KR101092571B1 - Nanofiber composite and method for manufacturing the same - Google Patents

Abstract

The present invention relates to a nanofiber composite and a method of manufacturing the same. The nanofiber composite includes i) first metal oxide nanofibers, and ii) second metal oxide nanoparticles attached to the nanofibers.

Nanofiber Composites, Metal Oxides, Nanoparticles, Electrospinning, Polymers

Description

NANOFIBER COMPOSITE AND METHOD FOR MANUFACTURING THE SAME

The present invention relates to a nanofiber composite and a method of manufacturing the same. More specifically, the present invention relates to a nanofiber composite in which metal oxide nanoparticles are uniformly dispersed in heterogeneous or homogeneous metal oxide nanofibers, and a method of manufacturing the same.

Nanofiber composites have a porous structure with a large specific surface area, have a large surface area relative to its volume, and have two or more kinds of materials, thereby having multifunctionality. Therefore, the nanofiber composite may be used in tissues, functional separators, sensors or energy storage materials.

Examples of the nanofiber composites include TiO ₂ / SiO ₂ nanofiber composites or ZnO / SnO ₂ nanofiber composites. TiO ₂ / SiO ₂ nanofiber composites are used as heat resistant materials or photocatalysts. In addition, ZnO / SnO ₂ nanofiber composite is used as a material for toluene detection sensor.

The present invention provides a nanofiber composite having a large specific surface area, high electrical stability and mechanical stability, and porous porosity. It is also an object of the present invention to provide a method for producing the nanofiber composite.

Nanofiber composite according to an embodiment of the present invention, i) the first metal oxide nanofibers, and ii) the second metal oxide nanoparticles attached to the nanofibers.

The second metal oxide nanoparticles may aggregate with each other to form a cluster. The weight ratio of the second metal oxide nanoparticles to the first metal oxide nanofibers may be 0.1 to 20. The nanofiber composite may include i) a plurality of first regions in which the metal oxide nanoparticles are located, and ii) a second region located between the plurality of first regions. An average width of the plurality of first regions may be greater than an average width of the second region.

The width of the nanofiber composite may be 50 nm to 2000 nm. The width of the nanofiber composite may be 100 nm to 1000 nm. The first metal oxide may include amorphous. The first metal oxide has a polycrystalline structure, and the average diameter of the nanoparticles included in the polycrystalline structure may be 5 nm to 200 nm.

The first metal oxide is MgO, SnO, SnO ₂ , ScO, TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Mn _x O _y (where x is 1 to 3, y is 2 to 4), Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, ZnO, Ga ₂ O ₃ , Al ₂ O ₃ , SiO, SiO ₂ , BaO, La ₂ O ₃ , HfO ₂ , Ta ₂ O ₃ , WO ₂ , Pb ₂ O It may include one or more materials selected from the group consisting of ₃ , Bi ₂ O ₃ , Nb ₂ O ₃ and lithium transition metal oxide. The second metal oxide is MgO, SnO, SnO ₂ , ScO, TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Mn _x O _y (where x is 1 to 3, y is 2 to 4), Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, ZnO, Ga ₂ O ₃ , Al ₂ O ₃ , SiO, SiO ₂ , BaO, La ₂ O ₃ , HfO ₂ , Ta ₂ O ₃ , WO ₂ , Pb ₂ O It may include one or more materials selected from the group consisting of ₃ , Bi ₂ O ₃ , Nb ₂ O ₃ and lithium transition metal oxide. When the first metal oxide or the second metal oxide includes a lithium transition metal oxide, the lithium transition metal oxide may include at least one material selected from the group consisting of LiMn ₂ O ₄ , LiFePO ₄ , LiCoO _2, and Li ₄ Ti ₅ O ₁₂ . It may include. The diameter of the second metal oxide nanoparticles may be 5 nm to 200 nm. Nanofibers can have one or more tissues selected from the group consisting of amorphous, nanograin, and polycrystalline structures. When the nanofibers are composed of nanoparticles, the particle size of the nanoparticles may be 5 nm to 200 nm. The second metal oxide nanoparticles may be uniformly attached to the nanofibers. Here, the attachment means that the second metal oxide is uniformly distributed inside and outside the first metal oxide nanofibers. The second metal oxide may be ZnO.

