KR20180016047A - Magnesium oxide structure and method of manufacturing the same - Google Patents

Abstract

A magnesium oxide structure and a manufacturing method thereof are disclosed. The method comprises the following steps: providing an organic precursor comprising magnesium; mixing the organic precursor with a solvent to provide a mixed precursor; and forming the magnesium oxide structure having nanopores from the mixed precursor through a gelation process. The present invention provides the magnesium oxide structure having improved carbon dioxide adsorbing ability.

Description

[0001] Magnesium oxide structure and method of manufacturing same [0002]

The present invention relates to a magnesium oxide material, and more particularly, to a magnesium oxide structure and a manufacturing method thereof.

In response to abnormal weather caused by the greenhouse effect, CO2 capture and storage technologies are rapidly expanding. Various materials such as calcium oxide and magnesium oxide have been used for the carbon dioxide capture and storage technology according to the carbon dioxide capture method. The conventional carbon dioxide adsorbent mainly uses calcium oxide having excellent adsorptivity. However, the carbon dioxide adsorption reaction using calcium oxide occurs at a high temperature of 600 ° C or higher. Therefore, the adsorption reaction using the calcium oxide does not occur with respect to the carbon dioxide generated due to the exhalation at room temperature.

As a result, magnesium oxide in which carbon dioxide adsorption reaction occurs at room temperature is used as an adsorbent. However, the magnesium oxide can adsorb carbon dioxide even at room temperature, unlike calcium oxide used at a high temperature, but has a problem that the carbon dioxide adsorbing ability is lower than that of the calcium oxide.

SUMMARY OF THE INVENTION The present invention provides a magnesium oxide structure having improved carbon dioxide adsorbing ability.

Another object of the present invention is to provide an adsorbent comprising a magnesium oxide structure having the above advantages.

Another object of the present invention is to provide a method for manufacturing a magnesium oxide structure having the above-described advantages.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: providing an organic precursor comprising magnesium; Mixing the organic precursor with a solvent to provide a mixed precursor; And forming a magnesium oxide structure having nano pores through a gelation process from the mixed precursor.

A method for preparing a magnesium oxide structure includes: aging a result of the gelation process; And drying the resultant.

The organic precursor may be one of magnesium methoxide, magnesium ethoxide, magnesium acetate, magnesium sulfate, magnesium nitrate and magnesium hydroxide, magnesium hydroxide, magnesium hydrogencarbonate, and magnesium carbonate.

The magnesium oxide precursor may further include at least one of fluorine and a phenyl group.

The gelation process may include at least one of hydrolysis and polycondensation.

The solvent may be alcohol-based, carbonate-based, ether-based or ketone-based daily.

And adding an acid catalyst to the mixed precursor.

The acid catalyst may comprise acetic acid or nitric acid.

According to another aspect of the present invention, there is provided a magnesium oxide structure in which nanopores are distributed.

The magnesium oxide structure may contain at least one of fluorine and a phenyl group.

The magnesium oxide structure has a three-dimensional network structure in which pores are distributed.

The magnesium oxide structure has a porosity of 50 vol% to 95 vol%.

The magnesium oxide structure has a specific surface area of from 300 m 2 / g to 800 m 2 / g.

The average pore diameter of the magnesium oxide structure is in the range of 10 nm to 50 nm.

According to another aspect of the present invention there is provided an adsorbent comprising a porous structure in which nanopores are distributed.

According to the embodiment of the present invention, by forming a magnesium oxide structure having nano pores through a sol-gel process, the specific surface area is increased and carbon dioxide adsorption ability is improved. Further, since carbon dioxide can be adsorbed even at room temperature, it can be applied to a gas mask using carbon dioxide adsorption.

1 is a view illustrating a magnesium oxide structure having nanopores according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a manufacturing procedure of a magnesium oxide structure having nanopores according to an embodiment of the present invention. Referring to FIG.
3A to 3D are views for explaining a method of manufacturing a magnesium oxide structure having nanopores according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified into various other forms, It is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more faithful and complete, and will fully convey the scope of the invention to those skilled in the art.

Like numbers refer to like elements in the drawings. Also, as used herein, the term "and / or" includes any and all combinations of any of the listed items.

The terms used herein are used to illustrate the embodiments and are not intended to limit the scope of the invention. Also, although described in the singular, unless the context clearly indicates a singular form, the singular forms may include plural forms. Also, the terms "comprise" and / or "comprising" used herein should be interpreted as referring to the presence of stated shapes, numbers, steps, operations, elements, elements and / And does not exclude the presence or addition of other features, numbers, operations, elements, elements, and / or groups.

