KR102020224B1 - Composite based melamine resin, and oil-water separating materials - Google Patents

Abstract

The present invention relates to an oil-separation material and a method for manufacturing the oil-separation material, wherein the oil-water separation material is a micro-nanosphere in which two or more zinc oxide particles are randomly agglomerated based on an arbitrary point on a surface of a melamine resin matrix having a porous sponge structure. It is not only excellent in durability, but also has a wide average BET specific surface area, lipophilic, superhydrophobic, and superhydrophobic, including a composite of a zinc oxide particle layer and a superhydrophobic coating layer forming a structure. It can be usefully used as a material for oil adsorption oil-water separation used for large-area oil-water separation, such as oil removal.

Description

Composite based melamine resin, and oil-water separating materials

The present invention relates to a composite based on melamine resin, and a material for oil and water separation comprising the same.

Recently, as the environmental problem is greatly highlighted, interest in oil-separated materials for removing contaminants in water is increasing, and the demand is increased due to the diversification of research and use fields for high-performance and application of the separated materials. It is becoming.

Conventionally, oil and water separation methods that are commonly used include specific gravity separation methods and adsorption methods. Among them, the specific gravity separation method has a small mechanical operating part, and thus the structure is simple, and consumables such as filters are not used to reduce costs. There are advantages to it. However, since the oil separation efficiency is low and the water (H ₂ O) content in the separated and discharged oil is high, it is difficult to recycle the oil and the amount is increased as the water is mixed, thereby increasing the cost of oil disposal or disposal. there is a problem. In addition, when the oil and water separation capacity is not large, such as oil spilled into the sea or river is wide, the oil can not be effectively separated in a short time there is a limit to difficult to control.

As an alternative, an in-depth study on the development of an optimal manufacturing process for expressing the characteristics of the separation material used in the adsorption method and the production of the separation material with high functionality by the surface treatment technology is being conducted.

As an example, the plasma surface treatment technology has been developed to improve the performance of the material by changing the surface of the polymer material used as the disk or filter in the adsorption method. However, the technologies developed to date require a surface treatment process such as plasma treatment, so that the manufacturing cost of the material is high, and the performance required for oil and water separation, for example, physical properties such as an adhesion angle indicating water affinity of the separation material. There is a limit to the degree of improvement.

Therefore, it is an adsorption type material that can separate oil and oil of large area in a short time, and it is easy to manufacture materials and large-area oil and water separation work, and it is economical, and it has excellent performance such as water affinity for oil and water separation efficiency. Development of separation materials is required.

Republic of Korea Patent Publication No. 10-0786678

SUMMARY OF THE INVENTION An object of the present invention is to provide a separation material having excellent oil and water separation efficiency due to easy manufacturing of materials and large area oil and water separation operations, economical efficiency, and water affinity for oil and water separation.

In order to solve the above problems,

The present invention in one embodiment,

Melamine resin matrix having a porous structure on the sponge;

A zinc oxide particle layer surrounding the surface of the matrix; And

It comprises a super hydrophobic coating layer surrounding the zinc oxide particle layer,

The zinc oxide particle layer has a structure in which two or more zinc oxide particles are randomly agglomerated at a random point on the surface of the matrix.

The superhydrophobic coating layer provides a composite comprising a silane superhydrophobic coating layer containing a silane compound substituted with a halogenated alkyl group and a fluorinated alkyl group having 10 to 30 carbon atoms and 4 to 20 carbon atoms.

In addition, the present invention in one embodiment,

Immersing the melamine resin matrix having a sponge-like porous structure in a zinc oxide precursor solution and irradiating microwaves to form a zinc oxide particle layer on the surface of the matrix; And

The superhydrophobic coating layer surrounding the zinc oxide particle layer by immersing the melamine resin matrix formed on the surface of the zinc oxide particle layer in a mixed solution of a C10 to C30 fatty acid, an alkyl fluoride group having 4 to 20 carbon atoms, and a silane compound substituted with a halogen group; Forming;

The zinc oxide particle layer provides a method for producing a composite having a structure in which two or more zinc oxide particles are randomly agglomerated based on any one point of a matrix surface.

Furthermore, in one embodiment, the present invention provides a material for oil / water separation containing the composite.

Since the composite according to the present invention is prepared through microwave irradiation, the manufacturing process is simple, and at least one zinc oxide particles are aggregated in a random radial manner at any one point on the surface of the melamine resin matrix having a porous sponge structure. The zinc oxide particle layer and the superhydrophobic coating layer forming the micro-nano structure are sequentially formed to be excellent in durability, and the average BET specific surface area is wide, and the lipophilic, superhydrophobic and superhydrophobic properties are excellent, resulting in excellent oil-water separation efficiency. It can be usefully used as a material for oil adsorption oil-water separation used for large-area oil-water separation, such as oil removal.

1 is a scanning electron microscope (SEM) analysis image of (a) the untreated group melamine sponge and (b) the composite prepared in Example 1. FIG.
Figure 2 is a graph showing the X-ray photoelectron spectroscopy (X-ray Photoelectron Spectroscopy, XPS) results of the untreated group melamine sponge and the composite prepared in Example 1.
3 is a graph showing Fourier transform-infrared spectroscopy (IR) results of the untreated group melamine sponge and the composite prepared in Example 1. FIG.
Figure 4 is a graph showing the water contact angle measurement results of the untreated group and the composite prepared in Example 1 and Comparative Example 1, respectively.
Figure 5 is a graph showing the oil and water separation efficiency according to the oil type of the composite prepared in Example 1.
Figure 6 is a graph showing the oil and water separation efficiency according to the number of reuse of the composite prepared in Example 1.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description.

