CN114136513A - High-sensitivity pressure-sensitive conductive nanofiber polymer film and sensor - Google Patents
High-sensitivity pressure-sensitive conductive nanofiber polymer film and sensor Download PDFInfo
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- CN114136513A CN114136513A CN202111430754.7A CN202111430754A CN114136513A CN 114136513 A CN114136513 A CN 114136513A CN 202111430754 A CN202111430754 A CN 202111430754A CN 114136513 A CN114136513 A CN 114136513A
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- polylactic acid
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- nanofiber
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- 239000002121 nanofiber Substances 0.000 title claims abstract description 80
- 229920006254 polymer film Polymers 0.000 title claims abstract description 19
- 229920000747 poly(lactic acid) Polymers 0.000 claims abstract description 107
- 239000002245 particle Substances 0.000 claims abstract description 105
- 239000004626 polylactic acid Substances 0.000 claims abstract description 105
- 239000012528 membrane Substances 0.000 claims abstract description 51
- 230000035945 sensitivity Effects 0.000 claims abstract description 8
- 238000009987 spinning Methods 0.000 claims description 66
- 239000000243 solution Substances 0.000 claims description 46
- 238000010041 electrostatic spinning Methods 0.000 claims description 28
- 150000001768 cations Chemical class 0.000 claims description 25
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 20
- 239000007864 aqueous solution Substances 0.000 claims description 19
- 238000001035 drying Methods 0.000 claims description 17
- 238000001914 filtration Methods 0.000 claims description 17
- 239000007788 liquid Substances 0.000 claims description 17
- PQXPAFTXDVNANI-UHFFFAOYSA-N 4-azidobenzoic acid Chemical compound OC(=O)C1=CC=C(N=[N+]=[N-])C=C1 PQXPAFTXDVNANI-UHFFFAOYSA-N 0.000 claims description 13
- OKKRPWIIYQTPQF-UHFFFAOYSA-N Trimethylolpropane trimethacrylate Chemical compound CC(=C)C(=O)OCC(CC)(COC(=O)C(C)=C)COC(=O)C(C)=C OKKRPWIIYQTPQF-UHFFFAOYSA-N 0.000 claims description 13
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 12
- 239000002041 carbon nanotube Substances 0.000 claims description 12
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 12
- 238000010438 heat treatment Methods 0.000 claims description 12
- 229920005597 polymer membrane Polymers 0.000 claims description 12
- 239000003504 photosensitizing agent Substances 0.000 claims description 11
- RHQDFWAXVIIEBN-UHFFFAOYSA-N Trifluoroethanol Chemical compound OCC(F)(F)F RHQDFWAXVIIEBN-UHFFFAOYSA-N 0.000 claims description 10
- 238000001179 sorption measurement Methods 0.000 claims description 9
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical compound [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 8
- 229910021389 graphene Inorganic materials 0.000 claims description 8
- 239000002042 Silver nanowire Substances 0.000 claims description 7
- 239000003365 glass fiber Substances 0.000 claims description 5
- 229910052709 silver Inorganic materials 0.000 claims description 5
- 239000004332 silver Substances 0.000 claims description 5
- 239000000203 mixture Substances 0.000 claims description 4
- 238000002360 preparation method Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 claims 7
- 239000000463 material Substances 0.000 abstract description 14
- 230000004044 response Effects 0.000 abstract description 3
- 230000008859 change Effects 0.000 description 12
- 230000000052 comparative effect Effects 0.000 description 12
- 239000010408 film Substances 0.000 description 12
- -1 4-methylthiophenyl Chemical group 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N acetone Substances CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 7
- 230000035699 permeability Effects 0.000 description 6
- 230000005489 elastic deformation Effects 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 4
- 239000011231 conductive filler Substances 0.000 description 3
- 238000004132 cross linking Methods 0.000 description 3
- 239000003431 cross linking reagent Substances 0.000 description 3
- 238000001523 electrospinning Methods 0.000 description 3
- 238000005187 foaming Methods 0.000 description 3
- 230000009477 glass transition Effects 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229920002472 Starch Polymers 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 230000007794 irritation Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 239000003361 porogen Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L1/00—Measuring force or stress, in general
- G01L1/20—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
- G01L1/22—Measuring force or stress, in general by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress using resistance strain gauges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/02—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in ohmic resistance, e.g. of potentiometers, electric circuits therefor, e.g. bridges, amplifiers or signal conditioning
- G01L9/06—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means by making use of variations in ohmic resistance, e.g. of potentiometers, electric circuits therefor, e.g. bridges, amplifiers or signal conditioning of piezo-resistive devices
Abstract
The invention relates to the field of sensor materials, and discloses a high-sensitivity pressure-sensitive conductive nanofiber polymer film and a sensor. The pressure-sensitive conductive nanofiber polymer film comprises 60-90 wt% of polylactic acid nanofiber film and 10-40 wt% of modified nano conductive particles; micropores are uniformly distributed in the polylactic acid nanofiber membrane, and the modified nano conductive particles are contained in the micropores. The pressure-sensitive conductive nanofiber polymer film has excellent piezoelectric sensitivity in response, has good biological mildness and ideal elasticity and strength by taking reinforced polylactic acid as a base film, and is particularly suitable to be used as an element material of various sensors of wearable electronic equipment.