Method for producing a nanofiber composite according to an embodiment of the present invention, i) preparing a solution of a metal salt precursor, a polymer and a solvent, ii) dispersing the metal oxide nanoparticles in a solution to prepare a suspension, iii) spinning the suspension to produce nanofibers, and iv) heat treating the nanofibers to produce nanofiber composites.

In preparing the solution, the amount of the metal salt precursor may be 10 wt% to 25 wt% of the solution. The amount of polymer may be from 8 wt% to 15 wt% of the solution. The polymer may be one or more materials selected from the group consisting of polyurethane and polyether uretan. The polymer is a cellulose derivative, and the cellulose derivative may be one or more materials selected from the group consisting of cellulose acetate, cellulose, acetate butylate, and cellulose acetate propinate. .

The polymer may be polymethyl methacrylate (PMMA), polymethyl acrylate (PMA), polyacrylic copolymer, polyvinylacetate copolymer, polyvinyl acetate (PVAc), polyvinylpyrroly Polyvinyl pyrrolidone (PVP), polymethyl alcohol (PVA), polyperfuryl alcohol (PPFA), polystyrene (PS), polystyrene copolymer, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene oxide At least one selected from the group consisting of copolymers, polypropylene oxide copolymers, polycarbonate (PC), polyvinyl chloride (PVC), polycaprolactone, polyvinyl fluoride, polyvinylidene fluoride copolymers and polyamides It may be a substance. In the step of preparing the suspension, the diameter of the nanoparticles may be 5nm to 200nm. The amount of nanoparticles can be up to 50 vol% of the suspension.

In the step of preparing a nanofiber composite, the heat treatment temperature of the nanofiber may be 300 ℃ to 700 ℃. In the step of preparing a solution, the metal salt precursor is Mg, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Li, In Ga, Al, Si, Ba, La, Hf, Ta It may include a cation of at least one metal selected from the group consisting of W, Pb and Bi.

In the step of preparing the suspension, the nanoparticles are MgO, SnO, SnO ₂ , ScO, TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Mn _x O _y (where x is 1 to 3, wherein y is 2 to 4), Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, ZnO, Ga ₂ O ₃ , Al ₂ O ₃ , SiO, SiO ₂ , BaO, La ₂ O ₃ , HfO ₂ , Ta ₂ O ₃ And WO ₂ , Pb ₂ O ₃ , Bi ₂ O ₃ , Nb ₂ O _3, and lithium transition metal oxides. In the step of making the nanofibers, the suspension can be electrospinning, melt-lown spinning, flash spinning or electrostatic melt-lown spinning.

Nanofiber composites having versatility and excellent crystallinity can be prepared. In addition, the amount of metal oxide contained in the nanofiber composite can be freely controlled. In addition, a nanofiber composite having a large surface area, high porosity, and excellent electrical and mechanical stability may be manufactured.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Commonly defined terms used are added to have meanings consistent with the related technical literature and the presently disclosed contents, and are not interpreted in an ideal or very formal sense unless defined.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an,” and “the” include plural forms as well, unless the phrases clearly indicate the opposite. As used herein, the meaning of "comprising" embodies a particular characteristic, region, integer, step, operation, element and / or component, and the presence of other characteristics, region, integer, step, operation, element and / or component It does not exclude the addition.

The term "nano" described in the specification means nano-scale, and may include micro units. In addition, the term "nanoparticle" described in the specification means a nano-scale object having a particle shape, the particle shape is not limited to a specific shape may be variously modified.

As used herein, the term "metal oxide nanofibers" refers to a state in which metal oxides are mixed in nanofibers or nanofibers are formed with only metal oxides. Here, the nanofiber mixing state of the metal oxide is not limited to a specific form.

1 schematically shows a method of manufacturing a nanofiber composite according to an embodiment of the present invention in order. The manufacturing method of the nanofiber composite of FIG. 1 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the manufacturing method of the nanofiber composite can be modified into other forms.

As shown in Figure 1, the method for producing a nanofiber composite, i) preparing a solution of a metal salt precursor, a polymer and a solvent (S10), ii) dispersing the metal oxide nanoparticles in a solution to prepare a suspension Step (S20), iii) spinning the suspension to produce nanofibers (S30) and iv) heat-treating the nanofibers to produce a nanofiber composite (S40). In addition, the manufacturing method of the nanofiber composite may further include other steps.

