Preparation method of high-sensitivity nanofiber composite slub core-spun yarn strain sensor

Abstract

The invention provides a preparation method of a high-sensitivity nanofiber composite slub core-spun yarn strain sensor, and belongs to the field of wearable flexible sensors. Comprising the following steps: S1, dissolving polyurethane in a solvent to prepare a spinning solution, preparing a nanofiber / traction filament composite yarn through an electrically-assisted core spinning technology, and endowing traction filaments with deformation by using a stretching device; s2, the composite yarn in the deformation state is placed in a conductive nanoparticle / polymer dilute solution to be soaked; s3, the impregnated composite yarn is impregnated in water, and a nanoparticle / polymer conductive layer is constructed on the surface of the composite yarn through non-solvent induced phase separation; s4, the stretching device is removed, heat treatment is conducted on the composite yarn, and the nanofiber composite slub core-spun yarn sensor is obtained. The sensor has a radial core-shell structure and an axial concave-convex structure, is high in sensitivity, has a stress detection limit as low as 0.01 N, and also has excellent mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the field of wearable flexible sensors, and in particular relates to a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor. Background Art

[0002] Yarn-based strain sensors have the advantages of good flexibility, easy weaving, and stretchable deformation, and have good application potential in human-computer interaction and smart wearable fields. The conjugate electrospinning process has technical advantages such as simple operation and a wide range of raw material sources. The obtained nanofiber yarn has the characteristics of small fiber diameter (300-1000nm) and easy deformation under external force. It has unique advantages in the preparation of yarn-based strain sensors. For example, patent CN201710451744.9 is a carbon / graphene flexible strain sensor. The carbon / graphene composite nanofiber yarn has the characteristics of high brittleness and high conductivity, which may cause the sensor to break easily when subjected to force, and its resistance change may be insensitive; patent CN202210296896.7 is a multi-element nanocarbon fiber yarn strain sensor. The performance of the sensor may decline after repeated use. If the performance remains unchanged after washing more than 30 times, it may affect its reliability for long-term use; patent CN202110795748.5 is a conductive spiral yarn self-powered sensor with a surface spacing structure that uses friction to generate electricity. There may be contact problems between the friction-generated layer and the conductive electrode, affecting the stability and durability of the sensor. The principle of the currently published nanofiber yarn sensors is that the slip of nanofibers brings about changes in yarn resistance, but after twisting, the nanofibers are closely arranged and cannot sense tiny external forces, and the response time is long; at the same time, these nanofiber yarn sensors have low mechanical strength and poor stability of sensing performance under multiple cycles of external forces, which limits their practical applications in human activity monitoring, sports behavior tracking, medical health recovery, user five senses recognition and other fields.

[0003] Therefore, it is necessary to provide a preparation method of a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor to overcome the defects of current yarn-based strain sensors, such as low sensing sensitivity, long response time, inability to sense tiny external forces, and poor stability of sensing performance under multiple cycles of external forces. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the current yarn-based strain sensor, such as low sensitivity, long response time, inability to sense small external forces, poor stability of sensing performance under multiple cycles of external forces, etc., and provide a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the preparation method is:

[0005] The first step is to dissolve polyurethane in a good solvent to prepare a spinning solution, prepare nanofiber / drawing filament composite yarns by electric-assisted core spinning technology, and add external stress to give the drawing filaments deformation;

[0006] Step 2: placing the nanofiber / drawing filament composite yarn in the above-mentioned deformed state in a conductive nanoparticle / polymer dilute solution for immersion;

[0007] Step 3: immersing the impregnated composite yarn in water to construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation;

[0008] Step 4: Remove the applied tensile stress, heat-treat the composite yarn to remove the non-solvent water, and obtain the concave-convex nanofiber composite bamboo core-spun yarn sensor.

[0009] As the preferred technical solution:

[0010] As described above, a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor is described, in which the first step is to use electrically assisted core spinning technology to prepare nanofiber / filament composite yarn, wherein the electrically assisted core spinning technology is a synergistic combination of a conjugate electrospinning process and a core-spun yarn forming process, two syringes encapsulating the spinning solution are respectively connected to a high-voltage positive electrode / negative electrode, and nanofibers are collected by pulling the filaments under a certain strain, and the nanofibers are coated on the pulled filaments to obtain a nanofiber composite yarn.

[0011] As described above, a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor is provided. In the first step, the polymer in the spinning solution of the electrically assisted core spinning technology is selected as polyurethane, and the solvent is selected as one or a combination of NNN dimethylformamide, dimethyl sulfoxide, NNN dimethylacetamide, and acetone, and the mass fraction of the polymer in the spinning solution is prepared to be 3 to 30%.

[0012] As described above, a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor is provided. In the first step, the polymer in the spinning solution of the electrically assisted core spinning technology is selected as polyurethane, and the solvent is selected as one or a combination of NNN dimethylformamide, dimethyl sulfoxide, NNN dimethylacetamide, and acetone, and the mass fraction of the polymer in the spinning solution is prepared to be 3 to 30%.

[0013] As described above, a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, in which the positive and negative high voltages in the conjugate electrospinning process of the electrically assisted core spinning technology are ±3 to ±30 kV, the spinning angles of the two syringes are 10 to 80°, the infusion speed is 0.5 to 5 mL / h, the receiving distance is 5 to 30 cm, the spinning environment temperature is 10 to 40°C, and the ambient humidity is 40% to 90% RH.

[0014] According to the preparation method of a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor as described above, in the second step of the impregnation process, the polymer is selected as one or a combination of polyvinyl butyral, polyamide, and polyvinyl pyrrolidone, the conductive nanoparticles are selected as one or a combination of silver nanoparticles, copper nanoparticles, and carbon black nanoparticles, and the solvent is selected as one or a combination of ethanol, nitrogen methyl pyrrolidone, and tert-butanol. The mass fraction of the polymer in the prepared impregnation solution is 1-5%, the mass fraction of the conductive nanoparticles is 1-30%, and the impregnation time is 10-60s.

