JP2005263551A - Method and apparatus for manufacturing oxide ceramic nanosheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for manufacturing an oxide ceramic nanosheet by a fluidized interfacial sol-gel process. <P>SOLUTION: In the manufacturing method, the oxide ceramic nanosheet having a uniform structure having a controlled thickness is manufactured continuously in large quantities using the fluidized interfacial sol-gel process carried out by dissolving a precursor polymerized by the partial hydrolysis of chemically modified metallic alkoxide in a solvent moderately soluble in water, dropping and spreading on the fluidized water surface by a precisely chemically designed process. By this method, a multiple oxide containing a water easily soluble component element is also manufactured and the manufactured oxide ceramic nanosheets are easily sintered. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a method for producing oxide ceramic nanosheets by a fluid interface sol-gel method and a production apparatus thereof, and the production of oxide ceramic nanosheets for stably producing oxide ceramic sheets by a fluid interface sol-gel method for a long time. The present invention relates to a method and an apparatus thereof.

  Conventionally, ceramic thin films are generally formed by a sol-gel method, a CVD method, a sputtering method, a laser ablation method, or the like, but most of them are thin films formed on a substrate. A self-supporting thin film without a so-called base material has to be peeled off from the base material by some method, which is extremely productive. On the other hand, as a method for producing a thin film that does not require a substrate, a partially hydrolyzed high-concentration metal alkoxide solution described in JP-A No. 2001-261434 is gelled at the gas-liquid interface, and barium titanate. A method for producing a self-supporting film, a method for obtaining an oxide ceramic thin film by polymerizing a metal alkoxide solution described in Japanese Patent No. 2592307 and Japanese Patent Laid-Open No. 63-166748 at a liquid-liquid interface, Japanese Patent Laid-Open No. 51-34219 There is known a method for obtaining a glass thin film by dropping a metal alkoxide solution described in Japanese Patent Publication No. 1 on a water surface. In addition, as a method not based on the so-called sol-gel method, a titania nanosheet composed of flake particles obtained by peeling off layered titanium oxide microcrystals and a method for producing the same are disclosed in JP-A-2002-265223 and JP-A-2001. -270022.

  The former method is intended to produce a thin film having a thickness of submicron or more, and it is difficult to control the rate of gelation by hydrolysis. Therefore, it is difficult to control the film thickness, and above all, mass production is impossible. In the latter method, titania nanosheets can be obtained, but this method is effective only for layered crystalline raw materials, and the process is complicated.

  The present inventor has already polymerized a metal alkoxide by partial hydrolysis, made the polymer into a solution of a desired concentration using a solvent having an appropriate solubility in water, and on the water surface where the solution flows. The present inventors have found a method for producing oxide ceramic nanosheets that employs a process of dropping continuously and precisely into gel nanosheets, a process of recovering the gel nanosheets, and a process of drying and firing. In addition, a gel obtained from a metal alkoxide that has been chemically modified to adjust the hydrolysis rate is further converted into a three-dimensional network polymer at the interface between the polymer solution and water, and the gel nanosheet formed is baked in an oxidizing atmosphere. It was found that oxide ceramic nanosheets can be obtained.

However, when manufacturing oxide ceramic nanosheets stably for a long time, unless the process is strictly controlled, the nanosheet thickness varies widely, the sheet composition changes, and in some cases, the solution cannot be dripped from the nozzle. The point became clear.
JP 2001-261434 A Japanese Patent No. 2592307 JP 63-166748 A Japanese Patent Laid-Open No. 51-34219 JP 2002-265223 A JP 2001-270022 A

  The present invention has been made in view of the above problems of the fluid interface sol-gel method, and provides a method for manufacturing oxide ceramic nanosheets for stably manufacturing oxide ceramic sheets for a long time and an apparatus for realizing mass production. It is intended to provide.