First, in step S10 to prepare a mixed solution. The mixed solution contains a metal salt precursor, a polymer, and a solvent. Here, the solvent may be a polar solvent such as water, ethanol, THF (tetrahydrofuran), DMF (dimethylformamide), DMAc (Ddmethylacetamide).

The metal salt precursor is Mg, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Li, In Ga, Al, Si, Ba, La, Hf, Ta, W, Pb or Bi, etc. It may include a cation of the metal of. Zinc salts, indium salts, titanium salts or tin salts and the like may be used as metal salt precursors to form the aforementioned cations. Moreover, these can also be mixed and used as a metal salt precursor. More specifically, zinc chloride, zinc acetate, zinc sulfate, zinc nitrate, zinc bromide or zinc perchlorate can be used. Moreover, indium chloride, indium acetate, indium sulfate, indium nitrate, etc. can be used as an indium salt. Titanium isopropoxide, titanium propoxide or titanium butoxide may be used as the titanium salt. As the tin salt, tin chloride, tin acetate, tin sulfate, tin nitrate or tin bromide can be used.

The amount of the metal salt precursor in step (S10) may be 10wt% to 25wt% of the solution. If the amount of the metal salt precursor is too small or too large, the metal oxide nanofiber shape is not formed.

In step S10, the polymer imparts viscosity to the solution for electrospinning. In addition, the metal oxide nanoparticles are uniformly dispersed in the solution due to the polymer.

As the polymer, a thermoplastic resin or a thermosetting resin can be used. For example, a polyurethane copolymer, a cellulose derivative or other polymer may be used as the polymer. Polyurethane or a polyether urethane etc. can be used as a polyurethane copolymer. As the cellulose derivative, cellulose acetate, cellulose, acetate butyrate or cellulose acetate propionate may be used. Other polymers include polymethyl methacrylate (PMMA), polymethyl acrylate (PMA), polyacrylic copolymer, polyvinylacetate copolymer, polyvinyl alcohol (PVA), polyperfuryl alcohol (PPFA), polyvinyl acetate (polyvinyl acetate, PVAc), polyvinyl pyrrolidone (PVP), polystyrene (PS), polystyrene copolymer, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene oxide copolymer, polypropylene oxide air Copolymer, polycarbonate (PC), polyvinyl chloride (PVC), polycaprolactone, polyvinyl fluoride, polyvinylidene fluoride copolymer or polyamide can be used.

The amount of the polymer in step (S10) may be 8wt% to 15wt% of the solution. If the amount of polymer is too small or too large, the solution does not have a viscosity suitable for electrospinning.

Next, in step (S20) to disperse the metal oxide nanoparticles in a solution to prepare a suspension. That is, the metal oxide nanoparticles are introduced into the reaction vessel containing the suspension. As the metal oxide nanoparticles, MgO, SnO, SnO ₂ , ScO, TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Mn _x O _y (where x is 1 to 3 and y is 2 to 4), Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, ZnO, Ga ₂ O ₃ , Al ₂ O ₃ , SiO, SiO ₂ , BaO, La ₂ O ₃ , HfO ₂ , Ta ₂ O ₃ , WO ₂ , Pb ₂ O ₃ , Bi ₂ O ₃ , Nb ₂ O ₃ or a lithium transition metal oxide may be used.

The diameter of the metal oxide nanoparticles in step S20 may be 5 nm to 200 nm. When the diameter of the metal oxide nanoparticles is too large, since the dispersibility of the metal oxide nanoparticles is reduced, it is difficult to prepare a nanofiber composite having the metal oxide nanoparticles uniformly attached thereto. In addition, it is difficult to manufacture metal oxide nanoparticles having a diameter of less than 5nm in the manufacturing process.

The amount of the metal oxide nanoparticles in step S20 may be 50 vol% or less of the suspension. If the amount of the metal oxide nanoparticles is too large, the dispersibility of the metal oxide nanoparticles is reduced. Therefore, the metal oxide nanoparticles are added to the mixed solution, and the mixed solution is stirred at room temperature for 10 minutes. Next, the mixed solution is sonicated (sonic) for 30 to 90 minutes to prepare a suspension. Nanoparticles obtained through microbead milling may also be used for more uniform dispersion.

Next, in step S30, the suspension is spun. The spinning may use electro-spinning, melt-blown, flash spinning or electrostatic melt-blown, or the like. By spinning the suspension, a metal oxide nanofiber composite including the metal oxide nanoparticles can be prepared. Here, the spinning process can be easily understood by those skilled in the art, the detailed description thereof will be omitted.

