KR20150094491A - Conductive stretchable fiber, fabric including the same and preparing methods thereof - Google Patents

Abstract

The present invention relates to a conductive stretchable fiber, fabric including the same and preparing methods thereof. The conductive stretchable fiber of the present invention is prepared by using a composite comprising first metal nanoparticles, a metal-carbon nanotube or a metal nanowire coated with second metal nanoparticles, and a polymer matrix.

Description

TECHNICAL FIELD [0001] The present invention relates to a conductive stretchable fiber, a fabric comprising the fiber, and a method of manufacturing the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a fiber formed using a composite comprising a first metal nanoparticle, a carbon nanotube or metal-nanowire coated with a second metal nanoparticle, and a polymer matrix, a conductive stretch fabric woven with the fiber, Fibers and fabrics.

In order to realize a flexible electronic device, not only semiconductors but also stretchable metals need to be developed. [0003] The wavy structure arrangement in which thin metals or semiconductors are applied on a pre-stretched polymer substrate has been intensively studied. On the other hand, bulk composites with elasticity and conductivity have been developed by inserting functional nanoparticles into elastic polymers to include metal parts. However, the composite exhibited inevitable conductivity reduction in the high strain region due to the volumetric expansion of the polymer matrix or disconnection of the conductive filler.

Multifunctional fibers made of carbon nanotubes have been studied for potential applications in intelligent garments, structural fabrics, woven electrodes, and artificial muscles. The multifunctional fibers include fibers produced by wet spinning from yarns drawn from a multi-walled carbon nanotube forest that provide light weight, high specific strength, high electrical and thermal conductivity, and strain / tensile drive . Wet spinning is a technology that can be mass-produced and can be widely employed in industries manufacturing ballistic fibers such as Kevlar.

On the other hand, Korean Patent Registration No. 10-1313149 discloses a method for producing a carbon nanotube-metal composite by reducing a mixed solution containing a carbon nanotube, a metal precursor and a reducing solvent in the presence of a cation-conducting polymer .

Accordingly, the present application is directed to fibers formed using a composite comprising a first metal nanoparticle, a carbon nanotube or metal-nanowire coated with a second metal nanoparticle, and a polymer matrix, a conductive stretch fabric woven with the fiber, To provide methods of making the fibers and fabrics.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

A first aspect of the present invention provides a fiber comprising a composite comprising a first metal nanoparticle, a metal-carbon nanotube or metal-nanowire coated with a second metal nanoparticle, and a polymer matrix.

A second aspect of the present invention is directed to a method of fabricating a metal nanotube comprising fabricating a fiber comprising a composite comprising a first metal nanoparticle, a second metal nanoparticle coated metal-carbon nanotube or metal-nanowire, and a polymer matrix, Provide fabric.

According to a third aspect of the present invention, there is provided a method for producing a metal nanowire comprising: obtaining a dispersion solution in which metal-carbon nanotubes or metal-nanowires coated with first metal nanoparticles and second metal nanoparticles are dispersed; Adding an ionic liquid to the dispersion solution to obtain a gel mixture; Adding a polymer matrix-containing solution to the gel mixture to form a complex solution; And spinning the composite solution to form the fibers.

A fourth aspect of the invention provides a method of making a fabric, comprising weaving the fibers according to the first aspect.

According to the present invention, by fabricating a fiber comprising a composite comprising a first metal nanoparticle, a second metal nanoparticle coated metal-carbon nanotube or metal-nanowire, and a polymer matrix, the electrical properties The present invention can be applied to the production of future flexible electronic products or flexible electrical leads, intelligent garments, structural fabrics, woven fabrics, and the like. Electrodes, artificial muscles, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a schematic diagram of a wet spinning apparatus according to one embodiment of the present disclosure. FIG.
FIG. 1B is a SEM image of 100 nm to 150 nm silver particles and HRTEM images of nAg-MWNTs according to one embodiment of the invention.
1C is a photograph of fibers synthesized by wet spinning using different coagulant solvents according to one embodiment of the present application.
1D is a photograph of fibers collected and synthesized on a winding drum according to one embodiment of the present application.
FIG. 1e is an SEM photograph of a fiber spun at a diameter of about 100 μm according to one embodiment of the present application. FIG.
FIG. 1F is a SEM photograph of hot rolled fibers according to one embodiment of the invention. FIG.
Figure 2a is a graph showing the effect of silver (Ag) grain concentration from 100 nm to 150 nm in conductivity and stretch according to one embodiment of the invention.
Figure 2B is a graph showing the conductivity and tensile strain of the fibers as a function of the fiber according to one embodiment of the invention.
Figure 2c is an optical photograph of the fiber before and after stretching (stretching) according to one embodiment of the invention.
FIG. 2D is a photograph before and after stretching according to the presence or absence of the hot rolling process according to one embodiment of the present application. FIG.
FIG. 2E is a graph showing the initial conductivity at break and the maximum tensile strain (elongation) in comparison with the control material according to one embodiment of the present invention. FIG.
Figure 3a is a cross-sectional view of a two-ply-rope, 4-ply-rope, and weft-woven fabric made from conductive stretchable fibers according to one embodiment of the present invention. It is an optical photograph.
3B is a photograph of a plain textured fabric made from a conductive stretchable fiber according to one embodiment of the present invention.
3C is a photograph showing fibers woven into a weft yarn before and after stretching (stretching) according to one embodiment of the present invention.
Figure 3d is a schematic view of a weaved weave fabric before and after stretching according to one embodiment of the present disclosure.
3E is a graph illustrating the normalized resistance and tensile strain (elongation) as a function of the embodiment of the present invention.
Figure 3f is a graph showing the cyclability of the woven fibers in a weft yarn according to one embodiment of the invention.
4A is an image of fibers fabricated on the basis of a polyurethane polymer matrix according to one embodiment of the invention.
FIG. 4B is a graph showing a change in resistance according to a strain of a fiber fabricated on the basis of a polyurethane polymer matrix according to an embodiment of the present invention. FIG.
5A is a schematic diagram of an assembled robot finger in accordance with one embodiment of the present application.
5B is a photograph showing the transmitted force (F, mN) and moment (M, mM · m) information when the robot finger according to one embodiment of the present invention is contacted with the piano key; 5C and 5D are enlarged photographs of the fabric before and after stretching.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, the term "combination (s) thereof " included in the expression of the machine form means a mixture or combination of one or more elements selected from the group consisting of the constituents described in the expression of the form of a marker, Quot; means at least one selected from the group consisting of the above-mentioned elements.

Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

Hereinafter, embodiments of the present invention are described in detail, but the present invention is not limited thereto.

A first aspect of the present invention provides a fiber comprising a composite comprising a first metal nanoparticle, a metal-carbon nanotube or metal-nanowire coated with a second metal nanoparticle, and a polymer matrix.

In one embodiment of the invention, the fibers may be, but are not limited to, having elasticity and conductivity.

In one embodiment of the invention, each of the first and second metal nanoparticles is independently selected from the group consisting of silver (Ag), gold (Au), copper (Cu), nickel (Ni), platinum But may be, but not limited to, aluminum (Al).

In one embodiment of the present invention, the carbon nanotubes may include single wall carbon nanotubes or multi wall carbon nanotubes, but the present invention is not limited thereto.

In one embodiment herein, the polymer matrix is selected from the group consisting of nitrile butadiene rubber, polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) matrix, poly (styrene-butadiene- styrene) (Styrene-isoprene-styrene) (SIS), polyurethane, polyaniline, polyacrylonitrile, polypyrrole, polyvinyl alcohol, alginate, , Nylon, or chitosan, but the present invention is not limited thereto.

In one embodiment of the present invention, the content of the first metal nanoparticles in the complex may be about 10% by weight to about 70% by weight, but the present invention is not limited thereto. For example, the content of the first metal nanoparticles in the complex may range from about 10 wt% to about 70 wt%, from about 20 wt% to about 70 wt%, from about 30 wt% to about 70 wt%, to about 40 wt% To about 70 wt%, from about 50 wt% to about 70 wt%, or from about 60 wt% to about 70 wt%.

In one embodiment of the present invention, the size of the first metal nanoparticles is larger than that of the second metal nanoparticles, the size of the first metal nanoparticles is about 50 nm to about 1 μm, The size of the 2-metal nanoparticles may be about 20 nm or less, but may not be limited thereto. For example, the size of the first metal nanoparticles may be about 50 nm to about 1 μm, about 60 nm to about 1 μm, about 70 nm to about 1 μm, about 80 nm to about 1 μm, about 90 nm to about About 100 nm to about 1 μm, about 150 nm to about 1 μm, about 200 nm to about 1 μm, about 300 nm to about 1 μm, about 400 nm to about 1 μm, about 500 nm to about 1 μm About 800 nm to about 1 μm, about 900 nm to about 1 μm, about 50 nm to about 0.9 μm, about 50 nm to about 0.8 μm, about 600 nm to about 1 μm, about 700 nm to about 1 μm, about 800 nm to about 1 μm, From about 50 nm to about 0.2 [mu] m, from about 50 nm to about 0.2 [mu] m, or from about 50 nm to about 0.5 [ lt; RTI ID = 0.0 > nm, < / RTI > For example, the size of the second metal nanoparticles may be greater than about 0 nm to about 20 nm, greater than about 0 nm to about 15 nm, greater than about 0 nm to about 10 nm, greater than about 0 nm to about 5 nm, From about 2 nm to about 20 nm, from about 4 nm to about 20 nm, from about 6 nm to about 20 nm, from about 8 nm to about 20 nm, or from about 10 nm to about 20 nm.

In one embodiment of the invention, the fibers may be of a diameter of about 100 microns or less and a length of about 10 m or more, but the present invention is not limited thereto. For example, the fibers may have a diameter of greater than about 0 탆 to about 100 탆, greater than about 0 탆 to about 80 탆, greater than about 0 탆 to about 60 탆, greater than about 0 탆 to about 40 탆, From about 10 μm to about 100 μm, from about 20 μm to about 100 μm, from about 30 μm to about 100 μm, from about 40 μm to about 100 μm, from about 50 μm to about 100 μm, from about 60 μm to about 100 μm mu] m, from about 70 [mu] m to about 100 [mu] m, from about 80 [mu] m to about 100 [mu] m or from about 90 to about 100 [mu] m. For example, the fibers may have a length of at least about 10 m, at least about 15 m, at least about 20 m, at least about 25 m, at least about 30 m, at least about 35 m, at least about 40 m, at least about 45 m, 50 m or more, but may not be limited thereto.

