KR102414751B1 - Polyphenol-silica hybrid coating layer and manufacturing method thereof - Google Patents

Abstract

The present invention provides a method for producing a hybrid coating film including an iron ion-tannic acid coating layer, a cysteamine coating layer and a silica coating layer, and/or a hybrid coating film or coating film prepared by the method. Unlike the conventional sol-gel method, the coating method provided by the present invention enables silica coating under mild conditions, and can be applied to all types of coating objects, so it has excellent utility, and the thickness of the coating film can be adjusted at the nanometer level. , stain resistance, stability against chemical decomposition, and stability against changes in acidity, pH and temperature are excellent. In addition, the hybrid coating film provided by the present invention exhibits an anti-fogging effect due to superhydrophilicity, and the anti-fogging effect can be applied in various environments due to the stability, thereby providing excellent industrial utility.

Description

Polyphenol-silica hybrid coating layer and manufacturing method thereof {Polyphenol-silica hybrid coating layer and manufacturing method thereof}

The present invention relates to a silica-polyphenol hybrid coating film, a manufacturing method and use thereof, and more specifically, it is applicable to all coating objects under mild conditions, thickness control is possible, and has excellent resistance to temperature change and acid resistance. and a silica-polyphenol hybrid coating method having a superhydrophobic surface, a coating film prepared by the manufacturing method, and uses thereof.

Silica coating is effective for surface protection because it is stable from external stimuli, and it can control surface wettability, so it is widely used in industries such as semiconductors, glass, and ceramics.

Among the silica coating methods, the most well-known method is the sol-gel method, which forms silica gel by hydrolysis and condensation reaction from silica alkoxide, a precursor of the sol, to gradually form a silica coating layer. However, since this method uses an acid or base catalyst and an organic solvent (ethanol) and in some cases requires a high temperature, there is a disadvantage in that it is impossible to coat materials and cells sensitive to the reaction environment. In addition, it is difficult to uniformly control the coating thickness according to demand, and time/cost inefficiency and sensitivity are required according to material selection and pretreatment process due to limited material surface properties.

As one of the examples of biosilicification in nature, marine sponges use an enzyme called silicatein to form exoskeleton silica structures with silicic acid contained in the sea. In more detail, the hydroxyl group (-OH group) of serine-26 and the imidazole group (imidazole group) of histidine-165 present in the active site of silicatein catalyze the hydrolysis and condensation reaction of the silica precursor.

Cysteamine (cysteamine, HSCH ₂ CH ₂ NH ₂ ) is known as a small molecule that chemically mimics the active site of the silicatein. Cysteamine contains an amine group (-NH2) and a thiol group (-SH), and since the distance between them is close, hydrolysis and condensation of silica precursors under mild conditions (e.g., neutral pH and/or room temperature) The reaction is catalyzed to form a silica structure.

Surface immobilization of cysteamine enables silica coating on the surface under mild conditions. As a priming layer for fixing cysteamine to various surfaces, tannic acid-iron ion nanocoating was performed. Tannic acid, a natural plant extract, is a polyphenol material containing a galloyl group (1,2,3-trihydroxyphenyl group) and rapidly forms a complex with metal cations (Fe(III), etc.) regardless of the surface properties of the material. Nanocoating with adjustable thickness is performed. In addition, the galloyl group performs the function of an adhesion motif through various non-covalent interactions such as hydrogen bonding and ð- ð interaction, and thus has easy adhesion to other materials.

The sol-gel method, which is a conventional silica coating method, uses an acid or base catalyst and an organic solvent (eg, ethanol), and in some cases requires high temperature conditions, so materials sensitive to the reaction environment and Cell coating is difficult, it is difficult to control the coating thickness, and there are limitations on the surface properties of the material to be coated.

In order to compensate for these shortcomings, the present inventors have completed the present invention by developing a silica nanocoating method utilizing biosilicification that occurs in nature.

An object of the present invention is to provide a polyphenol-silica hybrid coating method and a coating film prepared by the method. The coating film prepared by the above method has acid resistance, temperature change resistance, and/or super hydrophobic properties.

Another object of the present invention is to provide an anti-fog film comprising the coating film prepared by the above method.

In order to compensate for the disadvantages of silica coating by the conventional sol-gel method described above, in the present invention, a silica nanocoating method that can be grafted onto the iron ion-tannic acid nanocoating is completed using biosilicifiation that occurs in nature.

The present invention provides a method for performing polyphenol-silica hybrid coating on a coating target and a hybrid coating film prepared by the method.

The present invention also provides an antifogging film comprising the hybrid coating film prepared by the above method.

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

The present invention provides a method for performing polyphenol-silica hybrid coating on a coating object as a coating method. The coating method provided by the present invention has the advantage of being applicable to all kinds of coating objects under mild conditions, unlike silica coating by a conventional sol-gel method.

As used herein, the term "hybrid coating" refers to a coating in which a plurality of coating layers having different physical and / or chemical properties are combined, and in one example, an organic material layer containing an organic material and an inorganic material layer not containing an organic material As a combination, The organic layer and the inorganic layer may be bonded by a covalent bond or a non-covalent bond.

As used herein, "mild conditions" means conditions in which temperature and/or pH conditions are not severe, conditions that do not include a heating step and/or a cooling step, and/or conditions under which no acid or base catalyst is used. . The acid catalyst may be, for example, at least one selected from the group consisting of hydrochloric acid, nitric acid, acetic acid, sulfuric acid and hydrofluoric acid, and the base catalyst is, for example, one selected from the group consisting of aqueous ammonia, sodium hydroxide and potassium hydroxide may be more than one species. In one embodiment, the mild pH conditions are pH 5.5 to 8.5, pH 5.5 to 8.0, pH 5.5 to 7.5, pH 6.0 to 8.5, pH 6.0 to 8.0, pH 6.0 to 7.5, pH 6.5 to 8.5, pH 6.5 to 8.0, pH 6.5 to 7.5, pH 7.0 to 8.5, pH 7.0 to 8.0, or pH 7.0 to 7.5. In one embodiment, the mild temperature condition is room temperature, for example, 15 to 35 degrees Celsius, 15 to 30 degrees Celsius, 15 to 27 degrees Celsius, 18 to 35 degrees Celsius, 18 to 30 degrees Celsius. 18 to 27 degrees Celsius, 20 to 35 degrees Celsius, 20 to 30 degrees Celsius, 20 to 27 degrees Celsius, 23 to 35 degrees Celsius, 23 to 30 degrees Celsius, or 23 to 27 degrees Celsius, but is not limited thereto. .

In the present invention, "coated object" means an object or object that is a target of a nanofilm or nanocoating, and can be used regardless of type as long as it has mass and volume. For example, the coating target may be at least one selected from inanimate objects such as metal, metal oxide, ceramic, mineral, polymer, glass, and/or wood. In another example, the coating target may be one or more selected from living organisms such as fungi (eg, bacteria, fungi, etc.), plants, and animals, and may be an object in which an inanimate organism and an organism are combined. When the coating target is a plant or animal, it may be the plant or animal itself, or an organ or cell isolated therefrom.

The coating method provided by the present invention comprises: a first step of forming an iron ion-tannic acid coating layer comprising iron ions and tannic acid on a coating object; a second step of forming a cysteamine coating layer containing cysteamine on the iron ion-tannic acid coating layer; and a third step of forming a silica coating layer including silica (SiO ₂ ) on the cysteamine coating layer.

