KR20130045543A - Nanocomposite having ionic clathrate hydrates and clay particles and preparation method thereof - Google Patents

Abstract

PURPOSE: A manufacturing method of a nanocomposite is provided to manufacture the nanocomposite with improved mechanical property by impregnating an inner layer of clay particles with ionic clathrate hydrate. CONSTITUTION: 1.5-2.5 weight% of clay particles is dispersed in ionic clathrate hydrate for a nanocomposite. The mechanical property of the nanocomposite is improved by impregnating the inner layer of the clay particles with the ion clathrate hydrate. The ion clathrate hydrate is Me4NOH·5H2O. The clay particles are any one selected from sodium montmorillonite(Na-MMT), montmorillonite magnesium, montmorillonite calcium, and montmorillonite potassium. The manufacturing method of the nanocomposite comprises the following steps: a homogeneous solution is manufactured by dispersing the clay particles in the ionic clathrate hydrate; and the solid nanocomposite is manufactured by crystallizing the homogeneous solution at room temperature.

Description

Nanocomposite having ionic clathrate hydrates and clay particles and preparation method

The present invention relates to a nanocomposite comprising an ionic cluster hydrate and clay particles and a method for producing the same.

Nanocomposites are defined as two or multiphase solids, one of which is dispersed through the bulk phase in nanoscale dimensions. In general, solid matrixes in which physical and structural features differ in bulk matrix and in combination with nanodimensional phases can lead to improvements in physicochemical properties such as mechanical, electrical, optical, thermal, and catalytic properties. For this reason, nanocomposites are of great interest for both industrial applications and academic research.

In order to improve the properties of the nanocomposite, it is known that the compatibility between the nanofillers and the large area in contact with the matrix should be good and the dispersibility of the nanopillars should be excellent.

Water can be combined with various kinds of minerals or organics to make various structures of hydrates different from general ice. Water molecules form a lattice of solid phase by hydrogen bonds and maintain a stable structure by Van der Waals force with captured object molecules.

At this time, when the ionic material is used as the object molecule, the host lattice is ionized to facilitate the separation and movement of protons from the water molecule, and the nonionic hydrate acts as the coulomb attraction between the subject lattice and the object ion. It will have higher thermal stability. In particular, when the hydroxide anion becomes a constituent of the main lattice, the proton movement through the water main lattice occurs most easily among the anionic hydrates, and thus exhibits high ion conductivity and thermal stability.

Tetramethylammonium hydroxide (Me ₄ NOH) is a representative ionic clathrate hydrate former, and can form eight crystal structures according to hydration number and temperature. Of these, Me ₄ NOH · 10H ₂ O, Me ₄ NOH · 7.5H ₂ O, and Me ₄ NOH · 5H ₂ O are known as superionic conductors with low activation energy and high ion conductivity. In addition, the ion conductivity is _{Me 4 NOH · 10H 2 O,} Me4NOH · 7.5H 2 O, Me 4 NOH · The order of 5H ₂ O, the other hand a melting point of _{Me 4 NOH · 5H 2 O,} Me 4 NOH · 7.5H 2 O, Me ₄ NOH · 10H ₂ O It is known in order.

In the above-described peralkylammonium salt, hydrophilic anions of halogen or hydroxide form a main skeleton through hydrogen bonding with water molecules to form an inclusion compound structure, and large cations are caged in the skeleton. It is known to be enclosed in.

At this time, the crystal structure of the hydrate clathrate compound is determined in various ways depending on the size and shape of the cation and the water of hydration. One of the notable features of such an ionic cluster hydrate is that since anions bind to the skeleton, protons in the water skeleton tend to be more mobile than nonionic hydrates (Non-Patent Document 1). Thus, ionic cholate hydrates have been studied as potential proton conductors for decades.

Among various forms of ionic cholate hydrates, Me ₄ NOH.5H ₂ O has high conductivity and melting point, attracting attention as a proton conductor (Non-Patent Document 2).

On the basis of the beneficial properties described above, it has been reported that ionic crate hydrate is actually available as a proton conductor in nickel-metal battery systems (Non-Patent Document 3).

Patent Document 1 discloses a method for producing an electrochemical sensor that detects hydrogen gas with high sensitivity using tetramethylammonium hydroxide pentahydrate (Me ₄ NOH.5H ₂ O) as a hydrogen ion conductor.

Because of the brittleness contrary to the above beneficial properties of tetramethylammonium hydroxide pentahydrate (Me ₄ NOH.5H ₂ O), cracking or breaking may occur due to enhanced mechanical properties when used as a solid electrolyte in practical devices. There is a need to prevent problems.

Therefore, the present inventors used Me ₄ NOH · 5H ₂ O, which is one of the ionic cluster hydrates, but while studying the nanocomposite having enhanced mechanical properties, the nanocomposites in which clay particles were dispersed in the ionic cluster hydrate were clogged. While maintaining the same high ionic conductivity of slate hydrate inherently, ionic cluster hydrate penetrates into the interlayer of clay particles with high compatibility, which not only improves mechanical properties significantly but also provides a melting point that can be sufficiently used at room temperature. It has been found that the present invention has been completed.

Patent Document 1: Republic of Korea Patent Application 10-2009-0068582

[Non-Patent Document 1] Ratcliffe, C. I .; Garg, S. K .; Davidson, D. W. J. Inclusion Phenom. Mol. Recognit. Chem. 1990, 8, 159-175 [Non-Patent Document 2] Borkowska, Z .; Tymosiak, A .; Opallo, M. J. Electroanal. Chem. 1996, 406, 109-117 [Non-Patent Document 3] Kuriyama, N .; Sakai, T .; Miyamura, H .; Kato, A .; Ishikawa, H. J. Electrochem. Soc. 1990, 137, 355-356

It is an object of the present invention to provide nanocomposites with improved mechanical properties.

