KR20110029575A - Nanofiber web with network structure and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A nano-fiber network structure and a method for manufacturing the same are provided to connect high-denier nano-fiber in a network structure using low-denier nano-fiber based on the polarity difference of polyamide and vinyl monomer-based polymer. CONSTITUTION: High-denier nano-fiber based on a polyamide resin is manufactured by an electro-spinning method. The diameter of the high-denier nano-fiber is between 55 and 2,000nm. Low-denier nano-fiber based on vinyl monomer-based polymer is manufactured by the electro-spinning method. The diameter of the low-denier nano-fiber is between 0.1 and 50nm. The monomer is one or more selected from a group a monomer represented by chemical formula 1. In the chemical formula 1, R1 represents H, CH_3, Cl, Br, F, CN, benzene, COOH, CONH_2, CH_3COOH, OR CH_3COOCH_3.

Description

Nanofiber web with network structure and method of manufacturing the same

The present invention relates to a nanofibrous network structure having a network structure and useful as a carrier in the pharmaceutical field, and a method of manufacturing the same, and more specifically, to an electrospinning method, which is made of a polyamide resin, and has a relatively thick diameter of a fine island nano A structure consisting of polymers composed of one or more monomers selected from monomers of the general formula (I) having a main component between the fibers and connecting relatively fine-sized fine-fiber nanofibers in a network structure (hereinafter, referred to as "network structure"). It relates to a nanofiber network structure having a) and a method of manufacturing the same.

[In formula (I), R1 is H, CH ₃ , Cl, Br, F, CN, benzene, COOH, CONH ₂ , CH ₃ COOH or CH ₃ COOCH ₃ ]

In the present invention, the nanofiber network structure is defined as a nanofiber web having the network structure.

In addition, in this invention, a vinyl copolymerization monomer is defined as the copolymerization monomer containing a vinyl monomer.

In addition, the monomer of the said general formula (I) is defined as the vinyl monomer which has a double bond.

In the present invention, the polymer of the fine-grained nanofibers is a copolymer containing polyacrylonitrile and polyacrylonitrile (hereinafter referred to as "polyacrylonitrile copolymer") polyvinyl, copolymer containing polyvinyl ( Hereinafter referred to as "polyvinyl copolymer") and mixtures thereof.

In order to commercially manufacture a nanofiber web, Korean Patent No. 0412241, Korean Patent No. 0422459 and Korean Patent Application No. 2005-15610 propose a method of electrospinning a plurality of nozzles through a plurality of nozzles.

Specifically, in the conventional method, as shown in FIG. 6, the polymer solution is supplied to the plurality of nozzles 3 subjected to the high voltage through the metering pump 2, and then the high voltage having the opposite charge to the nozzle is applied. Nanofiber web was prepared by electrospinning on a fiber substrate placed on the hanging collector (4).

6 is a process schematic diagram showing an example of a conventional electrospinning process.

However, in the case of electrospinning a single polymer by the conventional electrospinning method, only nanofiber webs in which nanofibers having the same diameter are irregularly stacked with each other are manufactured, and (ⅰ) diameters made of different polymers are relatively It is composed of coarse nanofibers and (ii) nanofibers having a relatively small diameter, and a network in which the nanofiber fibers having a relatively thin diameter is connected between the relatively coarse nanofibers. It was not possible to produce nanofiber webs with structures.

Meanwhile, the polyamide polymer solution is first electrospun by the conventional electrospinning method to prepare a nanofiber web made of polyamide nanofibers having a relatively large diameter at a level of 55 nm or more, and then the polyamide prepared In the case of laminating polyacrylonitrile nanofibers having a relatively narrow diameter to a level of 50 nm or less by, for example, secondary electrospinning of a polyacrylonitrile solution on the nanofiber web by the conventional electrospinning method described above. Although two kinds of nanofibers having different diameters may be stacked in the nanofiber web, the method requires two electrospinning processes, which is complicated in the process, and the diameters between the relatively thick nanofibers A nanofiber web with a network structure connected by relatively thin nanofibers could not be manufactured. .

In the present invention, even when electrospinning a single polymer spinning solution through nozzles of the same size, the finer nanofibers having a relatively large diameter and the finer finer nanofibers having a relatively large diameter are formed at the same time. It is an object of the present invention to provide a nanofiber network structure having a network structure that connects between nanofibers and nanofibers, and a method of manufacturing the same.

In the present invention, in order to prepare a nanofiber network structure (poly) resin, the polyamide resin is added to at least one monomer selected from the monomer of the formula (I) in a polymer solution dissolved in a solvent and then electrospun it, poly Consists of an amide resin to form nanofibers having a relatively large diameter, and at least one monomer selected from monomers of the above formula (I) (hereinafter referred to as "vinyl monomer") is polymerized during electrospinning so that the main component is a vinyl monomer. It is composed of a polymer made of a relatively narrow diameter nanofibers.

In other words, in the present invention, the vinyl monomer (monomer) is added to the electrospun polymer solution, and then polymerized during the electrospinning process to form nanofibers of fineness.