Reference herein to a layer formed "on" a substrate or other layer refers to a layer formed directly on top of the substrate or other layer, or may be formed on intermediate or intermediate layers formed on the substrate or other layer Layer. ≪ / RTI > It will also be appreciated by those skilled in the art that structures or shapes that are "adjacent" to other features may have portions that overlap or are disposed below the adjacent features.

As used herein, the terms "below," "above," "upper," "lower," "horizontal," or " May be used to describe the relationship of one constituent member, layer or regions with other constituent members, layers or regions, as shown in the Figures. It is to be understood that these terms encompass not only the directions indicated in the Figures but also the other directions of the devices. In addition, reference numerals of members in the drawings refer to the same members throughout the drawings.

FIG. 1 is a view showing a magnesium oxide structure 100 having nanopores according to an embodiment of the present invention.

Referring to FIG. 1, a magnesium oxide structure 100 having nano pores according to an embodiment of the present invention has a three-dimensional network structure connected to each other, and a pore structure is formed between and between frames forming the three- Can be formed. In some embodiments, the magnesium oxide structure 100 may further comprise fluorine (F) or a phenyl group. The phenyl group is a functional group consisting of carbon and hydrogen and has the formula -C6H5. In addition, the magnesium oxide structure 100 may have a structure in which the linear structure of the magnesium oxide is integrated with the adjacent linear structure and connected to form a three-dimensional network structure without any additive for additional reinforcement such as a polymer (binder) or a fiber .

In some embodiments, the magnesium oxide structure 100 may have excellent mechanical strength by the fluorine and / or phenyl groups contained therein, and at the same time have flexibility properties by a three-dimensional network structure with pores . This is presumed to be due to the fact that the fluorine or phenyl group acts like a defect in a three dimensional network structure or acts like a flexible elastomer. The magnesium oxide structure 100 has flexibility when the external force is applied to the magnesium oxide structure 100 so that the magnesium oxide structure 100 is flexed to a certain degree of external force, It can be restored to its original state.

The porosity of the magnesium oxide structure 100 may be in the range of 10% to 99%, preferably in the range of 70% to 95%, and may be suitably adjusted in consideration of the required strength and flexibility. When the magnesium oxide structure 100 has a high porosity, the magnesium oxide structure 100 may be referred to as an aerogel. As the porosity increases, the strength decreases, but the flexibility can be enhanced. As the porosity decreases, the strength increases and the flexibility can be weakened. However, in any case, according to the embodiment of the present invention, a three-dimensional network structure can have a high porosity and a strength that is not easily broken or broken by an external force.

In some embodiments, the magnesium oxide structure 100 may have excellent thermal stability by the fluorine and / or phenyl groups. For example, the phenyl group may have a burning point higher than about 600 ° C, and may have a high burning point (about 600 ° C or higher) similarly to the fluorinated phenyl group. Thus, the magnesium oxide structure 100 containing fluorine and / or phenyl groups may have high temperature stability that is not collapsed or decomposed at temperatures above about 500 [deg.] C. Therefore, the magnesium oxide structure 100 can have excellent mechanical stability and flexibility while at the same time, excellent thermal stability.

In addition, when the magnesium oxide structure 100 does not contain a reinforcing additive such as a polymer (binder) or a fiber, there is a problem that the properties are deteriorated by the reinforcing additive, for example, the porosity and specific surface area decrease, The problem of increasing the density can be prevented. Accordingly, the magnesium oxide structure 100 may have a high porosity, a high specific surface area, a low thermal conductivity, and a low density.

The magnesium oxide structure 100 may have a specific surface area of at least about 300 m2 / g. In addition, the thermal conductivity of the magnesium oxide structure 100 may be as low as about 0.03 W / mk or less. On the other hand, the average pore diameter of the magnesium oxide structure 100 may be in the range of 10 nm to 0.5 mm. The pores of the magnesium oxide structure 100 may have a generally nanoscale, in which case the magnesium oxide structure 100 may be referred to as a " nanopore structure ". In some cases, some of the pores of the magnesium oxide structure 100 may have a microscale.

In some other embodiments, the magnesium oxide structure 100 may have hydrophobic properties due to contained fluorine or phenyl groups. 'Hydrophobic' can be useful in a variety of applications, such as coating materials, for example, because the magnesium oxide structure 100 has hydrophobicity and can reduce or suppress the problem of deterioration or denaturation of the properties by moisture adsorption .

