparation method of the graphene-polyimide yarn of the present embodiment comprises the following steps:

[0069] The graphene oxide aqueous solution with a concentration of 8mg / mL is fully stirred by a magnetic stirrer with a rotation speed of 300rpm at 25°C for 30min, and after stirring is completed, it is added into a spinning tank with a length of 20cm, a width of 3cm and a height of 4cm as a coating solution, and the tank has two roller wheels for ensuring that the yarn can be completely immersed in the coating solution and can rotate;

[0070] The polyimide yarn with fineness of 20s is released by a motor at a speed of 10 rpm and passes through a spinning slot, and then the yarn drawing the adsorbed graphene oxide solution is driven by another motor at a speed of 10 rpm and passes through a quartz tube for drying, hot air with a temperature of 200 DEG C is blown into the quartz tube to dry the yarn; the dried yarn is completely collected and considered as one coating, the coating process is repeated 5 times to obtain graphene oxide-polyimide yarn with 5 coating layers; the coated yarn is heated at 300 DEG C for 8 h for pre-reduction, and then further reduced by hydriodic acid at 80 DEG C for 30 min, finally the obtained reduced yarn is repeatedly washed with anhydrous ethanol and deionized water for 8 times and completely dried at 70 DEG C to obtain graphene-polyimide yarn.

[0071] The prepared graphene-polyimide yarn is connected with copper wires at both ends and directly used as a sensor for detecting bending strain, which can realize the detection of bending angle of 0-180 DEG; at the same time, the prepared graphene-polyimide yarn is directly used for detecting pressure, which can realize the detection of pressure.

[0072] Further, the prepared graphene-polyimide yarn is packaged with PDMS, specifically, the PDMS is prepared into a solution with a solution mass:solidifying agent mass ratio of 10:1, after uniform stirring, the solution is injected into a silicone hose, the prepared graphene-polyimide yarn is fixed along the axial center line in the silicone hose, and the yarn is longer than the silicone tube, and a metal tape is attached to the excess part as an electrode; the PDMS is cured at a temperature of 60 DEG C for 2 h, after cutting off and removing the silicone hose mold, a one-dimensional graphene-polyimide yarn multi-dimensional sensor with a flexible protective layer is obtained.

[0073] As shown in Figure 1 , the electron photo of the graphene-polyimide yarn of the embodiment can be seen that the surface is tightly wrapped with a layer of graphene, and the surface coating has no obvious breakage, and the overall morphology of the yarn is regular.

[0074] As shown in Figure 2 , the change of the sensing application of the graphene-polyimide yarn of the embodiment at different bending angles shows that it has the ability of bending strain sensing.

[0075] The above results show that the prepared graphene-polyimide yarn can realize the detection of bending strain and pressure, and realize the multi-dimensional sensing of a single yarn.

[0076] Example 2:

[0077] The preparation method of the graphene-polyimide yarn of the embodiment comprises the following steps:

[0078] The 10 mg / mL concentration of graphene oxide aqueous solution was stirred at 25°C by a magnetic stirrer at a speed of 200 rpm for 60 min. After the stirring was completed, the solution was added to a spinning slot with a length of 20 cm, a width of 3 cm, and a height of 4 cm, and two rollers were used to ensure that the yarn could be completely immersed in the coating solution and could rotate.

[0079] The polyimide yarn with a fineness of 20 s was released at a speed of 10 rpm by a motor and passed through the spinning slot. Then the yarn that was drawn out and absorbed the graphene oxide solution was driven by another motor at a speed of 10 rpm and passed through a quartz tube for drying. Hot air with a temperature of 200°C was blown into the quartz tube to dry the yarn. The dried yarn was completely collected and considered as one coating. The coating process was repeated 7 times to obtain a graphene oxide-polyimide yarn with 7 coating layers. The coated yarn was heated at 300°C for 8 h for pre-reduction, and then further reduced by hydriodic acid at 80°C for 30 min. Finally, the obtained reduced yarn was washed repeatedly with anhydrous ethanol and deionized water for 6 times and completely dried at 70°C to obtain a graphene-polyimide yarn.

[0080] The prepared graphene-polyimide yarn was connected to copper wires at both ends, and further packaged with PDMS to obtain a packaged graphene-polyimide yarn multi-dimensional sensor. As shown in Figure 3 , an electronic photo of the PDMS packaged graphene-polyimide yarn sensor. As shown in Figure 4 , the sensor can detect a bending angle of 0-180°. The prepared graphene-polyimide yarn can be directly used for detecting pressure, and can detect pressure and produce sensing to twisting and stretching.