In the coating method provided by the present invention, each coating layer forming step of the first to third steps is any coating within the objective range for forming a hybrid nano-coating (film) film on the surface of the coating target under mild conditions. It can be carried out by freely choosing a method. In one example, the coating method may be application (coating), immersion, or deposition on the surface to be coated. Specifically, the coating method may use one or more methods selected from the group consisting of paint brushing, spray coating, doctor blade, dip-pull method, and spin coating, but is not limited thereto.

In the coating method provided by the present invention, the step of forming the coating layer of the first to third steps comprises the steps of contacting the coating solution with the coating object; and washing and drying the coating object in contact with the coating solution.

The solvent of the coating solution may be appropriately selected according to the purpose of the coating, and in one example may be one or more solvents selected from the group consisting of deionized water, distilled water, sodium chloride aqueous solution and phosphate buffered saline.

All of the steps of forming the coating layer may be performed under mild conditions, and the mild conditions are as described above. The coating method provided by the present invention does not require a separate heating and / or cooling step, and does not use an acid catalyst and / or a base catalyst, so the coating target is not limited, and coating time and cost can be saved. , the economic efficiency is excellent.

In the step of forming the coating layer, the contact time of the coating solution and the coating target in the step of contacting the coating solution and the coating target may be appropriately selected within the objective range for forming the coating film, for example, 15 minutes to 180 minutes, 15 minutes to 150 minutes, 15 minutes to 120 minutes, 15 minutes to 90 minutes, 30 minutes to 180 minutes, 30 minutes to 150 minutes, 30 minutes to 120 minutes, 30 minutes to 90 minutes, 45 minutes to 180 minutes , 45 minutes to 150 minutes, 45 minutes to 120 minutes, or 45 minutes to 90 minutes.

Hereinafter, each step of the coating method provided by the present invention will be described in more detail.

The coating method provided by the present invention includes (1) a first step of forming an iron ion-tannic acid coating layer comprising iron ions and tannic acid on a coating target.

The iron ion-tannic acid coating layer can be coated regardless of the physical and chemical properties of the coating object, thereby contributing to the formation of a hybrid coating film without limitation. The iron ion-tannic acid coating layer includes a galloyl group, and the galloyl group may perform a function of helping a cysteamine coating layer to be formed on the iron ion-tannic acid coating layer.

The iron ion-forming step of the tannic acid coating layer may be repeated once or several times before the step of forming the cysteamine coating layer. When the iron ion-tannic acid coating layer is formed too thinly, the cysteamine coating layer and the silica coating layer may not be sufficiently formed. In one example, the iron ion-tannic acid coating film may have a thickness of 5 or more, 5 to 1000 nm (1um), 5 to 100 nm, 5 to 50 nm, or 5 to 30 nm. The thickness of the iron ion-tannic acid coating layer may be appropriately adjusted according to the desired thickness of the hybrid coating layer. When the iron ion-tannic acid coating layer has a thickness of less than 5 nm, the cysteamine layer and/or the silica layer may not be sufficiently formed.

The iron ion-tannic acid coating layer may have a characteristic of increasing the thickness by repeating the step of forming the iron ion-tannic acid coating layer a plurality of times, thereby providing a coating film capable of controlling the thickness at the nanometer level.

The iron ion-tannic acid coating layer may be performed by a method comprising the steps of contacting a coating target (eg, a substrate) with an iron ion solution and contacting the tannic acid solution. The iron ion solution and the tannic acid solution may be sequentially added, and in one example, the iron ion solution may be added first and then the tannic acid solution may be added, but the present invention is not limited thereto. can be done freely.

The iron ion solution may be freely prepared and used within the intended range for including Fe(III) ions, for example, iron chloride hexahydrate (FeCl ₃ .6H ₂ O), iron nitrate heptahydrate (Fe(NO ₃ ) ) ₃ ·9H ₂ O) and iron sulfate heptahydrate (FeSO ₄ ·7H ₂ O) may be one or more solutions selected from the group consisting of, but not limited thereto. The concentration of the iron ion solution can be freely adjusted within the range for the purpose of forming the iron ion-tannic acid coating film, for example, 5 to 200 mg/mL, 5 to 100 mg/mL, 5 to 70 mg/mL, 5 to 50 mg /mL, 10-200mg/mL, 10-100mg/mL, 10-70mg/mL, 10-50mg/mL, 30-200mg/mL, 30-100mg/mL, 30-70mg/mL, or 30-50mg/mL mL.

The concentration of tannic acid in the tannic acid solution can be freely adjusted within the range for the purpose of forming a coating film, for example, 1 to 100 mg/mL, 1 to 50 mg/mL, 1 to 30 mg/mL, 1 to 20 mg/mL, 3 to 100 mg/mL, 3-50 mg/mL, 3-30 mg/mL, 3-20 mg/mL, 5-100 mg/mL, 5-50 mg/mL, 5-30 mg/mL, 5-20 mg /mL, 7-100 mg/mL, 7-50 mg/mL, 7-30 mg/mL, or 7-20 mg/mL.

In one embodiment, 40 mg/mL distilled water aqueous solution of tannic acid and 10 mg/mL distilled water aqueous solution of FeCl ₃ ·6H ₂ O were prepared and used as stock solutions for coating.

The formation of the iron ion-tannic acid coating layer is mainly affected by the iron ion concentration, and the higher the iron ion concentration, the thicker the coating layer becomes and the roughness increases. When the concentration of iron ions is lower than the above range, the coating layer may not be formed normally, and when the concentration of tannic acid and iron ion solution is above the above range, particles are rapidly formed in the aqueous solution, so there is a problem in that the coating film is non-uniformly and irregularly formed. .

The iron ion-tannic acid coating layer formed by the above method may include a galloyl group, and serves to enable silica coating regardless of the type of coating target by allowing a cysteamine coating layer to be formed.

The coating method provided by the present invention includes a second step of (2) forming a cysteamine coating layer containing cysteamine on the iron ion-tannic acid coating layer.

The cysteamine is formed on the iron ion-tannic acid coating layer, and serves to help the silica coating layer to be formed. When the second step is omitted, the silica coating layer and the iron ion-tannic acid coating layer do not combine, A hybrid coating film is not formed.

The second step may include the step of contacting the cysteamine solution to the coating target on which the first step has been performed once or plural times. The concentration of the cysteamine solution may be freely changed within the range for the purpose of forming a coating film, and in one example, 10 to 200mM, 10 to 100mM, 10 to 75mM, 10 to 55mM, 30 to 200mM, 30 to 100mM, 30 to 75mM , or may be 30 to 55 mM, but is not limited thereto.

When the cysteamine concentration is too low, sufficient cysteamine is not formed, and thereafter, a problem in that the silica coating layer is not sufficiently formed may occur.

In one embodiment, the cysteamine coating solution was prepared using distilled water so that the cysteamine concentration was 50 mM.

The coating method provided by the present invention includes a third step of (3) forming a silica coating layer containing silica (SiO ₂ ) on the cysteamine coating layer.

The third step may include contacting the coating target on which the cysteamine coating layer is formed and a silica coating solution, and the silica coating solution may include a silica precursor.

The silica precursor is, for example, tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), 3-mercaptopropyl trimethoxysilane ((3-Mercaptopropyl) trimethoxysilane; MPTMS), mer Mercaptopropyltriethoxysilane (MPTES), aminopropyltriethoxysilane ((3-Aminopropyl)triethoxysilane), methoxyethoxysilane, dimethoxydiethoxysilane, ethoxytrimethoxysilane, methyltri At least one silica precursor selected from the group consisting of methoxysilane, methyltriethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, tetramethoxyethylsilane, but not limited thereto, It may be freely selected from the range of purposes for forming a silica coating layer in combination with the cysteamine coating layer.