  As a result of diligent research to solve the above problems, the inventor of the present invention has a process of polymerizing a metal alkoxide by partial hydrolysis in a fluid interface sol-gel method for producing oxide ceramic nanosheets. In a step of forming a solution of a desired concentration using a solvent having a solution, a step of dropping the solution continuously onto a flowing water surface into a gel nanosheet, a step of recovering it, and a step of drying and baking, It has been found that the above problems can be solved by strictly controlling the chemical design of the process and making it into an apparatus.

  As described above, according to the present invention, a polymerized precursor obtained by partially hydrolyzing a chemically modified metal alkoxide is dissolved in a solvent having an appropriate solubility in water, and flows through a precisely designed chemical process. Oxide ceramic nanosheet high-speed mass production equipment that enables continuous production of large quantities of oxide ceramic nanosheets with a uniform structure and a uniform structure by the fluidized interface sol-gel method that drops and develops on the water surface. Is supplied. This method can also be applied to composite oxides containing component elements that are easily soluble in water, and can supply ceramic nanosheets that could not be produced by the prior art to the market. In addition, since the nanosheet of the present invention is sintered at a lower temperature than conventional fine particles, it can be a material for forming a ceramic thin film having a new function. An advantageous effect of contributing to the development of technology is obtained.

  For example, it can be expected that the dielectric layers of multilayer ceramic capacitors will be further thinned, applied to visible light photocatalytic thin films, proton conductive films, and other electronic ceramics and thin films for energy conversion devices.

The present invention will be described in detail below.
The method for producing an oxide ceramic nanosheet of the present invention comprises a first step of polymerizing one or more chemically modified metal alkoxides by partial hydrolysis, and a desired solvent using a solvent having an appropriate solubility in water. The second step of making a solution of concentration, the third step of dripping the surrounding atmosphere precisely from a controlled nozzle onto the water surface where this solution flows to form a gel nanosheet, the second step of collecting and dispersing this The fourth step includes a fifth step of drying and baking.
In the first step according to the present invention, the metal element alkoxide constituting the target oxide ceramic is mixed in an organic solvent and polymerized by partial hydrolysis.

The metal alkoxide used in the first step may be a single alkoxide or a composite alkoxide. In order to strictly control the composition of the target oxide ceramic, the general formula M (OR) _x ( In the formula, R represents an alkyl group or an aryl group), and when the target oxide ceramic nanosheet is a composite oxide, two or more kinds of chemically modified metal alkoxides are used. It is preferable. Since R is removed from the oxide ceramics by firing, generally an ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl group or the like having a small number of carbon atoms is preferred. . In particular, when the ceramic nanosheet to be produced has a porous structure, an alkoxide having an alkyl group or aryl group having a large number of carbon atoms can also be used.

  In partial hydrolysis of the metal alkoxide in the first step, the hydrolysis rate can be adjusted by appropriately selecting an alkoxy group, but the metal alkoxide is chelated, transesterified, alkoxy exchanged, acidolysis, acid anhydride. It is preferable to adjust the hydrolysis rate by chemical modification by a reaction with an acid or a dibasic acid. Specifically, glycols such as ethylene glycol, diethylene glycol, octanediol and hexanediol, β-diketones such as acetylacetone, hydroxycarboxylic acids such as lactic acid, malic acid, tartaric acid and salicylic acid, methyl acetoacetate, acetoacetate Ketoesters such as ethyl acetate, O-coordination type ligands of ketoalcohols such as diacetone alcohol, N-coordination type ligands such as ethylenediamine, aminoalcohol, oxyquinoline, Schiff base, cyclopenta Chelation with C-coordinate type ligands such as dienyl compounds, P, B, and S-coordinate type ligands, transesterification with organic acid esters such as ethyl acetate, propyl acetate, and butyl acetate N-butyl alcohol, n-pentanol, etc. Alkoxy exchange reaction with alcohols with a long alkyl chain, acidolysis with carboxylic acids such as acetic acid, propionic acid, phenylacetic acid, acids such as acetic anhydride, heptanoic anhydride, phthalic anhydride, succinic anhydride, maleic anhydride By replacing some or all of the metal alkoxides with substitution machines with different hydrolysis rates by reaction with anhydrides, reaction with dibasic acids such as adipic acid, maleic acid, and phthalic acid, and some polymers Therefore, it is possible to adjust the hydrolysis rate by chemical modification. The ratio of the alkoxy group to be substituted varies depending on the type of metal and the type of alkoxy group, but 5 to 80% of all alkoxy groups are preferably substituted. If it is 5% or less, the effect is not sufficient, and if it exceeds 80%, polymerization is insufficient due to the following partial hydrolysis, which is not preferable because it is difficult to gel in the third step of forming a gel nanosheet.

