KR101726402B1 - Oil-water separation structure, method for preparing the same, oil-water separator, and oil-water separation method using the oil-water separator - Google Patents

Abstract

There is provided an oil water separating structure and a method of manufacturing the same, a oil water separating apparatus including the oil water separating structure, and a method of separating oil water using the oil water separating apparatus. Wherein the oil water separating structure comprises a porous substrate including a plurality of protrusions that form a nano pattern on at least one surface thereof; And inorganic particles disposed on ends of at least a part of the projections. The oil-water separating structure has hydrophilic to superhydrophilic surface properties, so that water in water and oil can be selectively passed through and oil can be easily separated and collected. The oil water separating structure is eco-friendly and can be made large in area. The oil water separating apparatus including the oil water separating structure can be used repeatedly to prevent further environmental pollution.

Description

TECHNICAL FIELD [0001] The present invention relates to an oil-water separation structure, a method for manufacturing the oil-water separation structure, a water-oil separator, and a method for separating oil from water using the oil- water separator}

The present invention relates to an oil-water separating structure for a nano-pattern structure on a surface thereof, a manufacturing method thereof, a water-oil separating apparatus including the water-oil separating structure, and an oil-water separating method using the oil-water separating apparatus.

Techniques for removing oil from oil spills in rivers or oceans use a method of separating and removing spilled oil from water by controlling surface energy such as hydrophilicity and hydrophobicity of the surface.

The technology for separating oil and water (hereinafter referred to as oil separation technology) can be roughly classified into two types. One of them is a method of passing oil and filtering water using a super-hydrophobic oil filter having a low surface energy, and the other is a method of passing water through a hydrophilic or super hydrophilic filter having a high surface energy, Which does not allow the oil to pass through. It is easy to use filters of the latter technique for selectively separating and collecting oil from water and oil. For this purpose, a technique for hydrophilizing the filter is required.

As a method of forming a hydrophilic or superhydrophilic surface on the surface of a material, wet etching, UV treatment or plasma / ion treatment may be used. Particularly, it is known that a hydrophilic or super hydrophilic surface can be obtained by increasing the roughness of the surface and adjusting the chemical properties of the surface using a material having hydrophilic properties.

However, attempts have been made to realize such hydrophilic properties on various materials and thin film surfaces, but the hydrophilicity formed on the surface of general materials has a disadvantage that they disappear easily over time. This is because the surface energy of the hydrophilic surface is relatively high, so that it tends to easily bond with fine particles such as water molecules or hydrocarbons in the air in order to lower the surface energy. When such bonding is performed, the surface energy is lowered and hydrophilicity is lost Because. Most of the hydrophilic or super-hydrophilic treatments by the methods known in the art lose their effects within a few hours or several days, and therefore various studies have been made to maintain the hydrophilic or super-hydrophilic properties for a long time. In addition, large area and mass production are also required in producing a hydrophilic or super hydrophilic surface.

On the other hand, as the industry becomes more sophisticated, environmental problems become more significant, and researches on materials for separating and / or removing specific substances from a mixture such as oil separation and seawater desalination are continuously increasing. In addition, a lot of research is being conducted for the oil separation technique which can recover the crude oil firstly, recycle the recovered crude oil, and does not cause the secondary environmental pollution that occurs during the recovery process .

Therefore, it is necessary to develop a large-scale water-oil separating structure that is environment-friendly and has excellent durability in the manufacturing process.

One aspect of the present invention is to provide a water separation structure that can be made large in area and has improved durability.

Another aspect of the present invention is to provide a water separation apparatus including the water separation structure.

Another aspect of the present invention is to provide a method of manufacturing the oil water separating structure.

Another aspect of the present invention is to provide a water separation method using the water separation apparatus.

According to an aspect of the present invention,

A porous substrate comprising a plurality of protrusions that form a nanopattern on at least one surface; And

An inorganic particle disposed at an end of at least a part of the projecting portion;

Is provided.

According to one embodiment, the substrate may be non-woven, woven, or net-like.

According to one embodiment, the substrate has a curved shape, and the nanopattern may be formed on at least the concave surface of the curved shape.

According to one embodiment, the substrate may comprise at least one of plastic, fiber, glass, metal, ceramic, and carbon-based materials.

According to one embodiment, the protrusion may be in the form of a nano-hair, a nan-fiber, a nano-pillar, a nano-rod or a nano-wire. .

According to one embodiment, the inorganic particles may include at least one of Ti, Cu, Au, Ag, Cr, Pt, Fe, Al, Si, alloys thereof, and oxides thereof. For example, the inorganic particles may include TiO _2.