In one example, the silica precursor concentration in the silica coating solution may be 50 to 200mM, 50 to 150mM, 50 to 120mM, 80 to 200mM, 80 to 150mM, or 80 to 120mM. When the concentration of the silica precursor is too high, the silica coating layer may not be uniformly formed due to viscosity or the like. For example, when the concentration of the silica precursor is too high, the reaction proceeds rapidly in the solution phase and a gel may be generated. may not be sufficiently formed. When the silica precursor concentration is too low, the silica coating layer may not be sufficiently formed.

In one embodiment, the silica coating solution was prepared by adding 1 mM HCl to 1M distilled water of TMOS and then diluting it with 1X PBS (10 mM Phosphate-buffered saline) so that the final TMOS concentration was 100 mM.

In one embodiment, as a result of performing infrared spectrum and XPS analysis on the surface of the hybrid coating film prepared by the above method, the presence of silicon ions was confirmed unlike the control in which only iron ion-tannic acid coating was performed. Therefore, the hybrid coating method provided by the present invention can be utilized to form a coating film containing silica on the surface of the coating film.

The present invention also provides a hybrid coating film in which an iron ion-tannic acid coating layer, a cysteamine coating layer, and a silica coating layer are sequentially stacked. Specifically, the iron ion-tannic acid coating layer may have a multilayer structure in which a cysteamine coating layer is accumulated on one or a plurality of layers, and a silica coating layer is accumulated on the cysteamine coating layer. In one example, the hybrid coating film may be manufactured by the above-described coating method.

The iron ion-tannic acid coating layer serves as a base layer that enables coating regardless of the physical and chemical properties of the coating target, and the cysteamine coating layer helps to form a silica coating layer on the iron ion-tannic acid coating layer. The silica coating layer determines the surface properties of the hybrid coating film. Therefore, the hybrid coating film and/or the surface of the coating film provided by the present invention may have acid resistance, temperature change resistance, and/or super hydrophobic properties.

In one embodiment, the iron ion-tannic acid coating layer may be a plurality of iron ions-tannic acid coating layers stacked, and in one example, 2 to 5 layers may be stacked.

The hybrid coating film provided by the present invention is a multilayer in which the iron ion-tannic acid coating layer, the cysteamine coating layer, and the silica coating layer are sequentially stacked as one unit, and the unit is laminated (repeated) a plurality of times to be formed. can The thickness of the final hybrid coating film can be controlled at the nanometer (nm) level by controlling the number of layers.

The coating film (hybrid coating film) provided by the present invention has acid resistance, pH change resistance, temperature change resistance, stain resistance, chemical decomposition resistance and/or super hydrophobic properties. Hereinafter, each characteristic will be described in more detail.

The hybrid coating film provided by the present invention has excellent acid resistance, so that the coating film can be stably maintained in acidic conditions. The acidic condition may mean a condition of less than pH 7, less than pH 6, less than pH 5, less than pH 4, less than pH 3, or less than pH 2.

In one embodiment, the hybrid coating film provided by the present invention may have a thickness reduction rate of 10% or less, 9% or less, 8% or less, 6% or less, or 5% or less in acidic conditions.

In one embodiment, the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) and the control ([Fe(III)-TA] ₆ ) coating film according to the reaction time with hydrochloric acid of pH 2 As a result of checking the thickness reduction rate, the control group already showed a thickness reduction rate close to 40% when the reaction time was 15 minutes, whereas the hybrid coating film provided by the present invention hardly occurred, and it was confirmed that the stability in acidic conditions was excellent. Therefore, the hybrid coating film provided by the present invention can be utilized to protect the surface of a material sensitive to acidic conditions, and there is a possibility that it can be utilized in industrial fields such as batteries.

The hybrid coating film provided by the present invention has resistance to changes in pH, and even if the pH around the coating film changes rapidly, its structure and physical and chemical properties can be maintained. In one example, the coating film provided by the present invention is pH 0 to 14, pH 0 to 13, pH 0 to 12, pH 1 to 14, pH 1 to 13, pH 1 to 12, pH 2 to 14, pH 2 to 13 Or have resistance to changes in pH within the range of pH 2 to 12, it is possible to maintain the surface properties.

In one embodiment, the hybrid coating film provided by the present invention ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) is a pH change cycle in 10 mM HCl aqueous solution of pH 2 and 10 mM NaOH aqueous solution of pH 12 Despite the repetition, the water contact angle was less than 5 degrees, confirming that the surface properties of the coating film were maintained even in environments with severe pH changes. Therefore, the hybrid coating film provided by the present invention has excellent stability against pH changes in various pH ranges and abrupt environments, so it can be used in industrial fields exposed to pH-sensitive environments and/or industrial fields with high frequency of exposure to harsh environments. .

The hybrid coating film provided by the present invention has resistance to temperature change, and even if the temperature around the coating film changes significantly, its structure and physical and chemical properties can be maintained. In one example, the coating film provided by the present invention is -20 to 100 degrees Celsius, -20 to 80 degrees Celsius, -20 to 60 degrees Celsius, -10 to 100 degrees Celsius, -10 to 80 degrees Celsius, -10 to Celsius It has resistance to temperature changes within the range of 60 degrees Celsius, -4 to 100 degrees Celsius, -4 to 80 degrees Celsius, or -4 to 60 degrees Celsius, so that the surface properties can be maintained.

In one embodiment, the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) provided by the present invention in one embodiment is a temperature change cycle in an oven at 60 degrees Celsius and a refrigerator at -4 degrees Celsius despite the repetition of the cycle and showed a water contact angle of 20 degrees or less, confirming that the surface properties of the coating film were maintained even in an environment with severe temperature change. Therefore, the hybrid coating film provided by the present invention has excellent thermal stability and can be used in a variety of industrial fields.

The hybrid coating film provided by the present invention has stain resistance and can maintain the coating structure, physical properties and/or chemical properties in an environment contaminated by oil or the like. In one example, the coating film provided by the present invention can maintain surface properties by preventing contamination by oil adsorption. In one embodiment, the coating film provided by the present invention can suppress the formation of an oil film on the surface of the coating film.

In one embodiment, the hybrid coating ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) glass exhibits a water contact angle of 15 degrees or less when washed with distilled water after immersion in edible oil, It showed superior image clarity and hydrophilicity compared to the control glass or the iron ion-tannic acid coated glass. Therefore, it was confirmed that the glass can be washed even in a contaminated environment due to oil, and the surface properties of the coating film are maintained thereafter.

The hybrid coating film provided by the present invention may have chemical degradation resistance. In one example, the hybrid coating film provided by the present invention may have resistance to chemical decomposition, for example, chemical decomposition by oxygen radicals. In one embodiment, the oxygen radical may be generated by sodium percarbonate.

In one example, the hybrid coating film provided by the present invention may have a residual ratio of 50% or more, 55% or more, 60% or more, 65% or more, 70% or more, or 75% or more when reacting with oxygen radicals. . The residual ratio of the coating film may be expressed as a percentage of the thickness of the coating film after the reaction compared to the thickness of the coating film before the reaction.