  Such chemical modification of the metal alkoxide introduces a fast-hydrolyzing substituent and a slow-displacer into the metal alkoxide molecule, and in some cases, effects similar to those achieved in part by hydrolysis. Can be expected. The metal alkoxide thus chemically modified is diluted with a solvent that dissolves water, such as ethanol, isopropanol, 1-butanol, 2-butanol, diethyl ether, to which a desired amount of water is dissolved in a similar solvent, Further, if necessary, an acid catalyst such as hydrochloric acid is added while stirring at a speed that does not cause the solution to become cloudy, so that it is partially hydrolyzed and polymerized.

  The chemically modified metal alkoxide is not necessarily diluted, but can be appropriately diluted with a solvent in order to ensure sufficient fluidity. The dilution solvent is preferably dehydrated.

  The amount of water to be mixed must be an amount that partially hydrolyzes the metal alkoxide, and must generally be determined stoichiometrically in the range of 0.5 to 2 moles of the metal alkoxide. I must. That is, in the present invention, the polymerization of the metal alkoxide is not only soluble in a solvent, but also in a step of precisely and continuously dropping onto a flowing water surface, which will be described later, to form a gel nanosheet, In order to convert to a polymer having a three-dimensional network structure at the interface to form a gel nanosheet, it is essential to obtain a chain polymer or a chain polymer having a branched structure. If the amount of water is less than 0.5 mol of metal alkoxide, alkoxide that does not form a chain polymer remains, and if it exceeds 2 mol, gelation or partial formation of inorganic fine particles makes it difficult to form a precursor solution. This is not preferable.

  The metal alkoxide polymer solution thus prepared can be used in the second step of the present invention. However, the development of the chain polymer or the chain polymer having a branched structure and the composition and concentration of the solution are strictly limited. It is desirable to age and concentrate under reduced pressure to control. The time required for concentration is sufficient for the aging time. A concentration temperature from room temperature to 100 ° C. is sufficient, and if it is 100 ° C. or higher, the purified polymer may gel, which is not preferable.

In the second step of the production method according to the present invention, the polymer obtained in the first step is adjusted to a solution having a desired concentration using a solvent having appropriate solubility in water.
Solvents having moderate solubility in water used in the second step are ethanol, isopropanol, 1-butanol, 2-butanol, propanal-1, butanal-1, diethyl ether, ethyl methyl ketone, ethyl acetate, dichloromethane , Chloroform, nitromethane, dimethyl sulfoxide, etc., depending on the nature of the polymer, for example, isopropanol or a mixed solvent such as isopropanol and 1-butanol, ethanol and 1-butanol, isopropanol and butanal-1 generally gives good results. . A solvent that is almost insoluble in water, such as cyclohexane, hexane, benzene, toluene, and xylene, can be used, but in such a solvent, a three-dimensional network structure formed by hydrolysis of the polymer is basically used in the third step of the present invention. It is not preferable in that generation does not occur, and therefore, the hydrolysis rate is extremely difficult to control, and the thickness of the nanosheet cannot be controlled.

  The concentration of the polymer must be strictly controlled to control the thickness of the nanosheet, with a concentration of 1-90% being preferred. If it is 1% or less, the thickness of the gel nanosheet cannot be substantially controlled, and if it is 90% or more, the increase in the viscosity of the solution due to the polymer becomes dominant, and the solution is difficult to be dropped from the nozzle in the third step. It becomes difficult to spread on the water surface when it is dropped or dropped on the flowing interface, so that a nanosheet cannot be obtained.