However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

In the present invention, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

In addition, it is to be understood that the accompanying drawings in the present invention are shown to be enlarged or reduced for convenience of description.

The present invention relates to a material for oil and water separation and a method of manufacturing the same.

Recently, as the environmental problem is greatly highlighted, interest in oil-separated materials for removing contaminants in water is increasing, and the demand is increased due to the diversification of research and use fields for high-performance and application of the separated materials. It is becoming.

Conventionally, the oil and water separation methods that are commonly used include specific gravity separation methods and adsorption methods. Among them, development of an optimal manufacturing process for expressing characteristics of the separation material used in the adsorption method and separation with high functionality by surface treatment technology are performed. In-depth research into material manufacturing techniques is underway. As an example, the plasma surface treatment technology has been developed to improve the performance of the material by changing the surface of the polymer material used as the disk or filter in the adsorption method. However, the technologies developed to date require a surface treatment process such as plasma treatment, so that the manufacturing cost of the material is high, and the performance required for oil and water separation, for example, physical properties such as an adhesion angle indicating water affinity of the separation material. There is a limit to the degree of improvement.

Accordingly, the present invention provides a composite based on the melamine resin, and a material for oil and water separation comprising the same.

Since the composite according to the present invention is prepared through microwave irradiation, the manufacturing process is simple, and at least one zinc oxide particles are aggregated in a random radial manner at any one point on the surface of the melamine resin matrix having a porous sponge structure. The zinc oxide particle layer and the superhydrophobic coating layer forming the micro-nano structure are sequentially formed to be excellent in durability, and the average BET specific surface area is wide, and the lipophilic, superhydrophobic and superhydrophobic properties are excellent, resulting in excellent oil-water separation efficiency. It can be usefully used as a material for oil adsorption oil-water separation used for large-area oil-water separation, such as oil removal.

Hereinafter, the present invention will be described in more detail.

Complex

In one embodiment, the present invention provides a composite based on the melamine resin.

Specifically, the composite according to the present invention comprises a melamine resin matrix having a spongy porous structure, surrounding the melamine resin matrix surface, and at least two zinc oxide particles aggregate randomly radially based on any one point of the matrix surface. It comprises a zinc oxide particle layer having a structure, and comprises a superhydrophobic coating layer surrounding the surface of the zinc oxide particle layer.

The present invention includes a sponge-like melamine resin matrix, for example, a melamine sponge, which has low manufacturing cost and is economical and has high hardness. The melamine resin matrix may include open pores. Specifically, the melamine resin matrix may include open pores having an average size or diameter of 50 μm to 500 μm, and more specifically 50 μm to 400 μm, 50 μm to 300 μm, 50 μm to 200 μm, and 50 μm. To 100 µm, 100 to 200 µm, 200 to 300 µm, 300 to 400 µm, 400 to 500 µm, 300 to 500 µm, 250 to 500 µm, 80 to 180 µm or 100 to 160 µm May be μm. The present invention can realize a high elastic force of the composite by including a surface of the melamine resin matrix on the surface having an open pore having a diameter as described above shows an excellent durability effect.

As an example, the composite may have a stress of 0.0003 to 0.00045 MPa, specifically 0.0003 to 0.00043 MPa, and 0.00031 to 0.000415 when compressing 50% or 70% of strain at room temperature (21 ± 2 ° C). MPa, 0.0003 to 0.00037 MPa, 0.0003 to 0.00035 MPa, 0.0003 to 0.00033 MPa, 0.00035 to 0.00043 MPa or 0.00039 to 0.00042 MPa. This is equivalent to the melamine resin sponge that can be easily obtained commercially in the art can be seen that the excellent elasticity of the composite according to the present invention is high durability.

In addition, the composite according to the present invention includes a zinc oxide particle layer surrounding the melamine resin matrix surface and having a structure in which two or more zinc oxide particles are randomly aggregated in a radial direction based on any one point of the matrix surface.

In this case, the average length of the zinc oxide particles is 1㎛ to 10㎛, the average thickness may be 0.1㎛ to 2㎛, more specifically the average length is 1㎛ to 8㎛, 1㎛ to 6㎛, 1㎛ To 4 μm, 2 μm to 10 μm, 4 μm to 10 μm, 6 μm to 10 μm, 8 μm to 10 μm, 2 μm to 8, 4 μm to 6 μm, 5 μm to 7 μm, 3 μm to 7.5 μm 5 μm to 6.5 μm, or 4.5 μm to 7.5 μm, and the average thickness is 0.1 μm to 1.5 μm, 0.1 μm to 1 μm, 0.5 μm to 1.5 μm, 1 μm to 1.5 μm, 0.6 μm to 1.0 μm, or 0.8 μm To 1.3 μm. In addition, the ratio of the average thickness (D) to the average length (L) of the zinc oxide particles may be 2 to 10, specifically 2 to 8, 2 to 5, 2 to 3, 4 to 10, 6 to 10, 8 to 10, 2.5 to 7.5, 3 to 7.5, 3 to 7, 4 to 8, 4 to 6, or 3 to 5.

According to the present invention, by controlling the average length and average thickness of the hydrophobic zinc oxide particles in the above range, the zinc oxide particles can be randomly aggregated upon aggregation on the surface of the melamine resin matrix, so that the zinc oxide particles grow vertically on the matrix surface. Compared with the zinc oxide particle layer, the surface roughness and the average BET specific surface area may be large. Conventionally, zinc oxide particles are known to have a high affinity for water by including a hydroxyl group (-OH) on the surface. However, the composite of the present invention has a large surface roughness and surface area through the random radial aggregation of zinc oxide particles on the surface of the melamine resin matrix, thereby inducing more air pocket formation on the surface, thereby increasing water repellency.