In one embodiment, as a result of reacting the hybrid coating ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) with an aqueous sodium percarbonate solution, the control ([Fe(III)-TA] ₆ ) The decomposition rate of the hybrid coating film was less than 10% after 90 minutes reaction, while the coating film was decomposed more than 60% when the reaction time was 90 minutes, and the decomposition rate was only about 13% even after the reaction for 3 hours.

In one embodiment, hybrid-coated ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) glass and iron ion-tannic acid coated glass and uncoated glass (Glass, control) were each treated with an aqueous sodium percarbonate solution As a result of confirming the antifogging effect after reacting for 150 minutes at As a result, it was confirmed that the hydrophilic surface properties were still maintained. Therefore, the hybrid coating film provided by the present invention has excellent resistance to chemical decomposition.

The hybrid coating film provided by the present invention may have a superhydrophobic surface. In one example, the hybrid coating film provided by the present invention may have a water contact angle of 15 degrees or less, 10 degrees or less, or 5 degrees or less. By using the superhydrophobic surface properties, the hybrid coating film provided by the present invention can be utilized for anti-fogging applications.

The present invention also provides an anti-fog film comprising the hybrid coating film, and a method for manufacturing an anti-fog film comprising the step of preparing the hybrid coating film. Details regarding the hybrid coating film and/or the manufacturing method of the coating film are the same as described above.

The anti-fog film provided by the present invention includes an iron ion-tannic acid coating layer, so that an anti-fogging coating is possible regardless of the physical and chemical properties of the coating target.

The antifogging film may have a super-hydrophobic surface having a contact angle with water of 20 degrees or less, 15 degrees or less, 10 degrees or less, or 5 degrees or less.

The anti-fog film provided by the present invention can be adjusted in thickness to a nanometer level, and is transparent when forming a nanometer-level thin film, so that it can be applied to an anti-fog glass and/or an anti-fog lens.

The anti-fog film provided by the present invention has stain resistance. In one example, the contaminants may be contaminants including oil.

The antifogging film provided by the present invention has resistance to chemical degradation. In one example, the chemical decomposition resistance may be decomposition resistance by oxygen radicals, and the oxygen radicals may be generated by, for example, sodium percarbonate.

The coating method provided by the present invention enables a silica coating with a thickness controllable on all objects regardless of surface properties under mild conditions, and the silica coating layer formed by the method forms a superhydrophilic surface to prevent fogging. The effect is excellent, and the coating layer and/or the surface properties of the coating layer can be stably maintained even in a polluted environment and in an environment with severe changes in various pH and temperature ranges by showing excellent acid resistance, stain resistance, and resistance to changes in pH and temperature. , the usability is excellent.

1 is a schematic diagram of the overall process of the polyphenol-silica hybrid coating method.
2 is a control ([Fe(III)-TA] coating layer) coating film, control ([(Fe(III)-TA) ₂ /SiO ₂ ] coating layer) coating film and polyphenol-silica hybrid coating film ([(Fe(III)) -TA) ₂ /Cys/SiO ₂ ] It is a graph of the change in the thickness of the coating film according to the number of cumulative coatings of the coating layer).
3 is a graph showing the result of measuring the thickness of the cysteamine layer and the silica layer formed thereon according to the cumulative number of the iron ion-tannic acid layer (Fe(III)-TA layer) constituting the polyphenol-silica hybrid coating film.
4 is a graph showing the thickness measurement results of the cysteamine layer and the silica layer formed on the iron ion-tannic acid layer (Fe(III)-TA layer) according to the cysteamine concentration in the cysteamine coating solution.
5 is a control ([Fe(III)-TA] ₆ ) coating film and a hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) is a graph of infrared spectrum analysis results.
6 is a control ([Fe(III)-TA] ₆ ) coating film and a hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) XPS analysis result graph.
7 is a surface photograph of the control ([Fe(III)-TA] ₆ ) coating film and the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) observed with a scanning electron microscope.
8 is a control ([Fe(III)-TA] ₆ ) coating film and a hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) The contact angle of water was measured to confirm the surface properties. It is the result.
9 shows uncoated glass (control), iron ion-tannic acid coating ([Fe(III)-TA] ₆ ) (control), and hybrid coating ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ) ] ₃ ) is the result of confirming the anti-fogging effect of the glass.
10 is a control ([Fe(III)-TA] ₆ ) coating film and a hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) Each temperature to confirm resistance to temperature change This is a graph of the change in contact angle of water according to the repetition of the change cycle.
11 shows uncoated glass (control) and iron ion-tannic acid coating ([Fe(III)-TA] ₆ ) and hybrid coating ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) This is the result of confirming the anti-fogging effect after repeating 5 cycles of the temperature change of the glass.
12 is a control ([Fe(III)-TA] ₆ ) coating film and a hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) Coating film according to reaction time under pH 2 conditions It is a graph in which the thickness change is expressed as a Degradation Percentage.
13 is a control ([Fe(III)-TA] ₆ ) coating film and a hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) pH change to confirm resistance to pH change It is a graph of change of contact angle of water according to cycle repetition
14 is an uncoated glass (control) and ([Fe(III)-TA] ₆ ) pH change in the coating film and the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) 5 The picture is the result of checking the anti-fogging effect after cycle repetition.
15 is an uncoated glass (control) and iron ion-tannic acid coating and hybrid coating ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) Measurement of contact angle of water after oil contamination of glass and the result of confirming the anti-fogging effect is a photograph.
16 is a control ([Fe(III)-TA] ₆ ) coating film and a hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) Reaction time with sodium percarbonate aqueous solution (incubation It is a graph showing the thickness retention rate (percent retention, %) according to time, min).
17 shows uncoated glass (Glass), iron ion-tannic acid ([Fe(III)-TA] ₆ ) coated glass, and hybrid ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ) This is a photograph of the result of confirming the anti-fogging effect after each coated glass was reacted with an aqueous sodium percarbonate solution.
18 shows the results of measuring the contact angle of water before coating and after hybrid coating by changing the coating target to gold, glass, aluminum, copper, polypropylene, rubber, tin, titanium, zinc, and stainless steel, respectively.

Hereinafter, the contents of the present invention will be described in more detail by way of examples. However, the following examples are only for illustrating the present invention, and the scope of the present invention is not limited by the following examples.

Example 1. Gold plate coating

1-1. Formation of iron ion-tannic acid (Fe(III)-TA) coating layer

Tannic acid (TA) and FeCl ₃ ·6H ₂ O were prepared to be 40 mg/mL and 10 mg/mL in distilled water, respectively, to prepare stock solutions for coating (tannic acid solution and iron ion solution, respectively).

Gold plate to be coated is immersed in piranha solution (3:1 (sulfuric acid: hydrogen peroxide volume ratio) mixture of sulfuric acid (H ₂ SO ₄ ) and hydrogen peroxide (H ₂ O ₂ )) for 30 minutes to perform piranha work, It was prepared by washing 3 times with distilled water. The gold substrate after the piranha operation was placed in a petri dish and 4900uL of distilled water was added thereto.

Next, 50 μL of the previously prepared iron ion solution was added, and after 10 seconds, 50 μL of the tannic acid solution was added and shaken to mix well for 1 minute. After putting the gold plate in 5 ml of 50 mM pH 7.4 Tris-HCl buffer solution for 3 minutes, the washing process was repeated 3 times with distilled water, and the remaining distilled water was removed with nitrogen (N ₂ ) gas. As a result, the gold plate was nano-coated in purple by the formation of an iron ion-tannic acid coating layer (Fe(III)-TA).

