KR102283577B1 - Porous structure, methods of fabricating thereof and triboelectric generator using the same - Google Patents

Abstract

The present invention relates to a porous structure, a method for manufacturing the same, and a triboelectric nanogenerator using the same, wherein the porous structure having pores comprises: first polymer block compounds having at least one first functional group; second polymer block compounds having a second functional group bonded to the first functional group of the first polymer block compound of some of the first polymer block compounds to form a first copolymer compound; and third polymer block compounds bonded to the first functional group of the first polymer block compound of another part of the first polymer block compounds to form a second copolymer compound, wherein the first polymer block compound is constituting the skeleton of the porous structure, wherein the pores are formed by competition between a first chemical bond between the first functional group and the second functional group and a second chemical bond between the first functional group and the third polymer block compound, The second polymer block compound and the third polymer block compound may constitute the surface of the pores. The first interaction may include a Lewis acid/base interaction, the second interaction may include hydrogen bonding, wherein the pores are formed without an etching process, and the average diameter of the pores is about 10 nm to 200 nm.

Description

Porous structure, manufacturing method thereof, and triboelectric generator using the same

The present invention relates to a new material technology, and more particularly, to a nanoporous thin film, a method for manufacturing the same, and a triboelectric generator using the same.

Recently, as energy-related problems such as depletion of fossil energy, environmental pollution, and increasing energy demand have emerged, there is a need to develop alternative energy that departs from the existing energy generation system. Accordingly, interest in energy harvesting technology that converts wasted energy existing around us into useful electrical energy as an alternative energy technology is increasing. Based on the principle of inducing static electricity through friction among the energy harvesting technologies, research on a device for converting kinetic energy into electrical energy is being conducted from various angles.

A triboelectric nanogenerator (TENG) as an energy harvester is a technology that converts mechanical energy into electricity by using the coupling effect between triboelectric charge and static electricity introduced through contact separation or grazing between two materials with relative tribopolarization. As a device, it can be configured with a simple device architecture that can be easily applied to other existing optoelectronic devices.

In relation to the TENG, research on a wide range of materials capable of selecting an appropriate contact pair according to surface charge affinity has been recently conducted. It may find particular use in the field of wearables and patchable devices suitable for human interactive electronics including small-scale electrical generators, self-powered sensors, biocompatible devices, miniature logic devices and hybrid power supplies with capacitors and batteries. Specifically. In addition to appropriate material selection, studies on physical and chemical surface modification have been actively conducted to further improve the performance of the TENG with a given contact pair. For example, chemical modification pathways such as self-assembled monolayer (SMA) treatment and plasma and surface metal decoration are effective, and general physical methods that can directly increase the contact area are mainly the contact surface. to nanostructure it. Various aligned or random topological nanostructures have been applied based on various top-down and bottom-up patterning principles, including nanoimprinting, transfer printing, and self-assembled templates.

However, since most conventional processes for forming nanostructures use reactive ion and plasma processes, the manufacturing process is complicated and manufacturing cost may increase. In addition, since nanopores are conventionally formed through a post-etching process, this may limit the material selection range of TENG.

Accordingly, the technical problem to be solved by the present invention is to provide a nanoporous thin film that has a simple manufacturing process by simplifying the pore forming process, reduces manufacturing cost, and does not require a post-etching process.

In addition, another technical problem to be solved by the present invention is to provide a method for manufacturing a nanoporous thin film having the above-described advantages.

In addition, another technical problem to be solved by the present invention is to provide a triboelectric nanogenerator using the nanoporous thin film having the above-described advantages.

According to an embodiment of the present invention, there is provided a porous structure having pores, comprising: first polymer block compounds having at least one first functional group; second polymer block compounds having a second functional group bonded to the first functional group of the first polymer block compound of some of the first polymer block compounds to form a first copolymer compound; and third polymer block compounds bonded to the first functional group of the first polymer block compound of another part of the first polymer block compounds to form a second copolymer compound, wherein the first polymer block compound is constituting the skeleton of the porous structure, wherein the pores are formed by competition between a first chemical bond between the first functional group and the second functional group and a second chemical bond between the first functional group and the third polymer block compound, A porous structure in which the second polymer block compound and the third polymer block compound constitute the surface of the pores may be provided. The first compounding bond may comprise a Lewis acid/base interaction, and the second compounding bond may comprise a hydrogen bond. The average diameter of the pores has a range of 10 nm to 200 nm, and is adjusted according to the ratio of the second polymer block compound to the third polymer, and the ratio of the second polymer block compound to the third polymer is 0.01 to 0.3 can have a range. The first functional group is at least one selected from the group consisting of a sulfonic acid group, a sulfonate group, a phosphate group, a sulfate group and a hydroxyl group, The second functional group may include an amine group.

In one embodiment, the first polymer block compound includes any one or more of polystyrene, syndiotactic polystyrene, sulfurnite polystyrene, and sulfurnite silsesquioxane, and the second polymer block compound is polyethylene oxide (poly( ethylene oxide)), and the third polymer block compound is poly-2-vinyl-pyridine (P2VP), pyrimidine, 2-methyl pyrimidine, 4-methyl pyrimidine, 5-methyl pyrimidine, 4,6 -dimethyl pyrimidine, 4.6-dimethoxy pyrimidine, 2-ethyl pyrimidine, 4-ethyl pyrimidine, 5-ethyl pyrimidine, 4,6-diethyl pyrimidine, 2-methoxy pyrimidine, 4-methoxy It may include any one or more of pyrimidine, 5-methoxy pyrimidine, 2-ethoxy pyrimidine, 4-ethoxy pyrimidine, 5-ethoxy pyrimidine polyamic acid, and polyolefin ketone.