In one embodiment of the invention, the complex may further include, but is not limited to, an ionic liquid. For example, the ionic liquid may be selected from the group consisting of 1-butyl-4-methylpyridinium tetrafluoroborate, 1-ethyl-3-methylimidazolium methylsulfate, Butyl-3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methyl Imidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium thiocyanate, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, 1-butyl- But are not limited to, those selected from the group consisting of 3-methylimidazolium bis (trifluoromethylsulfonyl) imide and combinations thereof.

In one embodiment of the present invention, the content ratio of the first metal nanoparticles, the metal-carbon nanotubes or metal-nanowires coated with the second metal nanoparticles, the ionic liquid, and the polymer matrix contained in the fibers is about 70 About 100 parts by weight: about 10 parts by weight: about 60 parts by weight: about 25 parts by weight, but may not be limited thereto.

The second aspect of the present invention provides a method for producing a metal nanowire comprising: forming a first metal nanoparticle, a second metal nanoparticle-coated metal-carbon nanotube or a metal nanowire according to the first aspect, ≪ / RTI > to provide a fabric.

In one embodiment of the invention, the fabric may have elasticity and conductivity, but may not be limited thereto.

In one embodiment of the invention, the maximum elongation is about 450%, and there may be no resistance change to elongation at about 200% elongation, but the present invention is not limited thereto.

In one embodiment herein, the resistance to elongation and elongation may be maintained, but not limited thereto, in a repeated stretching test of 3,000 times or less.

In one embodiment of the present invention, the content ratio of the first metal nanoparticles, the metal-carbon nanotubes or metal-nanowires coated with the second metal nanoparticles, the ionic liquid, and the polymer matrix contained in the fibers is about 70 To about 100 parts by weight: about 10 parts by weight: about 60 parts by weight: 25 parts by weight, but may not be limited thereto.

All of the above described with respect to the first aspect of the present application can be applied to the second aspect of the present application.

According to a third aspect of the present invention, there is provided a method for producing a metal nanowire comprising: obtaining a dispersion solution in which metal-carbon nanotubes or metal-nanowires coated with first metal nanoparticles and second metal nanoparticles are dispersed; Adding an ionic liquid to the dispersion solution to obtain a gel mixture; Adding a polymer matrix-containing solution to the gel mixture to form a complex; And spinning the composite to form the fibers. ≪ Desc / Clms Page number 5 >

In one embodiment of the invention, the spinning of the complex may be by wet spinning, but may not be limited thereto.

In one embodiment of the invention, the wet spinning may include, but is not limited to, extruding the composite into a coagulant.

In one embodiment of the invention, the ionic liquid is selected from the group consisting of 1-butyl-4-methylpyridinium tetrafluoroborate, 1-ethyl-3-methylimidazolium methyl sulfate, Butyl-3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium ethylsulfate, 3-methylimidazolium thiocyanate, 1-ethyl-3-methylimidazoliumbis (trifluoromethylsulfonyl) imide, 3-methylimidazolium trifluoromethanesulfonate, But are not limited to, those selected from the group consisting of 1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide and combinations thereof.

In one embodiment of the invention, the fibers may be, but are not limited to, having elasticity and conductivity.

In one embodiment of the invention, each of the first and second metal nanoparticles is independently selected from the group consisting of silver (Ag), gold (Au), copper (Cu), nickel (Ni), platinum But may be, but not limited to, aluminum (Al).

In one embodiment of the present invention, the carbon nanotubes may include single wall carbon nanotubes or multi wall carbon nanotubes, but the present invention is not limited thereto.

In one embodiment herein, the polymer matrix is selected from the group consisting of nitrile butadiene rubber, polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) matrix, poly (styrene-butadiene- styrene) (Styrene-isoprene-styrene) (SIS), polyurethane, polyaniline, polyacrylonitrile, polypyrrole, polyvinyl alcohol, alginate, , Nylon, or chitosan, but the present invention is not limited thereto.

In one embodiment of the present invention, the content of the first metal nanoparticles in the complex may be about 10% by weight to about 70% by weight, but the present invention is not limited thereto. For example, the content of the first metal nanoparticles in the complex may range from about 10 wt% to about 70 wt%, from about 20 wt% to about 70 wt%, from about 30 wt% to about 70 wt%, to about 40 wt% To about 70 wt%, from about 50 wt% to about 70 wt%, or from about 60 wt% to about 70 wt%.

In one embodiment of the present invention, the size of the first metal nanoparticles is larger than that of the second metal nanoparticles, the size of the first metal nanoparticles is about 50 nm to about 1 μm, The size of the 2-metal nanoparticles may be about 20 nm or less, but may not be limited thereto. For example, the size of the first metal nanoparticles may be about 50 nm to about 1 μm, about 60 nm to about 1 μm, about 70 nm to about 1 μm, about 80 nm to about 1 μm, about 90 nm to about About 100 nm to about 1 μm, about 150 nm to about 1 μm, about 200 nm to about 1 μm, about 300 nm to about 1 μm, about 400 nm to about 1 μm, about 500 nm to about 1 μm About 800 nm to about 1 μm, about 900 nm to about 1 μm, about 50 nm to about 0.9 μm, about 50 nm to about 0.8 μm, about 600 nm to about 1 μm, about 700 nm to about 1 μm, about 800 nm to about 1 μm, From about 50 nm to about 0.2 [mu] m, from about 50 nm to about 0.2 [mu] m, or from about 50 nm to about 0.5 [ lt; RTI ID = 0.0 > nm, < / RTI > For example, the size of the second metal nanoparticles may be greater than about 0 nm to about 20 nm, greater than about 0 nm to about 15 nm, greater than about 0 nm to about 10 nm, greater than about 0 nm to about 5 nm, From about 2 nm to about 20 nm, from about 4 nm to about 20 nm, from about 6 nm to about 20 nm, from about 8 nm to about 20 nm, or from about 10 nm to about 20 nm.