[0081] Example 3:

[0082] The preparation method of the graphene-polyimide multi-dimensional sensing fabric of the present embodiment comprises the following steps:

[0083] The graphene-polyimide yarn prepared in Example 1 was used as the warp yarn, and pure polyimide yarn was used as the weft yarn. Both the warp and weft yarns were single. The graphene-polyimide interwoven fabric, i.e. the graphene-polyimide multi-dimensional sensing fabric, was woven on a rapier sample machine by selecting plain weave as the weave of the fabric.

[0084] As shown in Figure 5 , the warp and weft distribution structure of the graphene-polyimide multi-dimensional sensing fabric; As shown in Figure 6 , the graphene-polyimide multi-dimensional sensing fabric can be used to detect bending strain and pressure, and realize multi-dimensional sensing.

[0085] Example 4:

[0086] The preparation method of the graphene-polyimide multi-dimensional sensing yarn of the embodiment comprises the following steps:

[0087] The graphene oxide solution with a concentration of 5 mg / mL is fully stirred at 25°C by a magnetic stirrer with a rotation speed of 300 rpm for 30 min. After the stirring is completed, the solution is added to the spinning groove as a coating solution. The polyimide yarn with a fineness of 20 s is released by a motor at a rotation speed of 10 rpm and passes through the spinning groove. Then, the yarn that is drawn out and adsorbed with the graphene oxide solution is driven by another motor at a speed of 10 rpm and passes through a quartz tube for drying. Hot air with a temperature of 200°C is blown into the quartz tube to dry the yarn. The dried yarn is completely collected and considered as one coating. The coating process is repeated 8 times to obtain the graphene oxide-polyimide yarn with 8 coating layers. The coated yarn is heated at 300°C for 8 h for pre-reduction, and then further reduced with hydriodic acid at 80°C for 30 min. Finally, the obtained reduced yarn is repeatedly washed with anhydrous ethanol and deionized water for 8 times and completely dried at 70°C to obtain the graphene-polyimide yarn.

[0088] The prepared graphene-polyimide yarn is used as the warp and weft respectively, and is woven into a cross-interlaced pure fabric by interweaving. The warp and weft are connected to copper wires respectively. PDMS is prepared into a solution with a solution mass to curing agent mass ratio of 10:1, and a flexible film is prepared as a substrate. Then, the prepared pure graphene-polyimide fabric is placed on the flexible substrate, and the PDMS solution is poured and cured at a temperature of 60°C for 2 h to obtain a two-dimensional fabric-based wearable sensor. It is tested that the sensor can detect the bending angle. At the same time, the prepared graphene-polyimide yarn is directly used for detecting pressure, and the detection of pressure can be realized.

[0089] Example 5:

[0090] The preparation method of the conductive composite yarn of the embodiment that is resistant to ultra-low temperature, high temperature, acid and alkali comprises the following steps:

[0091] The graphene oxide solution with a concentration of 5 mg / mL is fully stirred at 25°C by a magnetic stirrer with a rotation speed of 300 rpm for 30 min. After the stirring is completed, the solution is added to the spinning groove as a coating solution. The polyimide yarn with a fineness of 20 s is released by a motor at a rotation speed of 10 rpm and passes through the spinning groove. Then, the yarn that is drawn out and adsorbed with the graphene oxide solution is driven by another motor at a speed of 10 rpm and passes through a quartz tube for drying. Hot air with a temperature of 200°C is blown into the quartz tube to dry the yarn. The dried yarn is completely collected and considered as one coating. The coating process is repeated 8 times to obtain the graphene oxide-polyimide yarn with 8 coating layers. The coated yarn is heated at 300°C for 8 h for pre-reduction, and then further reduced with hydriodic acid at 80°C for 30 min. Finally, the obtained reduced yarn is repeatedly washed with anhydrous ethanol and deionized water for 8 times and completely dried at 70°C to obtain the graphene-polyimide yarn.

[0092] The polyimide yarn with fineness of 20s is released by a motor at a speed of 10 rpm and passes through a spinning slot, and then the yarn drawn out and adsorbed with the graphene oxide solution is driven by another motor at a speed of 10 rpm and passes through a quartz tube for drying, hot air with a temperature of 200℃ is blown into the quartz tube to dry the yarn. The dried yarn is completely collected as one coating, and the coating process is repeated 5 times to obtain graphene oxide-polyimide yarn with 5 coating layers;

[0093] The coated yarn is heated at 300℃ for 8h for pre-reduction, and then further reduced with hydriodic acid at 80℃ for 30min. Finally, the obtained reduced yarn is repeatedly washed with anhydrous ethanol and deionized water for 8 times and completely dried at 70℃ to obtain graphene-polyimide yarn.