Description
Technical Field
The invention relates to the field of sensor materials, in particular to a high-sensitivity pressure-sensitive conductive nanofiber polymer film and a sensor.
Background
The pressure-sensitive conductive rubber is a sensitive material with resistance strain effect, and is also called pressure-sensitive conductive rubber and piezoelectric rubber. Is formed by adding conductive filler into insulating high molecular material. When external force does not act, the distance between the conductive fillers is long, and the resistance value of the pressure-sensitive conductive rubber is high; after being pressed, the distance between the conductive fillers is reduced to form a conductive network, so that the resistance value is obviously reduced, and the conductive property is displayed. That is, the conductivity of the material can change with the change of external force, and the resistance value of the material has a certain functional relationship with the external force. By utilizing the characteristic, the pressure-sensitive conductive rubber can be used for manufacturing a series of components, such as pressure sensors, touch sensors, contacts, touch switch elements and the like.
With the development of technology, various wearable electronic devices have been developed in recent years, and some of these wearable electronic devices need to be provided with a pressure sensor or the like to be attached to the skin surface during use for detecting various human body motion signals, for example, the change of limb motion is converted into the change of pressure on the pressure sensor, and further into the change of resistance.
Unlike other application scenarios, the wearable electronic device requires the pressure sensor to meet the following requirements: (1) the material in contact with the skin has biological mildness and air permeability; (2) the sensitivity is high, and sometimes, a small pressure change needs to be converted into a corresponding signal; (3) has suitable elasticity and strength. The traditional pressure-sensitive conductive rubber does not have biological mildness and air permeability after being attached to the skin surface, and because the hardness of common rubber is higher, weak pressure is difficult to be sensitively converted into signals; therefore, the conventional pressure-sensitive conductive rubber is not suitable as a material of a sensor such as a pressure sensor of a wearable electronic device.
Disclosure of Invention
In order to solve the technical problems, the invention provides a pressure-sensitive conductive nanofiber polymer film with high sensitivity and a sensor. The pressure-sensitive conductive nanofiber polymer film has excellent piezoelectric sensitivity in response, has good biological mildness, air permeability and ideal elasticity and strength by taking reinforced polylactic acid as a base film, and is particularly suitable to be used as an element material of various sensors of wearable electronic equipment.
The specific technical scheme of the invention is as follows:
a high-sensitivity pressure-sensitive conductive nanofiber polymer film comprises 60-90 wt% of a polylactic acid nanofiber film and 10-40 wt% of modified nano conductive particles; micropores are uniformly distributed in the polylactic acid nanofiber membrane, and the modified nano conductive particles are contained in the micropores.
On the one hand, unlike the conventional pressure-sensitive conductive rubber, the present invention uses polylactic acid as a base material instead of rubber, and the polylactic acid can be made of natural raw materials such as starch, thus having good biodegradability, biocompatibility and air permeability, and causing no irritation to the skin and no discomfort even if it is in contact with the skin surface for a long time. Further, polylactic acid has good processability, can be processed into a nanofiber film by electrospinning, and is suitable as a component of a flexible sensor, a piezoresistive sensor, a pressure sensor, or the like.