As described above, the magnesium oxide structure 100 according to the embodiment of the present invention has high temperature stability, flexibility, and excellent mechanical strength, and also has a high specific surface area, low thermal conductivity, low density (ultra light weight) . ≪ / RTI > Therefore, the magnesium oxide structure 100 can greatly improve the commercialization possibility and utilization value.

Further, in the embodiment of the present invention, utilizing the high porosity and high specific surface area characteristics of the magnesium oxide structure 100, it can be utilized as an adsorbent capable of adsorbing carbon dioxide at room temperature. Such an adsorbent can be used as a filter adsorbent for improving the function of the respiratory surface. For example, the respiratory protection surface is a mechanism for protecting the respiratory apparatus by blocking external harmful air inflow, and may be difficult to use in an environment where oxygen concentration is insufficient because external air inflow is blocked. Therefore, in order to use the respirator in an environment where the oxygen concentration is insufficient, a separate oxygen supply device may be provided or a module for filtering the exhalation may be required. To this end, by using the above-described magnesium oxide structure 100 in the respiratory mask to adsorb and separate carbon dioxide by exhalation, the gas mask can be used even in an environment where oxygen is not supplied.

FIG. 2 is a flowchart illustrating a procedure for manufacturing a magnesium oxide structure according to an embodiment of the present invention. Referring to FIG.

Referring to FIG. 2, a method for preparing a magnesium oxide structure according to an exemplary embodiment of the present invention includes the steps of providing a magnesium oxide precursor (S10), adding a solvent capable of reacting with the magnesium oxide precursor to at least one of hydrolysis and polycondensation Adding a precursor to the magnesium oxide precursor to produce a mixed precursor (S20), and gelating the mixed precursor through a sol-gel process (S30). After the gelling step, an aging step (S40) for strengthening the mesh structure of the gel and a step (S50) for drying the aged gel to form the magnesium oxide structure (100).

In step S10, the magnesium oxide precursor may be an organic precursor including magnesium oxide. The magnesium oxide precursor may include magnesium methoxide, magnesium ethoxide, magnesium acetate, magnesium sulfate, magnesium nitrate, and magnesium hydroxide. However, it should be understood that the present invention is not limited thereto. For example, the magnesium oxide precursor may be one of magnesium hydroxide, magnesium hydrogencarbonate, magnesium carbonate, ethylmagnesium bromide, dimethylmagnesium, diethylmagnesium and magnesium halide magnesium. The organic precursor may be a liquid or solid at room temperature. In some embodiments, the magnesium oxide precursor may further comprise at least one of fluorine and a phenyl group. For example, the magnesium oxide organic precursor may be, for example, magnesium fluoride and magnesium methoxide to which the phenyl group is bonded.

In step S20, the solvent may be an alcohol-based solvent such as methanol, ethanol, or isopropyl alcohol capable of reacting with the magnesium oxide precursor and at least one of hydrolysis and polycondensation. However, the kind of the solvent 20 is not limited to the alcohol-based solvent, and the solvent can be, for example, a carbonate-based, ether-based, or ketone-based daily. For example, the carbonate-based solvent is selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methyl ethyl carbonate Ethylene carbonate (EC), propylene carbonate (PC), or butylene carbonate (BC). The ester solvent is selected from the group consisting of methyl acetate, ethyl acetate, n-propyl acetate, 1,1-dimethyl ethyl acetate, methyl propionate, ethyl propionate,? -Butyrolactone, decanolide, , Mevalonolactone, or caprolactone. ≪ / RTI >

The ether solvent may include dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, or tetrahydrofuran, and the ketone solvent may be cyclohexane Hexanone. ≪ / RTI > The organic solvents may be used alone or in combination.

When the step S40 is performed, the gel may be aged at an atmospheric pressure of 100 DEG C or lower. When the step S50 is performed, the gel may be dried through atmospheric pressure drying at normal pressure or through supercritical drying at high temperature and high pressure. For example, supercritical drying can be carried out in a high pressure reactor at about 300 DEG C, 100 bar for 5 to 24 hours. Further, in step S30, a step of adding a predetermined catalyst to the precursor solution may be further performed. The catalyst may be an acid catalyst such as, for example, acetic acid (C2H4O2) or nitric acid (HNO3). However, the present invention is not limited thereto. For example, the catalyst may be NH4F or hydrogen chloride (HCl) or ethylene glycol. Through these processes, a magnesium oxide structure 100 having nanopores as described in FIG. 1 can be obtained.