Specifically, the vinyl monomer added in the polymer solution during the electrospinning is polymerized by the electrostatic force existing between the nozzle and the collector, and the main component is composed of the polymer composed of the vinyl monomer, which is relatively thin in diameter (hereinafter referred to as "fineness degree" Nanofibers ").

On the other hand, the polyamide resin added to the polymer solution during the electrospinning is composed of a polyamide resin to form a relatively thick nanofibers (hereinafter referred to as "Taeseodo nanofibers").

The fine-grained nanofibers connect a network structure between the fine-grained nanofibers.

The nanofiber network structure of the present invention has a unique network structure and is useful as a carrier material, a drug and gene carrier, a wound treatment material, a filter material, a secondary battery material, a sensor material, a catalyst material, and the like in the pharmaceutical field.

In addition, the nanofibrous network structure of the present invention is particularly useful as a filter material for water treatment as well as a material for clothing as a web (Web) having one side hydrophilicity and the other side hydrophobic.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

First, the nanofiber network structure according to the present invention is manufactured by (i) electrospinning method as shown in Figs. 1 to 2, and the diameter is 55 nm to 2,000 nm and is composed of polyamide resin nano Fibers and (ii) are made of electrospun and composed of finely divided nanofibers composed of a polymer composed of one or more monomers selected from monomers of the formula (I) having a diameter of 0.1 to 50 nm and a main component, The fine fine nanofibers are connected between the fine fine nanofibers in a network structure, and the diameter of the fine fine nanofibers is more than three times the diameter of the fine fine nanofibers.

[In formula (I), R1 is H, CH ₃ , Cl, Br, F, CN, benzene, COOH, CONH ₂ , CH ₃ COOH or CH ₃ COOCH ₃ ]

More specifically, the nanofiber network structure according to the present invention has a network structure in which the fine-grained nanofibers are connected between the thimble nanofibers as a nanofiber web form.

The finely divided nanofibers composed of a polymer composed of at least one monomer selected from monomers of the formula (I) (hereinafter abbreviated as "vinyl monomer") are polyacrylonitrile, copolymers of polyacrylonitrile, polyvinyl or Polyvinyl copolymer and the like.

The fine-grained nanofibers are formed by polymerizing vinyl monomers added in an electrospun polymer solution by electrostatic force existing between the nozzle and the collector during the electrospinning process.

Formic acid, which is primarily a solvent in the polymer solution, acts as a reducing agent activated by high voltage. Subsequently, the hydrogen ions affect the double bond of the vinyl monomer to excite and subsequently polymerize. The polymer and the polyamide polymer having the main component formed as above are the vinyl monomers, and phase separation occurs during the electrospinning process, and the polyamide nanofibers are formed between the polyamide nanofibers due to the polarity difference between the polymer and the polyamide. The fibers appear to form network structures that connect to each other.

Specific examples of the vinyl monomers are acrylonitrile monomers, acrylonitrile copolymer monomers, vinyl monomers, vinyl copolymer monomers or mixed monomers thereof.

The diameter of the fineness nanofibers is 50 nm or more, preferably 55-2,000 nm, and the diameter of the fineness nanofibers is 50 nm or less, more preferably 0.1-30 nm, and the fineness polyamide nanofibers The diameter of is more than three times the diameter of the fine-grained polyacrylic acid nanofibers.

Next, a method for producing a nanofiber network structure according to the present invention will be described in detail.

The method for producing a nanofiber network structure according to the present invention is characterized in that the vinyl monomer is added to the polymer solution in preparing the nanofiber structure by electrospinning a polymer solution in which a polyamide resin is dissolved in a solvent.

The amount of the vinyl monomer added is preferably 70% by weight or less based on the weight of the polymer solution.

The vinyl monomer contained in the polymer solution is polymerized into a polymer composed of vinyl monomers as a main component by the electrostatic force applied between the nozzle and the collector during electrospinning to form fine fine nanofibers.

At this time, the formic acid (solution) contained in the polymer solution acts as a reducing agent activated by high voltage, and hydrogen ions are affected by the double bond of the vinyl monomer to be excited to cause the polymerization to occur continuously.

As described above, the polymerized main component is a polymer composed of vinyl monomers and polyamides originally dissolved in a solution. The phase separation is performed in the electrospinning process, and the main components are composed of finely divided nanofibers and polyamides, respectively. The fine islands form nanofibers, and due to the polarity difference between the polymer made of the polyamide and the vinyl monomer, the fine islands of nanofibers connect the Taiseo island nanofibers in a network structure.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1

Nylon 6 of Kolon Corporation having a relative viscosity of 2.8 was dissolved in a solvent in which formic acid and acetic acid were mixed at 4/1 to prepare a solution of 22 wt% nylon 6. The acrylonitrile monomer was added to this solution in the same volume ratio of 1: 1, and mixed at room temperature for 5 minutes. Electrospinning was performed using this mixed solution. The electrospinning experiment was carried out using a general electrospinning apparatus, and electrospinning was carried out with a distance of 12 cm between the nozzle and the collector under a voltage of 19 kV. Electron micrographs of the prepared nanofiber network structure were as shown in Figs. As can be seen in Figure 1, a network structure consisting of polyacrylonitrile fibers having an average diameter of 20 nm and nylon fibers having an average diameter of 100 nm was formed.