In one embodiment of the invention, the fibers may be of a diameter of about 100 microns or less and a length of about 10 m or more, but the present invention is not limited thereto. For example, the fibers may have a diameter of greater than about 0 탆 to about 100 탆, greater than about 0 탆 to about 80 탆, greater than about 0 탆 to about 60 탆, greater than about 0 탆 to about 40 탆, From about 10 μm to about 100 μm, from about 20 μm to about 100 μm, from about 30 μm to about 100 μm, from about 40 μm to about 100 μm, from about 50 μm to about 100 μm, from about 60 μm to about 100 μm mu] m, from about 70 [mu] m to about 100 [mu] m, from about 80 [mu] m to about 100 [mu] m or from about 90 to about 100 [mu] m. For example, the fibers may have a length of at least about 10 m, at least about 15 m, at least about 20 m, at least about 25 m, at least about 30 m, at least about 35 m, at least about 40 m, at least about 45 m, But it may not be limited thereto.

In one embodiment of the present invention, the content ratio of the first metal nanoparticles, the metal-carbon nanotubes or metal-nanowires coated with the second metal nanoparticles, the ionic liquid, and the polymer matrix contained in the fibers is about 70 To about 100 parts by weight: about 10 parts by weight: about 60 parts by weight: 25 parts by weight, but may not be limited thereto.

All of the above described contents of the first and second aspects of the present application can be applied to the third aspect of the present invention.

A fourth aspect of the invention provides a method of making a fabric, comprising weaving the fibers according to the first aspect.

The above-mentioned weaving method can be used without limitation, various weaving methods known in the art.

All of the above described contents of the first to third aspects of the present application can be applied to the fourth aspect of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are given for the purpose of helping understanding of the present invention, but the present invention is not limited to the following Examples.

[ Example ]

<Characteristic Analysis>

Ag particles and nAg-MWNTs were characterized by high-resolution transmission electron microscopy (HRTEM, JEOL, 300 kV) and field emission scanning electron microscopy (SEM, JEOL, JSM 890). Stretching (stretching) experiments were performed using in-house-built devices. The resistance of the fibers was measured as a function of tensile strain by the two-probe method (Fluke, 177 TRUE RMS multi-meter).

< Example  One: PVDF - HFP  Matrix based conductivity Linearity  Synthesis of fiber>

Multiwalled carbon nanotubes (nAg-MWNTs) coated with 3 to 5 nm silver (Ag) nanoparticles were synthesized using previously known protocols [Chun, KY et al. Highly conductive, printable and stretchable composite films of carbonnanotubes and silver. Nat Nanotechnol 5, 853-857 (2010); Ma, R. et al. Carbon-Nanotube / Silver Networks in Nitrile Butadiene Rubber for Highly Conductive Flexible Adhesives. Adv Mater 24, 3344-3349 (2012); Functionalized nano-silver particles are assembled on one-dimensional nanotube scaffolds for ultra-highly conductive silver / polymer composites. J Mater Chem 20, 3579-3582 (2010)]. Briefly, Ag nanoparticles were synthesized by mixing benzyl mercaptan (0.1 mol / L, 2.4 mL, Sigma Aldrich) in ethanol with AgNO3 solution (0.02 mol / L, 300 mL, Junsei) in ethanol and stirring for 48 hours. In the next step, MWNTs (100 mg, Hanwha Nanotech) dispersed in ethanol (200 mL) were added and further treated with a sonicator (200 W, 8 h). Finally, nAg-MWNTs were obtained by filtration (PTFE membrane, 0.2 [mu] m), which was washed with ethanol and dried in a vacuum chamber at room temperature.

The conductive stretchable fibers were synthesized by a wet spinning technique. First, 100 to 150 nm Ag particles were dispersed in 4-methyl-2-pentanone (10 mL) by sonication (560 W, 20 min). The gel mixture of ionic liquid (1-butyl-4-methylpyridinium tetrafluoroborate, 600 mg) and nAg-MWNTs (200 mg) was prepared by mixing and grinding for 20 minutes using a mortar and a bowl. In the next step, the gel mixture (800 mg) was added to the Ag particle dispersion and further sonicated (560 W, 20 minutes). Finally, a PVDF-HFP solution (5.875 wt% in 4-methyl-2-pentanone, 10 mL) was added and stirred for 2 hours to form a spinnable dope. The dope was extruded through a 200 urn diameter spinneret into a coagulant (hexane, Sigma Aldrich) with the aid of a syringe pump (3 mL / h) to remove the solvent. The spinning fibers were continuously collected in a winding drum. The fibers were further cured in an oven at &lt; RTI ID = 0.0 &gt; 135 C &lt; / RTI &gt; for 45 minutes after air-drying for 12 hours.

