KR20220158602A - Porous composite structure, preparing method thereof, article including the same, and air purifier including the same - Google Patents

Abstract

Presented are a porous composite structure, which includes: a substrate having a nanostructure; a particle layer disposed on at least one surface of the substrate; and a lubricating fluid, a method for manufacturing the same, articles and an air purifier including the same. According to one aspect, the porous composite structure has improved mechanical properties and durability.

Description

Porous composite structure, preparation method thereof, article containing the same, and air purifier {Porous composite structure, preparing method thereof, article including the same, and air purifier including the same}

Disclosed are a porous composite structure, a manufacturing method thereof, an article containing the porous composite structure, and an air purifying device including the porous composite structure.

Slippery Liquid Infused Porous Surface (SLIPS) was conceived from the wax-like material coated on the nanostructure of the leaves of C. It is a stable fixing technique.

A structure with SLIPS is manufactured according to methods such as multi-step lithography, 3D printing, and the like. However, SLIPS structures known so far have poor mechanical properties and are easily collapsed or, in particular, are easily reduced when in contact with an acid solution, so that durability is not sufficient and manufacturing costs are high, so improvement is needed.

According to one aspect, to provide a porous composite structure having improved mechanical properties and durability.

According to another aspect, it is to provide a method for manufacturing the porous composite structure described above.

According to another aspect, an article including the porous composite structure described above is provided.

Another aspect is to provide an air purifying device including the porous composite structure described above.

A substrate having a nanostructure according to one aspect;

a particle layer disposed on at least one surface of the substrate; And a porous composite structure containing a lubricating fluid is provided.

The porous composite structure further includes an interlayer, the interlayer is disposed on at least one side of the substrate, and a particle layer is disposed on at least one side of the interlayer.

The substrate and particle layer form a re-entrant structure. The porous composite structure includes a slippery liquid infused porous surface (SLIPS).

The porous composite structure further includes a material having affinity for lubricating fluid. A substance having affinity for the lubricating fluid is chemically bonded to the particle layer.

The substrate is a nanorod, nanoribbon, nanotube, nanoblade, nanoplate, template having regular or random pores, or a combination thereof. And the substrate includes a base layer and a plurality of pillar parts protruding from the bay layer,

The base layer and the pillar part are made of the same material, and the pillar part is a nanorod, a narrow ribbon, a nanotube, a nanoblade, a nanoplate, or a combination thereof.

The particle layer may be inorganic particles, organic particles, or a combination thereof.

According to one embodiment, the particle layer is an inorganic particle layer, and the inorganic particle layer includes one or more inorganic particles selected from SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZnO ₂ , WO ₃ , SnO ₂ , ZrO, ITO and CaCO ₃ do.

An intermediate layer is disposed on at least one surface of the substrate, a particle layer is formed on at least one surface of the intermediate layer, and the intermediate layer and the particle layer may be coupled by electrostatic attraction.

According to another embodiment, the particle layer is a silica layer, the silica layer is a plurality of layers, and may include a positively charged silica layer and a negatively charged silica layer.

The substance having affinity for the lubricating fluid is fluorinated silane, and the fluorinated silane is trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane, 1H, 1H, 2H, 2H-perfluorodecyltri ethoxysilane, or a combination thereof.

The substrate may include metal, metal oxide, metal hydroxide, polymer, glass, ceramic, or a combination thereof.

The contact angle of the porous composite structure with respect to water and organic solvent is 170 ° or more, and the slip angle is 10 ° or less.

The intermediate layer includes a product of hydrolysis, dehydration and condensation of a compound represented by Formula 1 below.

<Formula 1>

In Formula 1, R ₁ is a C1-C20 alkylene group or a C6-C20 arylene group, R ₂ is hydrogen,

C1-C20 alkyl group, C6-C20 aryl group, or Cl.

The compound represented by Formula 1 is (3-aminopropyl)trimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminoundecyltrimethoxysilane, aminophenyltrimethoxysilane, bis(trimethoxylyl) lylpropyl)amine, N-(2-aminoethylaminopropyl)trimethoxysilane, or a combination thereof.

According to another aspect, forming a particle layer on a substrate having a nanostructure to form a first structure; and

There is provided a method for producing a porous composite structure comprising the step of providing a lubricating fluid on top of the first structure.

The method may further include forming an intermediate layer on the nanostructured substrate prior to performing the step of forming the first structure by forming the particle layer on the nanostructured substrate. Forming the intermediate layer is a process of coating a compound of Formula 1 on a substrate.

<Formula 1>

In Formula 1, R ₁ is a C1-C20 alkylene group or a C6-C20 arylene group, R ₂ is hydrogen,

C1-C20 alkyl group, C6-C20 aryl group, or Cl.

Before performing the step of forming the first structure by forming the particle layer on the substrate having the nanomaterial, the step of forming an intermediate layer on the substrate having the nanostructure may be further included. The step of forming the first structure by forming a particle layer on the upper part of the intermediate layer is prepared by repeatedly contacting inorganic particles having negative charges and inorganic particles having positive charges on the upper part of the intermediate layer.

The particle layer is a silica layer, and the silica layer is a plurality of layers and includes a positively charged silica layer and a negatively charged silica layer.

The negatively charged inorganic particles are negatively charged colloidal silica, and the positively charged inorganic particles are positively charged colloidal silica.

The method may further include providing a material having affinity for the lubricating fluid to the upper part of the first structure before performing the step of providing the lubricating fluid to the upper part of the first structure.

The step of providing a material having affinity for the lubricating fluid coats the fluorinated silane.

The method for manufacturing the porous composite structure described above may further include oxygen plasma treatment.

The substrate having the nanostructure is manufactured by performing a process of removing impurities and a native oxide film of the substrate and then performing an etching process to form the nanostructure.

According to another aspect, an article including the porous composite structure described above is provided.

According to another aspect, an air purifier including the above-described porous composite structure is provided.

The porous composite structure according to one embodiment has improved mechanical properties and durability. When such a porous composite structure is used, fine dust and contaminants in the air are more easily collected in a liquid and discharged to the outside in a water/oil environment, thereby improving contaminant removal performance. In addition, since the liquid in which fine dust and contaminants are collected is easily discharged from the reactor, the burden of periodic management or replacement of the reactor can be reduced.

Figure 1a schematically shows the structure of a porous composite structure according to one embodiment.
Figures 1b and 1c is for explaining the manufacturing method of the porous composite structure of Figure 1a
they are drawings
Figure 2a schematically shows the structure of the porous composite structure according to another embodiment.
Figures 2b and 2c are views for explaining the manufacturing method of the porous composite structure of Figure 2a.
Figures 3a and 3b show the sand abrasion test results for the porous composite structure of Example 1.
Figures 3c and 3d show the sand abrasion test results for the porous composite structure of Example 2.
4a and 4b show the sand abrasion test results for the porous structure of Comparative Example 1.
4c and 4d show the sand abrasion test results for the porous structure of Comparative Example 2.
5 shows a state after applying aminosilane coating on a substrate having a nanostructure according to an embodiment.
6 is a scanning electron microscope image of the Cu(OH) ₂ nanorods prepared according to Example 1.
7 is a scanning electron micrograph of the porous composite structure prepared according to Example 1.
8 is a scanning electron micrograph of CuO nanoblades prepared according to Example 2;
9 is a scanning electron micrograph of the porous composite structure prepared according to Example 2.
10 is a schematic configuration diagram of an air purifying device according to an embodiment.
11 is a schematic perspective view showing an example of a dust collector in the air purifier of FIG. 10;
12 shows the results of an acid resistance test for the SLIPS porous composite structure of Example 1.
Figure 13 shows the acid resistance test results for the SLIPS porous composite structure of Example 2.
14 shows acid resistance test results for the structure of Comparative Example 1.
15 shows acid resistance test results for the structure of Comparative Example 2.