For the coated gold plate, the coating process after the above-described piranha operation was performed once more, to obtain a gold plate having an iron ion-tannic acid double coating layer ([Fe(III)-TA] ₂ ) formed thereon.

1-2. Cysteamine coating

A cysteamine solution was prepared using distilled water so that the concentration of cysteamine (Aldrich, >98.0%) was 50 mM, and then used in the coating step.

The iron ion-tannic acid double-coated ([Fe(III)-TA] ₂ )-coated gold plate prepared in Example 1-1 was placed in a petri dish, 5 mL of the prepared cysteamine solution was added thereto, and the mixture was shaken for 10 minutes. After repeating the distilled water washing process three times, the distilled water remaining as nitrogen (N ₂ ) gas was removed, and the addition of the cysteamine coating layer ((Fe(III)-TA) ₂ /Cys) was completed.

1-3. Silica (SiO ₂ ) nano coating

A 1M aqueous solution of tetramethyl orthosilicate (TMOS; Aldrich, >98.0%), a silica precursor, was prepared using distilled water, and added so that the HCl concentration became 1 mM, followed by stirring for 20 minutes. Then, 1X PBS (10 mM Phosphate-buffered saline) buffer aqueous solution (pH 7.4) was added to the solution (the TMOS and HCl solution: 1X PBS solution = 1:9 (volume ratio)), and the TMOS concentration in the final silica nanocoating solution A silica nano-coating solution was prepared by making it 100 mM.

The (Fe(III)-TA) ₂ /Cys-coated gold plate (substrate) prepared in Example 1-2 was put in a petri dish, 5 mL of the silica nano-coating solution was added thereto, and the mixture was shaken for 30 minutes. After repeating the washing process with distilled water three times, distilled water remaining as nitrogen (N ₂ ) gas was removed, and the silica coating layer was added ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] hybrid coating) was completed. .

Example 2. (Fe(III)-TA) ₂ /Cys/SiO ₂ Measurement of thickness of hybrid coating film

2-1. Check the thickness control ability according to the coating layer accumulation

Repeat steps 1-1 to 1-3 in the above embodiment to form a Fe(III)-TA) ₂ /Cys/SiO ₂ coating film (hybrid coating film) by accumulating (stacking) a plurality of times, and then repeating each number of coatings The thickness of the coating layer was measured according to

The thickness analysis of the coating film was analyzed with a model to which the Cauchy equation was applied. Specifically, the thickness was obtained by applying the Cauchy model based on the results detected after light in the visible region (300-700 nm) was reflected and refracted on the surface of the nanofilm. It was measured using a spectroscopic ellipsometer (JA Woolam Co., USA).

2 shows a graph of the measurement of the coating film thickness according to the number of coatings of the hybrid coating film, and Table 1 below shows the measurement results of the coating film thickness according to the number of repetitions of each coating.

Coating iterations One 2 3 4 5 Coating layer thickness (nm) 12.57 20.81 26.64 32.35 36.06 standard deviation (nm) 0.11 0.18 0.7 0.87 0.93

[Fe(III)-TA) ₂ /Cys/SiO ₂ ] _-- It was confirmed that the thickness of the coating layer gradually increased as the coating film was accumulated. Based on this result, the hybrid coating method provided by the present invention and the method It can be seen that the prepared hybrid coating film can precisely control the thickness at the nanometer level.

2-2. Check the thickness of the cysteamine coating layer and the silica coating layer according to the number of times of iron ion-tannic acid coating

In order to determine the effect of the iron ion-tannic acid coating layer on the formation of the thickness of the cysteamine and silica coating layer, the number of coatings in the iron ion-tannic acid coating layer formation step was varied ([(Fe(III)-TA) _n /Cys /SiO ₂ ] Hybrid coating layer formation, n is a natural number greater than or equal to 1) Each iron ion- The thickness change of the cysteamine coating layer and the silica coating layer formed on the tannic acid coating layer according to the number of iron ions-tannic acid coatings was measured. The specific thickness measurement method is the same as the method of Example 2-1.

4 shows a graph showing the results of measuring the thickness of the cysteamine and silica coating layers formed thereon when the number of times of iron ion-tannic acid coating is 1 to 5 times. Although the thickness of the iron ion-tannic acid coating layer increased, the thickness of the cysteamine and silica coating layers formed thereafter increased similarly. As an exception, when tannic acid-iron ion nanocoating is performed only once ([(Fe(III)-TA) ₁ /Cys/SiO ₂ ] hybrid coating), a complete coating layer cannot be formed on the substrate surface, so It can be seen that the thickness is less than 3 nm. Therefore, subsequent experiments were conducted using the [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] hybrid coating film formed by performing the iron ion-tannic acid nanocoating twice and then performing the cysteamine and silica coating as a single unit. Coating film accumulation was performed.

From the above results, it can be seen that the iron ion-the outermost exposed galloyl group of the tannic acid coating layer binds to cysteamine, which plays a key role in the formation of the silica coating layer.

2-3. Check the thickness of the cysteamine coating layer and the silica coating layer according to the concentration of the cysteamine coating solution

In order to check the influence of the cysteamine coating concentration on the thickness formation of the cysteamine coating layer and the silica coating layer, the change in the thickness of the silica coating layer was measured in substantially the same manner as in Example 2-1 by varying the cysteamine concentration. did

Specifically, the coating process of Examples 1-1 to 1-2 or 1-1 to 1-3 was performed by varying the concentration of cysteamine in the cysteamine coating solution to 25 mM and 50 mM, respectively, and iron ion-tannic acid on the gold plate /cysteamine coating film ([(Fe(III)-TA) ₂ /Cys]) or iron ion-tannic acid / cysteamine / silica coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ]) After forming, the thickness of the cysteamine coating layer and the silica coating layer was measured, respectively, and the results are shown in Table 2 and FIG. 4 below.

Cysteamine coating concentration (mM) 25 50 Cysteamine coating layer thickness (nm) 1.22 1.78 standard deviation (nm) 0.17 0.17 Silica coating layer thickness (nm) 1.08 5.22 standard deviation (nm) 0.24 0.03

As can be seen in Table 2, the higher the cysteamine concentration, the higher the thickness of the cysteamine coating film formed, and the silica in the case of using the cysteamine coating solution of 50 mM rather than the case of using the cysteamine coating solution of 25 mM. It was confirmed that the thickness of the coating layer was significantly increased. Therefore, the concentration of cysteamine is related to the degree of binding of cysteamine to the iron ion-tannic acid coating layer, and it can be seen that the amount of cysteamine bound plays a key role in the subsequent formation of the silica coating layer.

Comparative Example 1. Change in thickness of the coating film in which the cysteamine coating layer was omitted

In order to confirm the role of the cysteamine coating layer in the formation of the polyphenol-silica hybrid coating film, the cysteamine coating layer forming step of Example 1-2 was omitted and only the steps of Examples 1-1 and 1-3 were performed. [(Fe(III)-TA) ₂ /SiO ₂ ] _n hybrid coating film prepared by preparing a coating film ([(Fe(III) _-TA ) ₂ ] _n coating film) and the thickness of the coating film were compared. The thickness of the coating film was measured in substantially the same manner as in Example 2-1. In each of the above coating film symbols, n means the number of repetitions of the coating.