[0094] Example 6:

[0095] The preparation method of the conductive composite yarn with super-low temperature resistance, high temperature resistance, acid and alkali resistance of the embodiment comprises the following steps:

[0096] The graphene oxide solution with a concentration of 8mg / mL is fully stirred by a magnetic stirrer with a speed of 300rpm at 25℃ for 30min, and then added into a spinning slot with a length of 20cm, a width of 3cm and a height of 4cm as a coating solution, and two roller wheels in the slot are used to ensure that the yarn can be completely immersed in the coating solution and can rotate;

[0097] The polyimide yarn with fineness of 20s is released by a motor at a speed of 10 rpm and passes through a spinning slot, and then the yarn drawn out and adsorbed with the graphene oxide solution is driven by another motor at a speed of 10 rpm and passes through a quartz tube for drying, hot air with a temperature of 200℃ is blown into the quartz tube to dry the yarn. The dried yarn is completely collected as one coating, and the coating process is repeated 5 times to obtain graphene oxide-polyimide yarn with 5 coating layers;

[0098] The coated yarn is heated at 300℃ for 8h for pre-reduction, and then further reduced with hydriodic acid at 80℃ for 30min. Finally, the obtained reduced yarn is repeatedly washed with anhydrous ethanol and deionized water for 8 times and completely dried at 70℃ to obtain graphene-polyimide yarn.

[0099] Example 7:

[0100] The preparation method of the conductive composite fabric with super-low temperature resistance, high temperature resistance, acid and alkali resistance of the embodiment comprises the following steps:

[0101] The 8 mg / mL concentration graphene oxide solution was fully stirred at 25℃ by a magnetic stirrer with a rotation speed of 300 rpm for 30 min. After the stirring was completed, the solution was added to a spinning slot with a length of 20 cm, a width of 3 cm, and a height of 4 cm as a coating solution, and two roller wheels were arranged in the slot to ensure that the yarn could be fully immersed in the coating solution and could rotate;

[0102] The 20 s fineness polyimide yarn was released by a motor at a speed of 10 rpm and passed through the spinning slot. Then the yarn leading out and absorbing the graphene oxide solution was driven by another motor at a speed of 10 rpm and passed through a quartz tube for drying. Hot air with a temperature of 200℃ was blown into the quartz tube to dry the yarn. The dried yarn was fully collected and considered as one coating. The coating process was repeated 5 times to obtain graphene oxide-polyimide yarn with 5 coating layers;

[0103] The coated yarn was heated at 300℃ for 8 h for pre-reduction, and then further reduced by hydriodic acid at 80℃ for 30 min. Finally, the obtained reduced yarn was repeatedly washed with anhydrous ethanol and deionized water for 8 times and then completely dried at 70℃ to obtain graphene-polyimide composite yarn.

[0104] The graphene-polyimide composite yarn prepared above was used as the warp yarn, and pure polyimide yarn was used as the weft yarn. Both the warp and weft yarns were single. Plain weave was selected as the basic weave of the fabric. The graphene-polyimide interwoven fabric was woven on a rapier sample machine, as shown in Figure 7 .

[0105] Example 8

[0106] The preparation method of the conductive composite fabric with ultra-low temperature resistance, high temperature resistance, acid and alkali resistance of the embodiment comprises the following steps:

[0107] The 5 mg / mL concentration graphene oxide solution was fully stirred at 25℃ by a magnetic stirrer with a rotation speed of 300 rpm for 30 min. After the stirring was completed, the solution was added to a spinning slot as a coating solution.

[0108] The 20 s fineness polyimide yarn was released by a motor at a speed of 10 rpm and passed through the spinning slot. Then the yarn leading out and absorbing the graphene oxide solution was driven by another motor at a speed of 10 rpm and passed through a quartz tube for drying. Hot air with a temperature of 200℃ was blown into the quartz tube to dry the yarn. The dried yarn was fully collected and considered as one coating. The coating process was repeated 8 times to obtain graphene oxide-polyimide yarn with 8 coating layers.

[0109] The finished coated yarn is heated at 300 DEG C for 8h, then further reduced by hydroiodic acid at 80 DEG C for 30min, and finally the obtained reduced yarn is repeatedly washed by anhydrous ethanol and deionized water for 8 times and completely dried at 70 DEG C to obtain a graphene-polyimide composite yarn.

[0110] The prepared graphene-polyimide composite yarn is used as warp and weft respectively, and is woven into a cross-interlaced pure fabric by interweaving.

[0111] The verification of the super-low-temperature-resistant, high-temperature-resistant, acid and alkali-resistant conductive composite yarn and fabric of the embodiment is as follows:

[0112] (1) The super-low-temperature-resistant performance detection and results: the prepared graphene-polyimide composite yarn is directly placed in a liquid nitrogen environment (-196 DEG C) and repeatedly soaked to test the conductivity of the graphene-polyimide composite yarn, and the results show that the graphene-polyimide yarn still has conductivity.

[0113] (2) The high-temperature-resistant performance detection and results: the prepared graphene-polyimide composite yarn is placed in a high-temperature environment of 300 DEG C for 3h, and the results show that the graphene-polyimide composite yarn still has conductivity.