Hereinafter, a porous composite structure according to an embodiment, a manufacturing method thereof, an article containing the porous composite structure, and an air purifying device including the porous composite structure will be described in detail.

Water vapor/oil vapor is adsorbed and condensed on the surface of the substrate when using a general separation membrane collection method, resulting in an increase in operating differential pressure and contamination of the membrane. To solve this problem, a lubricating fluid supported porous surface (SLIPS) structure may be used. If such a SLIPS structure is used, the material condensed by external flow can be easily separated from the substrate. In these SLIPS materials, securing durability against the support and dissolution of lubricating liquid is essential for the stability and long-term sustainability of the system.

However, SLIPS structures known so far do not have enough durability, such as being easily collapsed due to lack of mechanical properties or being easily reduced when in contact with an acid solution, in particular, so improvement is needed.

Porous composite structure according to one embodiment was devised to improve the above problems, the porous composite structure is a base material having a nanostructure; a particle layer disposed on at least one surface of the substrate; and a lubricating fluid.

The porous composite structure may further include a self-assembled layer disposed on at least one surface of the substrate. A particle layer may be disposed on at least one surface of the self-assembled layer.

The porous composite structure may further include an interlayer. The intermediate layer may be disposed on at least one surface of the substrate and the particle layer may be disposed on at least one surface of the intermediate layer. The intermediate layer may be a self-assembly layer or an adhesive layer. The intermediate layer may be, for example, a polymer layer.

The porous composite structure may further include a material having affinity for a lubricant.

The substrate having the nanostructure may have a composite structure. The substrate may include metal, metal oxide, metal hydroxide, polymer, glass, ceramic, or a combination thereof.

In the porous composite structure according to one embodiment, the substrate and the particle layer may form a re-entrant structure.

In the porous composite structure according to another embodiment, the substrate, the intermediate layer, and the particle layer may form a re-entrant structure. By having such a reentrant structure, it is relatively difficult for the lubricating fluid and/or a substance having affinity for the lubricating fluid to enter the nanostructure of the substrate and then escape to the outside, so that excellent liquid repellency is maintained and durability is efficient. can be improved by In addition, when foreign substances are introduced into the porous composite structure, it is difficult for the foreign substances to enter the inside, thereby increasing the contamination removal efficiency. It is relatively difficult to enter the nanostructure of the substrate, so that excellent liquid repellency is maintained and durability can be efficiently improved. Here, the inside of the nanostructure of the substrate means between a plurality of nanostructure patterns constituting the substrate, and the nanostructure patterns represent nanorods, nanoblades, and the like. In this specification, nanostructure refers to a structure in which a plurality of pores are formed in a surface layer. And, in this specification, liquid repellency means a property of repelling moisture or oil. Such excellent liquid repellency can be confirmed from the contact angle or sliding angle of the porous composite structure.

The nanostructured substrate may be nanorods, nanoribbons, nanotubes, nanoblades, nanoplates, regular or random pore templates, or combinations thereof. Here, the template having regular pores or random pores represents a three-dimensional structure in which regular or random pores are formed.

A substrate having a nanostructure according to an embodiment includes a base layer and a plurality of pillar parts protruding from the base layer. The base layer and the pillar portion may be made of the same material. The base layer has a plate shape, and the pillar portion may be a nanorod, a narrow ribbon, a nanotube, a nanoblade, a nanoplate, or a combination thereof.

The base layer may have a shape such as mesh or foam.

Substrates with nanostructures may contain, for example, concavities and convexities.

The porous composite structure according to an embodiment is a SLIPS structure, and a process of imparting affinity for a lubricating fluid by modifying the surface properties of the substrate using a material having affinity for a lubricating fluid on a substrate having a porous nanostructure through, for example, using fluorinated silane to impart super-hydrophobic properties. It can then be prepared through the step of providing a lubricating fluid.

A material having an affinity for the lubricating fluid may have a structure chemically bonded to the particle layer. Here, the particle layer is, for example, a silica (SiO ₂ ) layer, and the material having affinity for the lubricating fluid may be, for example, fluorinated silane.

When fluorinated silane is used as a material having affinity for lubricating fluid, the fluorinated silane may have a structure chemically bonded to the silica layer. The hydroxyl group of the silica layer reacts with the functional group of the fluorinated silane, and the hydrolysis, dehydration and condensation reaction of the fluorinated silane proceeds, resulting in a state in which the product of the hydrolysis, dehydration and condensation reaction of the fluorinated silane is chemically bonded to the silica layer. will have

The particle layer may contain inorganic particles, organic particles, or a combination thereof.

The particle layer may be, for example, inorganic particles.

The inorganic particle layer of one embodiment is SiO ₂ , Al ₂ O ₃ , TiO2, ZnO ₂ , WO ₃ , SnO ₂ , ZrO, ITO. It may include one or more inorganic particles selected from CaCO ₃ . The inorganic particles may have a size of, for example, 1 to 80 nm, 3 to 65 nm, or 5 to 25 nm. When the size of the inorganic particles is within the above range, durability of the porous composite structure is further improved.

In the present specification, "size" indicates the particle diameter when the particle to be measured is spherical, and indicates the major axis length when the particle is non-spherical. The particle diameter is, for example, an average particle diameter, and the major axis length is, for example, an average major axis length. The average particle diameter and the average major axis length represent the average values of the measured particle diameter and the measured major axis length, respectively.

In the present specification, the particle size may be evaluated using a particle size analyzer, a scanning electron microscope, or a transmission electron microscope. As a particle size analyzer, for example, a HORIBA, LA-950 laser particle size analyzer can be used.

The average particle diameter is, for example, an average particle diameter observed with a scanning electron microscope (SEM), and can be calculated as an average value of particle diameters of about 10 to 30 particles using an SEM image.

When the particle size is measured using a particle size analyzer, the average particle diameter represents D50. D50 means the average diameter of particles whose cumulative volume is 50% by volume in the particle size distribution, and in the distribution curve accumulated in order from the smallest particle size to the largest particle size, when the total number of particles is 100%, the largest It means the value of the particle diameter corresponding to 50% of the small particles.

D50 can be measured using a particle size analyzer. Alternatively, D50 can be easily obtained through calculation after measuring using a measuring device using dynamic light-scattering, performing data analysis, and counting the number of particles for each particle size range. can

The inorganic particle layer may be formed in the form of a continuous or discontinuous layer.

The negatively charged inorganic particles are negatively charged colloidal silica, and the positively charged inorganic particles are positively charged colloidal silica.

In the porous composite structure according to one embodiment, the intermediate layer (eg, the self-assembled layer) and the inorganic particle layer may be coupled by electrostatic attraction. When coupled by electrostatic attraction in this way, mechanical properties and durability of the porous composite structure are further improved.

The intermediate layer may vary depending on the composition of the inorganic particle layer. An intermediate layer according to an embodiment may include a product of hydrolysis, dehydration, and condensation of a compound represented by Formula 1 below.

<Formula 1>

In Formula 1, R ₁ is a C1-C20 alkylene group or a C6-C20 arylene group, R ₂ is hydrogen,

C1-C20 alkyl group, C6-C20 aryl group, or Cl.

The intermediate layer may be a self-assembly layer or an adhesive layer.

The intermediate layer may contain, for example, a polymer. The intermediate layer containing such a polymer may serve as a self-assembly layer or an adhesive layer.

The inorganic particle layer is a silica layer, the silica layer has a multi-layered structure, and the multi-layered silica layer may contain a positively charged silica layer and a negatively charged silica layer.