According to another embodiment of the present invention, the method comprising: preparing an object to be processed; preparing a ternary polymer blend including a first polymer block compound, a second polymer block compound, and a third polymer block compound; and coating the ternary polymer blend on the object to form pores of the porous structure, wherein the first polymer block compound constitutes a skeleton of the porous structure, and the pores are formed with the first functional group The second functional group is formed by competition between a first chemical bond and a second chemical bond between the first functional group and the third polymer block compound, wherein the second polymer block compound and the third polymer block compound form the pores constituting the surface of the porous coating, including any one of spin coating, dip coating, spray coating, bar coating, and painting coating A method of making a structure may be provided.

According to another embodiment of the present invention, a triboelectric generator including the porous structure disclosed in claim 1 may be provided.

According to an embodiment of the present invention, in a nanoporous thin film comprising a first polymer block compound comprising a first functional group, a second polymer block compound comprising a second functional group different from the first functional group, and a third polymer block compound The pores are formed by competition between a first chemical bond between the first functional group and the second functional group and a second chemical bond between the first functional group and the third polymer block compound, thereby simplifying the pore forming process and reducing the manufacturing process. A nanoporous thin film that is simple and can reduce manufacturing cost can be provided. In addition, it is possible to prevent damage to the substrate due to the post-treatment process, it is possible to apply various coating processes to various substrates without being limited by the material and coating method of the substrate.

In addition, according to another embodiment of the present invention, a method for manufacturing a nanoporous thin film having the above-described advantages may be provided.

In addition, according to another embodiment of the present invention, a triboelectric nanogenerator using the nanoporous thin film having the above-described advantages may be provided.

1A and 1B are views for explaining the structure of a nanoporous thin film according to an embodiment of the present invention.
1C is a view for explaining a compound bond forming pores of a nanoporous thin film according to an embodiment of the present invention.
2A is a field emission scanning electron microscope (FE-SEM) image showing a cross-section of a nanoporous thin film according to an embodiment of the present invention.
2B is a tapping mode atomic force microscopy (TM-AFM) image showing the surface of a nanoporous thin film according to an embodiment of the present invention.
FIG. 2c is a depth profile of the image of FIG. 2b.
2D is a graph showing the pore size and domain size according to the weight ratio of the polymer block compound controlling the pores of the nanoporous thin film.
3a is a view for explaining a method of manufacturing a nanoporous thin film according to an embodiment of the present invention, FIG. 3b is an FE-SEM image of the nanoporous thin film according to the manufacturing method of FIG. It is a diagram showing the open-circuit voltage value of the nanoporous thin film according to the manufacturing method.
4A is a perspective view of a triboelectric nanogenerator using a nanoporous thin film according to an embodiment of the present invention, and FIG. 4B is a diagram showing an application example using the triboelectric nanogenerator.
5A is a view showing the open circuit voltage of the triboelectric nanogenerator according to the weight ratio of the polymer block compound that controls the pores of the nanoporous thin film.
5B is a diagram showing the short-circuit current of the triboelectric nanogenerator according to the weight ratio of the polymer block compound that controls the pores of the nanoporous thin film.
5C is a view showing the output power of the triboelectric nanogenerator according to the weight ratio of the polymer block compound that controls the pores of the nanoporous thin film.
5D is a view showing a state in which 40 lights are turned on by a triboelectric nanogenerator using a nanoporous thin film.
5E is a diagram showing the open circuit voltage and short circuit current of a triboelectric nanogenerator using a nanoporous thin film according to the number of contacts.
Fig. 5f is a FE-SEM image of the nanoporous thin film before contact and the nanoporous thin film after more than 50,000 contacts.
Figure 6a is a Kelvin Probe Force Microscopy (KPFM) image showing the surface potential (surface potential) of the nanoporous thin film according to an embodiment of the present invention, Figure 6b is the pores of the nanoporous thin film according to the embodiment of the present invention It is a graph showing the average contact potential difference according to the change of the polymer block compound controlling the
7 is a view showing an improvement rate of an open circuit voltage of a triboelectric nanogenerator including a nanoporous thin film disposed on various substrates.
8 is a diagram comparing the open circuit voltages of flat polydimethyl siloxane (PDMS), buckled PDMS, and corrugated PDMS coated with a nanoporous thin film.
9A is a diagram showing a nanoporous thin film attached to a finger, and FIG. 9B is an open circuit voltage between an FET tape uncoated with a nanoporous thin film and a finger skin and an opening between a FET tape coated with a nanoporous thin film and a finger skin It is a diagram comparing voltages.
10A is a diagram illustrating a nanoporous thin film having a large area, and FIG. 10B is a diagram illustrating an open circuit voltage according to a change in area of the nanoporous thin film.
11A is a view showing a nanoporous thin film coated on a graphene-coated fiber, and FIG. 11B is a diagram comparing the open circuit voltage between a fiber uncoated with the nanoporous thin film and a fiber coated with the nanoporous thin film.
Fig. 12a is a view showing a nanoporous thin film coated on a leaf, and Fig. 12b is a view comparing the open circuit voltage between a leaf uncoated with the nanoporous thin film and a fiber coated with the nanoporous thin film.
13A is a view showing a nanoporous thin film coated on a conductive fabric, and FIG. 13B is a diagram comparing the open circuit voltage between a conductive fabric uncoated with the nanoporous thin film and a conductive fabric coated with the nanoporous thin film.