Fabrics formed using composites comprising micro-scale silver (Ag) particles, 3-5 nm silver-coated multi-wall carbon nanotubes (nAg-MWNTs) and polymer matrix, and fabrics woven using the fibers Conductive flexibility at the same time. The conductivity of the fibers and fabrics was significantly increased by the addition of small amounts of nAg-MWNTs. Microscale Ag particles embedded in flexible nitrile butadiene rubber or stretch polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) matrix were connected by nanotubes with high aspect ratio. In addition, the contact interface was significantly improved by agglomeration between microscale Ag particles and nanoscale Ag particles previously adsorbed on the sidewalls of the carbon nanotubes during the curing process. The results of Example 1 are shown in Figs.

In this example, highly conductive stretchable fibers comprising 100 to 150 nm Ag particles, nAg-MWNTs, and PVDF-HFP matrix were synthesized by wet spinning. The average diameter of the fibers was ~ 100 mu m and their length was longer than 10 m. Figures 1A and 1B show a schematic view of the wet spinning process. 1A and 1B, a nozzle and a spinning apparatus 100 in the form of a syringe are devices for pushing a mixture containing metal particles, carbon nanotubes and the like through a nozzle through a nozzle, and the solvent 200 includes an organic solvent or an inorganic solvent In the case of PVDF, a hexane solvent is used. In the case of a polyurethane, water is used. A winder 300 is a device for winding a spiral wound yarn .

Briefly, 100 to 150 nm Ag particles were dispersed in 4-methyl-2-pentanone by ultrasonication. Thereafter, a mixture gel of nAg-MWNTs and an ionic liquid (1-butyl-4-methylpyridinium tetrafluoroborate) was added and sonicated. The ionic liquid enhanced the dispersion of nAg-MWNTs and increased the conductivity of the complex during stretching (stretching). The relative concentration of self-assembled Ag nanoparticles in MWNTs was pre-optimized to ~35 wt%. Finally, a PVDF-HFP solution was added to form a spinnable dope and stirred for 2 hours. The dope was extruded into a coagulant through a 200 탆 diameter spinneret with the aid of a syringe pump to remove the solvent. A number of different coagulants were tested, and hexane provided the highest stretchability of the fibers (FIG. 1c). The 4-methyl-2-pentanone was extracted while the ionic liquid was retained within the fiber by incompatibility with hexane. Filaments longer than 10 m were collected on a winding drum (Fig. 1d) and then cured in an oven at 135 占 폚. As shown in Fig. 1E, the diameter of the fibers was uniform (~ 100 mu m). The density of the wet spun fiber is 2.17 g cm ^{- 3,} which was measured by the Archimedes method (Archimedes method) (Electronic densimeter MD -300S). The density increased to 2.58 g cm &lt;& quot ^{; 3} &gt; after the hot rolling process (Fig. The fillers were more uniformly distributed, and the fibers became dense. The relative densities before and after the hot rolling process were 0.752 and 0.894, respectively. The relative density (RD) of the composite fibers was calculated using the following equation S1;

The ρ _composite is the experimentally measured density of the fiber, and ρ _theory is the theoretical maximum density. ρ was measured experimentally by the Archimedes method (Electronic densimeter MD-300S). Assuming the complete removal of the solvent during the wet spinning and curing process, the ρ _theory was calculated using the following equation: The Ag particles, carbon nanotubes, ionic liquid, and PVDF-HFP of the initial mixture were assumed to be retained in the fiber without loss.

M is the mass, and v is the volume. Subscripts represent each substance.

Typical widths and thicknesses of the fibers after the hot rolling process were ~250 mu m and ~ 17 mu m. The hot-rolled fibers could easily be deformed spirally as shown in the inset of Fig. 1F.

< Example  2: Synthesis of polyurethane matrix-based fibers>

The procedure of Example 1 was repeated except that fibers were prepared by using a polyurethane (Sigma Aldrich) matrix.

FIG. 4A is an image of fibers fabricated on the basis of the polyurethane polymer matrix obtained in Example 2, and the change in resistance according to the strain is shown in FIG. 4B. The initial resistance of the polyaniline-based fibers is 50 MΩ, and the polyurethane-based fibers have an initial resistance of 0.8 Ω and resistance characteristics of 1.67 MΩ at an extension of 120%.

Figure 2a shows the conductivity and peak tensile strain (elongation) of the spun fibers as a function of the 100-150 nm Ag particle volume fraction in the fibers. The mass fraction of the corresponding Ag particles in the initial mixture of four fibers is shown with the x-axis shown above. The mass and volume fraction of the silver particles in the fibers were increased by extraction of the solvent during the wet spinning and curing process. The mass of the other components in the initial mixture was the same for the four fibers. Briefly, in the initial mixture, the 100-150 nm Ag particle mass fraction was used to denote each fiber synthesized herein. The mass fraction of the nAg-MWNTs in the initial mixture was 1.06 wt% based on the specimen having 8.5 wt% of 100 to 150 nm Ag particles. As the mass fraction of the Ag particles increased, the conductivity increased and the stretchability decreased. The addition of Ag particles increased the brittleness of the fiber to stretching (stretching). The maximum strain (elongation) at the conductive and break at 7.4 wt% of the Ag particles was 236 S cm ^-1 and 490%. As the silver concentration increased to 10.4 wt%, the conductivity increased to 8,344 S cm ^-1 , but the elasticity decreased to 55%. Nonetheless, the fibers exhibited significantly better stretch than other CNT-based fibers.