Substances that have affinity for lubricants are fluorinated silanes, such as trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxy. silanes, or combinations thereof.

The porous composite structure according to one embodiment has a contact angle of 170° or more, for example, 170 to 180°, and a slip angle of 10° or less, for example, 1 to 10°. The organic solvent here is, for example, glycerol, diiodomethane or a mixture thereof.

Referring to the accompanying drawings, a porous composite structure according to an embodiment will be described. In the porous composite structure of the accompanying drawings, the particle layer is, for example, an inorganic particle layer, and the intermediate layer is, for example, a self-assembled layer.

Figure 1a schematically shows the structure of the porous composite structure (1) according to one embodiment. Referring to this, the porous composite structure 1 has a structure in which an intermediate layer (not shown) is formed on a portion of the substrate 10 having a nanostructure, and an inorganic particle layer 11 is disposed on the upper portion of the intermediate layer. For convenience, the intermediate layer is not shown in the drawings and is omitted. The intermediate layer may be, for example, a self-assembled layer. In the porous composite structure according to one embodiment, the intermediate layer may be omitted.

The inorganic particle layer 11 is, for example, a silica layer.

As shown in FIG. 1A , the substrate 10 includes a base layer 10a and a plurality of nanorod-shaped pillar portions 10b. The inorganic particle layer 11 is disposed on at least one surface (upper region A and side region B) of the pillar portion 10b having a nanorod shape. As shown in FIG. 1A, the inorganic particle layer 11 is mainly located in the upper region A of the pillar portion 10b having a nanorod shape, and the side region B of the plurality of pillar portions 10b has a very small size compared to the upper region A. exist in content. When the inorganic particle layer exists in the above-described structure, the substrate, the self-assembled layer, and the inorganic particle layer of the porous composite structure form a reentrant structure as shown in FIG. 1A.

As the inorganic particle layer 13 is positioned as described above, liquid and lubricating fluid having affinity for the lubricating fluid may also be disposed with the same concentration gradient as that of the inorganic particle layer. Here, the reentrant structure represents a mushroom column structure or an umbrella shape, and by having such a structure, the inorganic particle layer such as a silica layer is present in a larger amount in the upper region of the substrate than in the region between the plurality of substrates. As described above, when the reentry structure is provided, the lubricating fluid 12 is supported in the reentry structure and has a structure that does not come out well due to external stimuli. As a result, the impregnating ability of the lubricating fluid is improved compared to the case without such a reentry structure, and the durability is improved. And water-repellency and easy sliding of the porous composite structure containing lubricating fluid, as well as self-healing, ice-repellency, anti-frost, and anti-fouling. All other characteristics can be further improved.

The base layer 10a and the pillar portion 10b having a plurality of nanorod shapes may be made of the same material. The substrate serves as a support having porosity, and the substrate includes, for example, metal, metal oxide, metal hydroxide, polymer, glass, ceramic, or a combination thereof.

Examples of the metal include copper, tungsten, aluminum, and silicon. The metal hydroxide is, for example, copper hydroxide, and the metal oxide is, for example, copper oxide.

Examples of polymers usable as the substrate include fluoropolymers such as polytetrafluoroethylene (PTFE), polyvinyl fluoride, polyvinylidene fluoride, fluorinated ethylene propylene, polydimethylsiloxane and the like. Ceramics include, for example, alumina and silica.

A substrate having a nanostructure may have a nanoblade shape as shown in FIG. 1B. The nanoblade shape of FIG. 1B may have a triangular structure forming a ratchet shape. In addition, the substrate having a nanostructure may have a template shape containing regular pores or random pores.

The SLIPS porous composite structure 1 contains a material (not shown) having affinity for the lubricating fluid 12 . A substance having affinity for the lubricating fluid 12 may be contained in the inorganic particle layer 11 . According to one embodiment, the material having affinity for the lubricating fluid may have a structure chemically bonded to the inorganic particle layer 11 . According to another embodiment, a part of the material having affinity for the lubricating fluid 12 has a structure chemically bonded to the inorganic particle layer 11, and the other part of the material having affinity for the lubricating fluid has a structure chemically bonded to the inorganic particle layer 11. (11) It can exist in a state without chemical bonding in the surrounding area. The porous composite structure according to one embodiment may have a superhydrophobic surface.

The lubricating fluid 12 is contained inside the porous composite structure 1 as shown in FIG. 1A. The lubricating fluid may be, for example, silicone oil, fluorinated oil, paraffinic oil, petroleum oil, olive oil or combinations thereof.

The SLIPS porous composite structure 1 according to one embodiment has the above-described reentrant structure while having the inorganic particle layer 13, so that mechanical properties are improved and chemical stability and durability against acid solutions and the like are improved.

Figure 2a schematically shows the structure of a lubricating fluid-supported porous surface porous composite structure (SLIPS porous composite structure 2) according to another embodiment.

The SLIPS porous composite structure 2 of FIG. 2A is different from the SLIPS porous composite structure 1 of FIG. 1A in that the substrate 20 has a nanoblade shape. Referring to FIG. 2A , the substrate 20 includes a base layer 20a and pillars 20b having a plurality of nanorod shapes. A self-assembly layer (not shown) is formed on the substrate 20 and an inorganic particle layer 21 is formed thereon. A material (not shown) having affinity for the lubricating fluid 22 and the lubricating fluid 22 are disposed on the inorganic particle layer 21 .

The porous composite structure according to one embodiment is forming a first structure by forming a particle layer on a substrate having a nanostructure; and providing a lubricating fluid to the top of the first structure.

Before performing the step of forming the first structure by forming the particle layer on the substrate having the nanomaterial, the step of forming an intermediate layer on the substrate having the nanostructure may be further included. The intermediate layer is a self-assembly layer or an adhesive layer, and the step of forming the self-assembly layer is a process of coating the compound of Formula 1 on a substrate.

Before performing the step of forming the first structure by forming a particle layer on the substrate having the nanomaterial, further comprising forming an intermediate layer on the substrate having the nanostructure, wherein the intermediate layer is a self-assembled layer, The step of forming the first structure by forming a particle layer on the self-assembled layer may be prepared by repeatedly contacting inorganic particles having negative charges and inorganic particles having positive charges on the self-assembly layer.

The negatively charged inorganic particles are negatively charged colloidal silica, and the positively charged inorganic particles are positively charged colloidal silica. The method may further include providing a material having affinity for the lubricating fluid to the upper part of the first structure before performing the step of providing the lubricating fluid to the upper part of the first structure.

Forming a self-assembled layer on a substrate having a porous composite structure according to another embodiment; forming a first structure by forming an inorganic particle layer on the self-assembled layer; providing a material having affinity for lubricating fluid on the upper part of the first structure; and providing a lubricating fluid to the first structure provided with a material having affinity for the lubricating fluid.

The forming of the self-assembled layer includes a process of coating the compound of Chemical Formula 1, which is aminosilane, on a substrate having a nanostructure.

The aminosilane is (3-aminopropyl)trimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminoundecyltrimethoxysilane, aminophenyltrimethoxysilane, bis(trimethoxyrillylpropyl)amine , N-(2-aminoethylaminopropyl)trimethoxysilane or a combination thereof.

The inorganic particle layer is prepared by forming an inorganic particle layer on the self-assembled layer by repeatedly contacting inorganic particles having negative charges and inorganic particles having positive charges on the upper self-assembled layer.

The self-assembled layer may have a positive charge by containing moisture during the manufacturing process.