On the other hand, unlike the conventional pressure-sensitive conductive rubber in which conductive particles are simply physically dispersed in rubber, the conductive particles of the present invention are dispersed in a matrix material in the form of being contained in micropores, that is, there are minute gaps between the conductive particles and the matrix material. This brings about an advantage of effectively improving the piezoelectric sensitivity of the polylactic acid polymer film. The reason is that polylactic acid has a weak elastic deformation compared to rubber, and if conductive particles are directly and uniformly dispersed in polylactic acid, since polylactic acid cannot rapidly respond to an elastic deformation to an external pressure like rubber, it is not possible to sensitively convert an external pressure change signal into a resistance change signal. If the conductive particles are filled in the micropores, the gaps between the conductive particles and the base material provide deformation spaces for the film when the film is pressed, so that the film can quickly make elastic deformation response even if the film is subjected to a small pressure change signal. And more importantly, when the film is pressed, the conductive particles in the micropores can be rearranged according to the pressing condition, so that a more ideal three-dimensional conductive network is constructed. For example, conductive particles (carbon nanotubes, silver nanowires, etc.) in a tubular or short fiber shape are forced to align in a direction perpendicular to the deformation.
Preferably, the thickness of the polylactic acid-based film is 100-2000 microns. The particle size of the nano conductive particles is less than 100 nanometers.
A preparation method of a pressure-sensitive conductive nanofiber polymer film comprises the following steps:
(1) preparing modified nano conductive particles: uniformly dispersing the nano conductive particles into 0.5-2 wt% of hexadecyl trimethyl ammonium bromide aqueous solution according to the solid-to-liquid ratio of 5-15g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 10-20mg/mL p-azidobenzoic acid aqueous solution according to the solid-to-liquid ratio of 5-15g/100mL, enriching the p-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain the modified nano conductive particles.
In the step (1), the invention firstly carries out cation modification on the nano conductive particles to ensure that the surfaces of the nano conductive particles are positively charged and then the nano conductive particles are immersed in the aqueous solution of the p-azidobenzoic acid, and the p-azidobenzoic acid can be quickly enriched on the surfaces of the nano conductive particles under the electrostatic action because the p-azidobenzoic acid is negatively charged. The p-azidobenzoic acid is a foaming pore-foaming agent excited by ultraviolet light, and can be foamed and pore-formed in the subsequent operation.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 5-10 wt%; uniformly dispersing the modified nano conductive particles, trimethylolpropane trimethacrylate and photosensitizer in the polylactic acid solution under the condition of keeping out of the sun to obtain spinning solution; and (3) preparing the polylactic acid nanofiber membrane by electrostatic spinning of the spinning solution under the condition of keeping out of the sun.
In the step (2), the polylactic acid has excellent processability, and can be processed into a nanofiber membrane having good air permeability by electrospinning. It should be noted that the particle size of the nano conductive particles needs to be controlled within a reasonable size, otherwise the needles are easily blocked, and electrostatic spinning cannot be performed. In addition, because the strength of the pure polylactic acid is generally lower than that of other high polymer materials, the photosensitive cross-linking agent trimethylolpropane trimethacrylate is purposefully added into the spinning solution, and a certain cross-linking structure can be formed under the subsequent ultraviolet irradiation, so that the strength of the polylactic acid is improved.
(3) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 70-90 ℃, and placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment to obtain the pressure-sensitive conductive nanofiber polymer membrane.
In the step (3), ultraviolet irradiation is carried out on the polylactic acid nanofiber membrane, on one hand, the polyazidobenzoic acid can be excited to generate gas, and thus micropores are formed around the nano conductive particles; on the other hand, the photo-crosslinking reaction can be initiated, and the strength performance of the membrane material is improved. It should be noted that the polylactic acid nanofiber membrane needs to be subjected to heat treatment before ultraviolet irradiation, and the heat treatment temperature is at least properly higher than the polylactic acid glass transition temperature (the racemic polylactic acid glass transition temperature is about 55 ℃), at this time, the polylactic acid molecular chain has certain mobility, and the thin film is in a semi-softened state, which is beneficial to forming micropores. However, the heat treatment temperature should not be too high, otherwise the microstructure of the nanofiber membrane is excessively changed to affect the performance.
Preferably, in the step (1), the conductive particles are one or more of carbon nanotubes, graphene, silver nanowires and silver-coated glass fibers.