The electrical conductivity of the complex can be predicted theoretically using the power law relationship of equation S3;

σ = σ ₀ (V _f - V _c ) ^s (S 3)

V is the volume fraction of the filler, V _c is the volume fraction at the percolation threshold, and s is the fitting exponent (s), where s is the electrical conductivity of the composite, σ ₀ is the conductivity of the conductive filler, V _f is the volume fraction of the filler, )to be. Ag particles were modeled as uniformly distributed spheres, and the penetration threshold was calculated using an average inter-particle distance model. There was a good agreement between the theory and the result data. The optimized Ag concentration should be determined based on the requirements of the intended application.

Figure 2b shows the change in the conductivity of the fibers with two different Ag particle concentrations (8.5 and 10.4 wt%) as a function of tensile strain. The initial conductivity is 8,344 cm S with respect to the fiber having the Ag particles of 10.4% by ^weight and ^1. The initial conductivity is when the concentration of Ag particles hayeoteul reduced to 8.5 wt%, S 2,681 cm ^- decreased by ^one. However, the maximum strain (elongation) at break increased from 55% to 350%. The two types of fibers showed a decrease in conductivity with increasing tensile strain. Conductivity of the fiber (Ag: 10.4 wt%) calculated using three dimensional percolation theory was also shown.

As shown in equation S3, the conductivity of the composite can be explained theoretically using a power law relationship;

σ = σ ₀ (V _f - V _c ) ^s (S 3)

Where σ is the electrical conductivity of the composite, σ ₀ is the conductivity of the conductive filler, V _f is the volume fraction of the filler, V _c is the volume fraction at the percolation threshold, and s is the fitting index exponent. 100 to 150 nm Ag particles were considered as the main conductive filler and modeled as spherical particles with a diameter of 120 nm (Fig. 1A). The conductivity of Ag particles (σ ₀ is 630,000 S cm ^-1 . V _c Was calculated using the mean inter-particle distance model (equation S4);

D is the diameter of the Ag particles, D _IP is the distance between the conductive fillers for electron tunneling, V _c = 0.368 is obtained by assuming D _IP = 15 nm and the exponent s = &Lt; / RTI &gt; As shown in Figure 2a, there was a good match between the data and the theoretical prediction.

Stretching (stretching) reduces the volume change of the composite film while the volume of Ag particles (Vsilver) is fixed. This leads to a change in V _f in equation S3. The volume (V ₂ ) of the composite fibers can be described as a function of axial strain (?) Using the following formulas S5 to S8;

L ₁ and D ₁ are the length and diameter of the fiber before stretching (stretching), and L ₂ and D ₂ are the length and diameter of the fiber after stretching. The isotropic Poisson ratio was experimentally determined by the above equation (S5) (v = 0.243). Finally, V _f can be calculated using the following equation S9;

The simulated σ of the fiber as a function of ε is shown in FIG. 2b (initial Ag particle concentration = 10.4 wt%, V _silver = 2.037 × 10 ^-5 cm ³ ). As the ε increases, the σ decreases as the theoretically well.

Briefly, the volume change of the matrix polymer as a function of strain modulated V _f in equation S3 above. The diameter change of the fiber was measured experimentally and showed an isotropic Poisson ratio of 0.243. As the strain increased, the volume (V _matrix ) of the fiber composite increased while the volume (V _silver ) of the Ag particles remained unchanged. This leads to V _f (= V _silver / V _matrix ) and sigma reduction. There was a reasonable agreement between data and theory to identify the proposed mechanism. The theoretical prediction slightly overestimated the data. This may be due to disconnection of the conductive filler (Ag particles and nAg-MWNTs) for stretching not considered in the model. The conductivity of the fibers was increased after the hot rolling process (Figure 2b). The film became dense with increasing V _f after the hot rolling process. This has resulted in increased conductivity. Up to the initial conductivity (Ag: 10.4 wt%) is 17,460 cm S ^- and ^1. However, the decreasing trend of conductivity with increasing strain was similar.