In the step of forming the first structure by forming an inorganic particle layer on the self-assembling layer, the inorganic particle layer is formed on the self-assembling layer by repeatedly contacting inorganic particles having negative charges and inorganic particles having positive charges on the self-assembling layer. It can be manufactured by

The step of providing a material having affinity for the lubricating fluid is a process of coating fluorinated silane. The fluorinated silane is, for example, trichloro(1H,1H,2H,2H-perfluorooctyl)silane, 1H,1H,2H,2H-perfluorodecyltriethoxysilane, or combinations thereof.

According to the above manufacturing method, oxygen plasma treatment can be further performed. Oxygen plasma treatment can be applied to a substrate having a nanostructure or a structure in which an inorganic particle layer is formed. Oxygen plasma treatment may be performed as necessary in the middle of each step in the manufacture of the porous composite structure. As described above, when the oxygen plasma treatment is performed, impurities on a substrate having a nanostructure or a structure on which an inorganic particle layer is formed can be removed. Alternatively, OH groups may be introduced on the surface of a substrate having a nanostructure or a structure on which an inorganic particle layer is formed. In this way, when an OH group is introduced, a reaction with a functional group of a reactant provided in a subsequent step may proceed.

Referring to Figures 1b and 1c, a method for manufacturing the porous composite structure of Figure 1a will be described in more detail. As shown in FIG. 1B, a substrate 10 having a nanostructure is prepared.

The substrate 10 may be manufactured by first undergoing a process of removing impurities and a native oxide film of the substrate 10 and then performing an etching process to form a nanostructure.

Removal of impurities from the substrate may be performed using a sonication process using an organic solvent. As an organic solvent, ethanol, acetone, etc. can be used, for example. And the removal of the native oxide film of the substrate can be carried out using an acid solution. The acid solution may include, for example, a 1 to 3M HCl solution. By removing the impurities and the native oxide film of the substrate in this way, the subsequent self-assembled layer and the silica layer can be uniformly formed, and the adhesion of the self-assembled layer and the silica layer to the substrate can be improved.

An etching process for obtaining a substrate having a nanostructure may be performed by dry or wet etching. Dry etching uses reactive plasma/gas species, while wet etching can be performed using a suitable etchant.

A substrate having a nanostructure according to an embodiment may contain copper hydroxide, copper oxide, and the like. For example, the substrate having the nanostructure may include copper hydroxide nanorods, copper oxide blades, and copper oxide nanoplates.

A self-assembled layer (not shown) is formed on at least one surface of the substrate 10 . The self-assembled layer includes a process of coating aminosilane.

Aminosilane may be a compound represented by Formula 1 below.

<Formula 1>

In Formula 1, R ₁ is a C1-C20 alkylene group or a C6-C20 arylene group, and R ₂ is hydrogen, a C1-C20 alkyl group, a C6-C20 aryl group, or Cl.

The C1-C20 alkyl group is, for example, a C1-C10 alkyl group, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, etc., and a C6-C20 aryl group, for example, a C6-C20 alkyl group. -C10 It is an aryl group, and specifically includes a phenyl group and the like.

When the coating process using aminosilane is performed, the hydroxyl group of the substrate and the functional group of aminosilane, which is a material for forming the self-assembled molecular layer, react, resulting in hydrolysis of aminosilane, dehydration reaction, and condensation reaction of the hydrolysis product. As shown in , a substrate having a nanostructure having a self-assembled layer having an H ₂ N(+)-R ₁ -Si(O)- network at the terminal is obtained. A substrate having a nanostructure with such a self-assembly layer has a positive charge on the surface, and then a layer-by-layer (LbL) assembly using colloidal silica particles having a positive charge and colloidal silica particles having a negative charge. A silica layer may be formed by using.

The self-assembled molecular layer may be, for example, a self-assembled monomolecular layer.

As shown in FIG. 1C, an inorganic particle layer 11 is formed.

The inorganic particle layer 11 may be formed using a method such as a sol-gel method or a reaction using electrostatic attraction. The inorganic particle layer may be formed by the electrostatic force of two materials having opposite charges. Using this method, a porous composite structure with further improved chemical stability, durability and mechanical properties can be manufactured. More specifically, the inorganic particle layer 11 is repeatedly contacted with inorganic particles having negative charges and inorganic particles having positive charges on the upper part of the structure having the self-assembled molecular layer having positive charges. form a particle layer. The inorganic particle layer is formed in a multi-layered structure by repeatedly contacting inorganic particles with negative charges and inorganic particles with positive charges. The thickness of the inorganic particle layer 11 can be controlled by adjusting the above-described repetitive process. This repetitive process, for example, if the process of contacting inorganic particles with negative charges and inorganic particles with positive charges is set as one time, performing this process a total of 8 to 12 times, for example, about 10 times, improves durability. A porous composite structure can be prepared.

After contact between the structure having a self-assembled molecular layer having a positive charge and the inorganic particles having a negative charge, a water washing process is performed. When the water washing process is performed, impurities such as inorganic particles having an excessive negative charge after the reaction may be removed. After going through this washing process, a step of contacting inorganic particles having a positive charge is performed. Subsequently, after the water washing process is performed again, the above-described contact process of the negatively charged inorganic particles and the positively charged organic particles may be repeatedly performed.

The negatively charged inorganic particles are, for example, negatively charged colloidal silica, and the positively charged inorganic particles are, for example, positively charged colloidal silica.

Subsequently, a material (not shown) having affinity for lubricating fluid is provided to the resultant product. Substances having an affinity for the lubricating fluid are, for example, fluorinated silanes. Fluorinated silanes can have hydrolyzable functional groups and fluorine or fluorine-containing functional groups. Examples of the hydrolyzable functional group include a hydroxy group and an alkoxy group. Fluorinated silanes include, for example, trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, or combinations thereof.

The step of providing the fluorinated silane can be carried out, for example, under vacuum conditions.

The content of fluorinated silane can be controlled and supplied at a concentration of 1 to 5% by weight.

Subsequently, the liquid-provided product may be washed with ethanol or the like, and then a lubricating fluid may be supplied thereto to prepare a SLIPS porous composite structure. A method of supplying the lubricating fluid may use, for example, flow coating or spray coating.

The contact angle of the SLIPS porous composite structure according to one embodiment to water and organic solvent is 170 ° or more, and the slip angle is as low as 10 ° or less. Here, the organic solvent may include, for example, at least one selected from glycerol and diiodomethane. With these characteristics, the SLIPS porous composite structure according to one embodiment can easily separate the condensed material from the substrate by external flow. If such SLIPS material is used, durability against the support and dissolution of lubricating fluid is excellent, and the stability and long-term sustainability of the system are excellent. In addition, it is possible to implement a gas-liquid contact layer of a filter-less air purifier that can be used in a moisture/oil vapor environment. The liquid droplets in the gas-liquid contact layer are quickly discharged, so that an increase in differential pressure applied to the gas-liquid contact layer can be effectively suppressed.

The SLIPS porous composite structure according to one embodiment is a surface of a flow channel, a surface of an optical part, a surface of a sign or commercial graphic, a surface of a building material, a surface of a cooling member, a surface of a heat exchanger, a fluid transport device, a surface of a windmill, It may be provided on the surface of a turbine, a surface of a solar cell, a surface of an avionics device, a surface of a marine vessel or an underwater device, a surface of a fabric.

According to another aspect, an article containing a SLIPS porous composite structure according to an embodiment is provided.

The above items include heat exchangers, piping, exhaust gas, anti-corrosion devices, energy efficient fluid handling, transportation, optical sensing, medicine, self-cleaning, anti-fouling materials, solar cells, roof tiling, anti-fouling materials operating in extreme environments, etc. can be used in the field of The article can be used in various fields, such as removing ice from the surface of machines such as airplanes and automobiles, biofouling problems in blood vessels, and fields requiring self-cleaning.