[(Fe(III)-TA) ₂ /SiO ₂ ] _n hybrid coating film and [(Fe(III)-TA) ₂ ] _n coating layer thickness and standard deviation according to the cumulative number of coating repetitions of the coating film are shown in Table 3 below it was

coating film Coating repetition number ( _n ) One 2 3 4 5 [(Fe(III)-TA) ₂ ] _n Coating thickness (nm) 5.77 13.21 18.4 24.6 28.9 standard deviation (nm) 0.21 0.08 0.6 0.87 0.22 [(Fe(III)-TA) ₂ /SiO ₂ ] _n Coating thickness (nm) 5.84 12.82 17.98 24.31 29.57 standard deviation (nm) 0.34 0.29 0.92 0.07 0.26

As can be seen in Table 3, different coating film thicknesses appeared similar within the error range in the number of coating repetitions of both coating films, confirming that the silica coating layer was not formed normally. Therefore, it can be seen that the cysteamine coating layer is essential for the formation of the silica coating layer. That is, the formation of (1) iron ion-tannic acid coating layer, (2) cysteamine coating layer, and (3) silica coating layer must be sequentially and repeatedly performed in order to form a hybrid coating film with adjustable thickness.

Comparative Example 2. Iron ion-Tannic acid coating layer omitting thickness change of the coating film

In order to confirm the role of the iron ion-tannic acid coating layer, [Cys/SiO prepared by omitting the iron ion-tannic acid coating layer forming step of Example 1-1, and performing only the steps of Examples 1-2 and 1-3 ₂ ] The thickness of the _n coating film was measured in substantially the same manner as in Example 2-1.

However, when the iron ion-tannic acid coating layer was omitted, it was impossible to measure the thickness of the coating film, because cysteamine binds to the gold plate and forms an ultra-thin layer of about 4 Å, which makes it impossible to distinguish from the gold plate due to the limitation of the spectroscopic ellipsometer. is presumed to be

Example 3. Silica Coating Surface Analysis

3-1. Elemental analysis of coating layer surface

[(Fe(III)-TA) ₂ /Cys/SiO ₂ ] formed through the process of Examples 1-1 to 1-3 To check whether a silica coating layer is formed in the hybrid coating film, infrared (Infrared; IR) spectrum Absorbance (au) analysis was performed by

5 shows a graph of the infrared spectrum analysis result. As a result of infrared spectrum analysis, unlike the coating film (control) on which only iron ion-tannic acid (Fe(III)-TA) coating was performed, in the hybrid coating film, Si-O-Si symmetric stretching (800 nm), Si-OH bending (bending, 962 nm), and Si—O—Si asymmetric stretching (1098 nm) bands were respectively confirmed, confirming that a silica thin film was formed.

In addition, to confirm the formation of the silica coating layer, X-ray photoelectron spectroscopy (X-ray photoelectron spectroscopy, XPS) was performed. For XPS analysis, for control of the coating film thickness of the sample, as a control, a coating layer ([Fe(III)-TA] ₆ coating) in which only the iron ion-tannic acid nanocoating layer was accumulated 6 times, and the above as a sample for XPS surface analysis A coating layer ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating, hybrid coating) was prepared and used in the process of Examples 1-1 to 1-3 a total of three times.

Fig. 6 shows a graph of the XPS analysis result of each coating layer, and Table 4 below shows the electron counting rate (cps) for each peak in the graph of Fig. 6

coating C 1s O 1s Si 2p [Fe(III)-TA] ₆ 59.81 35.61 0 [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ 20.16 56.23 22.25

As can be seen in Tables 4 and 6, in the case of the sample subjected to the hybrid coating, a Si 2p peak not identified in the control was confirmed, reconfirming that the silica coating layer was successfully formed.

3-2. Confirmation of structural changes in the coating surface

In order to control the thickness of the coating layer of the sample, as a control, a coating film ([Fe(III)-TA] ₆ coating) in which only the iron ion-tannic acid coating layer was accumulated 6 times, and as a sample for XPS surface analysis, Example 1-1 After preparing a coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating, hybrid coating) in which the processes of to 1-3 were performed a total of three times, the surface of each coating sample was examined under a scanning electron microscope. (Scanning electron microsope, SEM) was used for observation.

7 shows the photos of the SEM observation results, respectively. It was confirmed that the particle size and density of particles on the surface of the coating film on which the hybrid coating was made were significantly increased compared to the control.

Example 4. Confirmation of surface properties using contact angle of water

In order to confirm the surface properties of the hybrid coating film provided by the present invention, the contact angle of water on the coating surface was measured. SmartDrop Plus (FEMTOBIOMED Inc., Republic of Korea) was used to measure the contact angle of water.

Specifically, the measurement of the contact angle of water was carried out by measuring the angle between the surface-droplet produced by dropping a water droplet of 10 μm on the nanofilm, and the results are shown in Tables 5 and 8 below. As a control, a coating film in which only iron ion-tannic acid nano-coating was repeated six times ([Fe(III)-TA] ₆ coating) was used, and a hybrid coating film was prepared by accumulating three times ([(Fe(III)-TA] ) ₂ /Cys/SiO ₂ ] ₃ ).

coating type Water contact angle (°) [Fe(III)-TA] ₆ 9.5±0.6 [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ≤5

When only iron ion-tannic acid nano-coating was performed without a silica coating layer, the contact angle of water was about 9.5°, and in the case of a coating film that was completed up to silica nano-coating (hybrid coating), a contact angle of 5° or less was measured, the present invention This provided silica nanofilm (hybrid coating film) was confirmed to have a super hydrophobic surface properties.

Example 5. Confirmation of anti-fogging effect of coated glass

[(Fe(III)] [(Fe(III)] -TA) ₂ /Cys/SiO ₂ ] ₃ nano-coated glass, [Fe(III)-TA] ₆ coated glass on which only the iron ion-tannic acid coating of Example 1-1 was performed was prepared, respectively.

For the coated glass and the uncoated glass (control group), the hydrophilic surface properties and the antifogging effect were confirmed, respectively. Specifically, the hydrophilic surface properties were confirmed by measuring the contact angle of water in the same manner as in Example 4, and the anti-fogging effect was obtained by placing the control glass and the coated glass at a distance of 5 cm from the surface of boiling water at 100 degrees Celsius for 1 minute. Afterwards, each glass was moved to room temperature and placed again for 10 seconds to check the degree of fogging.

9 shows a photograph of the result of the fogging experiment on the surface. Unlike the control glass, the iron ion-tannic acid coated glass and the hybrid coated glass did not form water vapor, so it was confirmed through the photograph that the fogging phenomenon did not appear.

Example 6. Confirmation of stability of the coating film

6-1. Confirmation of stability of coating film according to temperature change

[(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating film (hybrid coating film) was formed on the slide glass by the method of Examples 1-1 to 1-3, and as a control, Example 1-1 [Fe(III)-TA] ₆ coated slide glass was prepared by the method, and each coated glass was placed in an oven at 60 ° C for 2 hours and then placed in a refrigerator (-4 ° C) for 2 hours immediately as 1 cycle. Thus, the change in surface properties according to the number of repetitions of each cycle was confirmed as the water contact angle. The water contact angle was performed in substantially the same manner as in Example 4.

10 shows a graph of the change in contact angle of water on each coated glass according to the number of cycles of temperature change and a photograph of a water droplet on the substrate, and Table 6 below shows specific values of the contact angle of water.

Number of Cycles 0 One 2 3 4 5 [Fe(III)-TA] ₆ coating 10.2° 12.6° 36.9° 51.8° 54.1° 57.6° [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating ≤5° ≤5° ≤5° ≤5° 14° 17°

In the iron ion-tannic acid coating layer (control group) without a silica coating layer, the size of the water contact angle increased as the number of temperature change cycles increased. On the other hand, the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating) maintains the water contact angle less than 20° even with an increase in the number of repeated temperature change cycles, so there is no significant change in the water contact angle size. Not confirmed.