According to an embodiment, the oil-water separating structure may have a contact angle with respect to water in the air of 20 ° or less and a contact angle with respect to oil underwater of 140 ° or more.

In another aspect of the present invention, there is provided a water separation apparatus including the water separation structure.

According to an embodiment, the water-oil separating apparatus may be a sinker including the oil water separating structure and a support frame for fixing the oil water separating structure. The honeycomb can only emit oil from water and oil.

According to one embodiment, the oil water separating structure can be applied to an oil fence.

In another aspect of the present invention,

Preparing a porous substrate;

Positioning a metal mesh structure above the substrate; And

Plasma processing the substrate on which the metal mesh structure is located;

Wherein the oil separating structure is formed by a method comprising the steps of:

According to one embodiment, the substrate may be non-woven, woven, or net-like.

According to one embodiment, the substrate may comprise at least one of plastic, fiber, glass, metal, ceramic, and carbon-based materials.

According to one embodiment, the metal mesh structure may include at least one of Ti, Cu, Au, Ag, Cr, Pt, Fe, Al, Si, alloys thereof, and oxides thereof.

According to one embodiment, the metal net structure may be positioned above the substrate with an interval of 20 mm or less.

According to one embodiment, the plasma processing step comprises:

Depositing metal or metal oxide inorganic particles generated from the metal mesh structure on the substrate surface through a plasma treatment; And

And etching the remaining portion of the substrate other than the portion on which the metal or metal oxide inorganic particles are deposited through the plasma treatment.

The deposition step and the etching step may be performed simultaneously under the same plasma processing conditions.

According to one embodiment, the plasma treatment may be performed using at least one gas selected from O ₂ , CF ₄ , Ar, N ₂ , and H ₂ .

According to one embodiment, the metal mesh structure includes Ti, and the plasma treatment may be performed using O ₂ gas.

According to one embodiment, the plasma treatment may be carried out at a voltage of -100 V to -1000 V, at a pressure of 1 to 1000 mTorr for 10 seconds to 5 hours.

In another aspect of the present invention, there is provided an oil-water separation method comprising selectively passing water in water and oil and collecting oil using a water-oil separator.

According to one embodiment, before using the oil-water separating apparatus, the oil-water separating apparatus may further include a pretreatment step of wetting the oil-water separating apparatus with water.

According to one embodiment, after the oil collection, the oil separation apparatus may further include UV treatment.

The oil water separating structure according to one aspect has hydrophilic to superhydrophilic surface properties so that water in water and oil can be selectively passed through and the oil can be easily separated and collected. The oil water separating structure is eco-friendly and can be made large in area. The oil water separating apparatus including the oil water separating structure can be used repeatedly to prevent further environmental pollution.

1 is a schematic view showing a cross-sectional structure of a water separation structure according to an embodiment of the present invention.
2 is a schematic view for explaining a method of manufacturing a water separation structure according to an embodiment.
FIG. 3 is a view showing a stepwise production method of a water separation structure according to an embodiment.
FIG. 4 is a perspective view showing an appearance of an embossed pattern according to an embodiment of the present invention. FIG.
5 is a cross-sectional view schematically showing a cross section of the yard of Fig.
6 is a Scanning Electron Microscope (SEM) image showing a stepwise process of forming a nanopattern according to oxygen plasma treatment time in Example 1. FIG.
FIG. 7 shows the results of analysis of surface components of the water-oil separating structure prepared in Comparative Example 1 and Example 1 using an X-ray photoelectron spectroscopy (XPS).
8A is a comparative photograph showing wettability of the oil-water separating structure manufactured in Comparative Example 1 and Example 1 with respect to water.
FIG. 8B is a graph showing contact angles of water with respect to water according to plasma treatment time of the oil-water separation structure manufactured in Comparative Example 1 and Example 1. FIG.
9A is a photograph showing wettability of oil-water separating structure manufactured in Comparative Example 1 and Example 1 with respect to oil in air.
9B is a comparative photograph showing wettability of oil-water separating structure manufactured in Comparative Example 1 and Example 1 with respect to oil in water.
FIG. 9c is a graph showing contact angles of oil-water separating structure manufactured in Comparative Example 1 and Example 1 with respect to oil according to plasma treatment time. FIG.
10 is a view showing the concept of oil-water separation using a general nonwoven fabric (before (a) plasma treatment) used in Comparative Example 1 and an oil water separation structure (after (b) plasma treatment) prepared in Example 1. Fig.
11A is a photograph showing the oil-water separating effect of the honeycomb using the general nonwoven fabric used in Comparative Example 1 (before (a) plasma treatment).
Fig. 11B is a photograph showing the oil separation effect of the honeycomb using the oil water separating structure manufactured in Example 1 ((b) after plasma treatment).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of a water separation structure according to an embodiment of the present invention;

According to one aspect of the present invention,

A porous substrate comprising a plurality of protrusions that form a nanopattern on at least one surface; And

And inorganic particles disposed on ends of at least a part of the projections.