In step S30, when the suspension is electrospun, the suspension is filled in a syringe pump, and then ejected slowly at a constant speed. In this way, the ejected suspension is electrospun. During the electrospinning process, the sol-gel reaction is carried out by evaporation of the solvent. As a result, a nanofiber composite in which nanoparticles are evenly dispersed is produced.

Finally, in step S40, the manufactured nanofibers are heat treated. The nanofibers may be heat treated at a temperature of 300 ° C to 700 ° C. Here, when the heat treatment temperature of the nanofibers is too low, the polymer does not decompose and the metal salt does not oxidize well. On the contrary, when the heat treatment temperature of the nanofibers is too high, the nanofibers and the metal oxide nanoparticles may react to form new crystal phases.

Meanwhile, two metal salts may be dissolved in a polymer-containing solvent, followed by electrospinning and heat treatment to prepare a nanofiber structure. However, in this case, amorphous oxide or non-uniform oxide may be formed depending on the heat treatment temperature at the time of forming the nanofibers. In addition, it is difficult to prepare nanofiber composites having excellent crystallinity by stoichiometric control. And because the heat treatment for the different metal salts are performed at the same time, the crystallinity of the specific material becomes very small or unwanted crystals are generated.

Therefore, the nanofiber composite may be prepared in consideration of the above-described steps. Hereinafter, with reference to Figure 2 will be described in more detail of the nanofiber composite of FIG.

FIG. 2 schematically shows each step of the method of manufacturing the nanofiber composite of FIG. 1. The manufacturing method of the nanofiber composite of FIG. 2 is merely for illustrating the present invention, and the present invention is not limited thereto. Therefore, the manufacturing method of the nanofiber composite can be modified into other forms.

2 shows the steps S10 to S30 of FIG. 1, and the central part shows the step S40 of FIG. 1. In addition, the right part of FIG. 2 shows the nanofiber composites 13 and 14 manufactured through the above-described steps S10 to S40. Here, the nanofiber composites 13 and 14 may be made of the first nanofiber composite 13 or the second nanofiber composite 14.

As shown in the left part of FIG. 2, a solvent is prepared by mixing a solvent 11a, a polymer 11b and a nanoparticle 11c in which a metal oxide precursor is dissolved, followed by electrospinning. The electrospun suspension yields a material comprising the metal oxide precursor / polymer composite nanofibers 12a and nanoparticles 12b. When heat-treating this, as shown in the right part of FIG. 2, the 1st nanofiber composite 13 or the 2nd nanofiber composite 14 is obtained.

First, the first nanofiber composite 13 is formed by mixing nanofibers 13a composed of fine nanoparticles and nanoparticles 13b made of a metal oxide. Examples of the metal oxides include titanium dioxide (TiO ₂ ) and the like, and the metal oxides may include amorphous or have a polycrystalline structure. The average diameter of the crystals included in the polycrystalline structure may be 5nm to 200nm. If the average diameter of the crystals is out of the above-described range, the properties of the first nanofiber composite 13 may be degraded.

On the other hand, the metal oxide constituting the nanofiber 13a is MgO, SnO, SnO ₂ , ScO, TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Mn _x O _y (where x is 1 to 3, Y is 2 to 4), Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, ZnO, Ga ₂ O ₃ , Al ₂ O ₃ , SiO, SiO ₂ , BaO, La ₂ O ₃ , HfO ₂ , Ta _{It may be 2} O ₃ , WO ₂ , Pb ₂ O ₃ , Bi ₂ O ₃ , Nb ₂ O ₃ or a lithium transition metal oxide. Here, the lithium transition metal oxide may be LiMn ₂ O ₄ , LiFePO ₄ , LiCoO ₂ or Li ₄ Ti ₅ O ₁₂ .

The nanoparticles 13b may be made of the same or different types of metal oxides as the metal oxides described above. The nanoparticles 13b are attached to the nanofibers 13a and aggregated to form clusters. Here, the term "attachment" also includes a state in which the nanoparticles 13b are embedded in the nanofibers 13a.