FIG. 2 is an enlarged electron micrograph of FIG. 1.

Figure 3 shows that when the nanofiber network structure prepared by the method of Example 1 is sufficiently immersed in dimethylformamide solvent, nylon 6 is not dissolved at all, but only polyacrylonitrile is dissolved, and then dissolved with polyacrylonitrile. The results of electron microscopy confirmed that all fibers with a very small diameter having an average diameter of 20 nm disappeared.

Figure 4 is a result of analyzing the nuclear magnetic resonance (Nuclear Mgnetic Resonance: NMR) with a solution obtained by dissolving the nanofiber network structure of Figure 1 to 2 prepared by the method of Example 1 with dimethylformamide solvent As a graph showing that the acrylonitrile monomer is polymerized during electrospinning to confirm that polyacrylonitrile is formed. 4 shows pure acrylonitrile monomer and shows a strong peak at around 6 ppm. However, the upper picture of FIG. 4 shows peaks of a solution obtained by dissolving the nanofiber network structure of FIGS. The characteristic peak in the vicinity is evidence that acrylonitrile polymerizes during the electrospinning process to form a polymer. In the upper picture of Figure 4 it can be seen that the acrylonitrile monomer peak disappears.

Judging from such a basis, it can be confirmed that the fine-grained nanofibers forming a network structure are composed of polyacrylonitrile resin. It can be seen that various compositions are contained in the mat of electrospun nanofibers. This indirectly indicates that when the electrospinning of acrylonitrile monomer is added to the polyamide solution, the electrostatic force attacks the double bond of the acrylonitrile monomer to cause polymerization.

Example 2

Nylon 66 having a relative viscosity of 2.6 was dissolved in a solvent in which formic acid and acetic acid were mixed at 4/1 to prepare a solution of 20 wt% nylon 66. The acrylonitrile monomer was added to this solution in the same volume ratio of 1: 1, and mixed at room temperature for 5 minutes. Electrospinning was performed using this mixed solution. The electrospinning experiment was carried out using a general electrospinning apparatus, and electrospinning was carried out with a distance of 12 cm between the nozzle and the collector under a voltage of 25 kV. An electron micrograph of the prepared nanofiber network structure was as shown in FIG. 5. As can be seen in Figure 5, a network structure was formed of polyacrylonitrile fibers having an average diameter of 18 nm and nylon 66 fibers having an average diameter of 95 nm.

1 is an electron micrograph of a nanofiber network structure prepared in Example 1. FIG.

FIG. 2 is an electron microscope photograph of the enlarged image of FIG. 1; FIG.

3 is an electron micrograph showing a state in which the fine-fiber nanofibers made of polyacrylonitrile in the nanofiber network structure are removed by immersing the nanofiber network structure of FIG. 1 prepared in Example 1. FIG.

4 is a nanofiber network structure prepared in Example 1 in dimethylformamide and put in a shaker for 36 hours to extract a component solution consisting of polyacrylonitrile, with nuclear magnetic resonance (Nuclear Mgnetic Resonance: NMR) graph showing the results of the analysis.

5 is an electron micrograph of the nanofiber network structure prepared in Example 2.

6 is a process schematic diagram showing an example of a conventional electrospinning process.

Claims (4)

(Iii) Taeseomdo nanofibers prepared by electrospinning method and composed of polyamide resin with a diameter of 55 nm to 2,000 nm, and (ii) 0.1 to 50 nm in diameter produced by electrospinning method. (I) is composed of fine-grained nanofibers composed of a polymer consisting of at least one monomer selected from the monomers, wherein the fine-grained nanofibers are connected in a network structure between the Taiseo-do nanofibers, The diameter of the nanofiber nanofibers is nanofiber network structure, characterized in that more than three times the diameter of the fine microfiber nanofibers.

[In formula (I), R1 is H, CH ₃ , Cl, Br, F, CN, benzene, COOH, CONH ₂ , CH ₃ COOH or CH ₃ COOCH ₃ ] The nanofiber network structure according to claim 1, wherein the fineness nanofibers have a diameter of 0.1 to 30 nm. In preparing a nanofiber structure by electrospinning a polymer solution in which a polyamide resin is dissolved in a solvent, a nanofiber network comprising adding at least one monomer selected from monomers of the following formula (I) into the polymer solution Method of manufacturing a network structure.

[In formula (I), R1 is H, CH ₃ , Cl, Br, F, CN, benzene, COOH, CONH ₂ , CH ₃ COOH or CH ₃ COOCH ₃ ] The method of claim 3, wherein the polyamide resin is electrospun a polymer solution dissolved in a solvent to produce a nanofiber structure, the acrylonitrile monomer, acrylonitrile copolymer monomer, vinyl monomer and vinyl copolymer monomer in the polymer solution. Method for producing a nanofiber network (Network) structure, characterized in that the addition of at least one monomer selected from.

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