1 schematically shows a sectional structure of a water separation structure according to an embodiment. As shown in FIG. 1, protrusions 4a having a plurality of nano sizes are repeated at uniform intervals to form a uniform nano pattern over the entire surface of the base material 1, and at the end of the protrusion 4a The inorganic particles 3 are disposed.

The substrate 1 may have a flat or curved shape. When the base material 1 has a curved shape, the nanopattern may be formed on at least the concave surface of the curved shape. In the case where the substrate 1 has a curved surface shape, since the volatile oil is collected inside the curved surface to selectively pass the water in the water and the oil and collect only the oil, the surface area where the oil evaporates can be reduced, The collection efficiency of the oil can be improved.

The substrate 1 is not limited in size and may have an area of, for example, 100 cm ^{2 or} more. The substrate 1 may have a large area of, for example, 10 cm X 10 cm or more. The thickness of the substrate 1 is not limited.

The base material (1) is not limited in its shape as long as it is a porous or network structure having holes through which water can pass. The substrate 1 may be, for example, non-woven, woven, or net-like. When the base material 1 is a fiber material, it may be preferable that it is in the form of a nonwoven fabric. When the base material 1 is a material having a certain level of strength or more, it may be in a net form or a woven form. The net-like substrate 1 may be in the form of a mesh of, for example, 10 to 500 mesh. The water escapes in the mesh range, and only the oil can be filtered selectively. If the mesh is larger than 500 mesh, the mesh size is excessively small and the speed at which the water escapes may be significantly lowered, which may cause a problem in the efficiency of water separation. If the mesh size is too small, the mesh may be excessively large.

The base material 1 may include at least one of plastic, fiber, glass, metal, ceramic, and carbon-based material.

The plastic is not particularly limited and may include at least one of, for example, polypropylene, polyethylene terephthalate, polyvinylidene fluoride, polytetrafluoroethylene, copolymers thereof, and combinations thereof.

The fibers may comprise natural fibers, artificial fibers or combinations thereof. As the natural fibers, for example, cotton, hemp, wool, asbestos fibers, combinations thereof, and the like can be used. The man-made fibers include, for example, i) regenerated fibers such as rayon, modal, tencel, lyocell and polynosic; ii) semi-synthetic fibers such as acetate and triacetate; iii) polyamides such as nylon, Nomex and Kevlar, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, acrylics, poly (meth) acrylates, polyvinyl alcohol (PVA) Synthetic fibers such as urethane, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), and polystyrene; And inorganic fibers such as glass fibers, but are not limited thereto.

The metal may be at least one selected from the group consisting of Fe, Al, stainless steel, Cu, Pt, Au, Ag, Ti, Or alloys thereof, or a combination of these.

The carbon-based material may include graphite, carbon fiber, diamond, graphene, or a combination thereof.

At least one surface of the porous substrate 1 includes a plurality of protrusions 4a that form a nanopattern. The protrusions 4a may have a diameter in the range of 1 to 100 nm, a length in the range of 1 to 10,000 nm, and an aspect ratio in the range of 1 to 50. The protrusion may be in the form of a nano-hair, a nan-fiber, a nano-pillar, a nano-rod or a nano-wire, ) To form a nanopattern on the surface. According to the manufacturing method described below, the nanopattern can be uniformly formed on the substrate surface of a large area.

An inorganic particle (3) is disposed at an end of at least a part of the projecting portion (4a). A plurality of the inorganic particles (3) can be clustered to form a cluster. In addition, the inorganic particles 3 may be disposed at the ends of almost all or all of the protruding portions 4a. However, in the manufacturing method described below, some inorganic particles 3 may be cut off in the etching process by the plasma treatment, The inorganic particles 3 may not be disposed at the end of the projecting portion 4a.

The inorganic particles (3) may contain a metal or a metal oxide capable of imparting suitable surface characteristics depending on the application for oil-water separation. According to one embodiment, the inorganic particles 3 may include a metal or a metal oxide that imparts hydrophilicity to superhydrophilic property so that water passes through the oil separation structure and oil does not pass therethrough. The metal or metal oxide may be derived from a metal mesh structure used in a manufacturing process described later. For example, the inorganic particles may include at least one of Ti, Cu, Au, Ag, Cr, Pt, Fe, Al, Si, alloys thereof and oxides thereof. According to one embodiment, when the inorganic particles 3 containing TiO ₂ are disposed at the ends of the protrusions 4a forming the nanopatterns, the hydrophilic surface characteristics that the nanopatterns themselves can have are modified to be more hydrophilic .