In the third step of the production method according to the present invention, the precursor solution is continuously and precisely dropped onto the flowing water surface to obtain a gel nanosheet.
FIG. 1 is an explanatory view showing an apparatus for carrying out a part of the third step and the fourth step of the present invention. In the third step, in order to form a fluid interface in the water tank 1, water is circulated from the water tank 2 by a circulation pump, water is flowed from the water tank 1 toward the water tank 2, and the second water interface is formed on the formed water fluid interface. The polymer solution obtained in this step is dropped from a microsyringe while controlling the amount of droplets with a dispenser. Drops of the dropped polymer solution develop on the surface of the water, and the solvent dissolves in water mainly depending on the solubility in water. The polymerized metal alkoxide in the solution is condensed between the chain polymer or the chain polymer having a branched structure by hydrolysis at the interface between the solution and water to form a gel nanosheet. Since the gel nanosheet moves toward the water tank 2, as long as the dropping speed is adjusted so that the polymer solution does not drop on the gel nanosheet, the gel nanosheet can be mass-produced by continuously dropping the polymer solution. is there. The organic solvent component in water can be separated appropriately through a separation tank. In the third step of dropping the precursor solution onto the flowing water surface, it is preferable to drop the precursor solution from a nozzle whose ambient atmosphere is controlled as shown in FIG. That is, on the fluid interface with high water vapor pressure, the precursor solution gels at the tip of the nozzle, making it difficult to drip liquid droplets for a long time. Is preferably substituted.

  In the third step of the present invention, controlling the temperature of water forming the flowing interface from 0 ° C. to 100 ° C. controls the viscosity of the precursor solution developed at the flowing interface and the gelation rate by hydrolysis. As a result, it is preferable because the film thickness of the oxide ceramic nanosheet can be strictly controlled. When the water temperature is too low, the viscosity of the precursor is generally too high, and at a high temperature, the hydrolysis rate is too high or the vapor pressure of water on the water surface is too high. More preferably, it is controlled.

  Furthermore, in the third step of the present invention, a substance that controls the surface tension of water is dissolved in water that forms a flowing interface, and the development speed on the interface of the precursor solution is controlled, and the oxide ceramic nanosheet The film thickness can be controlled. The surface tension of water is usually 2-3 times greater than the surface tension of the precursor solution, so the rate of development of the precursor solution on the interface is very high. Therefore, generally adding a substance that lowers the surface tension of water, for example, a normal surfactant, propanol, butanol, myristyl alcohol, etc., reduces the surface tension of water and controls the film thickness of the gel nanosheet. Therefore, it is preferably used.

  In the third step of the present invention, a substance that controls the elution of the component elements from the gel nanosheet generated at the interface can be dissolved in the water that forms the flowing interface. For example, when using a precursor solution containing an alkali or alkaline earth metal such as barium titanate nanosheet having high solubility in water as a component element, these components are gelated by hydrolysis of the precursor solution. Easily dissolves in water when making nanosheets. In order to suppress this, it is extremely effective to dissolve an ionic compound containing these components in water that forms a fluid interface in advance. For example, when producing a barium titanate nanosheet, it is preferable to dissolve barium hydroxide to its solubility. Similarly, controlling the pH of the water that forms the flowing interface can control the rate of hydrolysis of the precursor solution on the interface, thus controlling the development area of the precursor solution, and thus the gel nanosheets. It is preferable because the film thickness can be controlled. The method of controlling pH can be achieved by dissolving a substance that controls pH in water that forms a flowing interface. Generally, ammonia water, KOH, NaOH, amines, hydrochloric acid, nitric acid, carboxylic acids, etc. Is preferred.