The nanofibers 13a may be formed of amorphous, nanograin or polycrystalline structures or metal oxides formed by mixing them. In particular, since the metal oxide precursor is heat-treated at a high temperature to form nanofibers through nucleation and particle growth, nanofibers are formed of fine nanoparticles. In this case, the polymer is completely decomposed and removed after the heat treatment. When the nanofibers 13a are composed of nanoparticles, the particle size of the nanoparticles may be 5 nm to 200 nm. If the nanoparticles are out of the above-described particle size range, the nanofiber composite is not well formed.

Here, the weight ratio of the heterogeneous or homogeneous nanoparticles 13b mixed with the nanofibers 13a to the nanofibers 13a may be 0.1 to 20. If the aforementioned weight ratio is too large or too small, the first nanofiber composite 13 may not exert the desired function.

Meanwhile, the first nanofiber composite 13 includes a plurality of first regions S13a and a plurality of second regions S13b disposed therebetween. Here, metal oxide nanoparticles 13b are positioned in the plurality of first regions S13b. The metal oxide constituting the metal oxide nanoparticles 13b and the metal oxide constituting the nanofibers 13a may be the same or different.

Meanwhile, the average width of the plurality of first regions S13a, that is, the average length of the nanofibers 13a cut in a direction crossing the length direction of the first nanofiber composite 13 is the plurality of second regions S13b. Is greater than the average width. This is due to the nanoparticles 13b protruding out of the nanofibers 13a.

As shown in FIG. 2, the second nanofiber composite 14 may be formed while having a different shape from the first nanofiber composite 13. The second nanofiber composite 14 includes nanofibers 14a and nanoparticles 14b. The nanoparticles 14b are uniformly attached to the surface and the inside of the nanofibers 14a.

Here, the width of the second nanofiber composite 14 may be 50nm to 2000nm. Preferably, the width of the second nanofiber composite 14 may be 100nm to 1000nm. If the width of the second nanofiber composite 14 is too small or large, the nanoparticles are not uniformly dispersed in the nanofibers. Therefore, by controlling the width of the second nanofiber composite 14 in the above range to ensure a large specific surface area.

The width of the second nanofiber composite 14 may be adjusted according to the metal oxide nanoparticles, the metal salt precursor concentration, the electrospinning conditions, and the heat treatment conditions, and the first nanofiber composite 13 or the second nanofiber composite 14 ) Can be prepared. However, as long as the nanofibers are produced by the electrospinning process, the width of the nanofibers is not limited.

Hereinafter, the present invention will be described through experimental examples. These experimental examples are only for illustrating the present invention, and the present invention is not limited thereto.

Experimental Example  One

Polyvinylacetate (PVAc) was used as a polymer, and titanium propoxide, dimethylformamide (DMF), and acetic acid were used. In addition, SnO ₂ nanoparticles having a size of 100 nm or less were used.

First, 2.558 g of titanium propoxide was placed in 7.5 g of dimethyl formamide and dissolved in 1 g of acetic acid. Next, titanium propoxide was dissolved at 50 ° C. with 0.75 g of polyvinylacetate. Thereafter, 0.15 g of SnO ₂ nanoparticles was added to the solution described above, stirred at room temperature for 10 minutes, and then ground by ultrasonication for 1 hour to prepare a suspension.

The suspension prepared as described above was charged to 20 ml of a syringe pump, and then electrospun while slowly ejecting at a rate of 10 µl / min. The humidity during electrospinning was 30%, the available voltage was 15.5kV, and the ambient temperature was 31 ℃. A polyvinylacetate / titanium salt nanofiber composite was obtained in which solid SnO ₂ nanoparticles were uniformly dispersed by a sol-gel reaction while the solvent evaporated during electrospinning. In Experimental Example 1, the nanofiber composite was not heat treated.

Experimental Example  2

Polyvinylacetate / titanium salt nanofiber composite was prepared in the same manner as in Experimental Example 1. The polyvinylacetate / titanium salt nanofiber composite thus prepared was heat treated at 500 ° C. for 1 hour. As a result, a nanofiber composite made of TiO ₂ having evenly dispersed SnO ₂ nanoparticles was obtained.

Experimental Example  3

Polyvinylacetate (PVAc) (molecular weight: 1.3 million) was used as the polymer, and tin (IV) chloride and dimethylformamide (DMF) were used. And TiO ₂ nanoparticles having a size of less than 30nm was used.