The magnesium oxide structure 100 having nano pores according to the above-described embodiments can be used as a carbon dioxide adsorbent. In addition, the magnesium oxide structure 100 can be applied as a separator of an insulating (super insulation) material, an insulating material, a low dielectric material, or a flexible battery. In addition, the magnesium oxide structure 100 can be utilized for various purposes in various industrial fields ranging from advanced electronic devices and space materials. In particular, the magnesium oxide structure 100 according to an embodiment of the present invention can be utilized as an eco-friendly material capable of replacing a conventional heat insulating material, and in this case, the heat loss due to the improved heat insulating performance can be significantly reduced . Further, since the magnesium oxide structure 100 has the characteristics of super lightweight and super heat insulating property, it can be utilized as a material for protecting electronic devices in spacesuits and spaceships in the space industry. In addition, the magnesium oxide structure 100 may be used as a substitute for a part of conventional plastic products. The embodiment of the present invention can realize the magnesium oxide structure 100 having a high specific surface area while having excellent mechanical strength and flexibility. Therefore, the possibility of commercializing and utilizing the material (that is, the magnesium oxide structure / the nanoporous structure) It can be greatly improved. The application fields specifically presented here are illustrative and can be used in various fields in other fields as well. In addition, the shape and size of the magnesium oxide structure 100 can be variously changed. For example, the magnesium oxide structure 100 may have a thin film or particle shape other than a bulk shape, and may have various other shapes.

As described above, magnesium oxide may be formed using a sol-gel reaction process that gels the sol through the magnesium oxide precursor and the solvent. In one embodiment of the present invention, the magnesium oxide precursor is homogeneously mixed with the solvent and then gelled through hydrolysis and polycondensation. In some embodiments, after aging to enhance the mesh structure of the gel, the magnesium oxide structure having nanopores may be formed through drying. The formed magnesium oxide nanoporous structure has fine pores inside and has a high specific surface area due to the existence of such fine pores.

3A to 3D are views for explaining a method of manufacturing the magnesium oxide structure 100 according to an embodiment of the present invention.

Referring to FIG. 3A, a magnesium oxide precursor 10 may be provided in a predetermined container (hereinafter referred to as a first container) C1. The magnesium oxide precursor may comprise one of magnesium methoxide, magnesium ethoxide, magnesium acetate, magnesium sulfate, magnesium nitrate, and magnesium hydroxide. However, it should be understood that the present invention is not limited thereto. For example, the magnesium oxide precursor may include one of magnesium hydroxide, magnesium hydrogen carbonate, magnesium carbonate, ethylmagnesium bromide, dimethylmagnesium, diethylmagnesium, and halogenated methylmagnesium. In some embodiments, the magnesium oxide precursor may further comprise at least one of fluorine and a phenyl group.

Referring to FIG. 3B, after the solvent 20 is provided in the second container C2, the solvent 20 may be mixed with the magnesium oxide precursor 10 to form a mixed precursor. Next, a stirring process for the mixed precursor may be performed. As a result, a mixed precursor 30 as shown in Fig. 3C can be obtained. The solvent 20 may be at least one selected from the group consisting of ethylene glycol, which is capable of reacting with the magnesium oxide precursor 10 and at least one of hydrolysis and polycondensation, alcoholic solvents such as methanol, ethanol, or isopropyl alcohol . However, the kind of the solvent 20 is not limited to the alcohol-based solvent, and the solvent can be, for example, a carbonate-based, ether-based, or ketone-based daily.

Referring to FIG. 3D, in one embodiment, a further predetermined catalyst 5 may be added to the mixed precursor 30. The catalyst (5) can induce and / or accelerate the hydrolysis reaction of the precursor material. The catalyst 5 may be, for example, an acid catalyst. As a specific example, the catalyst 5 may comprise acetic acid (C2H4O2), or nitric acid (HNO3). However, the material of the catalyst (5) is not limited thereto and can be variously changed. After the addition of the catalyst (5), a further stirring step can be carried out for dispersion. The stirring process may be performed at a speed of several hundred rpm, for example, about 400 rpm. However, the present invention is not limited thereto.

After the hydrolysis reaction of the mixed precursor 30 by the catalyst 5 proceeds, a gelation process through a condensation reaction may proceed. Such a reaction process (hydrolysis reaction and condensation reaction) can be carried out through an aging process at normal pressure of 100 DEG C or lower.