[0015] As described above, a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor is described. In the third step of the impregnation process, water is selected as a non-solvent to induce polymer phase separation, and a stable nanoparticle / polymer conductive layer is constructed on the surface of the nanofiber composite yarn. The impregnation time is 10 to 60 seconds and the immersion temperature is 20 to 30°C.

[0016] In the method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor as described above, the heat treatment temperature in the fourth step of the heat treatment process is 70-160° C., and the treatment time is 5-30 minutes to obtain the nanofiber composite bamboo core-spun yarn.

[0017] As described above, a method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor is provided, wherein the nanofiber composite bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. When an external force is applied, the nanofiber conductive layer produces a high-sensitivity stretching-deformation change, and the composite yarn sensor exhibits an excellent negative resistance response characteristic.

[0018] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor as described above, wherein the nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25), excellent linear sensing characteristics (correlation index R2=99.8%), and a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through a weaving process to achieve real-time detection of human movement status and physical health.

[0019] Beneficial effects of the present invention:

[0020] (1) The nanofiber composite bamboo core-spun yarn strain sensor of the present invention adopts the electric-assisted core spinning technology (combining the conjugated electrospinning process and the core-spun yarn forming process) to prepare the nanofiber / filament composite yarn, and adopts a stretching device to maintain a certain deformation of the involved filaments in the spinning process; and constructs the nanoparticle / polymer conductive layer by non-solvent induced phase separation technology under the stretching state. After completion, the external force of the stretching device is removed, and the involved filaments return to their original length, so that the final yarn has a radial core-shell structure and an axial concave-convex structure.

[0021] (2) The nanofiber composite bamboo core-spun yarn strain sensor in the present invention has an axial concave-convex structure, that is, the nanofiber conductive layer will form a regular arch structure in the axial direction of the filament. When an external force is applied, the nanofiber conductive layer will produce a highly sensitive stretching-deformation change, which improves the sensing sensitivity of the strain sensor and can quickly sense the external tiny external force.

[0022] (3) The nanofiber composite bamboo core-spun yarn strain sensor in the present invention has a radial core-shell structure, the inner layer is a polyurethane traction filament, and the outer layer is a nanofiber composite conductive layer. The inner layer of the traction filament ensures that the yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, breaking elongation ≥200%) and has stable sensing performance under multiple cycles of external force.

[0023] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0025] Figure 1 This is a schematic diagram of the preparation process of a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor in an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the structure of a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor in an embodiment of the present invention; wherein: 1 is a polyurethane traction filament, 2 is a nanofiber layer, and 3 is a nanoparticle / polymer conductive layer. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0028] Example 1

[0029] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0030] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 18% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are 10kV, the spinning angles of the two syringes are 30°, the spinning solution infusion speed is 1mL / h, the receiving distance is 10cm, the spinning environment temperature is 20℃, and the ambient humidity is 50%RH; the pulling filament uses 80dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament 80% deformation, and the polyurethane pulling filament moving rate is 0.2m / min.

[0031] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare a 1% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 10%; place the above-mentioned nanofiber / filament composite yarn in the 80% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 20 seconds.

[0032] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 20°C and the immersion time is 20s.

[0033] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 90°C, the treatment time is 10 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0034] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0035] Example 2

[0036] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0037] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 20% with dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±15kV, the spinning angles of the two syringes are 25°, the spinning solution infusion speed is 1.5mL / h, the receiving distance is 15cm, the spinning environment temperature is 25℃, and the ambient humidity is 60%RH; the pulling filament is a 100dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 90% deformation, and the polyurethane pulling filament moves at a rate of 0.5m / min.

[0038] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 2% solution by mass, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 15%; place the above-mentioned nanofiber / filament composite yarn in the 90% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 30 seconds.

[0039] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 25°C and the immersion time is 30s.

[0040] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 100°C, the treatment time is 20 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0041] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0042] Example 3

[0043] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0044] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 22% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±20kV, the spinning angles of the two syringes are 35°, the spinning solution infusion speed is 3mL / h, the receiving distance is 20cm, the spinning environment temperature is 30℃, and the ambient humidity is 70%RH; the pulling filament is a 150dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 100% deformation, and the polyurethane pulling filament moves at a rate of 3m / min.

[0045] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use tert-butyl alcohol as solvent to prepare a 3% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 25%; place the above-mentioned nanofiber / filament composite yarn in the 100% deformation state and immerse it in the conductive nanoparticle / polymer dilute solution for 40 seconds.

[0046] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 15°C and the immersion time is 40s.

[0047] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 150°C, the treatment time is 30 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0048] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0049] Example 4

[0050] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0051] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, prepare a polyurethane solution with a mass fraction of 25% with acetone as the solvent, in the conjugate electrospinning, the positive and negative high voltages are ±5kV, the spinning angles of the two syringes are 60°, the spinning solution infusion speed is 4mL / h, the receiving distance is 25cm, the spinning environment temperature is 16°C, and the ambient humidity is 55%RH; the pulling filament is a 200dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 110% deformation, and the polyurethane pulling filament moves at a rate of 1.5m / min.

[0052] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 4% solution by mass, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 5%; place the above-mentioned nanofiber / filament composite yarn in the 110% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 55 seconds.

[0053] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 22°C and the immersion time is 40s.

[0054] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 110°C, the treatment time is 15 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0055] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0056] Example 5

[0057] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0058] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 10% with dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±5kV, the spinning angles of the two syringes are 45°, the spinning solution infusion speed is 4mL / h, the receiving distance is 6cm, the spinning environment temperature is 16°C, and the ambient humidity is 55%RH; the pulling filament is a 160dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 120% deformation, and the polyurethane pulling filament moves at a rate of 0.4m / min.