Furthermore, the composite according to the present invention includes a superhydrophobic coating layer surrounding the zinc oxide particle layer, wherein the superhydrophobic coating layer is a C10 to C30 fatty acid having a low surface energy and an alkyl fluoride group and a halogen group having 4 to 20 carbon atoms. It may contain a substituted silane compound.

Here, the fatty acids include, for example, capric acid having 10 carbon atoms, lauric acid having 12 carbon atoms, myristic acid having 14 carbon atoms, palmitic acid having 16 carbon atoms, stearic acid having 18 carbon atoms, arachic acid having 20 carbon atoms, and carbon atoms 22 It may include one or more selected from the group consisting of individual behenic acid, specifically may include stearic acid.

The silane compound may be, for example, a silane substituted with a fluorinated alkyl group such as a perfluorohexyl group, a perfluorooctyl group, a perfluorodecyl group, a perfluorododecyl group, or a halogen group such as a chloro group or a bro group. Compound. For example, the superhydrophobic coating layer is at least one selected from the group consisting of perfluorohexyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane and perfluorododecyltrichlorosilane It may include, and specifically may include perfluorodecyltrichlorosilane (FDTS).

In addition, the average thickness of the superhydrophobic coating layer may be a thickness that can sufficiently lower the surface energy without lowering the surface roughness of the composite. Specifically, the average thickness of the superhydrophobic coating layer may be 20 nm or less, specifically 15 nm or less, 10 nm or less, 0.5 nm to 10 nm or 2 nm to 8 nm.

In general, the melamine resin matrix has a very high affinity for water, and thus it is impossible to measure the contact angle because it absorbs all the water in contact with the surface when measuring the static water contact angle. However, the composite according to the present invention includes a zinc oxide particle layer having a structure in which two or more zinc oxide particles are randomly agglomerated based on any one point on the surface of the melamine resin matrix to maximize the surface roughness, and increase the fatty acid and the silane compound. It is possible to implement both superhydrophobic and lipophilic on the surface of the melamine resin matrix because it can include a coating layer containing on the surface of the composite to significantly lower the surface energy.

As one example, the composite may be at least 160 ° when measuring an average static water contact angle indicating affinity for water, more specifically 160 ° to 180 °, 165 ° to 180 °, 165 ° to 177 °, 167 ° to 175 °, 169 ° to 173 °, 169 ° to 171 °, 170 ° to 174 ° or 172 ° to 174 °.

As another example, the composite may have an average sliding water contact angle and a shedding water contact angle each having a water repellency of 10 ° or less, more specifically, the average water slip Angles and average water flow angles of 1 ° to 8 °, 1 ° to 5 °, 8 ° to 13 °, 7 ° to 9 °, 8 ° to 10 °, 9 ° to 11 °, 2 ° to 7 °, 2 ° to 5 °, 3 ° to 5 °, 1 ° to 3 ° or 1.5 ° to 4.5 °.

As another example, the composite has a very high affinity for an organic material such as oil, so that all of the oil contacting the surface is absorbed when the average static oil contact angle is measured. It may not be possible, in which case the average static oil contact angle can be considered 0 °.

For example, the composite according to the present invention may have an average static water contact angle of 172 ± 1 °, an average water slip angle and an average water flow angle of 4 ± 0.5 ° and 2 ± 0.5 °, respectively.

In the composite according to the present invention, a zinc oxide particle layer and a superhydrophobic coating layer, which are randomly aggregated on a melamine resin matrix having a spongy porous structure and form a micro-nano structure, are sequentially formed to be excellent in durability and have a broad average BET specific surface area. It has excellent oil-water separation efficiency because it shows lipophilic, superhydrophobic and super-water-repellent, so it can be usefully used as an adsorptive oil-water separation material used for large-scale oil-water separation, such as oil spilled into the ocean.

Manufacturing method of the composite

In addition, the present invention in one embodiment,

Immersing the melamine resin matrix having a sponge-like porous structure in a zinc oxide precursor solution and irradiating microwaves to form a zinc oxide particle layer on the surface of the matrix; And

The superhydrophobic coating layer surrounding the zinc oxide particle layer by immersing the melamine resin matrix having a zinc oxide particle layer formed on the surface thereof in a mixed solution of 10 to 30 fatty acids, an alkyl fluoride group having 4 to 20 carbon atoms, and a silane compound substituted with a halogen group. Forming a,

The zinc oxide particle layer provides a method for producing a composite having a structure in which two or more zinc oxide particles are randomly agglomerated based on any one point of a matrix surface.

The method for preparing a composite according to the present invention comprises the steps of forming a random radially aggregated zinc oxide particle layer on the surface of the melamine resin matrix having a spongy porous structure and surrounding the zinc oxide particle layer formed on the surface to contain a fatty acid and a silane compound. Forming a coating layer.

Specifically, forming the zinc oxide particle layer on the surface of the melamine resin matrix is irradiated with microwaves after immersing the melamine resin matrix in a zinc oxide precursor solution in which a pH 9 to 12 and a predetermined concentration of zinc ions (Zn ^{2 +} ) are dissolved. Thereby, the zinc oxide particle layer aggregated in the random radial large surface roughness on a melamine resin matrix can be formed.