The lubricating fluid surface of the article is placed in contact with the foreign material of interest, the lubricating fluid being non-cyclable with the foreign material and such foreign material may exhibit little or no adhesion to the article.

According to another aspect, an air purifier containing a SLIPS porous composite structure according to an embodiment is provided.

An air purifier according to one embodiment includes a duct through which air containing fine dust flows; a droplet spraying unit spraying water into the duct to form a gas-liquid mixed fluid and collecting fine dust in the air; and a dust collector including a porous member that forms a microchannel through which the gas-liquid mixed fluid passes and collects droplets containing the fine dust. The air purifier may further include a discharge plasma generator generating discharge plasma in the dust collector. In addition, a catalyst reactor capable of removing ozone discharged from the dust collection unit using a catalyst may be further provided.

An air purifier according to an embodiment includes a porous composite structure according to an embodiment, for example, a SLIPS porous composite structure, and can be usefully utilized in a moisture/oil vapor environment. An air purifier according to an embodiment purifies air by collecting gas, for example, fine dust in the air, and may be applied to an industrial dust collection facility, an air conditioning/ventilation system in a building, and the like. In addition, since there is no filter, there is no need to replace or manage the filter, and fine dust and contaminants are ionized or decomposed by the discharge plasma and can be easily discharged from the reactor after being collected in the liquid passing through the reactor. Therefore, since fine dust and contaminants in the air are more easily collected in the liquid and discharged to the outside, excellent contaminant removal performance can be implemented. In addition, since the liquid in which fine dust and contaminants are collected is easily discharged from the reactor, the burden of periodic management or replacement of the reactor can be reduced.

A structure of an air purifier according to an embodiment will be described with reference to the accompanying drawings.

Referring to FIG. 10, the air purifier includes a duct 1 through which air containing fine dust flows, a droplet ejection unit 2 that collects fine dust in the air by injecting liquid into the duct 1, and gas-liquid. It may include a dust collection unit 3 that forms a microchannel 31 through which the mixed fluid passes and collects droplets containing fine dust. The surface of the microchannel 31 is incompatible with liquid. For example, a liquid-incompatible coating layer may be formed on the surface of the microchannel 31 .

The duct 1 forms an air flow path. The shape of the duct 1 is not particularly limited. For example, the cross-sectional shape of the duct 1 may be various, such as a circular shape and a polygonal shape. The cross-sectional shape of the duct 1 of this embodiment is a rectangle. For example, air containing fine dust is supplied to the duct 1 through the inlet 11 by the blower 5. Air is moved along the air flow path formed by the duct 1 and discharged through the outlet 12.

The droplet spraying unit 2 may spray droplets, for example, water into the duct 1 . The droplet ejection unit 2 may include one or more spray nozzles 21 . For example, water stored in the water tank 6 is pressurized by the pump 7 and sprayed into the duct 1 in the form of fine droplets through the spray nozzle 21. During this process, some of the fine dust contained in the air is captured in droplets. In the duct 1, a gas-liquid mixed fluid in which air and liquid droplets are mixed is formed. The gas-liquid mixed fluid flows along the duct 1 from the inlet 11 to the outlet 12.

The dust collecting unit 3 includes a plurality of micro-channels 31 . The gas-liquid mixed fluid passes through the plurality of microchannels 31 . While the gas-liquid mixed fluid passes through the plurality of microchannels 31 , some of the liquid droplets including fine dust collide with and adhere to the surfaces of the microchannels 31 . Some of the liquid droplets that do not contain fine dust also collide with and adhere to the surface of the microchannel 31 . A liquid film is formed on the surface of the microchannel 31 by the droplets. While passing through the plurality of micro-passages 31, the fine dust that is not collected in the droplets comes into contact with the liquid film formed on the surface of the micro-passages 31 and is collected in the liquid film. The liquid film flows downward along the surface of the microchannel 31 by gravity, for example. The dust collecting unit 3 may have outlets 32 through which liquid flowing down from the plurality of micro-channels 31 is discharged. The fine dust collected in the droplets is discharged from the dust collecting unit 3 through the outlet 32 together with the droplets. The microchannel 31 does not need to extend linearly in the direction of air flow. As the microchannel 31 is meandering, the contact area between the surface of the microchannel 31 and the liquid droplet increases, so that the liquid droplet can be more easily collected on the surface of the microchannel 31 .

At least one outlet 13, 14 may be provided in the duct 1. When the gas-liquid mixed fluid hits the inner wall of the duct 1, a liquid film is formed on the inner wall of the duct 1, and fine dust may be collected in the liquid film. The liquid film flows down the inner wall of the duct 1 in the direction of gravity (G), and is discharged out of the duct 1 through the outlets 13 and 14. For example, the outlet 13 may be disposed between the droplet spraying unit 2 and the dust collecting unit 3 . The outlet 14 may be disposed on the downstream side of the dust collector 3 . The liquid discharged through the outlets 13 and 14 and the outlet 32 of the dust collector 3 may be stored in the collection tank 8 .

A pressure drop occurs while the gas-liquid mixed fluid passes through the dust collector 3 . The amount of pressure drop is the difference between the pressure on the upstream side of the dust collector 3 and the pressure on the downstream side of the dust collector 3, and is also referred to as differential pressure. When the differential pressure increases, the energy efficiency of the fine dust collector decreases and the operating cost increases. The liquid film collected on the surface of the micro-channel 31 narrows the cross-sectional area of the micro-channel 31, which may cause an increase in differential pressure.

By rapidly separating the liquid film from the surface of the microchannel 31, an increase in differential pressure can be minimized or prevented. In this embodiment, the surface of the microchannel 31 is made to have a property that is not friendly to the liquid ejected from the droplet ejection unit 2 . According to this, the contact angle of the droplet with respect to the surface of the microchannel 31 is increased, so that the droplet can be easily separated from the surface of the microchannel 31 . The non-affinity of the surface of the microchannel 31 to liquid may be expressed by a contact angle of a liquid droplet with respect to the surface of the microchannel 31 . For example, the droplet ejection unit 2 may inject water into the air, and the microchannel 31 may be formed of a porous composite structure according to an embodiment. As such, since the liquid is easily separated from the surface of the microchannel 31, the pressure difference between the upstream and downstream sides of the dust collector 3, that is, the range of porosity of the dust collector 3 that can adjust the pressure drop is widened. . Therefore, compared to the conventional filtration method, the amount of pressure drop can be reduced, and energy consumption of the fine dust collecting device can be reduced. In addition, since the contact probability of fine dust and liquid droplets with the microchannel 31 can be increased, higher air purification efficiency can be obtained compared to conventional filtration methods. In addition, since droplets collected with fine dust are easily separated from the surface of the microchannel 31, the microchannel 31 is not clogged even when used for a long time, unlike conventional filtration methods. Accordingly, the burden of periodic management or replacement of the dust collecting unit 3 can be reduced. In some cases, it may not be necessary to replace the dust collector 3.

The larger the area of the surface of the microchannel 31 is, the larger the contact angle is, and the liquid droplets can be more easily separated from the surface of the microchannel 31 . To this end, the surface of the microchannel 31 may be uneven. The unevenness treatment may be performed by, for example, an etching process.

A structure forming the microchannel 31 is not particularly limited. As the surface area of the microchannel 31 increases, the contact rate between the gas-liquid mixed fluid and the surface of the microchannel 31 increases, and fine dust collection performance can be improved. As an example, the dust collector 3 may include a porous member forming the microchannel 31 . The dust collecting unit 3 may include a plurality of fillers forming the microchannel 31 . Hereinafter, embodiments of the dust collection unit 3 will be described.