[0059] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use ethanol as solvent to prepare a solution with a mass fraction of 3.5%, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 21%; place the above-mentioned nanofiber / filament composite yarn in the 120% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 22 seconds.

[0060] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 15°C and the immersion time is 34s.

[0061] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 75°C, the treatment time is 16 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0062] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0063] Example 6

[0064] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0065] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 26% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±8kV, the spinning angles of the two syringes are 65°, the spinning solution infusion speed is 2.3mL / h, the receiving distance is 26cm, the spinning environment temperature is 17°C, and the ambient humidity is 56%RH; the pulling filament uses 250dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 130% deformation, and the polyurethane pulling filament moves at a rate of 0.5m / min.

[0066] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use tert-butyl alcohol as solvent to prepare a solution with a mass fraction of 2.1%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 12%; place the above-mentioned nanofiber / filament composite yarn in the 130% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 13s.

[0067] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 26°C and the immersion time is 60s.

[0068] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 85°C, the treatment time is 26 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0069] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0070] Example 7

[0071] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0072] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 18% (3-30%) with acetone as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±16kV, the spinning angles of the two syringes are 22°, the spinning solution infusion speed is 3.5mL / h, the receiving distance is 14cm, the spinning environment temperature is 35°C, and the ambient humidity is 60%RH; the pulling filament uses 105dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 140% deformation, and the polyurethane pulling filament moves at a rate of 0.6m / mi.

[0073] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 4% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 8%; place the above-mentioned nanofiber / filament composite yarn in the 140% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 55 seconds.

[0074] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 23°C and the immersion time is 28s.

[0075] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 140°C, the treatment time is 16 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0076] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0077] Example 8

[0078] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0079] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 16% with dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±16kV, the spinning angles of the two syringes are 75°, the spinning solution infusion speed is 3mL / h, the receiving distance is 26cm, the spinning environment temperature is 18°C, and the ambient humidity is 55%RH; the pulling filament uses 270dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 150% deformation, and the polyurethane pulling filaments move at a rate of 3.3m / min.

[0080] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use ethanol as solvent to prepare a solution with a mass fraction of 4.5%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 16%; place the above-mentioned nanofiber / filament composite yarn in the 150% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 56 seconds.

[0081] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 27°C and the immersion time is 38s.

[0082] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 150°C, the treatment time is 23 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0083] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0084] Example 9

[0085] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0086] The first step: the nanofiber / filament composite yarn is prepared by electric-assisted core spinning technology, and a polyurethane solution with a mass fraction of 24% is prepared with NN dimethylformamide (as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±26kV, the spinning angles of the two syringes are 75°, the spinning solution infusion speed is 1.2mL / h, the receiving distance is 25cm, the spinning environment temperature is 36°C, and the ambient humidity is 46%RH; the traction filament uses 160dtex polyurethane filament, and an external stretching device is added to the polyurethane traction filament to deform by 160%, and the polyurethane traction filament moves at a rate of 4.8m / min.

[0087] Step 2: Prepare a conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 3.2% solution by mass, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 10% (1-30%); place the above-mentioned nanofiber / filament composite yarn in the 160% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 48 seconds.

[0088] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 22°C and the immersion time is 58s.

[0089] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 160°C, the treatment time is 80 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0090] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0091] Example 10

[0092] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0093] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, prepare a polyurethane solution with a mass fraction of 30% with acetone as the solvent, and in the conjugate electrospinning, the positive and negative high voltages are ±18kV, the spinning angles of the two syringes are 16°, the spinning solution infusion speed is 4mL / h, the receiving distance is 8cm, the spinning environment temperature is 34°C, and the ambient humidity is 88%RH; the pulling filament uses 270dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 170% deformation, and the polyurethane pulling filaments move at a rate of 0.6m / min.

[0094] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use tert-butyl alcohol as solvent to prepare a solution with a mass fraction of 4.5%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 16%; place the above-mentioned nanofiber / filament composite yarn in the 170% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 60 seconds.

[0095] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 23°C and the immersion time is 12s.

[0096] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 78°C, the treatment time is 8 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0097] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0098] Embodiment 11

[0099] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0100] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 26% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±4kV, the spinning angles of the two syringes are 70°, the spinning solution infusion speed is 3.9mL / h, the receiving distance is 30cm, the spinning environment temperature is 10℃, and the ambient humidity is 44%RH; the pulling filament uses 220dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 180% deformation, and the polyurethane pulling filament moves at a rate of 3.6m / min.

[0101] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare a 2% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 17%; place the above-mentioned nanofiber / filament composite yarn in the 180% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 55 seconds.

[0102] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 26°C and the immersion time is 20s.

[0103] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 155°C, the treatment time is 9 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0104] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0105] Example 12

[0106] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0107] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 6% with dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±24kV, the spinning angles of the two syringes are 56°, the spinning solution infusion speed is 3.2mL / h, the receiving distance is 17cm, the spinning environment temperature is 37°C, and the ambient humidity is 80%RH; the pulling filament is a 140dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 190% deformation, and the polyurethane pulling filament moves at a rate of 4.4m / min.

[0108] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare a solution with a mass fraction of 3.8%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 16%; place the above-mentioned nanofiber / filament composite yarn in the 190% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 27 seconds.

[0109] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 20°C and the immersion time is 17s.

[0110] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 78°C, the treatment time is 9 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0111] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0112] Embodiment 13

[0113] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0114] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 21% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±26kV, the spinning angles of the two syringes are 15°, the spinning solution infusion speed is 0.8mL / h, the receiving distance is 9cm, the spinning environment temperature is 25℃, and the ambient humidity is 46%RH; the pulling filament uses 55dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 200% deformation, and the polyurethane pulling filament moves at a rate of 2.5m / mi.