The oil-water separating structure may have a superhydrophilic surface property with a contact angle to water of 20 DEG or less by chemical bonding with inorganic particles that impart hydrophilicity to the surface of the substrate having the nanopattern formed thereon.

Such an oil-water separating structure having a superhydrophilic surface has a very high surface state, and thus may have a lipophilic property with respect to oil having a low surface energy. However, in the water, the oil is not absorbed by the oil-water separating structure, but exhibits superoleophobicity which maintains a spherical droplet shape. Accordingly, the oil water separating structure may have a contact angle with respect to oil underwater which is higher than 140 DEG for example in water.

Hereinafter, a method of manufacturing the oil water separating structure will be described.

According to an aspect of the present invention,

Preparing a porous substrate;

Positioning a metal mesh structure above the substrate; And

And plasma treating the substrate on which the metal mesh structure is located.

The method for producing the oil water separating structure is not limited to the area of the substrate or the cross-sectional shape, and it is possible to produce a water separating structure in which nano patterns are uniformly formed on the surface over a large area, relatively easily and environmentally friendly.

2 is a schematic view for explaining a method of manufacturing a water separation structure according to an embodiment.

FIG. 3 is a view showing steps of a method of manufacturing a nanocomposite structure according to an embodiment.

As shown in Figs. 2 and 3, the metal mesh structure 2 is placed above the substrate 1, and a plasma treatment is performed. The type and form of the base material 1 are the same as those described above with respect to the oil water separating structure according to one embodiment, and a detailed description thereof will be omitted here.

The metal mesh structure 2 is not only a raw material for the inorganic particles 3 to be coated on the surface of the oil water separating structure but also an inorganic particle of the metal or metal oxide generated from the metal mesh structure 2 during the plasma treatment, (3) can be uniformly deposited on the entire surface of the substrate (1). The inorganic particles 3 function as a mask or an inhibitor so that the portion of the substrate 1 on which the inorganic particles 3 are not deposited can be selectively etched, Can be formed. The use of the metal net structure 2 makes it possible to uniformly deposit the inorganic particles 3 on the entire surface of the base material 1, thereby making it possible to make the oil water separating structure larger.

The metal net structure 2 may include a metal or a metal oxide capable of imparting suitable surface characteristics depending on the purpose of oil-water separation. According to one embodiment, the metal net structure 2 may include a metal or a metal oxide that imparts hydrophilicity to superhydrophilic property so that water passes through the oil separation structure and oil does not pass therethrough. For example, the metal mesh structure 2 may include at least one of Ti, Cu, Au, Ag, Cr, Pt, Fe, Al, Si, alloys thereof, and oxides thereof. According to one embodiment, in the case of the metal net structure 2 containing Ti, a nanopattern coated with TiO ₂ particles may be formed to modify the surface of the oil water separating structure to superhydrophilic property.

The metal mesh structure 2 can be used without limitation as long as it has a net structure such that metal or metal oxide inorganic particles 3 generated therefrom can be uniformly deposited over the entire substrate 1. [

For example, the metal mesh structure 2 may be formed of a metal mesh woven in the form of a metal wire. The diameter, spacing and the like of the metal wire constituting the metal mesh structure 2 are not particularly limited and can be adjusted according to the desired nanopattern structure. For example, the interval of the metal wires constituting the metal net structure 2 may be in the range of 10 to 500 mu m.

The size of the metal net structure 2 can be selected to match the size of the substrate 1 to be formed with the nanopattern.

In order to position the metal mesh structure 2 on the substrate 1, the metal mesh structure 2 may be positioned on the substrate 1 at a certain interval. For example, it may be 20 mm or less of the substrate 1 and the metal mesh structure 2. The inorganic particles 3 of metal or metal oxide generated from the metal net structure 2 may fall on the surface of the base just below the metal net structure 2, 1) can be uniformly deposited over the entire surface. When the metal net structure 2 is in contact with the substrate 1, the portion of the substrate 1 with which the metal net structure 2 is in contact is not etched by the plasma treatment, The greater the water separation structure, the lower the efficiency of water separation. Therefore, it is preferable that the metal net structure 2 does not contact the surface of the substrate 1. [

Then, the substrate 1 on which the metal mesh structure 2 is placed is plasma-treated. By the plasma treatment, the surface of the substrate 1 may have a hydrophilic property or a super hydrophilic property.

According to one embodiment, the plasma processing step comprises:

Depositing metal or metal oxide particles generated from the metal mesh structure on the surface of the substrate through a plasma treatment; And

And etching the remaining portion of the substrate surface other than the portion on which the metal or metal oxide particles are deposited through a plasma treatment.