In this case, the zinc oxide precursor solution is a zinc oxide precursor such as zinc acetate (Zn (OAc) ₂ ), zinc chloride (ZnCl ₂ ), zinc hydroxide (Zn (OH) ₂ ), zinc nitrate (Zn (NO ₃ ) ₂ ) Is added to an aqueous solution of 0.1M to 2M dissolved in ammonia water, the pH is 9 to 12, 0.1M to 2M, specifically 0.1M to 1.5M, 0.1M to 1.2M, 0.1M to 1M, 0.1M To 0.8M, 0.1M to 0.6M, 0.1M to 0.5M, 0.1M to 0.3M, 0.3M to 0.5M, 0.4M to 0.7M, 0.5M to 1M, 0.7M to 1M, 1M to 1.5M, 0.8 M to 1.2M or 0.15M to 0.25M concentration of zinc ions (Zn ^{2 +} ) may be dissolved. The present invention is zinc oxide which is not only to form a melamine resin matrix zinc uniformly on the surface of oxide particles by controlling the concentration of zinc ions (Zn ^{2 +)} present in the zinc precursor oxidizing solution in the above range is formed on the matrix surface particles, The shape and growth direction of the control, and the zinc oxide particles can control the aggregation form in a random radial to maximize the surface roughness of the composite.

In addition, the microwave output may be 1,000 W to 1500 W, specifically 1,000 W to 1500 W, 1,050 W to 1,300 W, or 1,080 W to 1,200 W, and the frequency of the microwave is 2,000 MHz to 3,000 MHz, specifically May be 2,200 MHz to 2,600 MHz or 2,400 MHz to 2,500 MHz.

In addition, the microwave irradiation may include an irradiation step of microwave-processing the melamine resin matrix; And a aging step of leaving the microwave irradiated melamine resin matrix, and the irradiating step and the aging step may be repeated n times (an integer of n ≦ 10).

Here, the execution time of the irradiation step is 10 to 100 seconds, specifically 10 to 80 seconds, 20 to 80 total, 30 to 70 seconds, 40 to 80 seconds, 50 to 70 seconds, 30 to 100 seconds, 50 to 100 Seconds, 70 to 100 seconds or 55 to 65 seconds.

In addition, the performing time of the aging step is 1 to 60 seconds, specifically 1 to 50 seconds, 1 to 40 seconds, 5 to 40 seconds. 10 to 40 seconds, 20 to 40 seconds, 30 to 60 seconds, 50 to 60 seconds, or 25 to 35 seconds.

As one example, the microwave irradiation may comprise the irradiation step of microwave processing the melamine resin matrix for 57 to 62 seconds; And a ripening step of leaving the microwave irradiated melamine resin matrix for 27 to 32 seconds, and the irradiating step and the ripening step may be performed twice.

The present invention is not only to maintain the temperature of the zinc oxide precursor solution and the melamine resin matrix uniformly, but also to form the melamine resin matrix surface by repeating microirradiation and aging for a certain time to the melamine resin matrix immersed in the zinc oxide precursor solution. The shape and growth direction of the zinc oxide particles can be controlled and the surface roughness of the composite can be maximized because the zinc oxide particles can control the aggregation form in a random radial fashion.

Furthermore, coating the formed zinc oxide particle layer with a mixed solution containing a fatty acid and a silane compound to form a superhydrophobic coating layer is one minute in a mixed solution containing a fatty acid and a silane compound in a melamine resin matrix formed on the surface of the zinc oxide particle layer It is possible to form a super hydrophobic coating layer by dip coating for 10 minutes to dip. In this case, the mixed solution of the fatty acid and the silane compound may be a mixture of fatty acids 10 to 30 mol (mol) based on 1 mol (mol) of the silane compound, specifically, based on 1 mol (mole) of the silane compound 15 to 25 moles or 16 to 20 moles (mole) may be mixed. As one example, the present invention is to form a superhydrophobic coating layer by immersing the melamine resin matrix formed of zinc oxide particles on the surface in a solution of 18 ± 0.5 moles of fatty acids based on 1 mole of the silane compound. Can be. The present invention by controlling the content of the fatty acid and silane compound contained in the superhydrophobic coating layer in the above range can reduce the surface energy of the composite to implement superhydrophobicity as well as induce water repellency.

Examples of the fatty acids include capric acid having 10 carbon atoms, lauric acid having 12 carbon atoms, myristic acid having 14 carbon atoms, palmitic acid having 16 carbon atoms, stearic acid having 18 carbon atoms, arachic acid having 20 carbon atoms, and carbon atoms 22 It may include one or more selected from the group consisting of individual behenic acid, specifically may include stearic acid.

In addition, the silane compound may be, for example, a silane substituted with a fluorinated alkyl group such as a perfluorohexyl group, a perfluorooctyl group, a perfluorodecyl group, a perfluorododecyl group, or a halogen group such as a chloro group or a bro group. Compound. For example, the superhydrophobic coating layer is at least one selected from the group consisting of perfluorohexyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane and perfluorododecyltrichlorosilane It may include, and specifically may include perfluorodecyltrichlorosilane (FDTS).

Furthermore, the average thickness of the superhydrophobic coating layer may be a thickness that can sufficiently lower the surface energy without lowering the surface roughness of the composite. Specifically, the average thickness of the superhydrophobic coating layer may be 20 nm or less, specifically 15 nm or less, 10 nm or less, 0.5 nm to 10 nm or 2 nm to 8 nm, the average thickness of the melamine resin matrix fatty acid It can be controlled by the time and / or concentration of immersion in the mixed solution containing the per silane compound.