[0115] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare a solution with a mass fraction of 2.5%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 13%; place the above-mentioned nanofiber / filament composite yarn in the 200% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 22 seconds.

[0116] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 26°C and the immersion time is 58s.

[0117] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 155°C, the treatment time is 5 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0118] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0119] Embodiment 14

[0120] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0121] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a 5% polyurethane solution with a mass fraction using NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±6kV, the spinning angles of the two syringes are 14°, the spinning solution infusion speed is 1.5mL / h, the receiving distance is 15cm, the spinning environment temperature is 38°C, and the ambient humidity is 60%RH; the pulling filament uses 60dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 60% deformation, and the polyurethane pulling filament moves at a rate of 0.6m / min.

[0122] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare a 4% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 26%; place the above-mentioned nanofiber / filament composite yarn in the 60% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 46 seconds.

[0123] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 35°C and the immersion time is 45s.

[0124] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 76°C, the treatment time is 27 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0125] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0126] Embodiment 15

[0127] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0128] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, dimethyl sulfoxide is used as the solvent to prepare a polyurethane solution with a mass fraction of 18%. In the conjugate electrospinning, the positive and negative high voltages are ±3kV, the spinning angles of the two syringes are 26°, the spinning solution infusion speed is 3.8mL / h, the receiving distance is 11cm, the spinning environment temperature is 16°C, and the ambient humidity is 45%RH; 58dtex polyurethane filaments are used for the pulling filaments, and an external stretching device is added to give the polyurethane pulling filaments a 65% deformation, and the polyurethane pulling filaments move at a rate of 0.8m / min.

[0129] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use tert-butyl alcohol as solvent to prepare a 3% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 14%; place the above-mentioned nanofiber / filament composite yarn in the 65% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 25 seconds.

[0130] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 28°C and the immersion time is 14s.

[0131] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 85°C, the treatment time is 11 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0132] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0133] Example 16

[0134] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0135] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, prepare a polyurethane solution with a mass fraction of 25% with acetone as the solvent, and in the conjugate electrospinning, the positive and negative high voltages are ±5kV, the spinning angles of the two syringes are 78°, the spinning solution infusion speed is 3.3mL / h, the receiving distance is 23cm, the spinning environment temperature is 36°C, and the ambient humidity is 44%RH; the pulling filament uses 74dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 70% deformation, and the polyurethane pulling filaments move at a rate of 2.3m / min.

[0136] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a solution with a mass fraction of 2.4%, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 5%; place the above-mentioned nanofiber / filament composite yarn in the 70% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 35 seconds.

[0137] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 21°C and the immersion time is 17s.

[0138] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 80°C, the treatment time is 7 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0139] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0140] Embodiment 17

[0141] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0142] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a 5% polyurethane solution with a mass fraction using NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±11kV, the spinning angles of the two syringes are 13°, the spinning solution infusion speed is 1.1mL / h, the receiving distance is 6cm, the spinning environment temperature is 16°C, and the ambient humidity is 25%RH; the pulling filament uses 70dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 75% deformation, and the polyurethane pulling filaments move at a rate of 0.3m / min.

[0143] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use ethanol as solvent to prepare a solution with a mass fraction of 1.5%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 5%; place the above-mentioned nanofiber / filament composite yarn in the 75% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 45 seconds.

[0144] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 20°C and the immersion time is 15s.

[0145] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 145°C, the treatment time is 13 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0146] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0147] Embodiment 18

[0148] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0149] The first step: use the electric-assisted core spinning technology to prepare the nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 20% as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±12kV, the spinning angles of the two syringes are 60°, the spinning solution infusion speed is 0.8mL / h, the receiving distance is 24cm, the spinning environment temperature is 19°C, and the ambient humidity is 43%RH; the pulling filament uses 90dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments 85% deformation, and the polyurethane pulling filaments move at a rate of 5m / min.

[0150] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 3% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 16%; place the above-mentioned nanofiber / filament composite yarn in the 85% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 24 seconds.

[0151] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 27°C and the immersion time is 30s.

[0152] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 95°C, the treatment time is 7 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0153] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0154] Embodiment 19

[0155] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0156] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 23% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±5kV, the spinning angles of the two syringes are 76°, the spinning solution infusion speed is 1.5mL / h, the receiving distance is 15cm (5-30cm), the spinning environment temperature is 36°C, and the ambient humidity is 55%RH; the pulling filament uses 225dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 90% deformation, and the polyurethane pulling filaments move at a rate of 0.9m / min.

[0157] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use tert-butyl alcohol as solvent to prepare a 5% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 16%; place the above-mentioned nanofiber / filament composite yarn in the 90% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 38 seconds.

[0158] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 22°C and the immersion time is 26s.

[0159] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 75°C, the treatment time is 23 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0160] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0161] Embodiment 20

[0162] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0163] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 4% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±6kV, the spinning angles of the two syringes are 11°, the spinning solution infusion speed is 3.9mL / h, the receiving distance is 14cm, the spinning environment temperature is 22℃, and the ambient humidity is 53%RH; the pulling filament uses 150dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 95% deformation, and the polyurethane pulling filament moves at a rate of 0.8m / min.

[0164] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 2% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 14%; place the above-mentioned nanofiber / filament composite yarn in the 95% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 45 seconds.

[0165] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 21°C and the immersion time is 16s.

[0166] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 135°C, the treatment time is 6 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0167] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0168] Embodiment 21

[0169] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0170] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a 5% polyurethane solution with a mass fraction using NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±4kV, the spinning angles of the two syringes are 16°, the spinning solution infusion speed is 1.6mL / h, the receiving distance is 25cm, the spinning environment temperature is 15℃, and the ambient humidity is 58%RH; 300dtex polyurethane filaments are used for the pulling filaments, and an external stretching device is added to give the polyurethane pulling filaments a 115% deformation, and the polyurethane pulling filaments move at a rate of 2.6m / min.