As shown in FIG. 3, when the plasma treatment is performed, the metal or metal oxide inorganic particles 3 generated from the metal mesh structure 2 are first separated and deposited on the surface of the base material 1. The inorganic particles (3) can form a cluster during the plasma treatment.

When the substrate 1 on which the metal or metal oxide inorganic particles 3 are deposited is subsequently subjected to plasma treatment, portions where the metal or metal oxide inorganic particles 2 are not deposited on the surface of the substrate 1 are selectively etched A nanopattern structure can be formed on the surface of the substrate 1.

More specifically, where the metal or metal oxide inorganic particles 3 are deposited on the surface of the substrate 1, they act as inhibitors to the etching action of the plasma, where the etching rate is remarkably low, while the metal Or the surface of the substrate 1 on which the metal oxide inorganic particles 3 are not deposited is etched by the plasma so that the etching rate is increased there and as a result nano-hair, nano- It is possible to form a nano pattern composed of a first protrusion 4a in the form of a fiber, a nanofiber, a nano-pillar, a nano-rod or a nano-wire.

The step of depositing the metal or metal oxide inorganic particles 3 and the step of etching the substrate 1 may be performed simultaneously under the same plasma processing conditions.

As shown in FIG. 3, the metal mesh structure 2 can be continuously held on the substrate 1 without being removed during the etching by the plasma treatment. The metal or metal oxide inorganic particles 3 deposited on the substrate 1 are also slightly scraped off by sputtering during the etching process by the plasma treatment so that the inorganic particles 3 which will act as inhibitors in the long- It needs to be supplied. Therefore, by continuing the plasma treatment without removing the metal mesh structure 2, the metal or metal oxide inorganic particles 3 can be continuously supplied and the cluster can be maintained.

The plasma treatment can form various types of nanopattern structures by adjusting the condition and the treatment time.

The plasma treatment may be performed in the presence of at least one gas selected from O ₂ , CF ₄ , Ar, N ₂ , and H ₂ . In the case of using O ₂ gas, the surface of the substrate 1 can be bonded to oxygen by the plasma treatment to give a hydrophilic surface having persistence. On the other hand, the pressure during the plasma treatment may be, for example, 1 to 1000 mTorr, and higher atmospheric pressure may be possible.

The plasma treatment may be performed, for example, in a voltage range of -100 V to -1000 V, and is performed at a pressure of 1 to 1000 mTorr for 10 seconds to 5 hours Lt; / RTI > As the plasma treatment time becomes longer, the surface of the substrate may change from hydrophilic to superhydrophilic. According to one embodiment, when the plasma treatment time is prolonged, the contact angle with respect to water may be reduced to 20 DEG or less, 10 DEG or less, 5 DEG or less, or even 1 DEG or less, while the superfluidity of the substrate surface is increased. Herein, the contact angle of the substrate surface with respect to pure water is defined as a hydrophilic value of 20 DEG or less, and the contact angle of 10 DEG or less is defined as a superhydrophilic value.

The manufacturing method of the oil water separating structure is eco-friendly and can be surface-treated in a large area, thereby realizing the large-sized oil water separating structure.

The oil water separating structure thus manufactured can be applied to various oil water separating apparatuses.

The oil-water separating apparatus according to one aspect includes the oil-water separating structure described above. The oil-water separating apparatus may be implemented by any suitable means or various structures applicable to oil-water separation using the oil-water separating structure.

According to one embodiment, the oil water separating apparatus may further include a reinforcing member for supporting the oil water separating structure. The reinforcing material serves to support the oil water separating structure so that the oil water separating structure is not deformed by oil or high pressure externally applied during oil-water separation. The reinforcing material may be formed of at least one of a metal rod, a metal mesh, a polymer rod, and a polymer mesh. The stiffener may be disposed on the opposite surface of the oil water separating structure on which oil is drained, that is, on the surface from which the water escapes. The oil water separator can improve the structural stability by the reinforcing member. The reinforcing material may also be formed by forming a nano pattern having a plurality of protrusions on at least one surface through the plasma treatment.

According to one embodiment, the oil-water separating structure can be applied to an oil pan that can float oil existing on the water surface. The honeycomb may include the oil-water separating structure and a support frame capable of supporting the oil-water separating structure.

FIG. 4 is a perspective view showing an outer appearance of an embossed pattern according to an embodiment, and FIG. 5 is a cross-sectional view schematically showing a cross section of the embossing pattern of FIG.