First, 2.6 g of tin chloride was dissolved in 7.5 g of dimethyl formamide. Next, 0.75 g of polyvinylacetate was added to the solution described above and dissolved at 50 ° C. Thereafter, 0.15 g of TiO ₂ nanoparticles was added to the solution described above, stirred at room temperature for 10 minutes, and then ground by ultrasonication for 1 hour to prepare a suspension.

The suspension prepared as described above was charged to 20 ml of syringe pump and then electrospun with slow ejection at a rate of 10 μl / min. The humidity during electrospinning was 30%, the available voltage was 14.1kV, and the ambient temperature was 31 ℃. A polyvinylacetate / tin salt nanofiber composite was obtained in which solid TiO ₂ nanoparticles were uniformly dispersed by a sol-gel reaction while the solvent evaporated during electrospinning.

The prepared polyvinylpyrrolidone / tin salt nanofiber composite was heat-treated at 500 ° C. for 1 hour. As a result, a nanofiber composite made of SnO ₂ in which TiO ₂ nanoparticles were evenly dispersed was obtained.

Experimental Example  4

Polyvinylpyrrolidone (PVP) (molecular weight: 1.3 million) was used as a polymer, and manganese acetate, dimethylformamide (DMF), and ethanol were used. In addition, ZnO nanoparticles having a size of 30 nm or less were used.

First, 0.4 g of manganese acetate was dissolved in 2.58 g of dimethyl formamide. Next, 0.63 g of polyvinylpyrrolidone was added to the solution described above and dissolved at 50 ° C. Thereafter, 1.72 g of an ethanol suspension in which 0.012 g of ZnO nanoparticles were dispersed was added to the above-described solution, stirred at room temperature for 1 hour, and then ground by ultrasonication for 1 hour to prepare a suspension.

The suspension prepared as described above was charged to a 20 ml syringe pump and electrospun while slowly ejecting at a rate of 10 μl / min. The humidity during electrospinning was 30%, the available voltage was 15.3kV, and the ambient temperature was 29 ℃. Polyvinylpyrrolidone / manganese salt nanofiber composites in which solid ZnO nanoparticles were uniformly dispersed by a sol-gel reaction while the solvent evaporated during electrospinning were obtained.

The polyvinylpyrrolidone / manganese salt nanofiber composite prepared was heat-treated at 500 ° C. for 1 hour. As a result, a manganese oxide nanofiber composite in which ZnO nanoparticles were evenly dispersed was obtained.

Experiment result

Experimental Example  Tissue photo of nanofiber complex of 1

Figure 3 shows a low magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 1. FIG. 3 shows a scanning electron micrograph of a polyvinylacetate / titanium salt composite nanofiber in which SnO ₂ nanoparticles are dispersed.

As shown in Figure 3, it can be seen that the nanoparticles are attached to the elongated nanofibers. That is, SnO ₂ nanoparticles were well dispersed in the polyvinylacetate / titanium salt composite nanofibers. Here, the SnO ₂ nanoparticles are spaced apart from each other and attached to the polyvinylacetate / titanium salt composite nanofibers forming nodes.

Figure 4 shows a high magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 1. That is, FIG. 4 enlarges and shows FIG.

As shown in FIG. 4, the nanoparticles aggregated together to form clusters. Here, it was confirmed that some SnO ₂ nanoparticles not well dispersed locally form clusters inside the polyvinylacetate / titanium salt composite nanofibers.

Experimental Example  Tissue Picture of Nanofiber Complex of 2

Figure 5 shows a low magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 2.

As shown in FIG. 5, it was confirmed that a plurality of SnO ₂ nanoparticles were dispersed in the polycrystalline TiO ₂ nanofibers. In particular, since the nanofiber of FIG. 5 was heat-treated, the polymer therein was decomposed and the titanium salt was oxidized to form TiO ₂ .

Figure 6 shows a high magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 2. That is, FIG. 6 shows an enlarged view of FIG. 5.

As shown in FIG. 6, the nanoparticles aggregated together to form clusters. Here, it was confirmed that the SnO ₂ nanoparticles are embedded in the TiO ₂ nanofibers. In particular, the TiO ₂ nanofibers formed by heat treatment of the titanium salts formed nanofibers composed of nanoparticles having a particle size of 20 mm to 30 nm.

Experimental Example  Energy Dispersion Spectrum of Nanofiber Composite of 2

FIG. 7 schematically shows an energy dispersive spectrography (ESD) graph of the nanofiber composite according to Experimental Example 2. FIG.