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

Examples of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, and the scope of the present invention is as follows It is not limited to an Example. Rather, these examples are provided so that this disclosure will be more thorough and complete, and will fully convey the spirit of the invention to those skilled in the art.

In the drawings, like reference numerals refer to like elements. Also, as used herein, the term “and/or” includes any one and all combinations of one or more of those listed items.

The terminology used herein is used to describe the embodiments, and is not intended to limit the scope of the present invention. Also, although the singular is used herein, the plural form may be included unless the context clearly indicates the singular. Also, as used herein, the terms "comprise" and/or "comprising" specify the presence of the recited shapes, numbers, steps, actions, members, elements, and/or groups thereof. It does not exclude the presence or addition of other shapes, numbers, movements, members, elements and/or groups.

Reference herein to a layer formed “on” a substrate or other layer refers to a layer formed directly on the substrate or other layer, or an intermediate layer or intermediate layers formed on the substrate or other layer. It may also refer to a layer. Also, for those skilled in the art, a structure or shape disposed "adjacent" to another shape may have a portion disposed above or below the adjacent shape.

As used herein, “below”, “above”, “upper”, “lower”, “horizontal” or “vertical” Relative terms such as , may be used to describe the relationship that one constituent member, layer or region has with another constituent member, layer or region, as shown in the drawings. It should be understood that these terms encompass not only the orientation indicated in the drawings, but also other orientations of the device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to cross-sectional views schematically illustrating ideal embodiments (and intermediate structures) of the present invention. In these drawings, for example, the size and shape of the members may be exaggerated for convenience and clarity of description, and in actual implementation, variations of the illustrated shape may be expected. Accordingly, embodiments of the present invention should not be construed as limited to the specific shapes of the regions shown herein. Also, reference numerals for members in the drawings refer to the same members throughout the drawings.

1A and 1B are views for explaining the structure of a nanoporous thin film according to an embodiment of the present invention, and FIG. 1C is a view for explaining a compound bond forming pores of a nanoporous thin film according to an embodiment of the present invention am.

1A and 1B, the nanoporous thin film (NPF) includes a porous structure having pores (OP), and the porous structure includes at least one first polymer block compound having at least one first functional group (FG1) ( PB1); A second polymer block compound (PB2) having a second functional group (FG2) bonded to the first functional group of the first polymer block compound (PB1) of some of the first polymer block compounds to form a first copolymer compound field; and third polymer block compounds (FG3) bonded to the first functional group (FG1) of the first polymer block compound (PB1) of another part of the first polymer block compounds (PB1) to form a second copolymer compound The first polymer block compound (PG1) constitutes the skeleton of the porous structure, and the pores (OP) have a first chemical bond (CB1) between the first functional group (FG1) and the second functional group (FG2) and the first Formed by competition between a second chemical bond (CB2) between the functional group (FG2) and the third polymer block compound (PB3), the second polymer block compound (PB2) and the third polymer block compound (PB3) form pores (OP ) of the surface can be constructed.

In one embodiment, the nanoporous thin film (NPF) may be formed on the target substrate SB, the first polymer block compound (PB1) including the first functional group (FG1), the first functional group (FG1) and The second polymer block compound (PB2) and the third polymer block compound (PB3) including another second functional group (FG2) may be included. The first polymer block compound (PB1) may constitute a skeleton of the nanoporous thin film, and the second polymer block compound (PB2) and the third polymer block compound (PB3) may be located on the surface of the pores (OP). The pores OP may include open pores, and the average diameter of the open pores may range from 10 nm to 200 nm. The average diameter size of the pores (OP) may be adjusted according to the volume ratio of the second polymer block compound and the third polymer. The maximum average diameter of the open pores, which can be adjusted by the relative volume ratio of the second polymer block compound and the third polymer, does not exceed 200 nm, and in order to control the average diameter of the open pores to 10 nm or less, the second polymer block compound and the If the volume ratio of any one of the third polymer block compounds is very large, the volume ratio of the other must be very small (converge to 0), so it may be difficult to spontaneously form due to the pore formation principle described later. The ratio of the second polymer block compound (PB2) to the third polymer block compound (PB3) may be in the range of 0.01 to 0.3. When the ratio of the second polymer block compound (PB2) to the third polymer block compound (PB3) is 0.01 or less, that is, the concentration of the second polymer block compound (PB2) is relatively higher than that of the third polymer block compound (PB3). When it is low, the difference in surface roughness and the difference in surface potential are lowered due to the predominance of the formation of the micelle structure, so that it may be limited to use in a triboelectric nanogenerator to be described later. When the ratio of the second polymer block compound (PB2) to the third polymer block compound (PB3) is 0.3 or more, that is, the concentration of the second polymer block compound (PB2) is relatively higher than that of the third polymer block compound (PB3). When it is high, the formation of the cylinder structure is dominant, which leads to a decrease in the pore size of the entire structure, so that the third polymer block compound (PB3) having a relatively large surface potential becomes small and triboelectric when rubbing with the FOTS-SAM-treated substrate may be smaller.

In one embodiment, the first polymer block compound (PB1) includes any one or more of polystyrene, syndiotactic polystyrene, sulfurite polystyrene, and sulfurite silsesquioxane, and the second polymer block compound (PB2) is polyethylene oxide (poly(ethylene oxide)). The third polymer block compound (PB3) is poly-2-vinyl-pyridine (P2VP), pyrimidine, 2-methyl pyrimidine, 4-methyl pyrimidine, 5-methyl pyrimidine, 4,6-dimethyl pyrimidine, 4.6 -dimethoxy pyrimidine, 2-ethyl pyrimidine, 4-ethyl pyrimidine, 5-ethyl pyrimidine, 4,6-diethyl pyrimidine, 2-methoxy pyrimidine, 4-methoxy pyrimidine, 5-meth It may include any one or more of oxypyrimidine, 2-ethoxy pyrimidine, 4-ethoxy pyrimidine, 5-ethoxy pyrimidine polyamic acid, and polyolefin ketone.