[0114] (3) The strong acid and alkali-resistant performance detection and results: the prepared graphene-polyimide composite yarn is corroded in a strong acid hydroiodic acid and a strong alkali sodium hydroxide environment, and the results show that the graphene-polyimide composite yarn has a complete structure and still has conductivity, and exhibits excellent strong acid and alkali resistance.

[0115] Since there are many embodiments of the present application scheme, the raw materials and amounts involved can be selected according to actual needs within the limited range, and the experimental data of each embodiment are numerous and not suitable for listing and explaining one by one, but the contents to be verified and the final conclusions obtained by each embodiment are close. Therefore, the verification contents of each embodiment are not described one by one.

[0116] The above only describes the preferred embodiments and principles of the present application in detail, and for ordinary skilled persons in the art, the specific implementation manner can be changed according to the idea provided by the present application, and these changes should be regarded as the protection scope of the present application.

Claims

1. A method of preparing a graphene-polyimide composite yarn, characterized by, It comprises the following steps: (1) preparing a graphene oxide solution with a concentration of 1-10 mg / mL; (2) pouring the graphene oxide solution into a spinning tank, and immersing the polyimide yarn in the graphene oxide solution in the spinning tank under the control of two motors, then leading out and directly drying under the action of hot air to obtain a graphene oxide-coated polyimide yarn; the number of graphene oxide coating layers is 3-15 layers; (3) after heat reduction, the graphene oxide-coated polyimide yarn is treated with hydriodic acid reduction, and then washed repeatedly with ethanol and deionized water and dried to obtain a graphene-polyimide composite yarn; In step (3), the temperature for heat reduction is 280-320℃, and the reduction time is 3-8 h; The temperature for hydriodic acid reduction is 60-100℃, and the reduction time is 20-60 min; The drying temperature is 50-80℃; The graphene-polyimide composite yarn is used for detecting multi-dimensional sensing yarns of different bending angles and different pressures, and the bending angle detection range is 0-180°, and the pressure detection range is 1-500 g.

2. The production method according to claim 1, characterized by, In step (2), the fineness of the polyimide yarn is 10-50 s, and the number of yarn strands is 1-5 strands; The rotating speeds of the two motors are the same, and the rotating speed is 5-50 rpm; The hot air temperature is 120-300℃.

3. The graphene-polyimide composite yarn prepared according to the method of any one of claims 1-2, wherein, It is also used as a conductive yarn.

4. A method of producing a graphene-polyimide composite fabric, characterized by, It comprises the following steps: Traditional yarn and the graphene-polyimide composite yarn as claimed in claim 3 are used as warp and weft respectively to weave into an interwoven fabric to obtain a graphene-polyimide composite fabric.

5. The preparation method according to claim 4, characterized in that, The traditional yarn is one or more of cotton yarn, wool yarn, silk, hemp yarn, polyester, nylon, acrylic, polypropylene, vinylon, spandex, chlorofiber, polyimide yarn, rayon, and blended yarn; The fineness of the graphene-polyimide composite yarn is 20-50 s, and the number of yarn strands is 1-5 strands; The interwoven fabric organization is a combination of one or more of plain weave, twill, satin, changeable weave, and complex weave.

6. The graphene-polyimide composite fabric prepared according to the production method of claim 4 or 5, characterized in that, It is used for sensing bending strain and pressure, and the sensing range of bending strain is 0-180°, and the sensing range of pressure is 0-500 g; It is also used as a conductive fabric.

7. A method of fabricating a graphene-polyimide multi-dimensional sensor, characterized by, Based on the graphene-polyimide composite yarn as claimed in claim 3, a PDMS encapsulation is performed to construct a one-dimensional yarn-based wearable sensor; The process of PDMS encapsulation comprises: injecting a PDMS solution containing a curing agent into a silicone hose, fixing the graphene-polyimide composite yarn along the axial center line in the silicone hose, and extending the two ends of the graphene-polyimide composite yarn outside the silicone hose, and setting a metal tape as an electrode on the extended part; after the PDMS is cured, the silicone hose is cut open and removed to obtain a one-dimensional graphene-polyimide yarn multi-dimensional sensor with a flexible protective layer.

8. A method of fabricating a graphene-polyimide multi-dimensional sensor, characterized by, Based on the graphene-polyimide composite fabric as claimed in claim 6, a PDMS encapsulation is performed to construct a two-dimensional yarn-based wearable sensor; The process of PDMS encapsulation comprises: preparing a flexible film containing a curing agent as a flexible substrate, then placing the graphene-polyimide composite fabric on the flexible substrate, pouring and curing the PDMS solution, and obtaining a two-dimensional graphene-polyimide multidimensional sensor.

9. The graphene-polyimide multi-dimensional sensor of claim 7 or 8, wherein, Multidimensional sensor for twisting, stretching and pressing.

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