Thereafter, a predetermined drying process for the gelled material from the mixed precursor 30 may be performed to remove the solvent from the gelled material. Removal of the solvent may be carried out through atmospheric pressure drying at normal pressure or through supercritical drying at high temperature and high pressure. In the case of supercritical drying, the above-mentioned drying reaction process can be carried out over a period of 5 hours to 24 hours, for example, at a temperature of about 300 ° C and a pressure of about 100 bar. However, such temperature and pressure conditions are merely illustrative, and may vary widely depending on reaction time and reaction conditions. As a result, the magnesium oxide structure 100 as shown in Fig. 1 can be obtained. The three-dimensional network of the magnesium oxide structure 100 may contain at least one of fluorine and phenyl groups. The magnesium oxide structure 100 can have high temperature stability, flexibility and excellent mechanical strength, and can also have high specific surface area, low thermal conductivity, low density (light weight) and hydrophobic surface properties. According to the embodiment of the present invention, it is possible to control the porosity, pore size, and density of the magnesium oxide structure 100 by controlling the kind, concentration, amount of use, etc. of the magnesium oxide precursor 10, the solvent 20, , And the mechanical strength can be adjusted. For example, as the molar concentration of the precursor 10 and the concentration of the catalyst 5 become larger, the porosity and the pore size can be reduced, and the hardness can be increased accordingly.

The method described with reference to FIGS. 3A to 3D can be said to be a method of manufacturing the magnesium oxide structure 100 using a sol-gel process. The specific process conditions described in Figs. 3A to 3D are merely illustrative, and may be varied in various cases.

While many have been described in detail above, they should not be construed as limiting the scope of the invention, but rather as examples of specific embodiments. For example, those skilled in the art will appreciate that the magnesium oxide structure of FIG. 1 and the fabrication process of FIGs. 3a-3d may vary. In addition, it will be understood that the magnesium oxide structure according to the embodiments can be applied to various fields in addition to the heat insulating material, the sound insulating material, and the space material for various purposes. For example, the magnesium oxide structure can be utilized as an adsorbent on the respiratory surface. Therefore, the scope of the present invention is not to be determined by the described embodiments but should be determined by the technical idea described in the claims.

5: Catalyst
10: magnesium oxide precursor 20: solvent
30: mixed precursor 100: magnesium oxide structure
C1: first container C2: second container

Claims (15)

Providing an organic precursor comprising magnesium;
Mixing the organic precursor with a solvent to provide a mixed precursor; And
And forming a magnesium oxide structure having nanopores from the mixed precursor through a gelation process. The method according to claim 1,
Aging the result of the gelation process; And
And drying the resultant. ≪ RTI ID = 0.0 > 11. < / RTI > The method according to claim 1,
Wherein the organic precursor is one of magnesium methoxide, magnesium ethoxide, magnesium acetate, magnesium sulfate, magnesium nitrate and magnesium hydroxide, magnesium hydroxide, magnesium hydrogen carbonate, and magnesium carbonate. The method according to claim 1,
Wherein the magnesium oxide precursor is an organic precursor further comprising at least one of fluorine and a phenyl group. The method according to claim 1,
Wherein the gelation process is an organic precursor including at least one of hydrolysis and polycondensation. The method according to claim 1,
Wherein the solvent is an alcohol-based, carbonate-based, ether-based or ketone-based solvent. The method according to claim 1,
Further comprising adding an acid catalyst to the mixed precursor. ≪ RTI ID = 0.0 > 11. < / RTI > 8. The method of claim 7,
Wherein the acid catalyst comprises acetic acid or nitric acid. A magnesium oxide structure in which nano pores are distributed. 10. The method of claim 9,
Wherein the magnesium oxide structure contains at least one of fluorine and a phenyl group. 10. The method of claim 9,
Wherein the magnesium oxide structure has a three-dimensional network structure in which pores are distributed in the magnesium oxide structure. 10. The method of claim 9,
Wherein the magnesium oxide structure has a porosity of 50 vol% to 95 vol%. 10. The method of claim 9,
Wherein the magnesium oxide structure has a specific surface area of from 300 m 2 / g to 800 m 2 / g. 10. The method of claim 9,
Wherein the average pore diameter of the magnesium oxide structure is in the range of 10 nm to 50 nm. An adsorbent comprising a porous structure having nano pores distributed therein.

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