In one embodiment, the first functional group (FG1) is selected from the group consisting of a sulfonic acid group, a sulfonate group, a phosphate group, a sulfate group, and a hydroxyl group. It is one or more selected and the second functional group (FG2) may include a primary amine group. The third functional group (FG3) may include a secondary amine group of the pyridine unit of the third polymer block compound (PB3).

The first functional group (FG1) and the second functional group (FG2) may be bonded by a first chemical bond (CB1), and the bond between the first functional group (FG1) and the third polymer block compound (PB3) is a second It can be formed by chemical bonding. The first compounding bond (CB1) may include a Lewis acid/base interaction, and the second compounding bond (CB2) may include a hydrogen bonding.

In an embodiment of the present invention, the first polymer block compound (PB1) may be a polymer containing a sulfonate group, and the second polymer block compound (PB2) is a polymer containing an amine group. may be, and the third polymer block compound (PB3) may be a polymer having pyridine in which carbon in the benzene ring is substituted with a nitrogen atom that is easy to bond with hydrogen. Preferably, the first polymer block compound (PB1) may be sulfonated polystyrene (SPS), and the second polymer block compound (PB2) may be amine-terminated poly(ethylene oxide) (APEO), and the third The polymer block compound (PB3) may be poly-2-vinylpyridine (Poly(2-vinylpyridine): P2VP).

The principle of self-assembled nanoporosity in a nanoporous thin film (NPF) will be described by simplifying the pore formation process or as a fast one-step process without post-processing such as etching.

The present invention is based on a ternary polymer solution blend comprising a supramolecular assembly of a first polymer block compound (PB1), a second polymer block compound (PB2) and a third polymer block compound (PB3). In the ternary polymer blend, the second polymer block compound (PB2) is the interaction between the first polymer block compound (PB1) and the second polymer block compound (PB2), and the first polymer block compound (PB1) and the third polymer block compound (PB2) Acting as a pore-generating agent through competition between PB3) interactions, it can effectively activate spontaneous nanopore formation. Therefore, a one-step process using a ternary polymer solution can produce a thin large-area thin film with self-assembled ordered nanoporosity of a given diameter without an additional etching process.

Specifically, the first polymer block compound (PB1) (eg, SPS) and the third polymer block compound (PY3) (eg, P2VP) are self-assembled upon hydrogen bonding to form a core-shell (or corona) ))) to form spherical micelles. The core-shell structure may include a core layer formed inside the spherical micelles and a shell layer surrounding the outside of the core layer. In the spherical micelles, the first polymer block compound (PB1) may constitute the backbone of the formed spherical micelles, and the third polymer block compound (PB3) may constitute a hydrogen-bonded side chain with the first polymer block compound (PB1). can On the other hand, the first polymer block compound (PB1) (eg SPS) and the second polymer block compound (PY2) (eg APEO) are self-assembled during Lewis acid/base interaction to form a cylindrical nanostructure can be formed In an embodiment, an inter material dividing surface (IMDS) of the SPS:P2VP assembly may be larger than the IMDS of the SPS:APEO assembly.

The first polymer block compound (PB1) (eg, SPS) and the third polymer block compound (PY3) (eg, P2VP) are self-assembled upon hydrogen bonding to form a core-shell (or corona) The characteristics of forming spherical micelles of the structure and the first polymer block compound (PB1) (eg SPS) and the second polymer block compound (PY2) (eg APEO) self-assembly upon Lewis acid/base interaction ) to form a cylindrical nanostructure, comprising a supramolecular assembly of the first polymer block compound (PB1), the second polymer block compound (PB2) and the third polymer block compound (PB3) When the raw polymer solution blend is coated on the target substrate, open pores can be spontaneously formed in the surface of the thin film so that the formation of spherical micelles and the formation of cylindrical nanostructures interact.

That is, the curvature of the spherical micelles self-assembled by the first polymer block compound (PB1) (eg SPS) and the third polymer block compound (PY3) (eg P2VP) is the first polymer block compound (PB1) (eg: SPS) and the second polymer block compound (PY2) (eg, APEO) are self-assembled during Lewis acid/base interaction to form a cylindrical nanostructure, thereby reducing open pores can become

2A is a field emission scanning electron microscope (FE-SEM) image showing a cross-section of a nanoporous thin film according to an embodiment of the present invention. Nanoporous thin films were prepared through a ternary polymer blend of SPS:P2VP:APEO (0.7:0.15:0.15).

Referring to FIG. 2a , it can be seen that the nanoporous thin film has nanopores formed by APEO of the ternary polymer blend. In the thin SPS:P2VP binary thin film, dense micelles appear, but in the nanoporous thin film formed by the ternary polymer blend, nanopores with a diameter of about 33 nm appear.

Figure 2b is a tapping mode atomic force microscopy (TM-AFM) image showing the surface of the nanoporous thin film according to an embodiment of the present invention, Figure 2c is a depth curve (depth profile) of the image of Figure 2b, , FIG. 2D is a graph showing the pore size and domain size according to the weight ratio of the polymer block compound controlling the pores of the nanoporous thin film. To investigate the nanopores of nanoporous thin films, thin spin-coated films with a thickness of about 70 nm as a function of the relative amounts of APEO and P2VP in a ternary polymer blend were prepared. In the ternary polymer blend, SPS had a fixed volume fraction of 0.7, and the relative fractions of APEO and P2VP were varied to ensure the stoichiometry of the ternary polymer blend. Nanoporous structures were also confirmed by transmission electron microscopy (TEM), and depth profile analysis was based on TM-AFM results.