Considering that the contact angle of water is closely related to the structural and physicochemical properties of the surface, the control coating is vulnerable to temperature changes, whereas the hybrid coating film provided by the present invention ([(Fe(III)-TA) ₂ /Cys /SiO ₂ ] ₃ coating) has excellent resistance to temperature change, that is, thermal stability, and it was confirmed that it can supplement the thermal instability of the existing iron ion-tannic acid nanocoating.

In addition, it was confirmed in the same manner as in Example 5 whether the anti-fog effect is maintained even after performing 5 cycles of temperature change, and the result of confirming the anti-fogging effect is shown in FIG. 11 . [Fe(III)-TA] _{6 On} the coated glass, water droplets form on the surface, whereas [(Fe(III)-TA)2/Cys/SiO2]3 coating film (hybrid coating film) did not show fogging. Therefore, it was confirmed that the antifogging effect of the hybrid coating film was maintained even after the temperature change.

6-2. Checking the stability of the coating film against acidic conditions

A [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating film was formed on the gold substrate by the method of Examples 1-1 to 1-3, and as a control, [Fe(III)-TA) 2 /Cys/SiO 2 ] 3 was formed by the method of Example 1-1 as a control. (III)-TA] ₆ A coated gold substrate was prepared, and each gold substrate was immersed in a 10 mM HCl aqueous solution (pH 2) to measure the rate of decrease in the thickness of the coating film over time.

Specifically, when the reaction time with the aqueous hydrochloric acid solution reached 15 minutes, 30 minutes, 60 minutes, 90 minutes, 120 minutes, and 1 day, each substrate was taken out, washed three times with tertiary distilled water, and then dried with nitrogen (N ₂ ) gas. Then, the thickness of the coating film was measured in substantially the same manner as in Example 2-1. The thickness reduction rate (degradation percentage, %) of the coating film was calculated by the method of Equation 1 below.

[Equation 1]

Decomposition rate (%)={1-(coating film thickness after reaction / coating film thickness before reaction)}*100

12 and Table 7 show the results of the reduction rate (decomposition rate) of the coating film thickness according to the hydrochloric acid reaction time of each substrate.

Coating film type Coating film degradation rate according to acid exposure time (%)
0min 15min 30min 60min 90min 120min 1 day [Fe(III)-TA] ₆ coating 0 40.36 50.12 64.03 71.55 80.65 83.92 [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating 0 0.43 0.66 1.22 1.3 1.45 2.01

In the case of the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ), it would have been reacted in hydrochloric acid for 1 day, unlike the control, which showed a thickness reduction of about 40% even after only 15 minutes of reaction in acidic conditions. It also showed a low decomposition rate of less than 2.5%, confirming that the coating film was maintained even under strong acidic conditions and thus excellent stability to acid.

Therefore, unlike the iron ion-tannic acid nanocoating, which has difficulty in durability in an acidic environment, the hybrid coating film combined with silica coating further expands the applicability of the iron ion-tannic acid nanocoating by preventing the decomposition of the coating film in acidic conditions strong against acidic conditions, It was possible to protect the surface of a material sensitive to acidic conditions, so the possibility of useful application in industrial fields such as batteries was confirmed.

6-3. Checking the stability of the coating film against changes in pH

[(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating film (hybrid coating film) was formed on the slide glass by the method of Examples 1-1 to 1-3, and as a control, Example 1-1 [Fe(III)-TA] ₆ coated slide glass was prepared by the method, and each coated substrate was placed at pH 2 (10 mM HCl) for 10 minutes, washed once with distilled water, and immediately at pH 12 (10 mM NaOH). 1 cycle was set for 10 minutes, and the change in surface properties according to the number of repetitions of each cycle was confirmed by the water contact angle. The water contact angle was performed in substantially the same manner as in Example 4.

13 shows a graph of the change in contact angle of water on each substrate according to the number of cycles of pH change, and Table 8 below shows specific values of the contact angle of water.

Number of Cycles 0 One 2 3 4 5 [Fe(III)-TA] ₆ coating 10.2° 10.0° 26.8° 29.8° 31.4° 36.8° [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating ≤5° ≤5° ≤5° ≤5° ≤5° ≤5°

In the iron ion-tannic acid coating layer (control group) without a silica coating layer, the size of the water contact angle increased as the number of pH change cycles increased, but the hybrid coating layer ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating) was There was no significant change in the size of the water contact angle even with an increase in the number of repetitions of the pH change cycle.

Therefore, while the control coating is vulnerable to pH changes, it was confirmed that the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating) provided by the present invention showed stability in a wide pH range.

In addition, after performing 5 cycles of pH change, it was confirmed whether the antifogging effect was maintained in substantially the same manner as in Example 5, and FIG. 14 shows a photograph confirming the antifogging effect. [Fe(III)-TA] ₆ coated glass has water droplets on the surface as a result of the experiment, making it difficult to recognize characters beyond the glass, whereas [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating film (hybrid coating film) There was no fogging phenomenon. Therefore, it was confirmed that the antifogging effect was stably maintained by maintaining the surface properties of the hybrid coating film even after the pH change.

6-4. Checking the stability of the coating film against oil contamination

[(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating film (hybrid coating film) was formed on the slide glass by the method of Examples 1-1 to 1-3, and as a control, Example 1-1 [Fe(III)-TA] ₆ coated slide glass was prepared by the method, and each coated glass was immersed in edible oil, washed several times with distilled water, and then the water contact angle was measured to confirm the change in surface properties. The measurement of the contact angle of water was performed in substantially the same manner as in Example 4.

15 shows a photograph of a change in contact angle of water on each substrate according to oil contamination and a photograph of the antifogging effect.

In the case of the iron ion-tannic acid coating layer (control group) without a silica coating layer, the size of the water contact angle increased even after sufficient washing in case of oil contamination, but the hybrid coating layer ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating) was There was hardly any change in the size of the water contact angle. In addition, as a result of the anti-fog test, the iron ion-tannic acid coating layer (control group) had water droplets on the surface, so the clarity of the letters on the glass side was very low, but the hybrid coating layer ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating ) was confirmed to have an anti-fogging effect. Therefore, it was confirmed that the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating) provided by the present invention exhibits contamination resistance in a contaminated environment.

6-5. Checking the stability of the coating film against chemical decomposition

[(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating film (hybrid coating film) was formed on the gold substrate by the method of Examples 1-1 to 1-3, and as a control, Example 1-1 [Fe(III)-TA] ₆ coated gold substrate was prepared by the method, and each coated substrate was immersed in sodium percarbonate (2Na ₂ CO _{3 ·} 3H ₂ O ₂ ) aqueous solution (0.1mg/ml, 45℃). The rate of decrease in the thickness of the coating film over time was measured. Specifically, when the reaction time with the sodium percarbonate aqueous solution reaches 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes, and 180 minutes, each substrate is taken out and washed three times with tertiary distilled water, followed by nitrogen (N ₂ ) gas After drying, the thickness of the coating film was measured in substantially the same manner as in Example 2-1. 16 shows a graph of the coating film retention rate (Retention Percentage, %) according to the reaction time. The residual ratio was calculated as a percentage of the thickness of the coating film after the reaction compared to the thickness of the coating film before the reaction (reaction time 0 min).