  Furthermore, in the third step of the present invention, it is preferable to control the atmosphere on the flowing interface in order to stably produce the oxide ceramic nanosheet. For example, carbon dioxide in the air reacts with the barium hydroxide dissolved in the water forming the fluid interface described above to produce insoluble barium carbonate when producing barium titanate nanosheets. The coarsened particles in the nanosheet are purified. Therefore, it is preferable that the entire nanosheet manufacturing apparatus shown in FIG. 1 can be replaced with, for example, air or nitrogen gas from which carbon dioxide has been removed.

  In the fourth step of the production method according to the present invention, the gel nanosheet obtained in the third step is collected. Collection of the gel nanosheet is achieved by providing a separator 6 made of a glass filter or the like in the water tank 2 of FIG. 1, but when a large amount of gel nanosheets are continuously produced, the gel nanosheet can be recovered from the water tank 2 as appropriate. Good. The collection method includes scooping with a filter-like net or collecting the replaceable separator together.

  In the fifth step of the production method according to the present invention, the gel nanosheet collected in the fourth step is dried and fired. Specifically, since the obtained gel nanosheet contains water and an organic substance derived from a polymer, it is first dried in a temperature range of room temperature to 100 ° C. for the purpose of removing these from the recovered gel nanosheet. The atmosphere to be dried is air or oxygen atmosphere, but the drying speed is controlled, and if the gel nanosheet contains barium etc. to produce carbonate, the water vapor pressure is controlled or carbon dioxide is removed. It is preferable to use an atmosphere in which the water vapor pressure is controlled, air from which carbon dioxide is removed, an inert gas atmosphere such as nitrogen gas and argon gas. The dried gel nanosheet is further baked to a desired temperature in order to remove the remaining organic substances according to the type of oxide ceramics and obtain a desired structure. The heating rate at this time is important to convert the gel nanosheets to oxide ceramics while maintaining the nanosheet structure, and to further develop the three-dimensional bond between the metal and oxygen formed in the gel. It is necessary not to raise the temperature rapidly. Preferably, the temperature is raised at 1 to 200 ° C./hour in which the residual organic matter in the gel is gradually decomposed and oxidized. The firing temperature may be higher than the temperature at which carbon in the gel nanosheet is oxidized and removed, and generally 400 ° C. or higher. The atmosphere for firing may be air, but in order to promote densification of the oxide ceramic nanosheet and keep the composition constant, it is preferable to use an atmosphere in which the water vapor pressure is controlled or carbon dioxide is removed. Air in which the pressure is controlled and carbon dioxide is removed is preferred.

Next, in order to continuously produce oxide ceramic nanosheets by the fluid interface sol-gel method according to the present invention, an apparatus for producing oxide ceramic gel nanosheets capable of performing the chemical design of the above-described process will be described.
The manufacturing apparatus of the oxide ceramic gel nanosheet of this invention is comprised from the nanosheet manufacturing part and the control part.

  The nanosheet manufacturing unit is composed of a nanosheet forming unit (fluid interface forming unit) and a recovery unit. In the nanosheet manufacturing section, water is circulated by a pump to form a laminar flow in the nanosheet forming section to form a fluid interface. A laminar flow thickness of about 10 mm is sufficient, and the linear velocity may be 0.1 to 100 mm / second. In order to drop and spread the precursor solution on the fluid interface, a non-contact dispenser part that can dispense the precursor solution can be dispensed on the fluid interface, for example, and the weight of the precursor solution to be dripped is controlled from 1 mg to 100 mg. I can do it. Moreover, it is preferable that the clearance between the nozzle and the fluid interface can be controlled by 1 to 50 mm in accordance with the characteristics of the dropped precursor solution. In order to control the gelation rate of the developing precursor solution, it is preferable that the interface temperature at which nanosheet formation occurs can be controlled at 5 to 50 ° C. (± 0.5 ° C.). The gel nanosheet recovery part is a cartridge-type filter that can easily recover the nanosheets accumulated in the recovery part, with a separator for efficiently separating nanosheets with a thickness of 10 to 100 nm and a diameter of 10 μm or more. It is preferable to do. Furthermore, in order to manufacture the gel nanosheet stably for a long time, the atmosphere in the manufacturing unit can be controlled by supply and exhaust. For the same reason, it is preferable to install a pH meter, a monitoring camera, and a flow meter.