4 and 5, the honeycomb according to an embodiment includes a water separation structure 10 and a support frame 20 for supporting the same. The oil water separating structure 10 is fixed to the support frame 20. If the oil water separating structure 10 itself has sufficient rigidity, the additional supporting frame 20 may not be required. The poppet may further include a handle.

The oil water separating structure 10 fixed to the support frame 20 may have a curved shape as a whole in order to improve the collection efficiency of volatile oil. For example, the oil water separating structure 10 may have a hemispherical shape as a whole. However, the shape of the oil water separating structure 10 is not particularly limited. For example, the oil water separating structure may have a cylindrical shape having a flat bottom or a rectangular box shape.

As shown in FIG. 5, the inner surface of the honeycomb is formed with a nano pattern through the plasma treatment as described above, and only the water can be drained through the hole formed in the water separation structure of the honeycomb and the oil can be selectively filtered .

According to one embodiment, the oil water separating structure can be applied to an oil fence. The oil fence using the oil-water separating structure is used to prevent the oil leakage from the sea, the river, and the river when oil spills due to ship operation, ship sinking accident, oil tank accident on the ground, refinery, oil storage, oil pipe, Prevent spreading, so that oil does not spread across the water to the shore.

Also, the oil fence using the oil water separating structure can be installed so that oil can be confined in one place in case of oil leakage. Since the oil fence has a super-hydrophilic property on the surface and the water film formed after wetting with water has a super-oil-releasing property, the oil collected in the oil fence can be easily collected using another type of oil separator .

The oil-water separation method according to one aspect includes selectively passing water in water and oil and collecting oil using the oil-water separating apparatus described above.

As the oil water separating structure exhibits hydrophilic to super hydrophilic properties, the oil water separating device has high wettability and easily passes water. Therefore, when the liquid mixed with the oil and the water is passed through the oil-water separator, water easily passes through the oil-water separating structure, but the oil can not pass through the oil-water separating structure due to the repulsive force against water, .

According to one embodiment, in performing the water separation, the water separation apparatus may further include a pretreatment step of wetting the water separation apparatus with water before using the water separation apparatus. Through the wetting process, a water film can be formed on the surface of the oil water separating structure, and the oil can be more efficiently filtered thereon.

According to one embodiment, after the oil collection, the oil separation apparatus may further include UV treatment. The UV treatment can further improve the hydrophilicity of the inorganic particles coated on the nanopattern, and the oil-water separator used more than once through the UV treatment can be repeatedly used.

Hereinafter, the present invention will be described in more detail with reference to examples.

The morphology of the surfaces prepared in the following examples and comparative examples was examined with a scanning electron microscope (SEM, FEI, Nova NanoSEM 200, USA). The contact angle (CA) for water was measured with a contact angle meter (Goniometer, Rame-Hart, USA). The volume of each droplet used at the static contact angle was 8 μl. The average CA values were obtained by measuring at five different locations for the same sample.

Comparative Example  One

A circular polyethylene terephthalate nonwoven fabric (manufacturer: SK Chemical) having a diameter of 160 mm and a thickness of 1 mm was applied as an oil-water separation structure without plasma treatment as a porous substrate.

Example  One

As the porous base material, a circular polyethylene terephthalate nonwoven fabric (manufacturer: SK Chemical) having a diameter of 160 mm and a thickness of 1 mm was used.

As the metal mesh, a Ti mesh (Nilaco Co., Ltd., diameter: 160 mm, circularity, wire spacing: 320 μm, wire diameter: 180 μm) was used. The plasma processing apparatus was a radio frequency generator Product name: RTX-600) Respectively.

First, the substrate was placed on a cathode in a chamber of a plasma processing apparatus. The distance between the mesh and the substrate was adjusted by placing a Ti mesh at a distance of 2 mm on the substrate, placing a support on the mesh rim and placing a mesh thereon to fix the mesh. Then, plasma treatment was performed at a voltage of -400 V, a pressure of 50 mTorr, and an O ₂ gas of 10 sccm for 30 minutes to prepare an oil water separating structure.

FIG. 6 is a SEM photograph showing steps of forming a nanopattern according to oxygen plasma treatment time in the first embodiment. As shown in FIG. 4, the height of protrusions of the nano patterns formed on the fibers of the nonwoven fabric is proportional to the plasma treatment time and is formed in the range of 10 nm to 1 mm.

FIG. 7 shows the results of analysis of surface components of the water-oil separating structure prepared in Comparative Example 1 and Example 1 using an X-ray photoelectron spectroscopy (XPS). As shown in FIG. 7, when oxygen plasma treatment is performed using a Ti mesh, it can be confirmed that TiO ₂ is formed on the surface of the substrate. On the other hand, in the case where the plasma treatment is not carried out, it can be seen that there is no result on the metal surface on the substrate surface.