[0171] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare a solution with a mass fraction of 1.6%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 7%; place the above-mentioned nanofiber / filament composite yarn in the 115% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 48 seconds.

[0172] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 27°C and the immersion time is 17s.

[0173] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 146°C, the treatment time is 14 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0174] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0175] Embodiment 22

[0176] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0177] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 8% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±16kV, the spinning angles of the two syringes are 45°, the spinning solution infusion speed is 3.7mL / h, the receiving distance is 28cm, the spinning environment temperature is 33°C, and the ambient humidity is 78%RH; 55dtex polyurethane filaments are used for pulling filaments, and an external stretching device is added to give the polyurethane pulling filaments a 125% deformation, and the polyurethane pulling filaments move at a rate of 4m / min.

[0178] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use tert-butyl alcohol as solvent to prepare a solution with a mass fraction of 3.7%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 18%; place the above-mentioned nanofiber / filament composite yarn in the 125% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 47 seconds.

[0179] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 22°C and the immersion time is 20s.

[0180] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 77°C, the treatment time is 28 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0181] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0182] Embodiment 23

[0183] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0184] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a 5% polyurethane solution with a mass fraction using NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±17kV, the spinning angles of the two syringes are 35°, the spinning solution infusion speed is 5mL / h, the receiving distance is 14cm, the spinning environment temperature is 38°C, and the ambient humidity is 67%RH; the pulling filament uses 265dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 135% deformation, and the polyurethane pulling filaments move at a rate of 3.8m / min.

[0185] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use ethanol as solvent to prepare a solution with a mass fraction of 2.6%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 30%; place the above-mentioned nanofiber / filament composite yarn in the 135% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 56 seconds.

[0186] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 21°C and the immersion time is 46s.

[0187] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 79°C, the treatment time is 9 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0188] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0189] Embodiment 24

[0190] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0191] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, prepare a polyurethane solution with a mass fraction of 9% with acetone as the solvent, and in the conjugate electrospinning, the positive and negative high voltages are ±7kV, the spinning angles of the two syringes are 33°, the spinning solution infusion speed is 4.3mL / h, the receiving distance is 14cm, the spinning environment temperature is 37°C, and the ambient humidity is 44%RH; the pulling filament is a 74dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 145% deformation, and the polyurethane pulling filament moves at a rate of 0.8m / min.

[0192] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare a 2.3% solution by mass, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 26%; place the above-mentioned nanofiber / filament composite yarn in the 145% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 36 seconds.

[0193] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 29°C and the immersion time is 47s.

[0194] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 155°C, the treatment time is 26 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0195] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0196] Embodiment 25

[0197] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0198] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 28% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±27kV, the spinning angles of the two syringes are 56°, the spinning solution infusion speed is 4mL / h, the receiving distance is 22cm, the spinning environment temperature is 24℃, and the ambient humidity is 60%RH; the pulling filament uses 78dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 155% deformation, and the polyurethane pulling filament moves at a rate of 0.4m / min.

[0199] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 3.7% solution by mass, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 9%; place the above-mentioned nanofiber / filament composite yarn in the 155% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 11 seconds.

[0200] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 23°C and the immersion time is 41s.

[0201] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 89°C, the treatment time is 18 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0202] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0203] Embodiment 26

[0204] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0205] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a 3% polyurethane solution with a mass fraction using dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±22kV, the spinning angles of the two syringes are 52°, the spinning solution infusion speed is 4mL / h, the receiving distance is 24cm, the spinning environment temperature is 16°C, and the ambient humidity is 60%RH; the pulling filament uses 295dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 165% deformation, and the polyurethane pulling filaments move at a rate of 3.6m / min.

[0206] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 1% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 5%; place the above-mentioned nanofiber / filament composite yarn in the 165% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 41 seconds.

[0207] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 27°C and the immersion time is 24s.

[0208] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 147°C, the treatment time is 27 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0209] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0210] Embodiment 27

[0211] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0212] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, prepare a polyurethane solution with a mass fraction of 16% with acetone as the solvent, and in the conjugate electrospinning, the positive and negative high voltages are ±27kV, the spinning angles of the two syringes are 39°, the spinning solution infusion speed is 4.4mL / h, the receiving distance is 19cm, the spinning environment temperature is 15°C, and the ambient humidity is 66%RH; the pulling filament uses 63dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 175% deformation, and the polyurethane pulling filaments move at a rate of 0.5m / min.

[0213] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare a 4% solution by mass, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 22%; place the above-mentioned nanofiber / filament composite yarn in the 175% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 44 seconds.

[0214] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 26°C and the immersion time is 17s.

[0215] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 105°C, the treatment time is 24 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0216] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0217] Embodiment 28

[0218] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0219] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 27% with dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±6kV, the spinning angles of the two syringes are 55, the spinning solution infusion speed is 3.2mL / h, the receiving distance is 16cm, the spinning environment temperature is 33℃, and the ambient humidity is 66%RH; the pulling filament uses 119dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 185% deformation, and the polyurethane pulling filament moves at a rate of 4.4m / min.

[0220] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare a solution with a mass fraction of 4.5%, select carbon black nanoparticles), and the mass fraction of conductive nanoparticles is 11%; place the above-mentioned nanofiber / filament composite yarn in the 185% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 18s.

[0221] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 23°C and the immersion time is 54s.

[0222] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 156°C, the treatment time is 20 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0223] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0224] Embodiment 29

[0225] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0226] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 15% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±15kV, the spinning angles of the two syringes are 75°, the spinning solution infusion speed is 4.2mL / h, the receiving distance is 25cm, the spinning environment temperature is 36°C, and the ambient humidity is 48%RH; the pulling filament uses 190dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 195% deformation, and the polyurethane pulling filament moves at a rate of 3m / min.