2b and 2d, it can be seen that the binary polymer blend of SPS:P2VP (0.7:0.3) forms a supramolecular nanostructure composed of micelles with a diameter of about 50 nm with the core and corona of SPS and P2VP, respectively. there is. However, adding a small amount of APEO can transform the microporous film into a nanoporous film. As the relative fraction of APEO in the ternary polymer blend was 50% (ie, SPS:P2VP:APEO (0.7: 0.15: 0.15)), nanopores were clearly visible. As the amount of APEO increases in the ternary polymer blend, the nanopores become smaller but more densely formed.

Referring to FIGS. 2c and 2d , the depth profile analysis reveals that the surface convex profile generated in the micelle assembly was converted into a concave surface with APEO in the tertiary blend. The blend of SPS:P2VP:APEO (0.7:0.15:0.15) produces a nanoporous structure with a maximum pore depth of approximately 15 nm.

3a is a view for explaining a method of manufacturing a nanoporous thin film according to an embodiment of the present invention, FIG. 3b is an FE-SEM image of the nanoporous thin film according to the manufacturing method of FIG. 3a, and FIG. 3b is a diagram of FIG. 3a It is a diagram showing the open-circuit voltage value of the nanoporous thin film according to the manufacturing method.

A method for manufacturing a nanoporous thin film includes the steps of preparing an object to be treated, preparing a ternary polymer blend including a first compound block, a second compound block, and a third compound block; and coating the ternary polymer blend on the object to form open pores of the nanoporous thin film.

In the step of preparing the ternary polymer blend, the first polymer block compound (PB1), the second compound (PB2) and the third polymer block compound (PB3) are mixed with a dispersion solvent to form a first polymer block compound (PB1) and A mixture comprising a spherical micelle in which the third polymer block compound (PB3) is self-assembled at the same time as binding, and a cylindrical nanostructure in which the first polymer block compound (PB1) and the second polymer block compound (PB2) are self-assembled at the same time as binding solution can be formed. At least one of the first polymer block compound (PB1) and the third polymer block compound (PB3) may be a polymer including a functional group (FG) capable of hydrogen bonding. At least one of the first polymer block compound (PB1) and the second polymer block compound (PB2) may be a polymer including a functional group (FG) capable of Lewis acid/base bonding.

In one embodiment, the dispersion solvent is an aliphatic or aromatic hydrocarbon (eg, heptane, toluene), a halogenated aliphatic or aromatic hydrocarbon (eg, dichloromethane, bromobenzene), an ether (eg, diethyl ether) ), water, ethanol, and methanol, or a mixture thereof, and the present invention is not limited thereto as long as it is a polar solvent. Preferably, the dispersion solvent may be benzene or methanol. The first polymer block compound (PB1) and the third polymer block compound (PB3) mixed in the dispersion solvent are hydrogen by the functional group (FG) included in the first compound (PB1) and the third polymer block compound (PB3). can be combined The first compound (PB1) and the second polymer block compound (PB2) mixed in the dispersing solvent form a Lewis acid by a functional group (FG) included in the first polymer block compound (PB1) and the second polymer block compound (PB2). /can be base-bonded

The third polymer block compound (PB1) may be a polymer having a lower solubility in the dispersion solvent than the first polymer block compound (PB2). When the third polymer block compound (PB3) and the first polymer block compound (PB1) are hydrogen-bonded in the dispersion solvent, the first polymer block compound (PB1) having high affinity with the dispersion solvent may be included in the shell layer, The third polymer block compound (PB3) having a relatively low affinity with the dispersion solvent may be included in the core layer.

In this case, the size of the pores, particularly the open pores, may be controlled by the volume ratio of the second polymer block compound (PB1) and the third polymer block compound (PB3).

In an embodiment, the coating step may include any one of spin coating, dip coating, spray coating, and bar coating. However, the present invention is not limited thereto. For example, the coating step may include printing, vacuum filtration, impregnation coating, and application coating.

Referring to Figure 3a, it is also possible that the ternary polymer blend is compatible with most wet coating processes such as spin, bar, spray and dip coating to produce fast wet processable nanoporous thin films.

Referring to FIGS. 3B and 3C, all representative shapes of nanoporous thin films formed by four different coating processes exhibit characteristic nanopores over a large area. Nanoporous thin films can also be successfully adopted for TENG, and the open circuit voltage of TENG can be greatly improved due to the nanostructure. The reason for the rather small improvement in the open circuit voltage of TENG formed by dip coating is that the nanoporous thin film is much thinner than that formed by other coating methods.

In another embodiment of the present invention, a triboelectric nanogenerator using the aforementioned nanoporous thin film (NPF) may be provided. In the triboelectric nanogenerator, a nanoporous thin film (NPF) may be used as a friction material layer to generate friction. The triboelectric nanogenerator has a vertical contact-separation mode, a lateral sliding mode, a single-electrode mode, and a free It can be classified as a triboelectric nanogenerator operating in any one of the freestanding triboelectric-layer mode.

4A is a perspective view of a triboelectric nanogenerator using a nanoporous thin film according to an embodiment of the present invention, and FIG. 4B is a diagram showing an application example using the triboelectric nanogenerator.