Oil-water separation material

Furthermore, in one embodiment, the present invention provides a material for oil and water separation comprising the composite according to the present invention.

The oil-separation material according to the present invention has a zinc oxide particle layer and a superhydrophobic coating layer sequentially formed on a melamine resin matrix having a porous porous structure on a sponge to form a micro-nano structure, thereby providing excellent durability and an average BET specific surface area. Including the composite of the present invention exhibiting this wide, lipophilic, superhydrophobic and superhydrophobic, it is reusable and excellent in oil-water separation efficiency.

Specifically, melamine sponge having a porous structure used as a general oil and water separation material can implement super hydrophobicity through various surface treatments, but it does not exhibit water repellency, so when oil is used in fresh water and / or ocean, it is used for oil separation. Together, they absorb a significant amount of water and are present in the water. However, the oil-water separation material according to the present invention exhibits lipophilic and super-hydrophobicity as well as super water-repellency, so that when oil is leaked into fresh water and / or the ocean, it selectively absorbs only the oil floating on the water and does not sink into water, thus separating oil and water. It is excellent in efficiency and easy to treat after oil and water separation.

As an example, the oil-separating material exhibits lipophilic, superhydrophobic and superhydrophobic, including the composite according to the present invention. The material is fixed in the reactor and methanol, hexane (n-hexame), vacuum oil, gasoline, canola oil or diesel and water 1: When oil-water separation is performed by pouring the mixed solution in 1 volume ratio, oil is absorbed by the material and passed through, but water is not absorbed by the material and remains on the surface. The separation efficiency of the separated water is the volume of water contained in the mixed solution. 95% or more, specifically 97% or more.

As another example, the oil-water separation material is excellent in durability, including the composite according to the present invention, methanol, hexane (n-hexame), vacuum oil (vacuum oil), gasoline (gasoline), canola When the oil-water separation is performed 50 times for a solution in which oil (diesola) or diesel oil and water are mixed in a 1: 1 volume ratio, the separation efficiency of the oil shows 30% or more separation efficiency for all oil components. When the glass is separated 50 times, a low molecular oil component such as hexane (n-hexane) and methanol (methanol) may exhibit a separation efficiency of 80% or more.

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

However, the following Examples and Experimental Examples are only illustrative of the present invention, and the content of the present invention is not limited to the following Examples and Experimental Examples.

Example  One

A melamine sponge having a width of 3 cm, a length of 3 cm, and a thickness of 3 cm was prepared, and the prepared melamine sponge was washed three times with distilled water and ethanol to remove impurities remaining on the surface.

Separately, 25 wt% aqueous ammonia was added dropwise to 100 ml of a 0.2 M zinc acetate (Zn (OAc) ₂ ) aqueous solution to dissolve all white zinc acetate precipitated in the zinc acetate aqueous solution. At this time, the pH of the solution was 10-11. The dissolved zinc acetate aqueous solution was added to the reaction flask, and the previously prepared melamine sponge was immersed in the zinc acetate aqueous solution for 30 minutes, followed by a microwave oven (Model: KR-G20EW) commonly used in the art. Daewoo Co., Ltd. investigated the microwave (output: 1120 ± 20 W, frequency: 2450 ± 10 MHz). At this time, the ripening to leave the melamine sponge irradiated with microwaves was performed continuously with the microwave irradiation, this process was repeated three times. In addition, each irradiation step of irradiating microwaves was performed for 60 ± 2 seconds, each aging step of leaving the microwave irradiation melamine sponge was performed for 30 ± 2 seconds. After the above treatment was completed, the temperature of the zinc acetate aqueous solution was cooled to room temperature (20 ± 1 ℃) for 10 minutes, the melamine sponge immersed in the zinc acetate aqueous solution was taken out, washed with distilled water and ethanol, and naturally dried. The dried melamine sponge is a stearic acid solution (90 mL, stearic acid content: 900 mmol) dissolved in ethanol at a concentration of 10 mM dissolved in ethanol and a perfluorodecyltrichlorosilane (FDTS) solution dissolved in ethanol at a concentration of 5 mM. (10 mL, perfluorodecyltrichlorosilane content: 50 mmol) was immersed in a mixed solution mixed for 5 minutes, and then dried to prepare a complex (MS-ZnO-SA + FDTS), whereby a superhydrophobic surface coated The average thickness of the coating layer was 3-8 nm.

Comparative example  One

A melamine sponge having a width of 3 cm, a length of 3 cm, and a thickness of 3 cm was prepared, and the prepared melamine sponge was washed three times with distilled water and ethanol to remove impurities remaining on the surface.

Separately, 25% by weight of ammonia water was added dropwise to 100 ml of 1M zinc acetate (Zn (OAc) ₂ ) aqueous solution to dissolve all white zinc acetate precipitated in the zinc acetate aqueous solution. At this time, the pH of the solution was 10-11. The dissolved zinc acetate solution was added to the reaction flask, and the previously prepared melamine sponge was immersed in the zinc acetate solution, followed by a microwave oven commonly used in the art (model: KR-G20EW, manufacturer: Daewoo) ) Was irradiated with microwave (output: 1120 ± 20 W, frequency: 2450 ± 10 MHz). At this time, the ripening to leave the melamine sponge irradiated with microwaves was performed continuously with the microwave irradiation, this process was repeated three times. In addition, each irradiation step of irradiating microwaves was performed for 60 ± 2 seconds, each aging step of leaving the microwave irradiation melamine sponge was performed for 30 ± 2 seconds. After the treatment was completed, the temperature of the zinc acetate aqueous solution was cooled to room temperature (20 ± 1 ° C.) for 5 minutes. Thereafter, the melamine sponge immersed in an aqueous zinc acetate solution was taken out, distilled water was washed, and naturally dried to prepare a composite (MS-ZnO).