The air purifier of FIG. 10 is provided with a discharge plasma generating device 33 generating discharge plasma inside the dust collection unit. A discharge region in which discharge plasma is generated is formed in the dust collector by using the discharge plasma generator 33 . Ozone (0 ₃ ) may be generated from oxygen (O ₂ ) in the air by the discharge plasma generator 33 .

The catalytic reactor 34 is disposed at the rear end of the dust collecting unit to remove ozone discharged from the dust collecting unit using a catalyst. As an example, the catalyst included in the catalytic reactor 34 may include a metal oxide or a metal nitride, for example, one or more of manganese oxide, copper oxide, aluminum oxide, and titanium oxide, or one or more of a mixture of the above substances. .

As described above, the air purifying device 1 according to one embodiment can purify polluted air by simultaneously applying decomposition by discharge plasma and collection by liquid. Hereinafter, fine dust (PM), water-soluble organic compounds, water-insoluble organic compounds, and ozone contained in polluted air will be classified, and purification of polluted air (Air ₁ ) using discharge plasma and liquid will be described in more detail.

7 is a schematic perspective view of an example of the dust collecting unit 3 . Referring to this, the porous member may include a housing 330 and a plurality of fillers 331 filled in the housing 330 . The microchannel 31 is formed by gaps between the plurality of fillers 331 . The housing 330 is provided with an outlet 32 through which liquid droplets collected on the surface of the plurality of fillers 331 are discharged. The housing 330 may include an inlet 330a through which a gas-liquid mixed fluid including liquid droplets is introduced and an outlet 330b through which the gas-liquid mixed fluid is discharged. A mesh screen 333 may be disposed at the inlet 330a and the outlet 330b.

Filler 331 may be a bead, for example. The beads may be formed of, for example, glass or metal. The diameter of the plurality of beads may be uniform or non-uniform. A number of beads may be regularly or irregularly packed inside the housing 330 . A plurality of beads may be stacked in one or more layers in the flow direction F of the gas-liquid mixed fluid. The microchannel 31 may be formed by gaps between a plurality of beads. The beads may be spherical beads as shown in FIG. 10 . A number of beads may have the same diameter. A plurality of beads may be packed inside the housing 330 in various forms. The packing form of the plurality of beads is, for example, a simple cubic (PCC: primitive centered cubic) structure, a face centered cubic (FCC: face centered cubic) structure, a cubic structure such as a body centered cubic (BCC: body centered cubic) structure, a hexagonal (HCP: Hexagonal Closed-Packed) structure, etc. The porosity of the simple cubic structure is about 48.6%. The porosity of the face-centered cubic structure is about 26%. The porosity of the body-centered cubic structure is about 32%. The microchannel 31 may be defined by at least three adjacent beads. In order to increase the probability of contact between the gas-liquid mixed fluid and the plurality of beads while passing through the microchannel 31, the plurality of beads may be stacked in at least two layers. Between the inlet 330a and the outlet 330b, the cross-sectional area of the microchannel 31 repeats contraction and expansion at least once in the flow direction F of the gas-liquid mixed fluid. Accordingly, the probability of contact between the gas-liquid mixed fluid and the plurality of beads may be increased, and the efficiency of collecting fine dust may be improved. The filler 331 may be a raschig ring as shown in FIG. 11 . A number of lashig rings may be regularly or irregularly packed inside the housing 300 .

The gas-liquid mixed fluid passes through the microchannel 31 formed by the plurality of fillers 331 . During this process, droplets are collected on the surface of the microchannel 31, that is, the surface of the filler 331. Droplets fall in the direction of gravity (G). The surface of the filler 331 may be treated to have a non-affinity to the liquid droplets so that the droplets can be easily separated from the surface of the filler 331 . For example, the filler 331 may be formed using a porous composite structure according to an embodiment.

A surface of the filler 331 may be roughened. The mesh screen 333 may be formed using a SLIPS porous composite structure according to an embodiment. The mesh screen 333 may be uneven. The porous member may include a plurality of housings 330 disposed in the air flow direction F and a filler 331 filled in the plurality of housings 330 . In this case, the diameters of the fillers 331 packed in the plurality of housings 330 may or may not be the same.

According to another embodiment, a porous composite structure according to one embodiment, for example, a SLIPS porous composite structure, may be formed on the surface of a porous substrate such as a mesh screen or foam.

Hereinafter, an embodiment will be described in detail. The examples are provided for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[Example]

Example 1: Cu(OH) ₂ Preparation of SLIPS porous composite structure using nanorods

The Cu plate (20*100*2 mm) was subjected to sonication for 15 minutes in a mixed solution of ethanol:acetone in a volume of 1:1 to remove impurities. Then, after drying the resultant product, it was immersed in a 2M HCl solution for 10 minutes to remove the natural oxide layer formed on the surface of the Cu plate to perform pretreatment.

The Cu plate pretreated according to the above process was immersed in a mixed solution of 2.5 M NaOH and 0.1M (NH ₄ ) ₂ S ₂ O ₈ for 10 minutes, and then the obtained sample was sufficiently washed with DI to obtain Cu(OH) ₂ nanorods. manufactured.

After oxygen plasma treatment was performed on the Cu(OH) ₂ nanorods, they were impregnated with a 1.5 wt% (3-aminopropyl)triethoxysilane (APTES)/ethanol (EtOH) solution for 24 hours. Subsequently, a sample was recovered from the resultant, washed with an excess of ethanol (EtOH) and dried to prepare a structure in which a self-assembled layer was formed on the Cu(OH) ₂ nanorods. Here, the self-assembly layer contains the hydrolysis, dehydration and condensation reaction products of (3-aminopropyl)triethoxysilane, which are the dehydration of the functional group (H) of the hydrolyzate and the OH group of the Cu(OH) ₂ nanorods. It is formed by condensation reaction.

The structure having the self-assembled layer was immersed in a dispersion of negatively charged colloidal silica particles (LUDOX HS) (Aldrich) for 1 minute, and then washed with water. Subsequently, the washed product was impregnated with a dispersion of positively charged colloidal silica particles (LUDOX CL) (Aldrich) for 1 minute, and then washed with water. The impregnation/washing process using colloidal silica having a negative charge/colloidal silica having a positive charge was repeatedly performed a total of 10 times to obtain a structure in which a self-assembled layer and a silica layer were disposed on Cu(OH) ₂ nanorods. A structure was prepared with

After subjecting the structure to oxygen plasma treatment, the structure and 0.2 mL of trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane (Trichloro(1H, 1H, 2H, 2H- perfluorooctyl)silane): PFOTS) was placed. Subsequently, after maintaining a vacuum state at -0.97 bar using a vacuum pump, the PFOTS coating was performed on the structure by maintaining the pressure at this pressure for 20 minutes. Subsequently, the obtained sample was washed with ethanol and then dried at 75° C. for 1 hour to obtain a PFOTS-coated structure.

Fluorinated synthetic oil (Krytox GPL 103 oil), which is a lubricating fluid, is provided to the dried result, then it is evenly distributed on the surface of the structure using an air gun, and then hung vertically to remove excess lubricating fluid to form a SLIPS porous composite structure (FL -SiO ₂ -Cu(OH) ₂ ) was prepared. In FL-SiO ₂ -Cu(OH) ₂ ), FL represents PFOTS, SiO ₂ represents a silica layer, and Cu(OH) ₂ ) represents a Cu(OH) ₂ nanorod.

Example 2: Preparation of SLIPS porous composite structure using CuO nano-blades

The Cu plate (20*100*2 mm) was subjected to sonication for 15 minutes in a mixed solution of ethanol:acetone in a volume of 1:1 to remove impurities. Then, after drying the resultant product, it was immersed in a 2M HCl solution for 10 minutes to remove the natural oxide layer formed on the surface of the Cu plate to perform pretreatment.