Further preferably, the conductive particles are a composition of graphene and at least one of carbon nanotubes, silver nanowires, and silver-coated glass fibers.
The long strip-shaped structures of the carbon nano tube, the silver nano wire and the silver-coated glass fiber are compounded with the lamellar structures of the graphene and the like, so that the three-dimensional conductive network structure is more favorably constructed.
Preferably, in step (1), the electrostatic adsorption time is 1-2 h.
Preferably, in the step (2), the concentration of the trimethylolpropane trimethacrylate in the spinning solution is 0.1 to 0.5 wt%, and the concentration of the photosensitizer in the spinning solution is 0.1 to 0.5 wt%.
Preferably, in the step (2), the electrospinning conditions are: the spinning speed is 0.2-0.4 mm/s, the needle is 24-26G, the spinning distance is 10-15 cm, the spinning voltage is 10-15 kv, the spinning temperature is 30-40 ℃, and the humidity is 40-60%.
Preferably, in the step (3), the irradiation time is 100-.
Compared with the prior art, the invention has the following technical effects:
(1) the polylactic acid is used as a base material instead of rubber, has good biocompatibility and air permeability, and does not irritate the skin and feel uncomfortable even if the polylactic acid is contacted with the surface of the skin for a long time.
(2) The conductive particles of the present invention are dispersed in the matrix material in the form of being contained in micropores, that is, a minute gap is formed between the conductive particles and the matrix material, and thus the piezoelectric sensitivity of the polylactic acid polymer film can be effectively improved.
(3) The invention skillfully carries out cationic modification on the nano conductive particles to ensure that the surfaces of the nano conductive particles are positively charged and then are soaked in the aqueous solution of the p-azidobenzoic acid, and the p-azidobenzoic acid can be quickly enriched on the surfaces of the nano conductive particles under the electrostatic action, so that the nano conductive particles are filled in micropores after foaming and pore forming.
(4) According to the invention, the photosensitive cross-linking agent trimethylolpropane trimethacrylate is added into the spinning solution, so that a certain cross-linking structure can be formed under the subsequent ultraviolet irradiation, and the intensity of polylactic acid is improved.
(5) The pressure-sensitive conductive nanofiber polymer film of the present invention can be used for preparing elements of flexible sensors, piezoresistive sensors, pressure sensors, and the like.
Detailed Description
The present invention will be further described with reference to the following examples.
Example 1
(1) Preparing modified nano conductive particles: uniformly dispersing nano conductive particles (a mixture of a carbon nano tube and graphene in a ratio of 1: 1) with the particle size range of 50-100 nanometers in a hexadecyl trimethyl ammonium bromide aqueous solution with the weight percentage of 1.5 according to the solid-to-liquid ratio of 10g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 15mg/mL aqueous solution of the para-azidobenzoic acid according to the solid-to-liquid ratio of 10g/100mL, standing for 1.5h, enriching the para-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain the modified nano conductive particles.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 8 wt%; uniformly dispersing modified nano conductive particles with a mass ratio of 30:70 to polylactic acid, 0.3 wt% of trimethylolpropane trimethacrylate and 0.3 wt% of photosensitizer 2-methyl-1- (4-methylthiophenyl) -2-morpholine-1-acetone into the polylactic acid solution under a dark condition to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.3mm/s, the needle is 25G, the spinning distance is 12cm, the spinning voltage is 12.5kv, the spinning temperature is 35 ℃, and the humidity is 50%; and preparing the polylactic acid nanofiber membrane with the thickness of about 1000 microns after electrostatic spinning.
(3) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 80 ℃, placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment for 150 seconds, forming micropores in the membrane and simultaneously realizing a cross-linked structure, and finally obtaining the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 1000 microns.
Example 2
(1) Preparing modified nano conductive particles: uniformly dispersing nano conductive particles (carbon nano tubes) with the particle size range of 50-100 nanometers into 1.5 wt% of hexadecyl trimethyl ammonium bromide aqueous solution according to the solid-to-liquid ratio of 10g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 15mg/mL aqueous solution of the para-azidobenzoic acid according to the solid-to-liquid ratio of 10g/100mL, standing for 1.5h, enriching the para-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain the modified nano conductive particles.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 8 wt%; uniformly dispersing modified nano conductive particles with a mass ratio of 30:70 to polylactic acid, 0.3 wt% of trimethylolpropane trimethacrylate and 0.3 wt% of photosensitizer 2-methyl-1- (4-methylthiophenyl) -2-morpholine-1-acetone into the polylactic acid solution under a dark condition to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.3mm/s, the needle is 25G, the spinning distance is 12cm, the spinning voltage is 12.5kv, the spinning temperature is 35 ℃, and the humidity is 50%; and preparing the polylactic acid nanofiber membrane with the thickness of about 1000 microns after electrostatic spinning.