Referring to FIG. 4A , the triboelectric nanogenerator (TENG) is formed on the above-described nanoporous thin film (STENF) formed on a first electrode and a second electrode (electrode) and faces friction with the nanoporous thin film (STENF) It may include a thin film (FOTS-SAM). The friction thin film (FOTS-SAM) may include a polymer layer and self-assembled monolayers (SAMs) formed on the polymer layer. In addition, a PDMS layer may be further included between the second electrode and the friction thin film (FOTS-SAM).

The polymer layer may be made of a polymer or a non-metal material. For example, it may be formed of a polymer containing oxygen such as polydimethylsiloxane (PDMS), polyethylene terephthalate, polyimide, or a non-metallic material such as silicon oxide or aluminum oxide.

Self-assembled monolayers (SAMs) are organic monomolecular films that are spontaneously formed on a solid surface, and include a head group binding to the surface of the first nanoporous thin film (PL1), and a terminal group (or functional group) positioned on the surface; It may include a hydrocarbon chain connecting the head group and the functional group. Through various selection of the functional groups, self-assembled monolayers having various different properties may be formed, and the magnitude of triboelectric energy generated may vary according to the functional groups. In addition, the self-assembled monolayer (SAMs) may be any one of a self-assembled monolayer of alkanoic acid, a self-assembled monolayer of organic sulfur, and a self-assembled monolayer of organic silicon.

Self-assembled monolayers (SAMs) have a head group that is a silane group or silanol group (Si(OCH3) 3, Si(OC2H5)3) that binds to oxygen of the first nanoporous thin film PL1, and a functional group (eg, CH3, CF3). , COOH, NH2), and hydrocarbons and/or fluorocarbons that are carbon chains connecting them. For example, the self-assembled monolayer (SAMs) may be a hydrocarbon-silane containing a silane group. For example, self-assembled monolayers (SAMs) are one of (3_Aminopropyl)triethoxysilane (APTES), n-Propyltriethoxysilane (PTES), (3,3,3-Trifluoropropyl)trimethoxysilane (FAS3), (3-Mercaptopropyl)trimethoxysilane (MTS) may include.

When an external load is applied in the vertical direction, two different materials that are spaced apart (eg, nanoporous membrane (STENF) and friction membrane (FOTS-SAM)) are rubbed and can generate positive and negative charges on their respective surfaces. there is. When the external load is removed, each of the charged surfaces can be spaced apart again, creating a potential difference inside the harvester. In this case, electrons may move between the first electrode and the second electrode through an external circuit (or an electrical load) in order to maintain a charge balance inside the device to generate an output current. Continuous output production may be possible by applying repetitive external loads based on the above mechanism.

Referring to FIG. 4B , the triboelectric nanogenerator (TENG) has flexibility and may be formed on skin such as a wrist. And with the other hand, an external load can be applied to a triboelectric nanogenerator (TENG) to generate an output current.

The triboelectric nanogenerator of the present invention described above is easily combined with other power storage devices such as rechargeable batteries, electric double layer capacitors (EDLCs), metal oxide pseudo capacitors or supercapacitors. Thus, a hybrid power supply can be provided. In addition, triboelectric nanogenerators can be directly integrated with optoelectronic components to provide a variety of self-powered devices such as sensors, light emitting devices, transistors, and non-volatile memories. In the present invention, a suitable pair of friction materials can be provided that can lead to maximum power performance and mechanical stability upon contact (or friction). Moreover, the electrostatic induction can be improved by providing a chemically and/or topologically modified surface, thereby triboelectric nanogenerators. For example, an increase in the contact area with a micro-patterned pyramidal arrangement and a nanoporous/nanowire thin film can improve the output performance more efficiently than a contact area with a thin film without pores.

5A is a view showing the open circuit voltage of the triboelectric nanogenerator according to the weight ratio of the polymer block compound that controls the pores of the nanoporous thin film.

Referring to Figure 5a. The open-circuit voltage of the triboelectric nanogenerator tends to decrease after the relative ratio of the polymer block compound (eg APEO) that controls the pores of the nanoporous thin film increases to 0.15. This is because the pore size and domain size controlled by the polymer block compound controlling the pores of the nanoporous thin film are related to the open circuit voltage of the triboelectric nanogenerator, as shown in FIG. 2D above. Specifically, since the performance of the triboelectric nanogenerator is greatly affected by the friction contact surface area, it is speculated that the behavior of the open circuit voltage of the triboelectric nanogenerator depends on the increase of the contact area, which is particularly affected by the pore size.

5B is a diagram showing the short-circuit current of the triboelectric nanogenerator according to the weight ratio of the polymer block compound that controls the pores of the nanoporous thin film.

Referring to FIG. 5B , the short-circuit current value of the triboelectric nanogenerator shows an operation similar to that of the open circuit voltage of FIG. 5A . Specifically, the short-circuit current of the triboelectric nanogenerator shows a tendency to decrease after the relative ratio of the polymer block compound (eg, APEO) that controls the pores of the nanoporous thin film increases to 0.15.

5C is a view showing the output power of the triboelectric nanogenerator according to the weight ratio of the polymer block compound that controls the pores of the nanoporous thin film. To obtain the output power of the triboelectric nanogenerator, the voltage and current were measured according to the external load resistance of 1kΩ to 50MΩ, and then the power was calculated as the product of each voltage and current.

Referring to FIG. 5C , the output current of the triboelectric nanogenerator shows an operation similar to that of the open circuit voltage and the short circuit current of FIGS. 5A and 5B . Specifically, the output current of the triboelectric nanogenerator shows a tendency to decrease after the relative ratio of the polymer block compound (eg, APEO) that controls the pores of the nanoporous thin film increases up to 0.15.