As shown in FIG. 7, Ti: Sn was present in an atomic ratio of 10.82: 1.22. That is, the number of atoms of Ti was 10 times the number of atoms of Sn. In other words, the number of atoms of Ti to the number of atoms of Sn was 10. This was similar to 9: 1, the ratio of Ti: Sn input.

Experimental Example  Tissue photo of nanofiber complex of 3

Figure 8 shows a low magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 3. That is, FIG. 8 shows SnO ₂ nanofibers with TiO ₂ nanoparticles attached thereto.

As shown in FIG. 8, it was confirmed that the nanoparticles of TiO ₂ were evenly dispersed in the nanofibers. That is, when TiO ₂ nanoparticles were more dispersed, TiO ₂ nanoparticles were evenly distributed in SnO ₂ nanofibers.

Figure 9 shows a high magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 3. That is, FIG. 9 is an enlarged view of FIG. 8.

As shown in FIG. 9, the TiO ₂ nanoparticles did not aggregate well and were uniformly distributed in the SnO ₂ nanofibers.

Experimental Example  Tissue Picture of Nanofiber Complex of 4

Figure 10 shows a low magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 4. That is, FIG. 10 shows Mn ₃ O ₄ nanofibers in which ZnO ₂ nanoparticles are dispersed.

As shown in Figure 10, it was confirmed that the nanoparticles of a plurality of ZnO evenly dispersed in the nanofibers.

Figure 11 shows a high magnification scanning electron micrograph of the nanofiber composite prepared according to Experimental Example 4. That is, FIG. 11 enlarges and shows FIG.

As shown in FIG. 11, when fabricating composite nanofibers using well dispersed ZnO nanoparticles, ZnO nanoparticles are very uniform without being distinguished from manganese oxide nanoparticles constituting Mn ₃ O ₄ nanofibers. Distributed composite nanofibers could be formed. Therefore, by controlling the degree of dispersion of the nanoparticles could be prepared composite nanofibers in which the nanoparticles agglomerate, it was possible to produce a composite nanofibers in which the nanoparticles are uniformly distributed.

It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the following claims.

1 is a flow chart schematically showing a method of manufacturing a nanofiber composite according to an embodiment of the present invention.

FIG. 2 is a view schematically illustrating each step of the method of manufacturing the nanofiber composite of FIG. 1.

3 is a low magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 1 of the present invention.

Figure 4 is a high magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 1 of the present invention.

5 is a low magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 2 of the present invention.

6 is a high magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 2 of the present invention.

7 is a graph showing the energy dispersion spectrum of the nanofiber composite according to Experimental Example 2 of the present invention.

8 is a low magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 3 of the present invention.

9 is a high magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 3 of the present invention.

10 is a low magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 4 of the present invention.

11 is a high magnification scanning electron micrograph of the nanofiber composite according to Experimental Example 4 of the present invention.

Claims (29)