(3) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 80 ℃, placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment for 150 seconds, forming micropores in the membrane and simultaneously realizing a cross-linked structure, and finally obtaining the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 1000 microns.
Example 3
(1) Preparing modified nano conductive particles: uniformly dispersing nano conductive particles (graphene) with the particle size range of 50-100 nanometers in 1.5 wt% of hexadecyl trimethyl ammonium bromide aqueous solution according to the solid-to-liquid ratio of 10g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 15mg/mL aqueous solution of the para-azidobenzoic acid according to the solid-to-liquid ratio of 10g/100mL, standing for 1.5h, enriching the para-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain the modified nano conductive particles.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 8 wt%; uniformly dispersing modified nano conductive particles with a mass ratio of 30:70 to polylactic acid, 0.3 wt% of trimethylolpropane trimethacrylate and 0.3 wt% of photosensitizer 2-methyl-1- (4-methylthiophenyl) -2-morpholine-1-acetone into the polylactic acid solution under a dark condition to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.3mm/s, the needle is 25G, the spinning distance is 12cm, the spinning voltage is 12.5kv, the spinning temperature is 35 ℃, and the humidity is 50%; and preparing the polylactic acid nanofiber membrane with the thickness of about 1000 microns after electrostatic spinning.
(3) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 80 ℃, placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment for 150 seconds, forming micropores in the membrane and simultaneously realizing a cross-linked structure, and finally obtaining the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 1000 microns.
Example 4
(1) Preparing modified nano conductive particles: uniformly dispersing nano conductive particles (a mixture of silver nanowires and graphene in a ratio of 1: 1) with the particle size range of 50-100 nanometers in a hexadecyl trimethyl ammonium bromide aqueous solution with the weight percent of 2 according to a solid-to-liquid ratio of 15g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 20mg/mL p-azidobenzoic acid aqueous solution according to the solid-to-liquid ratio of 15g/100mL, standing for 2h, enriching the p-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain the modified nano conductive particles.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 10 wt%; uniformly dispersing modified nano conductive particles with a mass ratio of 20:80 to polylactic acid, 0.5 wt% of trimethylolpropane trimethacrylate and 0.5 wt% of photosensitizer 2-methyl-1- (4-methylthiophenyl) -2-morpholine-1-acetone into the polylactic acid solution under a dark condition to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.4mm/s, the needle is 26G, the spinning distance is 15cm, the spinning voltage is 15kv, the spinning temperature is 40 ℃, and the humidity is 60%; and after electrostatic spinning, preparing the polylactic acid nanofiber membrane with the thickness of about 500 microns.
(3) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 85 ℃, placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment for 200 seconds, forming micropores in the membrane and simultaneously realizing a cross-linked structure, and finally obtaining the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 500 micrometers.
Comparative example 1
(1) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 8 wt%; uniformly dispersing nano conductive particles (with the particle size range of 50-100 carbon nano tubes) with the mass ratio of 30:70 to polylactic acid, 0.3 wt% of trimethylolpropane trimethacrylate and 0.3 wt% of photosensitizer 2-methyl-1- (4-methylthiophenyl) -2-morpholine-1-acetone in the polylactic acid solution under the condition of keeping out of the sun to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.3mm/s, the needle is 25G, the spinning distance is 12cm, the spinning voltage is 12.5kv, the spinning temperature is 35 ℃, and the humidity is 50%; and preparing the polylactic acid nanofiber membrane with the thickness of about 1000 microns after electrostatic spinning.
(2) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 80 ℃, placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment for 150 seconds, and finally obtaining the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 1000 microns.