Comparative example  2

The same melamine sponge as in Example 1 was immersed in a stearic acid solution (100 ml) at a concentration of 10 mM instead of immersing the melamine sponge in which a zinc oxide particle layer was formed in a mixed solution of a stearic acid solution and a perfluorodecyltrichlorosilane (FDTS) solution. Performed by the method to prepare a complex (MS-ZnO-SA). At this time, the average thickness of the stearic acid layer of the surface was 3-8 nm.

Comparative example  3

Instead of immersing the melamine sponge in which the zinc oxide particle layer was formed, in a mixed solution of stearic acid solution and perfluorodecyltrichlorosilane (FDTS) solution, it was immersed in 5 mM perfluorodecyltrichlorosilane (FDTS) solution (100 ml). Except that was carried out in the same manner as in Example 1 to prepare a composite (MS-ZnO-FDTS). At this time, the average thickness of the silane coating layer coated on the surface was 3 ~ 8 nm.

Experimental Example  One

In order to confirm the surface properties of the composite according to the present invention, a scanning electron microscope (Scanning Electron Microscope, SEM) was performed on the composite prepared in Example 1 (MS-ZnO-SA) and the melamine sponge that is not treated group, The results are shown in FIG.

As shown in FIG. 1, the composite according to the present invention has a surface structure of a micro-nano type, and it can be seen that the BET surface area is excellent.

Specifically, referring to FIG. 1, the composite of Example 1 was found to have a micro-nano structure on the surface of zinc oxide particles randomly aggregated on a melamine sponge having open pores. In addition, the average size of the pores formed in the composite is about 100㎛ to 150㎛, randomly agglomerated zinc oxide particles have an average thickness of about 1 to 1.5㎛, the average length of about 5 to 7㎛ rod It was confirmed to be a type particle.

From these results, the composite according to the present invention has a micro-nano structure in which zinc oxide particles are randomly aggregated on the surface of the porous melamine sponge having three-dimensional open pores, thereby maximizing the surface roughness of the composite, and obtaining an average BET. It can be seen that surface properties such as specific surface area are excellent.

Experimental Example  2

Fourier transform-infrared spectroscopy in the infrared region of 1,000 to 4,000 cm ^-1 after preparing KBr pellets for each of the untreated group melamine sponge and the composite prepared in Example 1 to confirm the surface component of the composite according to the present invention (FT-IR) analysis was performed.

In addition, X-ray photoelectron spectroscopy (XPS) of the melamine sponge and each of the composites was measured, and the measured results are shown in FIGS. 2 and 3.

2 and 3, it can be seen that the composite according to the present invention has a structure in which a silane compound is coated on the surface of the zinc oxide particle layer aggregated on the melamine sponge.

Specifically, Figure 2 is a graph showing the X-ray photoelectron spectroscopy (XPS) results of the untreated melamine sponge and the composite prepared in Example 1, in the case of melamine sponge, oxygen element (O), nitrogen element (N) and carbon The peak indicating the 1s bond of the element (C) was confirmed, wherein the ratio of the peak intensity ((P _C0 / P _N0 ) of the nitrogen element (N) and the carbon element (C) was found to be about 0.9 to 1.1.

In contrast, the composite of Example 1 has a peak representing a 1s bond of an oxygen element (O), a nitrogen element (N) and a carbon element (C), and a peak representing a 2p3 bond of zinc oxide (Zn) of zinc oxide. It was confirmed at 1022 ± 5 eV and the ratio of peak intensity ((P _C1 / P _N1 ) of nitrogen element (N) and carbon element (C) was about 1.35 to 1.6 due to stearic acid contained in the superhydrophobic coating layer. In addition, a peak showing a 1s bond of the fluorine element (F) due to the silane compound substituted with an alkyl fluoride group, that is, perfluorodecyltrichlorosilane (FDTS) contained in the superhydrophobic coating layer, was found at 690 ± 5 eV. .

In addition, Figure 3 is a graph showing the Fourier transform-infrared spectroscopy (FT-IR) results of the untreated melamine sponge and the composite prepared in Example 1, unlike the untreated melamine sponge, the composite of Example 1 is 2862 ± Peaks exhibiting symmetrical and asymmetric stretching vibrations of alkylene groups (-CH _2- ) derived from stearic acid (SA) at 2 cm ^-1 and 2930 ± 2 cm ^-1 were identified. In addition, the peak of the composite of Example 1 exhibiting the stretching vibration of the haloalkylene group (CF) derived from perfluorodecyltrichlorosilane (FDTS) was found at 1150 to 1250 cm ^-1 .

From these results, the composite of the present invention means that the zinc oxide particle layer is set on the melamine sponge, and the surface is surrounded by a superhydrophobic coating layer containing a fatty acid and a silane compound.

Experimental Example  3

In order to evaluate the oil / water separation efficiency of the composite according to the present invention, the following experiment was performed.

end) Contact angle  evaluation

Static water contact angle, water using a contact angle measuring device (model name: SmartDrop, manufacturer: Femtofab Co. Ltd) for the untreated melamine sponge and the composites prepared in Examples 1 and Comparative Examples 1 to 3 Sliding water contact angle, shedding water contact angle and static oil contact angle were measured. At this time, each measurement was carried out by dropping a drop of 10 μl of water or oil on the surface every measurement, it was repeated three times to derive the average value. The results are shown in Table 1 and FIG. 4.