[0227] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 2% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 25%; place the above-mentioned nanofiber / filament composite yarn in the 195% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 55 seconds.

[0228] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 20°C (20-30°C) and the immersion time is 29s.

[0229] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 142°C, the treatment time is 16 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0230] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0231] Embodiment 30

[0232] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0233] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 8% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±12kV, the spinning angles of the two syringes are 36°, the spinning solution infusion speed is 1.2mL / h, the receiving distance is 17cm, the spinning environment temperature is 29°C, and the ambient humidity is 53%RH; the pulling filament uses 85dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 58% deformation, and the polyurethane pulling filament movement rate is 0.8m / min.

[0234] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use tert-butyl alcohol as solvent to prepare a solution with a mass fraction of 1.8%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 12%; place the above-mentioned nanofiber / filament composite yarn in the 58% deformation state in the conductive nanoparticle / polymer dilute solution and immerse it for 26 seconds.

[0235] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 24°C and the immersion time is 30s.

[0236] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 80°C, the treatment time is 5 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0237] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0238] Embodiment 31

[0239] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0240] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, prepare a polyurethane solution with a mass fraction of 25% with acetone as the solvent, and in the conjugate electrospinning, the positive and negative high voltages are ±24kV, the spinning angles of the two syringes are 40°, the spinning solution infusion speed is 3mL / h, the receiving distance is 26cm, the spinning environment temperature is 17°C, and the ambient humidity is 60%RH; the pulling filament uses 90dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 69% deformation, and the polyurethane pulling filament moves at a rate of 5m / min.

[0241] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use nitrogen methyl pyrrolidone as solvent to prepare a solution with a mass fraction of 3.9%, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 10% (1-30%); place the above-mentioned nanofiber / filament composite yarn in the 69% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 16s.

[0242] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 21°C and the immersion time is 40s.

[0243] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 88°C, the treatment time is 27 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0244] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0245] Embodiment 32

[0246] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0247] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 28% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±14kV, the spinning angles of the two syringes are 33°, the spinning solution infusion speed is 3.6mL / h, the receiving distance is 12cm, the spinning environment temperature is 34°C, and the ambient humidity is 68%RH; the pulling filament uses 98dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 72% deformation, and the polyurethane pulling filament moves at a rate of 4.5m / min.

[0248] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use ethanol as solvent to prepare a solution with a mass fraction of 2.5%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 13%; place the above-mentioned nanofiber / filament composite yarn in the 72% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 56 seconds.

[0249] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 26°C and the immersion time is 10s.

[0250] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 88°C, the treatment time is 28min, and the nanofiber composite bamboo core-spun yarn is obtained.

[0251] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0252] Embodiment 33

[0253] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0254] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 6% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±18kV, the spinning angles of the two syringes are 32°, the spinning solution infusion speed is 3.4mL / h, the receiving distance is 21cm, the spinning environment temperature is 16°C, and the ambient humidity is 58%RH; the pulling filament uses 60dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament 86% deformation, and the polyurethane pulling filament moves at a rate of 1.4m / min.

[0255] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare a solution with a mass fraction of 1.8%, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 21%; place the above-mentioned nanofiber / filament composite yarn in the 86% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 43 seconds.

[0256] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 24°C and the immersion time is 46s.

[0257] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 149°C, the treatment time is 27 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0258] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0259] Embodiment 34

[0260] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0261] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, prepare a polyurethane solution with a mass fraction of 8% with acetone as the solvent, in the conjugate electrospinning, the positive and negative high voltages are ±27kV, the spinning angles of the two syringes are 75°, the spinning solution infusion speed is 3.2mL / h, the receiving distance is 24cm, the spinning environment temperature is 33°C, and the ambient humidity is 73%RH; the pulling filament is a polyurethane filament of 198dtex (50-300dtex), and an external stretching device is added to give the polyurethane pulling filament a 96% deformation, and the polyurethane pulling filament moves at a rate of 0.6m / min.

[0262] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a solution with a mass fraction of 2.6%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 16%; place the above-mentioned nanofiber / filament composite yarn in the 96% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 44 seconds.

[0263] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 20°C (20-30°C) and the immersion time is 40s.

[0264] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 76°C, the treatment time is 26 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0265] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0266] Embodiment 35

[0267] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0268] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 25% with dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±3kV, the spinning angles of the two syringes are 77°, the spinning solution infusion speed is 2mL / h, the receiving distance is 20cm, the spinning environment temperature is 21°C, and the ambient humidity is 60%RH; the pulling filament is a 200dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 106% deformation, and the polyurethane pulling filament moves at a rate of 4m / min.

[0269] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use ethanol as solvent to prepare a 3% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 23%; place the above-mentioned nanofiber / filament composite yarn in the 106% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 56 seconds.

[0270] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 22°C and the immersion time is 36s.

[0271] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove non-solvent water, the heat treatment temperature is 150°C, the treatment time is 6 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0272] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0273] Embodiment 36

[0274] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0275] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a 6% polyurethane solution with a mass fraction using dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±4kV, the spinning angles of the two syringes are 11°, the spinning solution infusion speed is 3.7mL / h, the receiving distance is 23cm, the spinning environment temperature is 36°C, and the ambient humidity is 89%RH; the pulling filament uses 67dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 118% deformation, and the polyurethane pulling filaments move at a rate of 0.9m / min.

[0276] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare a 2.8% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 26%; place the above-mentioned nanofiber / filament composite yarn in the 118% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 29 seconds.

[0277] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 26°C and the immersion time is 54s.