Comparative example 2
(1) Preparing modified nano conductive particles: uniformly dispersing nano conductive particles (carbon nano tubes) with the particle size range of 50-100 nanometers into 15mg/mL aqueous solution of p-azidobenzoic acid according to the solid-to-liquid ratio of 10g/100mL, standing for 1.5h, filtering, and drying to obtain the modified nano conductive particles.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 8 wt%; uniformly dispersing modified nano conductive particles with a mass ratio of 30:70 to polylactic acid, 0.3 wt% of trimethylolpropane trimethacrylate and 0.3 wt% of photosensitizer 2-methyl-1- (4-methylthiophenyl) -2-morpholine-1-acetone into the polylactic acid solution under a dark condition to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.3mm/s, the needle is 25G, the spinning distance is 12cm, the spinning voltage is 12.5kv, the spinning temperature is 35 ℃, and the humidity is 50%; and preparing the polylactic acid nanofiber membrane with the thickness of about 1000 microns after electrostatic spinning.
(2) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 80 ℃, placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment for 150 seconds, and finally obtaining the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 1000 microns.
Comparative example 3
(1) Preparing modified nano conductive particles: uniformly dispersing nano conductive particles (carbon nano tubes) with the particle size range of 50-100 nanometers into 1.5 wt% of hexadecyl trimethyl ammonium bromide aqueous solution according to the solid-to-liquid ratio of 10g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 15mg/mL aqueous solution of the para-azidobenzoic acid according to the solid-to-liquid ratio of 10g/100mL, standing for 1.5h, enriching the para-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain the modified nano conductive particles.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 8 wt%; uniformly dispersing modified nano conductive particles with a mass ratio of 30:70 to polylactic acid, 0.3 wt% of trimethylolpropane trimethacrylate and 0.3 wt% of photosensitizer 2-methyl-1- (4-methylthiophenyl) -2-morpholine-1-acetone into the polylactic acid solution under a dark condition to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.3mm/s, the needle is 25G, the spinning distance is 12cm, the spinning voltage is 12.5kv, the spinning temperature is 35 ℃, and the humidity is 50%; and preparing the polylactic acid nanofiber membrane with the thickness of about 1000 microns after electrostatic spinning.
(3) Ultraviolet light irradiation treatment: and placing the polylactic acid nanofiber membrane in an ultraviolet environment at room temperature for irradiation treatment for 150 seconds to finally obtain the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 1000 microns.
Comparative example 4
(1) Preparing modified nano conductive particles: uniformly dispersing nano conductive particles (carbon nano tubes) with the particle size range of 50-100 nanometers into 1.5 wt% of hexadecyl trimethyl ammonium bromide aqueous solution according to the solid-to-liquid ratio of 10g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 15mg/mL aqueous solution of the para-azidobenzoic acid according to the solid-to-liquid ratio of 10g/100mL, standing for 1.5h, enriching the para-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain the modified nano conductive particles.
(2) Preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 8 wt%; uniformly dispersing modified nano conductive particles with the mass ratio of 30:70 to polylactic acid in the polylactic acid solution in a dark condition to obtain spinning solution; and (2) carrying out electrostatic spinning on the spinning solution under the condition of keeping out of the sun, wherein the electrostatic spinning condition is as follows: the spinning speed is 0.3mm/s, the needle is 25G, the spinning distance is 12cm, the spinning voltage is 12.5kv, the spinning temperature is 35 ℃, and the humidity is 50%; and preparing the polylactic acid nanofiber membrane with the thickness of about 1000 microns after electrostatic spinning.
(3) Ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 80 ℃, placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment for 150 seconds, and finally obtaining the pressure-sensitive conductive nanofiber polymer membrane with the thickness of about 1000 microns.
Firstly, testing mechanical properties
The pressure-sensitive conductive nanofiber polymer films obtained in examples 1 to 2 and comparative examples 1 to 4 were subjected to mechanical property tests, and the results are shown in the following table:
as can be seen from the above data, the pressure-sensitive conductive nanofiber polymer films obtained in examples 1-2 and comparative examples 1-3 are excellent in tensile strength. In contrast, comparative example 4 has a lower tensile strength because no photosensitive crosslinking agent is introduced and no crosslinked structure is further formed. In contrast, in the elastic modulus of comparative example 1, since no micropores were introduced, the elastic modulus was high, i.e., the elastic deformation property was poor.