The maximum output power value achieved is approximately 231 μW for SPS:P2VP:APEO (0.7:0.15:0.15) and 56.9 μW for SPS:APEO (0.7:0.0:0.3), SPS:P2VP with an external load resistance of 12 MΩ. (0.7:0.3:0.0) is approximately 121 μW, and SPS:P2VP:APEO (0.7:0.15:0.15) is 3.5 more than SPS:APEO (0.7:0.0:0.3) and SPS:P2VP (0.7:0.3:0.0), respectively. twice as high as twice as high.

5D is a view showing a state in which 40 lights are turned on by a triboelectric nanogenerator using a nanoporous thin film.

Referring to Figure 5d, the maximum output power of a triboelectric nanogenerator using SPS:P2VP:APEO (0.7:0.15:0.15) can simultaneously turn on 40 conventional red light emitting diodes (LEDs) connected to the circuit.

5e is a diagram showing the open circuit voltage and short circuit current of a triboelectric nanogenerator using a nanoporous thin film according to the number of contacts, and FIG. 5f is an FE-SEM image of the nanoporous thin film before contact and after 50,000 or more contacts. .

Referring to FIGS. 5E and 5F , it can be confirmed that the triboelectric nanogenerator is very stable without significant deterioration even after repeated frictional contact for more than 50,000 times in both open voltage and short circuit current. In addition, it can be seen that the nanoporous structure of the triboelectric nanogenerator is well maintained even after repeated 50,000 cycles or more.

Figure 6a is a Kelvin Probe Force Microscopy (KPFM) image showing the surface potential (surface potential) of the nanoporous thin film according to an embodiment of the present invention, Figure 6b is the pores of the nanoporous thin film according to the embodiment of the present invention It is a graph showing the average contact potential difference (CPD) according to the change of the polymer block compound that controls the. The surface charge characteristics of the nanoporous thin film according to the nanostructure shape were investigated through KPFM in the tapping mode. Electrical contact between two surfaces of triboelectric nanogenerators (FOTS-SAM, homopolymer, SPS/P2VP/APEO), their Fermi levels are aligned by electron flow through electron tunneling, and the system reaches equilibrium. The large difference between the two layers in terms of Fermi energy levels creates a high electrostatic charge flow. CPD measured through KPFM can be evaluated using the equation CPD = (Фsample-Фtip)/e to evaluate the work function (Ф) and difference between the sample and the conductive AFM tip. where Фsample is the work function of the sample material, Фtip is the work function of the conducting AFM tip, and e is the electronic charge. The Fermi energy of an electron is derived using EF = Evac-Фsample, where EF is the Fermi energy of the electron and Evac is the energy of the vacuum level. As expected from FOTS with high electron affinity, the negative potential value of CPD is about -23.5 mV.

6A and 6B , the largest positive CPD value is observed in the nanoporous thin film of SPS:P2VP:APEO (0.7:0.15:0.15) of about 520 mV. And, the largest surface potential difference was generated with the FOTS-SAM layer of about 543 mV.

7 is a view showing an improvement rate of an open circuit voltage of a triboelectric nanogenerator including a nanoporous thin film disposed on various substrates.

Referring to FIG. 7 , the nanoporous thin film (STENF) was tested on various substrates including oxides, metals and polymers. The improvement rate of the output voltage of the triboelectric nanogenerator with and without the nanoporous thin film (STENF) was determined by ITO (Indium -Tin-Oxide) increased substantially to about 100%.

In order to more clearly explain the compatibility of various types of wet coating methods and the nanoporous thin film, the nanoporous thin film formed in various wet processes as shown in FIGS. 8 to 13B was applied to a triboelectric nanogenerator.

8 is a diagram comparing the open circuit voltages of flat polydimethyl siloxane (PDMS), buckled PDMS, and corrugated PDMS coated with a nanoporous thin film. Nanoporous thin films were fabricated by spin coating a ternary polymer blend of SPS: P2VP:APEO (0.7:0.15:0.15) onto corrugated PDMS.

Referring to Figure 8, it was observed that the open-circuit voltage of the triboelectric nanogenerator using the nanoporous thin film formed in the corrugated PDMS was improved up to 2 times greater than that of the flat PDMS.

9A is a diagram showing a nanoporous thin film attached to a finger, and FIG. 9B is an open circuit voltage between an FET tape uncoated with a nanoporous thin film and a finger skin and an opening between a FET tape coated with a nanoporous thin film and a finger skin. It is a diagram comparing voltages.

9A and 9B, after a thin nanoporous thin film was formed on an acrylic tape (PET) by spin coating, it was attached to a human finger to form a triboelectric nanogenerator, and the open circuit voltage of the triboelectric nanogenerator was measured. . Referring to the results, the triboelectric nanogenerator exhibits excellent triboelectric performance, which is about 3 times higher than that without the nanoporous thin film.

10A is a diagram illustrating a nanoporous thin film having a large area, and FIG. 10B is a diagram illustrating an open circuit voltage according to a change in area of the nanoporous thin film.

Referring to FIGS. 10A and 10B , a nanoporous thin film was coated on an A4 size PET substrate. The transmittance values of the nanoporous thin film for PET are similar to those of pure PET. It can be seen that the open circuit voltage of the triboelectric nanogenerator increases when a large-area nanoporous thin film is applied to the triboelectric nanogenerator to increase the surface area.

11A is a view showing a nanoporous thin film coated on a graphene-coated fiber, and FIG. 11B is a diagram comparing the open circuit voltage between a fiber uncoated with the nanoporous thin film and a fiber coated with the nanoporous thin film.