Table 9 below shows the measurement results of the reduction rate (decomposition rate) of the coating film thickness according to the hydrochloric acid reaction time of each substrate. The decomposition rate of the coating film was calculated in substantially the same manner as in Example 6-2.

Coating film type Coating film degradation rate according to acid exposure time (%) 0min 30min 60min 90min 120min 150min 180min [Fe(III)-TA] ₆ coating 0 4.42 23.85 60.13 67.13 70.24 72.25 [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating 0 2.15 5.83 8.53 12 12.18 13.02

Control ([Fe(III)-TA] ₆ ) Coating film was already decomposed by more than 20% when reacted with sodium percarbonate aqueous solution for 1 hour (60 min), and more than 50% ( Decomposition rate 60.13% at reaction time of 90 min) The coating film was decomposed and showed a very unstable appearance to sodium percarbonate, whereas in the case of the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ ), sodium percarbonate Even when reacted for 180 minutes in aqueous solution, the degradation rate was as low as 13%. Therefore, it was confirmed that the hybrid coating film provided by the present invention has excellent stability against chemical decomposition by oxygen radicals present in sodium percarbonate aqueous solution.

In addition, a slide glass and an uncoated slide in which [(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating film (hybrid coating film) and [Fe(III)-TA] ₆ coating film were respectively formed by the above method Each glass was immersed in sodium percarbonate aqueous solution and reacted for 150 minutes, washed several times with distilled water, and then the anti-fogging effect was confirmed. The antifogging effect was tested in substantially the same manner as in Example 5 above.

17 shows the results of the antifogging effect of each substrate according to the chemical decomposition using an aqueous sodium percarbonate solution.

As a result of chemical treatment using sodium percarbonate, as a result of anti-fogging test, the iron ion-tannic acid coating film ([Fe(III)-TA] ₆ coating film) has water droplets on the surface, so the distortion of the letters is so severe that it is difficult to distinguish the letters beyond the glass. , in the uncoated control group (Glass), the glass became opaque due to fogging, but the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating) was It was confirmed that the same anti-fogging effect was exhibited. Therefore, the hybrid coating film ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] ₃ coating) provided by the present invention is stable against chemical decomposition (eg, chemical decomposition by oxygen radicals) (chemical decomposition resistance) , it was confirmed that there is chemical degradation resistance).

Example 7. Test of surface properties of the coating layer according to the type of the coating object (substrate)

Gold (Au), glass (Glass), aluminum (Al), copper (Cu), polypropylene (PP), rubber (rubber), tin (Sn), titanium (Ti), zinc (Zn) and stainless steel (SS), hybrid nano-coating was performed three times in substantially the same manner as in Examples 1-1 to 1-3, and the contact angles of water before and after coating were compared.

Specifically, gold and glass were coated after performing the same piranha process as in Example 1-1, and the remaining coating objects were soaked in ethanol and acetone for 15 minutes each in ethanol and acetone instead of the piranha process, sonicated, washed, and then coated.

The water contact angle measurement results before and after coating of each coating object (substrate) are shown in Table 10 and FIG. 18 .

Substrate (to be coated) Water contact angle before coating (°) Water contact angle after coating (°) gold 68.9 ≤5 glass 47.2 ≤5 aluminum 49.1 ≤5 Copper 63.0 ≤5 polypropylene 99.9 ≤5 rubber 104.1 ≤5 Remark 70.3 ≤5 titanium 72.9 ≤5 zinc 45.3 ≤5 stainless steel 72.9 ≤5

Regardless of the physical and chemical properties of the coating target, when the hybrid coating ([(Fe(III)-TA) ₂ /Cys/SiO ₂ ] coating) of the present invention is made, all are superhydrophobic having a water contact angle within 5 degrees The surface properties were confirmed. Therefore, it was confirmed that hybrid nano-coating in which a silica coating layer is formed on the surface is universally possible regardless of the constituent components and surface properties of the material to be coated, and thereby the surface properties of the object to be coated can be changed.

Therefore, by using the hybrid coating method provided by the present invention, it is possible to overcome the limitations of surface plasma treatment and selective substrate introduction, which are generally applied to perform silica coating.

Claims (17)

A first step of forming an iron ion-tannic acid coating layer containing iron ions and tannic acid on the coating target;
a second step of forming a cysteamine coating layer containing cysteamine on the iron ion-tannic acid coating layer; and
A polyphenol-silica hybrid coating method comprising a third step of forming a silica coating layer comprising silica (SiO ₂ ) on the cysteamine coating layer. The method according to claim 1, wherein the first step is performed a plurality of times before the second step is performed. The method according to claim 1 or 2, wherein the first to third steps are sequentially performed a plurality of times. The method of claim 1, wherein the formation of the silica coating layer is performed using a coating solution containing a silica precursor. 5. The method of claim 4, wherein the silica precursor is tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), 3-mercaptopropyl trimethoxysilane ((3-Mercaptopropyl) trimethoxysilane; MPTMS) , Mercaptopropyltriethoxysilane (MPTES), aminopropyltriethoxysilane ((3-Aminopropyl)triethoxysilane), methoxyethoxysilane, dimethoxydiethoxysilane, ethoxytrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, dimethyldimethoxysilane, diethyldiethoxysilane, and one or more silica precursors selected from the group consisting of tetramethoxyethylsilane, the method . The method of claim 4, wherein the coating solution containing the silica precursor contains 50 mM to 200 mM of the silica precursor. The method of claim 1, wherein the first to third steps of forming the coating layer include: contacting a coating solution with a coating target; and washing and drying the coating object in contact with the coating solution. The method according to claim 1, wherein the formation of the coating layer in the first to third steps is performed at a temperature of 15 to 35 degrees Celsius. The method according to claim 1, wherein the formation of the coating layer in the first to third steps is performed without an acid catalyst, a base catalyst or an acid catalyst and a base catalyst. The method of claim 1, wherein the polyphenol-silica hybrid coating film formed by the coating method has one or more properties selected from the group consisting of superhydrophilicity, stain resistance, acid resistance, pH and temperature change resistance. An iron ion-tannic acid coating layer, a cysteamine coating layer, and a silica coating layer are sequentially combined, a polyphenol-silica hybrid coating film. The polyphenol-silica hybrid coating film according to claim 11, wherein the iron ion-tannic acid coating layer is a plurality of layers stacked. 12. The method of claim 11, wherein the polyphenol-silica hybrid coating film is formed by stacking the units a plurality of times using a multilayer sequentially stacked iron ion-tannic acid coating layer, cysteamine coating layer, and silica coating layer as one unit. Phosphorus, polyphenol-silica hybrid coating film. The polyphenol-silica hybrid coating film of claim 11, wherein the polyphenol-silica hybrid coating film has a water contact angle of 0 to 10°. According to claim 11, wherein the polyphenol-silica hybrid coating film has one or more properties selected from the group consisting of superhydrophilicity, stain resistance, acid resistance, pH change resistance, chemical degradation resistance, and temperature change resistance, polyphenol -Silica hybrid coating film. An antifogging film comprising a polyphenol-silica hybrid coating film in which an iron ion-tannic acid coating layer, a cysteamine coating layer, and a silica coating layer are sequentially stacked. The antifogging film of claim 16, wherein the antifogging film has one or more properties selected from the group consisting of superhydrophilicity, stain resistance, acid resistance, pH change resistance, chemical degradation resistance, and temperature change resistance.

Images