Second, piezoelectric property test
The pressure-sensitive conductive nanofiber polymer films obtained in examples 1-2 and comparative examples 1-4 were subjected to a piezoelectricity test, the test method was to cut the pressure-sensitive conductive nanofiber polymer film into a specification with a diameter of 20mm and a thickness of 1mm, copper sheets were respectively adhered to the upper and lower surfaces of the film with conductive adhesive, the two copper sheets were connected to a resistance test meter through a wire, the pressure-sensitive conductive nanofiber polymer film was placed flat on a platform of a press, the pressure was applied by a press head of the press, the pressure was gradually increased, and the resistance during recording was recorded, the specific data are shown in the following table:
as can be seen from the above data, examples 1-2 exhibited excellent piezoelectric sensitivity at different pressures, whereas comparative example 1 exhibited poor elastic deformation due to no introduction of micropores, and thus the resistance did not change significantly when the pressure reached 1000. Comparative example 2, which is not cation-modified, results in failure to effectively enrich the foaming porogen, resulting in less generation of micropores or failure to accommodate a large amount of conductive particles within the micropores, and the resistance change after 1500 f is insignificant. Comparative example 3 is a case where the ultraviolet irradiation was performed at room temperature, and the glass transition temperature of polylactic acid was not reached, resulting in a small amount of micropores, and the resistance change was not significant after 1500 c.
Claims (10)
1. A pressure sensitive conductive nanofiber polymer membrane of high sensitivity, characterized in that: comprises 60-90 wt% of polylactic acid nano fiber film and 10-40 wt% of modified nano conductive particles; micropores are uniformly distributed in the polylactic acid nanofiber membrane, and the modified nano conductive particles are contained in the micropores.
2. The pressure sensitive conductive nanofiber polymer film of claim 1, wherein: the thickness of the polylactic acid-based film is 100-2000 microns.
3. The pressure sensitive conductive nanofiber polymer film of claim 1, wherein: the particle size of the nano conductive particles is less than 100 nanometers.
4. A method for preparing a pressure sensitive conductive nanofiber polymer film as claimed in any one of claims 1 to 3, characterized in that the method comprises:
(1) preparing modified nano conductive particles: uniformly dispersing the nano conductive particles into 0.5-2 wt% of hexadecyl trimethyl ammonium bromide aqueous solution according to the solid-to-liquid ratio of 5-15g/100mL, filtering and drying to obtain cation modified nano conductive particles; uniformly dispersing the cation modified nano conductive particles into 10-20mg/mL p-azidobenzoic acid aqueous solution according to the solid-to-liquid ratio of 5-15g/100mL, enriching the p-azidobenzoic acid on the surfaces of the cation modified nano conductive particles through electrostatic adsorption, filtering and drying to obtain modified nano conductive particles;
(2) preparing a polylactic acid nanofiber membrane: dissolving racemic polylactic acid in trifluoroethanol to obtain a polylactic acid solution with the concentration of 5-10 wt%; uniformly dispersing the modified nano conductive particles, trimethylolpropane trimethacrylate and photosensitizer in the polylactic acid solution under the condition of keeping out of the sun to obtain spinning solution; preparing the polylactic acid nanofiber membrane by electrostatic spinning of the spinning solution under a light-proof condition;
(3) ultraviolet light irradiation treatment: heating the polylactic acid nanofiber membrane to 70-90 ℃, and placing the polylactic acid nanofiber membrane in an ultraviolet environment for irradiation treatment to obtain the pressure-sensitive conductive nanofiber polymer membrane.
5. The method of claim 4, wherein: in the step (1), the conductive particles are one or more of carbon nanotubes, graphene, silver nanowires and silver-coated glass fibers.
6. The method of claim 5, wherein: the conductive particles are a composition of graphene and at least one of carbon nanotubes, silver nanowires and silver-coated glass fibers.
7. The method of claim 4, wherein: in the step (2), the concentration of the trimethylolpropane trimethacrylate in the spinning solution is 0.1-0.5 wt%, and the concentration of the photosensitizer in the spinning solution is 0.1-0.5 wt%.
8. The method of claim 4, wherein: in the step (2), the electrostatic spinning conditions are as follows: the spinning speed is 0.2-0.4 mm/s, the needle is 24-26G, the spinning distance is 10-15 cm, the spinning voltage is 10-15 kv, the spinning temperature is 30-40 ℃, and the humidity is 40-60%.