First metal oxide nanofibers, and Second metal oxide nanoparticles attached to the nanofibers Including, The second metal oxide nanoparticles are aggregated together to form a cluster, and the weight ratio of the second metal oxide nanoparticles to the first metal oxide nanofibers is 0.1 to 20, The first metal oxide and the second metal oxide are MgO, SnO, SnO ₂ , ScO, TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Mn _x O _y (where x is 1 to 3, wherein y is 2 to 4), Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, ZnO, Ga ₂ O ₃ , Al ₂ O ₃ , SiO, SiO ₂ , BaO, La ₂ O ₃ , HfO ₂ , Ta ₂ Nanofiber composite comprising at least one material selected from the group consisting of O ₃ , WO ₂ , Pb ₂ O ₃ , Bi ₂ O ₃ , Nb ₂ O ₃ and lithium transition metal oxide. delete delete The method of claim 1, The nanofiber composite, A plurality of first regions in which the metal oxide nanoparticles are located, and A second region located between the plurality of first regions Including, The nanofiber composite of claim 1, wherein an average width of the plurality of first regions is greater than an average width of the second region. The method of claim 1, The nanofiber composite has a width of 50nm to 2000nm. The method of claim 5, The nanofiber composite has a width of 100nm to 1000nm. The method of claim 1, The first metal oxide is a nanofiber composite containing amorphous. The method of claim 1, The first metal oxide has a polycrystalline structure, the average diameter of the crystals contained in the polycrystalline structure is 5nm to 200nm nanofiber composite. delete The method of claim 1, When the first metal oxide includes a lithium transition metal oxide, the lithium transition metal oxide is nano-containing one or more materials selected from the group consisting of LiMn ₂ O ₄ , LiFePO ₄ , LiCoO ₂ and Li ₄ Ti ₅ O ₁₂ Fiber composites. delete The method of claim 1, When the second metal oxide includes a lithium transition metal oxide, the lithium transition metal oxide is nano containing one or more materials selected from the group consisting of LiMn ₂ O ₄ , LiFePO ₄ , LiCoO ₂ and Li ₄ Ti ₅ O ₁₂ Fiber composites. The method of claim 1, The diameter of the second metal oxide nanoparticles is 5nm to 200nm nanofiber composite. The method of claim 1, The nanofibers are nanofiber composites having one or more tissues selected from the group consisting of amorphous, nanograin and polycrystalline structures. The method of claim 14, When the nanofibers include the nanograins, the nanograins have a particle size of 5nm to 200nm. The method of claim 1, The second metal oxide nanoparticles are nanofiber composites uniformly attached to the nanofibers. The method of claim 16, The second metal oxide is ZnO nanofiber composite. Preparing a solution of a metal salt precursor, a polymer and a solvent, Preparing a suspension by dispersing the metal oxide nanoparticles in the solution, Spinning the suspension to produce nanofibers, and Heat-treating the nanofibers to prepare a nanofiber composite Including, In the step of preparing the solution, the metal salt precursor is Mg, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn, Li, In Ga, Al, Si, Ba, La, Hf At least one metal selected from the group consisting of Ta, W, Pb and Bi, In the step of preparing the suspension, the diameter of the nanoparticles is 5nm to 200nm, the amount of the nanoparticles is 50vol% or less of the suspension, the nanoparticles are MgO, SnO, SnO ₂ , ScO, TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Mn _x O _y (where x is 1 to 3, y is 2 to 4), Fe ₂ O ₃ , Co ₃ O ₄ , NiO, CuO, ZnO, Ga ₂ O ₃ , Al ₂ O ₃ , SiO, SiO ₂ , BaO, La ₂ O ₃ , HfO ₂ , Ta ₂ O ₃ , WO ₂ , Pb ₂ O ₃ , Bi ₂ O ₃ , Nb ₂ O ₃ and lithium transition metal oxides At least one substance selected from the group consisting of: In the step of preparing the nanofiber composite, the nanoparticles are agglomerated with each other to form a cluster (cluster) while the nanofiber composite manufacturing method attached to the nanofibers. The method of claim 18, In the preparing of the solution, the amount of the metal salt precursor is 10wt% to 25wt% of the solution. The method of claim 19, The amount of the polymer is 8wt% to 15wt% of the solution of the nanofiber composite production method. 21. The method of claim 20, The polymer is a polyurethane copolymer, The polyurethane copolymer is a method for producing a nanofiber composite is at least one material selected from the group consisting of polyurethane (polyuretan) and polyetherurethane (polyether uretan). 21. The method of claim 20, The polymer is a cellulose derivative, The cellulose derivative is cellulose acetate, cellulose, cellulose, acetate butylate and cellulose acetate propionate. 21. The method of claim 20, The polymer may be polymethyl methacrylate (PMMA), polymethyl acrylate (PMA), polyacrylic copolymer, polyvinylacetate copolymer, polyvinyl acetate (PVAc), polyvinyl p Lollidon (polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), polyperfuryl alcohol (PPFA), polystyrene (PS), polystyrene copolymer, polyethylene oxide (PEO), polypropylene oxide (PPO), polyethylene Oxide copolymer, polypropylene oxide copolymer, polycarbonate (PC), polyvinyl chloride (PVC), polycaprolactone, polyvinyl fluoride, polyvinylidene fluoride copolymer and polyamide selected from the group consisting of Method for producing a nanofiber composite that is the above material. delete delete The method of claim 18, In the step of preparing the nanofiber composite, the heat treatment temperature of the nanofiber is 300 ℃ to 700 ℃ manufacturing method of the nanofiber composite. delete delete The method of claim 18, In the step of preparing the nanofibers, the suspension is electrospinning, melt-lown spinning, flash spinning or electrostatic melt-lown spinning nano Method of making a fiber composite.

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