[0278] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 142°C, the treatment time is 8 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0279] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0280] Embodiment 37

[0281] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0282] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 22% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±16kV, the spinning angles of the two syringes are 62°, the spinning solution infusion speed is 4.7mL / h, the receiving distance is 18cm, the spinning environment temperature is 36°C, and the ambient humidity is 77%RH; the pulling filament uses 230dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 127% deformation, and the polyurethane pulling filament moves at a rate of 2.2m / min.

[0283] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare a 2% solution by mass, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 13%; place the above-mentioned nanofiber / filament composite yarn in the 127% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 40 seconds.

[0284] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 20°C (20-30°C) and the immersion time is 32s.

[0285] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 136°C, the treatment time is 26 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0286] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0287] Embodiment 38

[0288] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0289] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 34% with acetone as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±5kV, the spinning angles of the two syringes are 68°, the spinning solution infusion speed is 3.9mL / h, the receiving distance is 17cm, the spinning environment temperature is 17℃, and the ambient humidity is 90%RH; 56dtex polyurethane filaments are used for the pulling filaments, and an external stretching device is added to give the polyurethane pulling filaments a 132% deformation, and the polyurethane pulling filaments move at a rate of 4.1m / min.

[0290] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a solution with a mass fraction of 3.3%, select copper nanoparticles, and the mass fraction of conductive nanoparticles is 29%; place the above-mentioned nanofiber / filament composite yarn in the 132% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 45 seconds.

[0291] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 22°C and the immersion time is 15s.

[0292] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 135°C, the treatment time is 13 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0293] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0294] Embodiment 39

[0295] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0296] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 23% with dimethyl sulfoxide as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±11kV, the spinning angles of the two syringes are 36°, the spinning solution infusion speed is 2.9mL / h, the receiving distance is 26cm, the spinning environment temperature is 34°C, and the ambient humidity is 80%RH; the pulling filament uses 60dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 147% deformation, and the polyurethane pulling filaments move at a rate of 0.6m / min.

[0297] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl pyrrolidone polymer, use ethanol as solvent to prepare a 5% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 17%; place the above-mentioned nanofiber / filament composite yarn in the 147% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 51 seconds.

[0298] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 25°C and the immersion time is 50s.

[0299] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 120°C, the treatment time is 20 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0300] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0301] Embodiment 40

[0302] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0303] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 14% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±7kV, the spinning angles of the two syringes are 28°, the spinning solution infusion speed is 3.8mL / h, the receiving distance is 9cm, the spinning environment temperature is 39°C, and the ambient humidity is 60%RH; the pulling filament uses 280dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 159% deformation, and the polyurethane pulling filament moves at a rate of 5m / min.

[0304] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 4% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 6%; place the above-mentioned nanofiber / filament composite yarn in the 159% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 13s.

[0305] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 27°C and the immersion time is 46s.

[0306] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 86°C, the treatment time is 9 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0307] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0308] Embodiment 41

[0309] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0310] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 28% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±8kV, the spinning angles of the two syringes are 47°, the spinning solution infusion speed is 3mL / h, the receiving distance is 11cm, the spinning environment temperature is 30℃, and the ambient humidity is 64%RH; the pulling filament uses 220dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 168% deformation, and the polyurethane pulling filament moves at a rate of 3.2m / min.

[0311] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 3% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 26%; place the above-mentioned nanofiber / filament composite yarn in the 168% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 36 seconds.

[0312] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 20°C (20-30°C) and the immersion time is 31s.

[0313] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 121°C, the treatment time is 23 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0314] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0315] Embodiment 42

[0316] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0317] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 17% with acetone as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±19kV, the spinning angles of the two syringes are 77°, the spinning solution infusion speed is 2mL / h, the receiving distance is 3cm, the spinning environment temperature is 28°C, and the ambient humidity is 78%RH; the pulling filament uses 260dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 173% deformation, and the polyurethane pulling filaments move at a rate of 0.5m / min.

[0318] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare a solution with a mass fraction of 2.9%, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 26%; place the above-mentioned nanofiber / filament composite yarn in the 173% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 37 seconds.

[0319] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 20°C (20-30°C) and the immersion time is 13s.

[0320] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 93°C, the treatment time is 7 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0321] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0322] Embodiment 43

[0323] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0324] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 14% with NN dimethylformamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±21kV, the spinning angles of the two syringes are 16°, the spinning solution infusion speed is 0.6mL / h, the receiving distance is 14cm, the spinning environment temperature is 27℃, and the ambient humidity is 88%RH; the pulling filament uses 296dtex polyurethane filament, and an external stretching device is added to give the polyurethane pulling filament a 182% deformation, and the polyurethane pulling filament moves at a rate of 0.7m / min.

[0325] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyamide polymer, use nitrogen methyl pyrrolidone as solvent to prepare a 3% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 22%; place the above-mentioned nanofiber / filament composite yarn in the 182% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 50 seconds.

[0326] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 23°C and the immersion time is 29s.

[0327] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 147°C, the treatment time is 8 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0328] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0329] Embodiment 44

[0330] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0331] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 12% with acetone as the solvent. In the conjugate electrospinning, the positive and negative high voltages are ±16kV, the spinning angles of the two syringes are 42°, the spinning solution infusion speed is 2.6mL / h, the receiving distance is 25cm, the spinning environment temperature is 33°C, and the ambient humidity is 66%RH; 56dtex polyurethane filaments are used for the pulling filaments, and an external stretching device is added to give the polyurethane pulling filaments a 194% deformation, and the polyurethane pulling filaments move at a rate of 4.1m / min.

[0332] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use tert-butyl alcohol as solvent to prepare a 4% solution by mass, select silver nanoparticles, and the mass fraction of conductive nanoparticles is 10% (1-30%); place the above-mentioned nanofiber / filament composite yarn in the 194% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 32s.

[0333] Step 3: Immerse the above-mentioned impregnated composite yarn in water, construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation, and improve the conductivity of the composite yarn. The water temperature is controlled at 25°C and the immersion time is 47s.