The Cu plate pretreated according to the above process was added to a mixture of sodium chlorite (NaClO ₂ ), NaOH, sodium phosphate (Na ₃ PO ₄ 12H ₂ O) and deionized water (3.75:5:10:100 weight ratio) at 95 to 97 C, impregnation was performed for 10 minutes. After impregnation, the obtained sample was sufficiently washed with deionized (DI) water and dried at about 120° C. to obtain CuO nano-blades.

SLIPS porous composite _structure ( FL-SiO ₂ -CuO) was obtained.

Comparative Example 1

The Cu plate (20*100*2 mm) was subjected to sonication for 15 minutes in a mixed solution of ethanol:acetone in a volume of 1:1 to remove impurities. Then, after drying the resultant product, it was immersed in a 2M HCl solution for 10 minutes to remove the natural oxide layer formed on the surface of the Cu plate to perform pretreatment.

The Cu plate pretreated according to the above process was immersed in a mixed solution of 2.5M NaOH and 0.1M (NH ₄ ) ₂ S ₂ O ₈ for 10 minutes, and then the obtained sample was sufficiently washed with DI to obtain Cu(OH) ₂ nanorods. manufactured.

Oxygen plasma treatment was performed on the Cu(OH) ₂ nanorods, and then oxygen plasma-treated Cu(OH) ₂ nanorods and 0.2 mL of trichloro (1H, 1H, 2H, 2H-purple After placing Trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane (PFOTS), the vacuum was maintained at -0.97 bar using a vacuum pump, and maintained at this pressure for 20 minutes. PFOTS coating was performed on Cu(OH) ₂ nanorods. Subsequently, the obtained sample was washed with ethanol and then dried at about 75° C. for 1 hour to obtain a PFOTS-coated structure.

Fluorinated synthetic oil (Krytox GPL 103 oil) is provided to the dried product, then it is evenly dispersed on the surface using an air gun, and then hung vertically to remove excess lubricating fluid, and the lubricating fluid supporting structure (FL-Cu( OH) ₂ ) was prepared.

Comparative Example 2

The Cu plate (20*100*2 mm) was subjected to sonication for 15 minutes in a mixed solution of ethanol:acetone in a volume of 1:1 to remove impurities. Then, after drying the resultant product, it was immersed in a 2M HCl solution for 10 minutes to remove the natural oxide layer formed on the surface of the Cu plate to perform pretreatment.

The Cu plate pretreated according to the above process was added to a mixture of sodium chlorite (NaClO ₂ ), NaOH, sodium phosphate (Na ₃ PO ₄ 12H ₂ O) and deionized water (3.75:5:10:100 weight ratio) at 95 to 97 C, impregnation was performed for 10 minutes. After impregnation, the obtained sample was thoroughly washed with DI to obtain CuO nano-blades.

Except for using CuO nan-blades instead of Cu(OH) ₂ nanorods, the silica layer formation and lubricating fluid impregnation process were performed in the same manner as in Comparative Example 1 to form a lubricating fluid supporting structure (FL-CuO) got

Evaluation Example 1: Sand abrasion test

A sand abrasion test was performed on the SLIPS porous composite structure of Example 1-2 and the structure of Comparative Example 1-2. The sand abrasion test was carried out by tilting each sample at 45 ° and dropping 5 g of sea sand with a size of 30 - 50 mesh from a height of 1 m.

The sand abrasion test results are shown in FIGS. 3a, 3b, 3c, 3d, 4a, 4b, 4c and 4d. 3a and 3b show the sand abrasion test results for the porous composite structure of Example 1, and FIGS. 3c and 3d show the sand abrasion test results for the porous composite structure of Example 2. 4a and 4b show the sand abrasion test results for the structure of Comparative Example 1, and FIGS. 4c and 4d show the sand abrasion test results for the structure of Comparative Example 2.

Referring to this, it was found that the porous structure of Comparative Example 1-2 showed a large change in surface state after the sand abrasion test, as shown in FIGS. 4A to 4D. In contrast, in the SLIPS porous composite structures of Examples 1 and 2, as can be seen from FIGS. 3A to 3D, it was found that the SLIPS surface maintained its original surface structure even after the sand abrasion test. From this, it was found that the SLIPS porous composite structures of Examples 1 and 2 had improved mechanical properties compared to the structures of Comparative Examples 1 and 2.

Evaluation Example 2: Acid resistance test

After dropping 1 drop of 2M HCl (approximately 10 - 20 uL) on the surface of the SLIPS porous composite structure of Example 1-2 and the structure of Comparative Example 1-2, the surface change state of each structure was evaluated, and the surface state was changed Time was measured. The measurement results are shown in FIGS. 12 to 15 .

As shown in FIG. 14, the structure of Comparative Example 1 was reduced to the original Cu surface within 1 minute, and more reduction was observed after 5 minutes. In addition, the structure of Comparative Example 2 was reduced after 2 minutes. Observed. As such, it was found that the structure of Comparative Example 1-2 initiated a surface reduction reaction within 2 minutes.

In contrast, the SLIPS porous composite structure of Example 1 maintained its surface state even after 1 hour, as can be seen from FIG. 12 . In the SLIPS porous composite structure of Example 2, as can be seen from FIG. 13, a surface reduction reaction was observed after 20 minutes.

From the above results, it can be seen that the SLIPS porous composite structure of Example 1-2 is effectively suppressed from being reduced in an acid solution compared to the structures of Comparative Examples 1 and 2, and thus the durability is greatly improved.

Evaluation Example 3: Scanning electron microscope

(1) Example 1

Scanning electron microscopy was performed on the Cu(OH) ₂ nanorods prepared in Example 1 and the porous composite structure of Example 1. Hitachi's S-4700 was used for scanning electron microscope analysis. Scanning electron microscope analysis results for the Cu(OH) ₂ nanorods and the porous composite structure prepared according to Example 1 are shown in FIGS. 6 and 7 .

Referring to FIG. 6 , the shape of the Cu(OH) ₂ nanorods prepared in Example 1 could be confirmed. And it was found that the porous composite structure had a structure in which a silica layer was formed, as shown in FIG. 7 .

(2) Example 2

Scanning electron microscopic analysis was performed on the CuO nanoblades prepared according to Example 2 and the porous composite structure of Example 2. Hitachi's S-4700 was used for scanning electron microscope analysis. Scanning electron microscope analysis results for the CuO nanoblades and the porous composite structure prepared according to Example 2 are shown in FIGS. 8 and 9 .

The shape of the CuO nanoblades prepared in Example 1 could be confirmed with reference to FIG. 8 . And referring to FIG. 9, it was confirmed that the porous composite structure had a structure in which a silica layer was disposed.

Evaluation Example 4: Analysis of lubrication performance

In order to analyze the lubricating performance of the SLIPS porous composite structure of Example 1, the sliding angle for water, glycerol, and diiodomethane was measured.

The wettability of water, glycerol, and diiodomethane, which are liquids having various surface tensions, was measured using a sliding angle measuring stage. A droplet of 10 µl was dropped on 10 different locations on the SLIPS porous composite structure of Example 1. Sliding angle angle was measured by dropping a droplet of 10 μl on a tilt stage using a high-speed camera.

As a result of the evaluation, as a result of measuring the sliding angle of the SLIPS porous composite structure of Example 1 with respect to water, glycerol, and diiodomethane, it can be confirmed that a low value of 10 ° or less is maintained. From this, it was found that the SLIPS porous composite structure of Example 1 had hydrophobicity.

Evaluation Example 5: Contact angle

The contact angles of the SLIPS porous composite structures of Examples 1 and 2 with respect to water were measured using a contact angle measuring instrument.