11A and 11B , for application to wearable electronic products, a nanoporous thin film is formed on the conductive fiber by dip coating. The conductive fiber includes graphene. When the nanoporous membrane-coated fiber comes into contact with human skin, a triboelectric voltage is generated, the open-circuit voltage of pure fibers is approximately 0.01 V on average, and the open-circuit voltage of the nanoporous membrane-coated fiber is improved to 0.07 V.

Fig. 12a is a view showing a nanoporous thin film coated on a leaf, and Fig. 12b is a view comparing the open circuit voltage between a leaf uncoated with the nanoporous thin film and a fiber coated with the nanoporous thin film.

12A and 12B , a nanoporous thin film may be formed on leaves by spray coating. When the nanoporous thin-film-coated leaf is in contact with the Cu plate, an improved open-circuit voltage is produced which is approximately 5 times greater at maximum voltage than without the nanoporous thin-film.

13A is a view showing a nanoporous thin film coated on a conductive fabric, and FIG. 13B is a diagram comparing the open circuit voltage between a conductive fabric uncoated with the nanoporous thin film and a conductive fabric coated with the nanoporous thin film.

13A and 13B , a nanoporous thin film may be formed on the fabric by spray coating. When the nanoporous membrane coated on the fabric comes into contact with the skin, an improved open circuit voltage is produced compared to the case without the nanoporous membrane.

As described above, nanoporous thin films suitable for high-performance triboelectric nanogenerators (TENGs) can be realized using a one-step fast wet processing process based on a simple ternary polymer solution blend with supramolecular assembly. Self-assembled ordered nanopores with a diameter of about 40 nm can be formed on a thin, large-area thin film without an additional etching process. It can be formed by competition of supramolecular APEO-SPS interactions and P2VP-SPS interactions. In addition, by adding APEO to the binary mixture of SPS and P2VP, the formation of spontaneous nanopores was efficiently activated, so that TENG using a nanoporous thin film was realized, and the open-circuit voltage and power density were improved to about 1.5 and 2 times higher values. can The on-plane ternary polymer blend can be suitable for a variety of wet coating processes such as spin coating, rod coating, spray coating and dip-coating to produce high-performance nanoporous thin films. In addition, the nanoporous thin films can be rapidly produced on numerous flat surfaces such as metals, polymers and oxides, as well as topological surfaces including corrugated and rough surfaces, textile fibers, natural leaves and large-area textiles. A cost-effective and easily accessible nanostructuring method based on a simple ternary polymer solution blend is widely applicable and scalable for future wearable and patchable nanopatterning devices.

Although many matters have been specifically described in the above description, they should be construed as examples of specific embodiments rather than limiting the scope of the invention, and various modifications may be made. Therefore, the scope of the present invention should not be determined by the described embodiments, but should be determined by the technical idea described in the claims.

SB: object to be processed
NPF: Nanoporous Thin Film
CB1: first chemical bond
CB1: second chemical bond
PB1, PB2, PB3: first polymer block compound, second polymer block compound, third polymer block compound
FG1, FG2, FG3: first functional group, second functional group, third functional group
OP: Qigong

Claims (5)

A porous structure having pores, comprising:
First polymer block compounds comprising at least one sulfonic acid group (Sulfonated Polystyrene: SPS) having a sulfonic acid group;
A formulation comprising polyethylene oxide (poly(ethylene oxide)) having an amine group bonded to the sulfonic acid group of the first polymer block compound of some of the first polymer block compounds to form a first copolymer compound 2 polymer block compounds; and
Third polymer block compounds including poly-2-vinyl-pyridine (P2VP) bonded to the sulfonic acid group of the first polymer block compound of another part of the first polymer block compounds to form a second copolymer compound and
The first polymer block compound constitutes the skeleton of the porous structure,
The pores are formed by competition between the first interaction between the sulfonic acid group and the amine group and the second interaction between the sulfonic acid group and the third polymer block compound, and the second polymer block compound and the third polymer block compound constituting the surface of the pores,
wherein the first interaction comprises a Lewis acid/base interaction;
wherein the second interaction comprises hydrogen bonding;
The pores are formed without an etching process, and the average diameter of the pores is in the range of 10 nm to 200 nm. The method of claim 1,
The average diameter of the pores is adjusted according to the volume ratio of the second polymer block compound and the third polymer block compound,
A porous structure having a volume ratio of the second polymer block compound and the third polymer block compound is in the range of 0.01 to 0.3. delete delete A first polymer block compound comprising sulfonated polystyrene (SPS) having a sulfonic acid group, a first polymer block compound of some of the first polymer block compounds to form a first copolymer compound Another part of the first polymer block compound to form a second polymer block compound and a second copolymer compound containing polyethylene oxide (poly (ethylene oxide)) having an amine group bonded to the sulfonic acid group of preparing a ternary polymer blend comprising a third polymer block compound including poly-2-vinyl-pyridine (P2VP) bonded to the sulfonic acid group of the first polymer block compound; and
forming pores of a porous structure by coating the ternary polymer blend on an object to be treated;
The first polymer block compound constitutes the skeleton of the porous structure,
The pores are formed by competition between the first interaction between the sulfonic acid group and the amine group and the second interaction between the sulfonic acid group and the third polymer block compound, and the second polymer block compound and the third polymer block compound constituting the surface of the pores,
The coating includes any one of spin coating, dip coating, spray coating, bar coating, and painting coating,
wherein the first interaction comprises a Lewis acid/base interaction;
wherein the second interaction comprises hydrogen bonding;
The pores are formed without an etching process, and the average diameter of the pores is in the range of 10 nm to 200 nm.

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