  The control unit can monitor, measure, and operate the nanosheet manufacturing unit from the front, and the control panel is a running indicator, alarm device, emergency stop device, status indicator, pH indicator, temperature indicator, recording It consists of a meter, flow meter, sequencer, drip dispenser controller and monitoring monitor.

Next, specific examples of the present invention will be described, but the present invention is not limited to these examples.
After 1 mol of pentaethoxytantalum was chelated with 1 mol of ethyl 3-oxobutanoate and the exotherm subsided, partial hydrolysis was performed with 1 mol of water over 1 hour with stirring. Further, the mixture was heated to 60 ° C. under reduced pressure using a rotary evaporator and concentrated to obtain a viscous product. Isopropanol or isopropanol was added thereto to prepare 50 to 90% solutions.

Using the oxide ceramic nanosheet manufacturing apparatus of the present invention, these solutions were accurately dropped as 5-20 mg droplets on a flowing water surface controlled at 23 ° C. with the atmosphere around the nozzle being a nitrogen atmosphere, and gel The nanosheet was continuously produced for 5 hours or more. The obtained gel nanosheet was dried in the air at 100 ° C. for 3 hours, then heated to 1000 ° C. in the air at a heating rate of 200 ° C./hour and held for 1 hour. The oxide ceramic nanosheet having a thickness of about 100 to 400 nm was obtained. From the half-width of the diffraction line, the nanosheet structure was confirmed to be composed of crystal grains having a crystallite size of about 12 to 23 nm from Ta ₂ O ₅ . However, when dripping from the nozzle was performed in the atmosphere, the precursor solution gelled at the tip of the nozzle in a few minutes and could not be dripped. Moreover, when dripped on the flowing water surface which is not temperature-controlled, the area of the gel nanosheet developed on the water surface could not be controlled, and as a result, the thickness of the nanosheet varied.

  In the same manner as in Example 1, 1 mol of tetraisopropoxytitanium was chelated with 0.6 mol of ethyl 3-oxobutanoate. After the exotherm subsided, 1 mol of water was partially mixed with stirring over 1 hour. The gel nanosheet was prepared from a 70% isopropanol solution on a flowing water surface controlled at 19 ° C. by hydrolysis and polymerization. This was recovered, dried at 80 ° C. for 6 hours, heated to 500 ° C., held for 1 hour and fired. The thickness of the obtained titania nanosheet was approximately 100 nm, and the crystallite size was estimated to be 10.2 nm from the results of X-ray diffraction measurement. Transition from the anatase phase to the rutile phase was observed in the nanosheet fired at 1000 ° C.

  The ethoxy group of pentaethoxytantalum was converted to a butoxy group, and polymerized in the same manner as in Example 1. A gel nanosheet was prepared by using the obtained polymer as a 70% solution in the same manner as in Example 1. Further, after drying at 100 ° C. for 3 hours, the mixture was heated to 1000 ° C. at 100 ° C./hour, and held for 1 hour for firing. The thickness of the sheet was about 70 nm.

  Pentaethoxytantalum was polymerized by the same method as in Example 2. The obtained polymer was made into a 70% solution in the same manner as in Example 1, and 10 wt% of isopropanol was dissolved in the fluidized interface forming water to reduce the surface tension of the water to prepare a gel nanosheet. Further, after drying at 100 ° C. for 3 hours, the mixture was heated to 1000 ° C. at 100 ° C./hour, and held for 1 hour for firing. The thickness of the sheet was about 120 nm, and the film thickness could be controlled to be thick by reducing the surface tension of water.