FIG. 8A is a photograph showing wettability of the oil-water separating structure manufactured in Comparative Examples 1 and 1 to water, and FIG. 8B is a graph showing the wettability of the oil-water separating structure prepared in Comparative Example 1 and Example 1 And a contact angle with respect to water.

As shown in FIGS. 8A and 8B, in the case of the porous substrate before the plasma treatment, since the contact angle to water is 126 DEG, the water can not enter the pores and is present only on the surface of the porous substrate, Since the hydrophilic chemical bonds on the surface of the substrate are increased, the contact angle with water is 0 °, allowing the water to pass between the pores of the porous substrate, so that if the amount of water is sufficient, Able to know.

FIG. 9A is a photograph showing the wettability of the oil-water separating structure manufactured in Comparative Example 1 and Example 1 with respect to oil in air. FIG. 9B is a graph showing the wettability of oil in the water of the oil water separating structure manufactured in Comparative Example 1 and Example 1 FIG. 9c is a graph showing contact angles of the oil-water separating structure prepared in Comparative Example 1 and Example 1 with respect to oil according to the plasma treatment time. FIG.

As shown in FIG. 9A, it can be seen that the oil is well absorbed in the air both before and after the plasma treatment. This is because the hydrophilization of the surface by the oxygen plasma has a very high surface energy, and therefore, the oil has a more affinity with oil having low surface energy. However, it can be seen that superoleophobicity, which maintains spherical droplet shape, is not absorbed in the water after the plasma treatment.

As shown in FIG. 9B, no porous membrane was formed on the surface of the porous substrate before the plasma treatment, and the oil contacted the porous structure to form a contact angle of 40 °. On the other hand, in the plasma-treated porous substrate, the bonding force between the water film and the porous substrate was improved due to the improvement of hydrophilicity, so that oil did not directly contact the porous substrate due to the water film formed on the surface of the porous substrate, . The submergence phenomenon in this water can be explained by the formula for the three-phase system consisting of the solid / water / oil shown below. [Cheng et al, ACS Applied Materials & Interfaces, 21 (2013), 11363-70)

θ _w , θ _o , θ _ow : contact angle of water in air, oil in air, oil in water

? _ow ,? _wa ,? _oa : Surface tension of oil / water, water / air, oil / air

When a hydrophilic group is formed on the surface of the porous substrate by the plasma treatment, as θ _w decreases, θ _ow Is increased. Here ,? _Ow ,? _Wa ,? _Oa Are all constants, and θ _o Lt; RTI ID = 0.0 > 0. ≪ / RTI >

Fig. 10 is a conceptual diagram of oil separation using a general nonwoven fabric (before (a) plasma treatment) used in Comparative Example 1 and an oil water separation structure (after (b) plasma treatment) prepared in Example 1 and a photograph to be.

As shown in FIG. 10, in the case of Comparative Example 1 in which plasma treatment was not performed, the surface of the porous substrate having a curved surface showed hydrophobicity and water could not pass through the pores, so that water and oil mixed on the porous substrate, The oil is smaller in specific gravity than water and floats on the water, so that water and oil are trapped in the curved surface at the same time, and the oil separation does not occur. However, in the case of the plasma-treated porous substrate of Example 1, nanopatterns having superhydrophilic characteristics were formed on the surface, and when water and oil were present together, water having a high specific gravity preferentially contacted with the surface of the hydrophilic porous substrate And due to the strong coupling between the water and the substrate, the water coating is formed and the remaining water falls downward by gravity. Thereafter, the oil comes into contact with the surface of the porous substrate on which the water film is formed, and is not allowed to pass between the pores due to the repulsion by the water film. Using this principle, when the oil is spilled out into the water, when the oil is floated, the water is drained through the sieve and the oil is left, so that the oil can be stored in another oil container. The oil thus separated can be reused as it is.

While a great many have been described in the foregoing description, they should not be construed as limiting the scope of the invention, but rather as examples of embodiments. Accordingly, the scope of the present invention should not be limited by the illustrated embodiments but should be determined by the technical idea described in the claims.