9. The method of claim 4, wherein: in the step (3), the irradiation time is 100-200 seconds.
10. Use of a pressure sensitive conductive nanofibrous polymer membrane according to one of claims 1 to 3 for the preparation of flexible sensors, piezoresistive sensors, pressure sensors.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105970486A (en) * | 2016-06-26 | 2016-09-28 | 郭舒洋 | Preparation method of anti-static polyvinylidene fluoride/polylactic acid composite porous fiber membrane |
| WO2017109671A1 (en) * | 2015-12-22 | 2017-06-29 | Consiglio Nazionale Delle Ricerche | A functionalization process of a porous material, porous material thus obtained and uses thereof |
| CN108189525A (en) * | 2017-12-12 | 2018-06-22 | 昆明理工大学 | A kind of method for improving laminated film adhesive property |
| US20180238750A1 (en) * | 2017-02-23 | 2018-08-23 | Winbond Electronics Corp. | Pressure sensor and manufacturing method thereof |
| CN108955964A (en) * | 2018-04-10 | 2018-12-07 | 浙江欧仁新材料有限公司 | Flexible pressure-sensitive sensor |
| CN109520645A (en) * | 2018-11-22 | 2019-03-26 | 南方科技大学 | A kind of integral type capacitance type sensor and its preparation method and application |
| CN110987248A (en) * | 2019-11-28 | 2020-04-10 | 同济大学 | Flexible touch sensor and preparation method thereof |
| WO2020191947A1 (en) * | 2019-03-25 | 2020-10-01 | Southern University Of Science And Technology. | Sensor dielectric layer and preparation method and use thereof |
| CN111879230A (en) * | 2020-06-18 | 2020-11-03 | 山东师范大学 | Method for preparing polylactic acid flexible strain sensor of silver nanowires and application thereof |
| CN111875839A (en) * | 2020-07-31 | 2020-11-03 | 山东大学 | Carbon nanotube-polypyrrole conductive pressure-sensitive composite material and preparation method and application thereof |
| CN113279139A (en) * | 2021-04-26 | 2021-08-20 | 杭州诗蓝过滤科技有限公司 | Preparation method of high-strength fluffy melt-blown fabric |
-
2021
- 2021-11-29 CN CN202111430754.7A patent/CN114136513A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017109671A1 (en) * | 2015-12-22 | 2017-06-29 | Consiglio Nazionale Delle Ricerche | A functionalization process of a porous material, porous material thus obtained and uses thereof |
| CN105970486A (en) * | 2016-06-26 | 2016-09-28 | 郭舒洋 | Preparation method of anti-static polyvinylidene fluoride/polylactic acid composite porous fiber membrane |
| US20180238750A1 (en) * | 2017-02-23 | 2018-08-23 | Winbond Electronics Corp. | Pressure sensor and manufacturing method thereof |
| CN108189525A (en) * | 2017-12-12 | 2018-06-22 | 昆明理工大学 | A kind of method for improving laminated film adhesive property |
| CN108955964A (en) * | 2018-04-10 | 2018-12-07 | 浙江欧仁新材料有限公司 | Flexible pressure-sensitive sensor |
| CN109520645A (en) * | 2018-11-22 | 2019-03-26 | 南方科技大学 | A kind of integral type capacitance type sensor and its preparation method and application |
| WO2020191947A1 (en) * | 2019-03-25 | 2020-10-01 | Southern University Of Science And Technology. | Sensor dielectric layer and preparation method and use thereof |
| CN110987248A (en) * | 2019-11-28 | 2020-04-10 | 同济大学 | Flexible touch sensor and preparation method thereof |
| CN111879230A (en) * | 2020-06-18 | 2020-11-03 | 山东师范大学 | Method for preparing polylactic acid flexible strain sensor of silver nanowires and application thereof |
| CN111875839A (en) * | 2020-07-31 | 2020-11-03 | 山东大学 | Carbon nanotube-polypyrrole conductive pressure-sensitive composite material and preparation method and application thereof |
| CN113279139A (en) * | 2021-04-26 | 2021-08-20 | 杭州诗蓝过滤科技有限公司 | Preparation method of high-strength fluffy melt-blown fabric |
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