Evaluation of the contact angle for the SLIPS porous composite structure of Example 1, it was found that the contact angle was 170 ° or more. In addition, the contact angle evaluation of the SLIPS porous composite structure of Example 2 showed contact angle characteristics similar to those of the SLIPS porous composite structure of Example 1.

In the above, one embodiment has been described with reference to drawings and embodiments, but this is only exemplary, and those skilled in the art can understand that various modifications and equivalent other implementations are possible therefrom. will be. Therefore, the scope of protection of the present invention should be defined by the appended claims.

1 ... duct 2 ... water jet
21 ... injection nozzle 13, 14 ... water outlet
3... Dust collection part 31... Fine flow path
32 ... outlet 310 ... porous foam
320 ... mesh 330 ... filler
5... blower 6... water tank
7...Pump 8...Collecting tank
33: discharge plasma generator 34: catalytic reactor

Claims (34)

a substrate having a nanostructure;
a particle layer disposed on at least one surface of the substrate; and
A porous composite structure containing a lubricating fluid. The method of claim 1, wherein the porous composite structure further comprises an interlayer,
The intermediate layer is disposed on at least one surface of the substrate, and the particle layer is disposed on at least one surface of the intermediate layer, a porous composite structure. The porous composite structure according to claim 1, wherein the substrate and the particle layer form a re-entrant structure. The porous composite structure of claim 1, wherein the porous composite structure includes a slippery liquid infused porous surface (SLIPS). The porous composite structure according to claim 1, wherein the porous composite structure further comprises a material having affinity for lubricating fluid. The porous composite structure according to claim 5, wherein a material having affinity for the lubricating fluid is chemically bonded to the particle layer. The porous composite structure according to claim 5, wherein the material having affinity for the lubricating oil agent is fluorinated silane. 8. The method of claim 7, wherein the fluorinated silane is trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, or a combination thereof. Porous composite structure. The porous composite structure according to claim 1, wherein the substrate is a nanorod, nanoribbon, nanotube, nanoblade, nanoplate, template having regular pores or random pores, or a combination thereof. The method of claim 1, wherein the substrate includes a base layer and a plurality of pillar parts protruding from the base layer,
The base layer and the pillar portion are made of the same material,
The pillar portion is a porous composite structure that is a nanorod, a narrow ribbon, a nanotube, a nanoblade, a nanoplate, or a combination thereof. The porous composite structure according to claim 1, wherein the particle layer is an inorganic particle, an organic particle, or a combination thereof. The method of claim 1, wherein the particle layer is an inorganic particle layer,
The inorganic particle layer is SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZnO ₂ , WO ₃ , SnO ₂ , ZrO, ITO. A porous composite structure containing at least one inorganic particle selected from CaCO ₃ . The method of claim 1, wherein an intermediate layer is disposed on at least one side of the substrate,
A particle layer is formed on at least one surface of the intermediate layer, and the intermediate layer and the particle layer are coupled by electrostatic attraction, a porous composite structure. The method of claim 1, wherein the particle layer is a silica layer,
The silica layer is a plurality of layers, a porous composite structure comprising a positively charged silica layer and a negatively charged silica layer. The porous composite structure of claim 1, wherein the substrate includes a metal, metal oxide, metal hydroxide, polymer, glass, ceramic, or a combination thereof. The porous composite structure according to claim 1, wherein the porous composite structure has a contact angle of 170° or more and a sliding angle of 10° or less with respect to water and organic solvent. The porous composite structure of claim 2, wherein the intermediate layer comprises a hydrolysis, dehydration, and condensation reaction product of a compound represented by Formula 1:
<Formula 1>

In Formula 1, R ₁ is a C1-C20 alkylene group or a C6-C20 arylene group;
R ₂ is hydrogen, a C1-C20 alkyl group, a C6-C20 aryl group, or Cl. The method of claim 17, wherein the compound represented by Formula 1 is (3-aminopropyl)trimethoxysilane, 3-aminopropyltriethoxysilane, 2-aminoundecyltrimethoxysilane, aminophenyltrimethoxysilane , bis(trimethoxyrillylpropyl)amine, N-(2-aminoethylaminopropyl)trimethoxysilane, or a porous composite structure that is a combination thereof. forming a first structure by forming a particle layer on a substrate having a nanostructure; and
Method for producing a porous composite structure comprising the step of providing a lubricating fluid on top of the first structure. The method of claim 19, before performing the step of forming the first structure by forming a particle layer on the substrate having the nano-material,
A method for producing a porous composite structure, further comprising forming an intermediate layer on a substrate having a nanostructure. 21. The method of claim 20, wherein forming the intermediate layer,
Method for producing a porous composite structure, which is a process of coating a compound of Formula 1 on a substrate:
<Formula 1>

In Formula 1, R ₁ is a C1-C20 alkylene group or a C6-C20 arylene group;
R ₂ is hydrogen, a C1-C20 alkyl group, a C6-C20 aryl group, or Cl. The method of claim 21, wherein the compound represented by Formula 1 is (3-aminopropyl)triethoxysilane, 3-aminopropyltriethoxysilane, 2-aminoundecyltrimethoxysilane, aminophenyltrimethoxysilane , Bis (trimethoxyryllylpropyl) amine, N- (2-aminoethylaminopropyl) trimethoxysilane, or a method for producing a porous composite structure that is a combination thereof. The method of claim 19, before performing the step of forming the first structure by forming a particle layer on the substrate having the nano-material,
Further comprising forming an intermediate layer on the substrate having a nanostructure,
Forming a first structure by forming a particle layer on top of the intermediate layer,
A method for producing a porous composite structure produced by repeatedly contacting inorganic particles having negative charges and inorganic particles having positive charges on the upper portion of the intermediate layer. The method of claim 23, wherein the negatively charged inorganic particles are negatively charged colloidal silica,
A method for producing a porous composite structure in which the inorganic particles having positive charges are colloidal silica having positive charges. The method of claim 19, prior to performing the step of providing a lubricating fluid on top of the first structure, of the porous composite structure further comprising the step of providing a material having affinity for the lubricating fluid on top of the first structure. manufacturing method. The method of claim 25, wherein the step of providing a material having affinity for the lubricating fluid is a step of coating with fluorinated silane. 27. The method of claim 26, wherein the fluorinated silane is trichloro(1H, 1H, 2H, 2H-perfluorooctyl)silane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, or a combination thereof. Manufacturing method of porous composite structure. [Claim 20] The method of claim 19, wherein the method further comprises performing an oxygen plasma treatment. The method of claim 19, wherein the substrate having the nanostructure,
A method for producing a porous composite structure, which is manufactured by performing a process of removing impurities and a native oxide film of a substrate and then performing an etching process to form a nanostructure. An article containing the porous composite structure of any one of claims 1 to 18. An air purifier containing the porous composite structure of any one of claims 1 to 18. The air purifier according to claim 31, wherein the air purifier comprises: a duct through which air containing fine dust flows; a droplet spraying unit spraying water into the duct to form a gas-liquid mixed fluid and collecting fine dust in the air; a dust collecting unit including a porous member that forms a microchannel through which the gas-liquid mixed fluid passes and collects droplets containing the fine dust, wherein the porous member includes a substrate having a nanostructure; a particle layer disposed on at least one surface of the substrate; and a porous composite structure containing a lubricating fluid. 32. The air purifier according to claim 31, wherein the air purifier further comprises a discharge plasma generator for generating discharge plasma in the dust collector. 32. The method of claim 31, wherein the air purifier promotes the ozone discharged from the dust collector.
An air purifier further comprising a catalytic reactor that can be removed using a medium.

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