Tetraisopropoxytitanium was polymerized by the same method as in Example 2, and diethoxybarium dissolved in 2-methoxyethanol was added. Further, the mixture was heated to 60 ° C. under reduced pressure using a rotary evaporator and concentrated to obtain a viscous product. This was adjusted to a 50 wt% solution using a 3: 1 mixed solvent of isopropanol and butanal, and the atmosphere around the nozzle and barium hydroxide were dissolved to adjust the pH to 7, 10, 12, and 14, and the fluid interface Gel nanosheets were produced using the above atmosphere as a nitrogen atmosphere. The obtained gel nanosheet was dried in air from which carbon dioxide had been removed at 80 ° C. for 3 hours, then heated to 1000 ° C. at 100 ° C./hour in an oxygen atmosphere, and held for 1 hour to be fired. In the obtained nanosheet, coarse particles were not observed, and the thickness was 50 to 150 nm. The result of the X-ray diffraction measurement of the sheet produced at each pH is shown in FIG. At pH 7, 10, and 12, since Ba elutes in water forming a fluid interface, a BaTi ₂ O ₅ phase lacking Ba is generated, whereas at pH 14, only a BaTiO ₃ phase is generated.

For comparison, the barium titanate nanosheet prepared from the fluidized interface at pH 14 by the method of performing all operations in the air except that the atmosphere around the nozzle was changed to a nitrogen atmosphere substantially formed a BaTi ₂ O ₅ phase. In the surface and inside of the sheet, coarse particles were observed. It was found that this was because barium carbonate particles were formed in the fluidized interface formation water by carbon dioxide in the atmosphere, and barium carbonate particles were formed in the gel nanosheet during the drying and firing processes.

It is explanatory drawing which shows notionally the apparatus for implementing a part of 3rd process and 4th process of this invention. It is an X-ray diffraction pattern of the barium titanate nanosheet obtained by baking the gel nanosheet obtained by controlling the pH of a fluid interface at 1000 degreeC.

Claims (9)

A first step of polymerizing one or more chemically modified metal alkoxides by partial hydrolysis, a second step of making the polymer into a solution of a desired concentration using a solvent having an appropriate solubility in water, this solution The third step of precisely dropping the surrounding atmosphere onto the flowing water surface from a controlled nozzle to form a gel nanosheet, the fourth step of collecting and dispersing this, the fifth step of drying and firing A method for producing oxide ceramic nanosheets, comprising continuously producing oxide ceramic nanosheets by a fluid interface sol-gel method. The oxide according to claim 1, wherein at least one metal alkoxide having a hydrolysis rate adjusted by chemical modification by reaction with chelation, transesterification, alkoxy exchange, acidolysis, acid anhydride, dibasic acid or the like is used as necessary. Manufacturing method of ceramic nanosheet. The manufacturing method of the oxide ceramic nanosheet of Claim 1 or 2 which controls the temperature of the water which forms the flowing interface from 0 degreeC to 100 degreeC. The method for producing an oxide ceramic nanosheet according to claim 1, wherein a substance that controls the surface tension of water is dissolved in water that forms a flowing interface. The manufacturing method of the oxide ceramic nanosheet in any one of Claims 1-4 which dissolve the substance which controls the elution of the component element from the gel nanosheet produced | generated at the interface in the water which forms the flowing interface. The manufacturing method of the oxide ceramic nanosheet in any one of Claims 1-5 which controls pH of the water which forms the interface which flows. The method for producing an oxide ceramic nanosheet according to claim 1, wherein the atmosphere on the flowing interface is controlled. The manufacturing method of the oxide ceramic nanosheet in any one of Claims 1-7 which controls the atmosphere of the process of drying and baking a gel nanosheet. In order to continuously produce oxide ceramic nanosheets by the fluid interface sol-gel method according to claim 1, means capable of performing chemical design of the process according to any one of claims 3 to 6, and An apparatus for producing an oxide ceramic gel nanosheet comprising: a means capable of performing a heat treatment design of a process of drying and firing the described gel nanosheet.