[0334] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 160°C, the treatment time is 23 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0335] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

[0336] Embodiment 45

[0337] A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, the specific steps are:

[0338] The first step: use the electric-assisted core spinning technology to prepare nanofiber / filament composite yarn, and prepare a polyurethane solution with a mass fraction of 16% with NN dimethylacetamide as solvent. In the conjugate electrospinning, the positive and negative high voltages are ±6kV, the spinning angles of the two syringes are 72°, the spinning solution infusion speed is 2.8mL / h, the receiving distance is 7cm, the spinning environment temperature is 34°C, and the ambient humidity is 82%RH; the pulling filament uses 298dtex polyurethane filaments, and an external stretching device is added to give the polyurethane pulling filaments a 54% deformation, and the polyurethane pulling filament movement rate is 0.7m / min.

[0339] Step 2: Prepare conductive nanoparticle / polymer impregnation modification solution: select polyvinyl butyral polymer, use ethanol as solvent to prepare a 2% solution by mass, select carbon black nanoparticles, and the mass fraction of conductive nanoparticles is 5%; place the above-mentioned nanofiber / filament composite yarn in the 54% deformation state in the conductive nanoparticle / polymer dilute solution and immerse for 57 seconds.

[0340] Step 3: Immerse the above-mentioned impregnated composite yarn in water, and construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation to improve the conductivity of the composite yarn. The water temperature is controlled at 26°C and the immersion time is 30s.

[0341] Step 4: Remove the external stress of the stretching device, heat treat the composite yarn to remove the non-solvent water, the heat treatment temperature is 98°C, the treatment time is 17 minutes, and the nanofiber composite bamboo core-spun yarn is obtained.

[0342] The prepared bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure. The nanofiber composite bamboo core-spun yarn strain sensor has extremely high sensitivity (S≥25) and excellent linear sensing characteristics (correlation index R 2 =99.8%), with a stress detection limit as low as 0.01N. At the same time, the bamboo core-spun yarn has excellent mechanical properties (tensile breaking strength ≥100MPa, elongation at break ≥200%), and can be compounded into the fabric through the weaving process to achieve real-time detection of human movement status and physical health.

Claims

1. A method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor, characterized in that: The preparation method is: The first step is to dissolve polyurethane in a good solvent to prepare a spinning solution, prepare nanofiber / drawing filament composite yarns by electric-assisted core spinning technology, and add external stress to give the drawing filaments deformation; Step 2: placing the nanofiber / drawing filament composite yarn in the above-mentioned deformed state in a conductive nanoparticle / polymer dilute solution for immersion; Step 3: immersing the impregnated composite yarn in water to construct a nanoparticle / polymer conductive layer on the surface of the composite yarn through non-solvent induced phase separation; Step 4: Remove the applied tensile stress, heat-treat the composite yarn to remove the non-solvent water, and obtain the concave-convex nanofiber composite bamboo core-spun yarn sensor.

2. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: In the first step, the electrically assisted core spinning technology is used to prepare the nanofiber / filament composite yarn, wherein the electrically assisted core spinning technology is a conjugated electrospinning process and a core-spun yarn forming process, two syringes encapsulating the spinning solution are respectively connected to the high-voltage positive electrode / negative electrode, and the nanofibers are collected by pulling the filaments under strain, and the nanofibers are coated on the pulled filaments to obtain the nanofiber composite yarn.

3. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: In the first step of the electrically assisted core spinning technology, the traction filament is a polyurethane filament with a specification of 50 to 300 dtex; preferably, the strain added to the polyurethane filament has a strain rate of 50 to 200%, and the traction filament movement rate is 0.1 to 5 m / min.

4. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: In the spinning solution of the first step of the electric-assisted core spinning technology, the good solvent is selected from one or a combination of NN dimethylformamide, dimethyl sulfoxide, NN dimethylacetamide, and acetone, and the mass fraction of the polymer in the spinning solution is 3-30%.

5. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1 or 2, characterized in that: In the electric-assisted core spinning technology conjugate electrospinning process, the positive and negative high voltages are ±3 to ±30 kV, the spinning angles of the two syringes are 10 to 80 degrees, the injection speed is 0.5 to 5 mL / h, the receiving distance is 5 to 30 cm, the spinning environment temperature is 10 to 40°C, and the ambient humidity is 40% to 90% RH.

6. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: The polymer in the dilute polymer solution in the second impregnation process is selected from one or a combination of polyvinyl butyral, polyamide, and polyvinyl pyrrolidone; preferably, the solvent of the dilute polymer solution in the second impregnation process is selected from one or a combination of ethanol, nitrogen methyl pyrrolidone, and tert-butanol; preferably, the conductive nanoparticles in the second impregnation process are selected from one or a combination of silver nanoparticles, copper nanoparticles, and carbon black nanoparticles.

7. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: The mass fraction of polymer in the impregnation liquid prepared in the second impregnation process is 1-5%, and the mass fraction of conductive nanoparticles is 1-30%; preferably, the impregnation time of the second impregnation process is 10-60s.

8. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: In the third step of the impregnation process, water is selected as a non-solvent to induce polymer phase separation, and a stable nanoparticle / polymer conductive layer is constructed on the surface of the nanofiber composite yarn. The impregnation time is 10 to 60 seconds and the immersion temperature is 20 to 30°C.

9. The method for preparing a high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor according to claim 1, characterized in that: In the fourth step of the heat treatment process, the heat treatment temperature is 70-160° C. and the treatment time is 5-30 minutes.

10. A high-sensitivity nanofiber composite bamboo core-spun yarn strain sensor obtained by the preparation method according to any one of claims 1 to 9, characterized in that: The nanofiber composite bamboo core-spun yarn strain sensor has a radial core-shell structure and an axial concave-convex structure.

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