Claims (36)

A porous substrate comprising a plurality of protrusions that form a nanopattern on at least one surface; And
And an inorganic particle disposed at an end portion of at least a part of the projecting portion to impart ultra hydrophilic surface characteristics to the porous substrate,
Wherein the projecting portion is formed by etching the surface of the porous substrate,
Wherein the porous substrate comprises at least one of plastic, fiber, glass, ceramic and carbon-based materials. The method according to claim 1,
The protrusion may be in the form of a nano-hair, a nanofiber, a nano-pillar, a nano-rod or a nano-wire. The method according to claim 1,
The protrusions having a diameter in the range of 1 to 100 nm, a length in the range of 1 to 10,000 nm, and an aspect ratio of 1 to 50. The method according to claim 1,
Wherein the inorganic particles comprise at least one of Ti, Cu, Au, Ag, Cr, Pt, Fe, Al, Si, alloys thereof, and oxides thereof. The method according to claim 1,
Water separation structure in which the inorganic particles comprise TiO _2. The method according to claim 1,
Wherein the inorganic particles form clusters. The method according to claim 1,
The base material has a curved surface shape, and the nanopattern is formed on at least the concave surface of the curved surface shape. The method according to claim 1,
The substrate is a nonwoven fabric, fabric, or net-like oil-water separation structure. The method according to claim 1,
Wherein said substrate is in the form of a mesh of 10 to 500 mesh. delete The method according to claim 1,
Wherein the plastic comprises at least one of polypropylene, polyethylene, polyethylene terephthalate, polystyrene, polymethyl methacrylate, polyvinylidene fluoride, polytetrafluoroethylene, and copolymers thereof. The method according to claim 1,
Wherein the fibers comprise at least one of natural fibers, man-made fibers, and combinations thereof. 13. The method of claim 12,
Wherein the natural fibers comprise at least one of cotton, hemp, wool, silk, and asbestos,
The synthetic fibers may be selected from the group consisting of rayon, modal, tencel, lyocell, polynosic, acetate, triacetate, polyamide, polyolefin, polyester, acrylic, poly (meth) acrylate, polyvinyl alcohol An oil-water separating structure comprising at least one of polyurethane, urethane, polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polystyrene, glass fibers, and copolymers thereof. delete The method according to claim 1,
Wherein the carbonaceous material comprises at least one of graphite, carbon fiber, diamond, and graphene. The method according to claim 1,
Wherein the oil water separating structure has an air contact angle with water of 20 DEG or less. The method according to claim 1,
Wherein the oil water separating structure has a contact angle with respect to oil underwater of 140 ° or more. An oil water separator comprising the oil water separating structure according to any one of claims 1 to 9, 11 to 13, and 15 to 17. 19. The method of claim 18,
And a reinforcing member for supporting the oil water separating structure. An ingot comprising an oil separation structure according to any one of claims 1 to 9, 11 to 13, 15 to 17. 21. The method of claim 20,
And a support frame for fixing the oil water separating structure. An oil fence comprising an oil separation structure according to any one of claims 1 to 9, 11 to 13, 15 to 17. Preparing a porous substrate;
Positioning a metal mesh structure above the substrate; And
Plasma processing the substrate on which the metal mesh structure is located;
Wherein the plasma processing step comprises:
Depositing metal or metal oxide particles generated from the metal mesh structure on the surface of the substrate through a plasma treatment; And
Etching the remaining portion of the substrate surface other than the portion on which the metal or metal oxide particles are deposited through the plasma treatment;
Wherein the oil separation structure is formed by a method comprising the steps of: 24. The method of claim 23,
Wherein the substrate is a nonwoven fabric, a woven fabric, or a net. 24. The method of claim 23,
Wherein the substrate comprises at least one of plastic, fiber, glass, metal, ceramic, and carbon-based material. 24. The method of claim 23,
Wherein the metal net structure is positioned above the substrate with an interval of 20 mm or less. 24. The method of claim 23,
Wherein the metal network structure comprises at least one of Ti, Cu, Au, Ag, Cr, Pt, Fe, Al, Si, alloys thereof and oxides thereof. 24. The method of claim 23,
Wherein the mesh spacing of the metal mesh structure is in the range of 10 탆 to 500 탆. delete 24. The method of claim 23,
Wherein the deposition step and the etching step are performed simultaneously under the same plasma processing conditions. 24. The method of claim 23,
Wherein the plasma treatment is performed using at least one gas selected from O ₂ , CF ₄ , Ar, N ₂ , and H ₂ . 24. The method of claim 23,
Wherein the plasma treatment is performed in a voltage range of -100 V to -1000 V for 10 seconds to 5 hours at a pressure of 1 to 1000 mTorr. 24. The method of claim 23,
Wherein the metal mesh structure comprises Ti, and the plasma treatment uses O ₂ gas. 18. A method for oil-water separation comprising selectively passing water in water and oil and collecting oil using the oil water separating apparatus according to claim 18. 35. The method of claim 34,
Further comprising a pretreatment step of wetting the oil water separating apparatus with water before using the oil water separating apparatus. 35. The method of claim 34,
Further comprising, after the oil collection, UV treatment of the oil separation apparatus.

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