Water (H ₂ O) Static contact angle Slip angle Flow angle No treatment group Not measurable Not measurable Not measurable Example 1 173 ± 1 ° 4 ± 1 ° 2 ± 1 ° Comparative Example 1 90 ± 1 ° Not measurable Not measurable Comparative Example 2 159 ± 1 ° 10 ± 1 ° 8 ± 1 ° Comparative Example 3 160 ± 1 ° 10 ± 1 ° 8 ± 1 °

As shown in Table 1 and Figure 4, the composite according to the present invention can be seen that the superhydrophobic, water-repellent and lipophilic on the surface.

Specifically, the composite prepared in Example 1 was found to have a static water contact angle of 171 ° to 175 ° indicating affinity for water, and a water slip angle and water flow angle indicating water repellency of less than 9 °, specifically, It was confirmed that they were 1-5 degrees each. In addition, the complex was unable to measure the static oil contact angle showing all the oil lipophilic.

On the other hand, untreated melamine sponge has high affinity for both water and oil, so it absorbs all the water or oil dropped on the surface when measuring contact angle, so it is impossible to measure water or static oil contact angle as well as slip angle and flow angle for water. (Virtually 0 degrees). In addition, the composites prepared in Comparative Examples 1 to 4 exhibited hydrophobicity by including zinc oxide particle layers or superhydrophobic coating layers on their surfaces, respectively, but their performance was weak, and the static water contact angle was less than 165 °. In addition, the composites of Comparative Examples 1 to 4 showed low water repellency and a slip angle and a flow angle with respect to water exceeded 6 °.

From these results, the composite according to the present invention has a structure in which a zinc oxide particle layer is randomly aggregated on a melamine sponge, and the surface is surrounded by a superhydrophobic coating layer containing fatty acid and a silane compound, thereby affinity for oil. In addition to being high, it can be seen that superhydrophobicity and water repellency are remarkably excellent.

B) Evaluation of oil-water separation efficiency according to oil type

A non-treated melamine sponge, each of the composites prepared in Examples 1 and 3 (diameter 7 ± 2 cm, height 1 cm), was fixed to a 7 cm diameter tube equipped with a stainless steel mesh as a stopper, A beaker was prepared under the tube. Then a solution (30 ml) mixed with oil and water in a volume ratio of 1: 1 was poured into the tube and waited until all the oil in the solution passed through the untreated melamine sponge or composite, where it was mixed with water Methanol, hexane (n-hexame), vacuum oil (vacuum oil), gasoline (gasoline), canola oil (canola oil) or diesel (diesel) was used as the oil. When all the oil in the solution is absorbed and passed through the untreated melamine sponge or composite, the volume of water remaining in the upper portion without passing through the melamine sponge or the composite is measured, and the separation efficiency of oil and water is derived using Equation 1 below. It was. The derived results are shown in FIG. 5.

[Equation 1]

Oil-water Separation Efficiency (k) = V ₁ / V ₀ X 100

In Equation 1

V ₁ represents the volume of water remaining on top of the melamine sponge or composite after separation,

V ₀ represents the volume of water contained in the mixed solution before separation.

As shown in Figure 5, the composite according to the present invention can be seen that the oil-water separation efficiency is excellent regardless of the oil type.

Specifically, it was confirmed that the composite prepared in Example 1 is separated from water with a high efficiency of 95% or more with respect to oils such as hexane, vacuum oil, gasoline, canola oil and diesel oil. In particular, the complex has been shown to separate at least about 98% of the hydrophilic methanol from water.

On the contrary, the composites prepared in Comparative Examples 1 to 3 hardly separate water and oil, and thus the water separation efficiency was less than 10% with respect to oil.

From these results, it can be seen that the composite according to the present invention has excellent oil and water separation efficiency.

Experimental Example  4.

In order to evaluate the durability of the composite according to the present invention was carried out the following experiment.

A) stress assessment for deformation of the composite;

The untreated melamine sponge and the composite prepared in Example 1 (diameter 7 ± 2cm, height 1cm) were prepared, and the prepared complex was fixed in a universal testing machine and then shown in Table 4 at room temperature (21 ± 2 ° C). The stress of the composite was measured by compressing with 50% or 70% strain as described. In addition, the static water contact angle of the compressed composite was measured, and the measured results are shown in Table 2.

No treatment group Complex of Example 1 transform 50% 70% 50% 70% Stress (MPa) 0.00032 ± 0.00005 0.000399 ± 0.00005 0.000318 ± 0.00005 0.00041 ± 0.00005 Static water contact angle - - 171 ± 1 ° 170 ± 1 °

As shown in Table 2 it can be seen that the composite according to the present invention has excellent durability against the force applied from the outside.

Specifically, it was confirmed that the composite prepared in Example 1 had a stress of 0.00031 to 0.00042 equivalent to that of melamine sponge (untreated group) having high elasticity when 50% or 70% of deformation was applied. In addition, the composite of Example 1 was found to maintain surface energy and surface roughness even after deformation was applied to achieve a high static water contact angle of 165 ° or more.

From these results, it can be seen that the composite according to the present invention is excellent in durability and the elastic force is not damaged even when a force is applied from the outside, and excellent superhydrophobicity is realized.