Fig. 2C shows an optical image before and after stretching of the fiber (Ag: 8.5 wt%) exhibiting excellent stretchability. SEM images of the fibers with and without a hot rolling process are provided in Figure 2D. The Ag particles were more uniformly introduced into the polymer matrix after the hot rolling process. Increased length spacing between the Ag particles could be observed to reduce the conductivity after stretching as discussed above. Fig. 2e is a schematic representation of a filled symbol and the method of Sekitani, T. et al. A rubberlike stretchable active matrix using elastic conductors. Science 321, 1468-1472 (2008); Sekitani, T. et al. Stretchable active-matrix organic light-emitting diode display using printable elastic conductors. Nat Mater 8, 494-499 (2009); 7 Chun, KY et al. Highly conductive, printable and stretchable composite films of carbonnanotubes and silver. Nat Nanotechnol 5, 853-857 (2010); Kim, Y. et al. Stretchable nanoparticle conductors with self-organized conductive pathways. Nature 500, 59-63 (2013); 11 Hu, LB et al. Stretchable, Porous, and Conductive Energy Textiles. Nano Lett 10, 708-714 (2010); Behabtu, N. et al. Strong, light, multifunctional fibers of carbon nanotubes with ultrahigh conductivity. Science 339,182-186 (2013); Chun, KY et al. Free-standing nanocomposites with high conductivity and extensibility. Nanotechnology 24, 165401 (2013); 21 Lipomi, DJ et al. Skin-like pressure and strain sensors based on transparent elastic films of carbon nanotubes. Nat Nanotechnol 6, 788-792 (2011); 22 Park, M. et al. Highly stretchable electric circuits from a composite material of silver nanoparticles and elastomeric fibers. Nat Nanotechnol 7, 803-809 (2012); 23 Shin, MK et al. Elastomeric Conductive Composites Based on Carbon Nanotube Forests. Adv Mater 22, 2663-2667 (2010)]. &Lt; / RTI &gt; In general, stretchability can be improved by sacrificing conductivity. This could be controlled by the Ag particle concentration here. The conductivity of the hot rolled fibers was as high as 17,460 S cm ^-1 at a reasonably high strain of ~ 50% (Ag: 10.4% by weight). The maximum strain at break increased by 490% due to a decrease in silver concentration (7.4 wt%), but the initial conductivity decreased to 236 S cm ^-1 . Only one control specimen (high density carbon nanotube fibers synthesized by wet spinning) provided superior conductivity compared to the fibers of the present invention. However, its elasticity was very small (~ 1.4%). Polymer-CNT composites generally provided lower conductivity and higher stretchability. These are vinylidene fluoride-hexafluoropropylene-SWNT films, vinylidene fluoride-tetrafluoroethylene-hexafluoropropylene-SWNT films, and vinylidene fluoride- A textile-SWNT film, a poly (dimethylsiloxane) -SWNT film, or a polyurethane-MWNT film. Higher conductivities can be obtained by polymer-metal or polymer-metal-carbon nanotubes, or nanowire composites, at the expense of elasticity. Polyurethane-gold film, poly (styrene-block-butadiene-block-styrene) -Ag mat], PVDF-Ag- MWNT films, and polystyrene-polyisoprene-polystyrene-Ag-MWNT films belong to this category.

Achieving both high conductivity and stretch by composite fibers or films is challenging. On the other hand, the stretchability of the garment was obtained when the fabric was knitted using rigid fibers. Figure 3a shows an optical image of a weft weave fabric (purl stitch) fabricated from 2-ply-rope, 4-ply-rope, and conductive stretchable fibers . The 2-ply rope was made by twisting and relaxing twisted two fibers to reach strain balance. The 4-fluorope was obtained by twisting and relaxing two 2-fluorophores. The fabric was hand woven using long spun fibers. The purl stitch fabric is widely employed in infant and children garments due to its excellent stretchability. The stretchability was dependent on the pattern of the fabric. Plain weave fabrics were made for comparison, but their stretch was not improved (Fig. 3b). An optical image of the weft-woven fabric as a function of strain is shown in Figure 3c. The structure of the fabric was first strained and then stretched (stretched). A schematic view of the fabric before and after stretching was provided in FIG.

Figure 3e compares the normalized resistance changes of a single strand of spinning fiber, 2-flip rope, 4-flip rope, and weft woven fabric as a function of tensile strain. The conductivity change could not be calculated by deformation of the non-uniform cross section. The stretchability of the ropes was superior to that of the one strand of the fibers. The increase in the stretchability of these ropes was previously observed by CNT yarns. The increase in the normalized resistance with increasing strain was inhibited by the manufacture of 2-plies and 4-plies compared to the strands of fibers. The resistance was measured by clipping each end of all the fibers. However, the resistance of the 4-flip rope still increased to ~ 333 times at a strain of 200%. In contrast, the increase in the resistance of the weft-woven fabrics showed little change up to ~ 200% strain. The resistance was measured by clipping each end of the fiber used against the fabric. The resistance slightly decreased to ~ 150% strain. This can be due to the denser contact of the fibers in the stitch cross-section. As shown in Fig. 4A, this remarkable stability at resistances up to about 200% strain (elongation) is sufficient to employ the conductive stretch fabric for practical applications of industrial robots. The resistance was increased ~ 22 times even at 450% strain where the fabric was ruptured. Figure 3f shows the stretching (stretching) cyclability of the fabric. The fabric was stretched at 0-100% tensile strain (elongation) and relaxed. The resistance measured at 100% strain did not change up to 3,000 stretching cycles (repetition).

Figures 5A-5D illustrate performance demonstrations of the conductive stretch fabric employed in the Controller Area Network (CAN) data bus system of a robot finger. The specific manufacturing process of the robot finger has been provided in other documents [Jung, K. et al. Evaluation of fingertip F / T sensor for dexterous manipulation. Ubiquitous Robots and Ambient Intelligence (URAI), 442-445 (23-26 Nov. 2011)], a schematic view of the disassembled robot finger is shown in FIG. 5A. Briefly, when the robot finger-tip was contacted by an object, 6-axis force and moment information was calculated using the data from the six strain gauges installed in the finger-tip sensor frame by the embedded microprocessor. Two wires were required to transmit the processed data via the CAN interface, and one wire was replaced by the fabric. The fabric was attached to the outside of the robot finger for visual demonstration. As shown in FIG. 5B, when the robot finger was touched to the piano key, the force and moment information was transferred to the main control through the fabric at a sampling rate of 100 Hz. Location information was calculated using custom software in the main control unit. The contact position and force were visualized using arrows in the control image. The signal was successfully transmitted even though the fabric experienced more than 100% of stretching during the finger touch operation (FIGS. 5C and 5D). This demonstrates excellent compatibility of the fabric for CAN data bus systems commonly used in the robotization and automotive industries. The conductive stretch wire and fabric find practical applications in the robotics industry because conventional rigid wires hamper the joint movement of robots that involve stretching.