B) Evaluation of oil-water separation efficiency by reuse

The composite prepared in Example 1 (diameter 7 ± 2 cm, height 1 cm) was fixed to a 7 cm diameter tube equipped with a stainless steel mesh as a stopper, and a beaker was prepared under the tube. Thereafter, a solution (30 ml) of a mixture of oil and water in a volume ratio of 1: 1 was poured into the tube and waited until all the oil in the solution passed through the complex, wherein the oil mixed with water was methanol (methanol). ), Hexane (n-hexame), vacuum oil (vacuum oil), gasoline (gasoline), canola oil (canola oil) or diesel (diesel) was used. When all the oil in the solution passed through the complex, the separation efficiency of the oil and water was derived by measuring the volume of water remaining in the upper portion without passing through the complex. This process was repeated 50 times and the results are shown in Figure 6 and Table 3.

unit: % Methanol Hexane Vacuum oil Gasoline Canola oil Via 1 time 99.99 99.82 98.99 98.20 98.39 98.21 5th 99.55 98.23 96.56 97.99 94.32 96.22 10 times 99.11 97.01 95.36 96.25 93.89 92.50 15 times 98.32 96.32 90.23 95.32 94.09 87.22 20 times 95.32 95.21 89.36 92.10 92.33 85.36 25 times 93.00 95.00 86.32 90.00 91.33 83.22 30 times 90.64 94.32 76.12 83.21 87.23 80.33 35 times 88.20 90.02 63.05 77.32 82.01 67.06 40 times 87.33 88.32 55.99 72.01 77.67 61.32 45 times 86.21 87.06 49.36 68.99 71.22 57.21 50 times 84.32 86.32 45.22 65.09 68.23 45.32

As shown in Figure 6 and Table 3 it can be seen that the complex according to the present invention can be separated from the oil and water with high efficiency even after repeated use.

Specifically, it was confirmed that the composite prepared in Example 1 exhibited a high separation efficiency of 80% or more regardless of oil components by performing 30 times of oil and water separation of a solution in which oil and water were mixed at a volume ratio of 1: 1. . In addition, for oil components such as hexane (n-hexane) and methanol (methanol), even if the oil-water separation more than 50 times was shown to show a high separation efficiency of more than 80%.

From these results, the composite according to the present invention is a random radial agglomerate on the melamine resin matrix having a spongy porous structure to form a micro-nano structure zinc oxide particle layer and a superhydrophobic coating layer is formed in order to have a wide average BET specific surface area In addition, it is excellent in durability, lipophilic, super hydrophobic and super water-repellent and excellent in oil-water separation efficiency, so it can be usefully used as an oil adsorption-type oil-water separation material used for large-scale oil-water separation, such as oil spilled into the ocean.

Claims (13)

Melamine resin matrix having a porous structure on the sponge;
A zinc oxide particle layer surrounding the surface of the matrix; And
It comprises a super hydrophobic coating layer surrounding the zinc oxide particle layer,
The zinc oxide particle layer has a structure in which two or more zinc oxide particles are randomly agglomerated at a random point on the surface of the matrix.
The zinc oxide particles have an average length of 2㎛ 10㎛, the ratio (L / D) of the average thickness (D) to the average length (L) is 2 to 10,
The superhydrophobic coating layer contains a silane compound substituted with an alkyl fluoride group and a halogen group having 10 to 30 carbon atoms and 4 to 20 carbon atoms,
The silane compound is a complex comprising at least one selected from the group consisting of perfluorohexyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane and perfluorododecyltrichlorosilane.
delete The method of claim 1,
The complex is
Average static water contact angle is 160 ° or more,
Composites with an average sliding water contact angle of 10 ° or less.
The method of claim 1,
Melamine resin matrix comprises open pores,
The average size of the pores is 50 ㎛ to 500 ㎛ composite.
The method of claim 1,
The fatty acid is a complex comprising at least one selected from the group consisting of capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachic acid, and behenic acid.
delete The method of claim 1,
The average thickness of the superhydrophobic coating layer is 20 Composites less than or equal to nm.
Immersing the melamine resin matrix having a sponge-like porous structure in a zinc oxide precursor solution and irradiating microwaves to form a zinc oxide particle layer on the surface of the matrix; And
The superhydrophobic coating layer surrounding the zinc oxide particle layer by immersing the melamine resin matrix formed on the surface of the zinc oxide particle layer in a mixed solution of a C10 to C30 fatty acid, an alkyl fluoride group having 4 to 20 carbon atoms, and a silane compound substituted with a halogen group; Forming;
The zinc oxide particle layer has a structure in which two or more zinc oxide particles are randomly agglomerated at a random point on the surface of the matrix.
The zinc oxide particles have an average length of 2㎛ 10㎛, the ratio (L / D) of the average thickness (D) to the average length (L) is 2 to 10,
The silane compound is a complex of a complex comprising at least one selected from the group consisting of perfluorohexyltrichlorosilane, perfluorooctyltrichlorosilane, perfluorodecyltrichlorosilane and perfluorododecyltrichlorosilane Manufacturing method.
The method of claim 8,
Zinc oxide precursor solution is a method for producing a composite containing zinc ions (Zn ^{2 +} ) of 0.1M to 2M.
The method of claim 8,
Microwave power is 1,000W to 1500W of the composite.
The method of claim 8,
The frequency of the microwave is a method for producing a composite of 2,000 MHz to 3,000 MHz.
The method of claim 8,
Microwave probe,
An irradiation step of microwave treating the melamine resin matrix for 10 to 100 seconds; And
A aging step of leaving the microwave irradiated melamine resin matrix for 1 to 60 seconds,
Method for producing a complex to perform the irradiation step and the aging step n times (an integer of n≤10) repeatedly.
Oil-water separation material comprising a composite according to claim 1.

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