In summary, highly conductive stretchable fibers including 100 to 150 nm Ag particles, nAg-MWNTs, and PVDF-HFP matrix were synthesized by wet spinning. As the Ag particle concentration increased, the initial conductivity increased but the stretchability decreased. The initial conductivity was as high as 17,460 S cm ^-1 and the maximum strain at break was 490%. There has been an inevitable reduction in the conductivity of the fibers as the strain is increased by a decrease in the volume fraction of the filler and by a break in the conductive filler in the matrix. This was significantly demonstrated by the weft-woven fabrics to the extent that the increase in resistance was negligible up to ~ 200% strain. When the fabric had undergone 3,000 stretching cycles at 0% to 100% strain (elongation), there was also no change in resistance. The successful implementation of the fabric for the robot finger's CAN data bus system demonstrates the great potential for practical applications in the electronics and robotics industries.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

100: Nozzle and radiator
200: Solvent
300: winder

Claims (20)

A metal-carbon nanotube or metal-nanowire coated with a first metal nanoparticle, a second metal nanoparticle, and a composite comprising a polymer matrix.
The method according to claim 1,
Wherein the fibers are stretchable and conductive.
The method according to claim 1,
Each of the first metal nanoparticles and the second metal nanoparticles may be independently selected from the group consisting of Ag, Au, Cu, Ni, Pt, or Al Phosphorus, fiber.
The method according to claim 1,
Wherein the carbon nanotubes comprise single walled carbon nanotubes or multiwalled carbon nanotubes.
The method according to claim 1,
The polymer matrix may be selected from the group consisting of nitrile butadiene rubber, polyvinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) matrix, poly (styrene-butadiene-styrene) (SBS), poly (styrene-isoprene- (SIS), polyurethane, polyaniline, polyacrylonitrile, polypyrrole, polyvinyl alcohol, alginate, nylon, or chitosan &lt; / RTI &gt; chitosan.
The method according to claim 1,
Wherein the content of the first metal nanoparticles in the composite is 10 wt% to 70 wt%.
The method according to claim 1,
The size of the first metal nanoparticles is larger than the size of the second metal nanoparticles,
Wherein the size of the first metal nanoparticles is 50 nm to 1 μm and the size of the second metal nanoparticles is 20 nm or less.
fiber.
The method according to claim 1,
Wherein the fibers have a diameter of 100 占 퐉 or less and a length of 10 m or more.
The method according to claim 1,
Wherein the composite further comprises an ionic liquid.
A fabric woven using the fibers according to any one of claims 1 to 9,
A fabric produced by weaving a formed fiber comprising a composite comprising a first metal nanoparticle, a second metal nanoparticle coated metal-carbon nanotube or metal-nanowire, and a polymer matrix.
11. The method of claim 10,
The fabric has elasticity and conductivity.
11. The method of claim 10,
Wherein the maximum elongation is 450% and there is no change in resistance to elongation even at a 200% elongation.
11. The method of claim 10,
Wherein a resistance to elongation and elongation is maintained in a repeated stretching test of 3,000 cycles or less.
Obtaining a dispersion solution in which metal-carbon nanotubes or metal-nanowires coated with the first metal nanoparticles and the second metal nanoparticles are dispersed;
Adding an ionic liquid to the dispersion solution to obtain a gel mixture;
Adding a polymer matrix-containing solution to the gel mixture to form a complex solution;
And spinning the composite solution to form fibers
&Lt; / RTI &gt; The method of any one of claims 1 to 9, wherein the fiber is a fiber.
15. The method of claim 14,
A process according to any one of claims 1 to 9, wherein the spinning of the composite is carried out by wet spinning.
16. The method of claim 15,
The method of any one of claims 1 to 9, wherein the wet spinning comprises extruding the composite into a coagulant.
15. The method of claim 14,
The ionic liquid may be selected from the group consisting of 1-butyl-4-methylpyridinium tetrafluoroborate, 1-ethyl-3-methylimidazolium methylsulfate, 3-methylimidazolium ethylsulfate, 1-butyl-3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl- Methyl-imidazolium thiocyanate, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide, 1-butyl- Wherein the fiber comprises a fiber selected from the group consisting of a fiber, a fiber, a fiber, a fiber, a fiber, a fiber, a fiber, a fiber, a fiber, a fiber and a fiber.
15. The method of claim 14,
The method according to any one of claims 1 to 9, wherein the fibers are stretchable and conductive.
15. The method of claim 14,
Each of the first metal nanoparticles and the second metal nanoparticles may be independently selected from the group consisting of Ag, Au, Cu, Ni, Pt, or Al &Lt; / RTI &gt; by weight of the fibers.
A method of making a fabric, comprising weaving the fibers according to any one of claims 1 to 9.

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