Another object of the present invention is to provide a method for producing the nanocomposite.

Still another object of the present invention is to provide a method of manufacturing a hydrogen electrochemical sensor including the nanocomposite.

Another object of the present invention is to provide a hydrogen electrochemical sensor comprising the nanocomposite.

In order to achieve the above object, the present invention is the nanocomposite (1.5-2.5% by weight of clay particles are dispersed in the ionic hydrate hydrate, the ionic hydrate hydrate penetrates into the inner layer of the clay particles and improved mechanical properties (nanocomposite) ).

In addition, the present invention comprises the steps of preparing a homogeneous solution formed by dispersing 1.5-2.5% by weight of clay particles in the ionic cluster hydrate penetrated into the inner layer of the clay particles (step 1); And

It provides a method for producing a nanocomposite with improved mechanical properties, including the step (step 2) of preparing a solid nanocomposite by crystallizing the homogeneous solution prepared in step 1 at room temperature.

Furthermore, the present invention comprises the steps of slowly adding a platinum powder (Pt black) to distilled water and completely wet, then adding a Nafionperfluorinated resin solution and stirring to disperse (step 1);

Adding isopropyl alcohol to the dispersion, dispersing the catalyst particles well by repeating stirring and sonication (step 2);

Uniformly loading the dispersion onto the surface of the electroconductive carbon electrode, evaporating the organic solvent loaded together in the air, and then loading platinum on the carbon electrode to obtain an anode (step 3);

Placing the anode thus obtained on one side of a cell made of Teflon, and connecting the anode and the cathode with an ammeter using a carbon electrode which has not been loaded on the other side of the anode as a cathode (step 4); And

Injecting the nanocomposite in the liquid state at a temperature above the melting point between the anode and the cathode in the Teflon cell, and crystallizing at room temperature for at least overnight to produce a hydrogen ion conductor (step 5) of the hydrogen electrochemical sensor It provides a manufacturing method.

The present invention also provides a hydrogen electrochemical sensor, characterized in that the nanocomposite is located as a solid electrolyte between the anode and the cathode.

Nanocomposites in which clay particles are dispersed in ionic hydrate hydrates according to the present invention maintain high ionic conductivity inherent in the hydrate hydrate, while infiltrating the hydrate of the clay hydrate between layers within the clay particles with high compatibility. Not only is the mechanical properties significantly improved, but also has a melting point that is sufficiently usable at room temperature, and thus may be useful as a solid electrolyte in an electrochemical system as a proton conductor.

1 is a graph showing a stress-strain curve of a nanocomposite according to an embodiment of the present invention.
2 is a graph showing the compressive strength of the nanocomposite according to an embodiment of the present invention.
3 is an image observed in a TEM by preparing a sample according to Example 2 of the present invention in ultrathin sections (in FIG. 3, the term "Intercalation" refers to the "insertion" of an ionic clathrate hydrate penetrating into the interlayer structure of clay particles). The term "Exfoliation" refers to a phenomenon in which the clay particles are "peeled" by the dispersion process).
4 is an image observed in a TEM by preparing a sample according to Example 4 of the present invention in ultrathin slices.
5 is a graph analyzing the distance between the clay particle layer by PXRD prepared with a powder according to an embodiment of the present invention.
Figure 6 is a graph of the clay particle interlayer distance analysis by PXRD prepared with pure clay particles as a powder.
Figure 7 is a graph measuring the phase shift temperature of the samples according to an embodiment of the present invention by differential scanning calorimetry (DSC) (in Figure 7 tetramethylammonium hydroxide pentahydrate (Me ₄ NOH.5H ₂ O) Is a solid-solid phase transition depending on the temperature, where "α phase" is a phase in which some hydrogen bonds are broken, "β phase" is a phase in which hydrogen bonds are broken, and "I" and "II" are "α phase". Between " and " β phase "
8 is a graph showing the ion conductivity according to the temperature change of the samples according to an embodiment of the present invention.
9 is a TEM image of a nanocomposite in which an ionic hydrate hydrate is "intercalated" into the interlayer structure of clay particles, and the interlayer structure of the clay particles is "exfoliated" by dispersion. It is a schematic diagram which imaged.

Hereinafter, the present invention will be described in detail.

The present invention provides a nanocomposite having 1.5-2.5% by weight of clay particles dispersed in ionic hydrate hydrate so that the ionic hydrate hydrate penetrates into the inner layers of the clay particles, thereby improving mechanical properties.

In the nanocomposite according to the present invention, the ionic cluster hydrate may use Me ₄ NOH · 5H ₂ O, Me ₄ NOH · 7.5H ₂ O, Me ₄ NOH · 10H ₂ O, etc. It is preferable to use Me ₄ NOH.5H ₂ O from the viewpoint of having.

In addition, the clay may be a clay containing a hydrophilic cation such as sodium montmorillonite (Na-MMT), montmorillonite magnesium, montmorillonite calcium, montmorillonite potassium.

At this time, from the viewpoint of improving the mechanical properties of the nanocomposite, the content of clay is preferably 1.5-2.5% by weight. More preferably, the clay content is 1.8-2.2% by weight. Even more preferably, the clay content is 1.9-2.1% by weight.

If the content of the clay is less than 1.5% by weight, there is a problem that the mechanical strength does not increase. If the content of the clay is more than 2.5% by weight, the clay does not disperse well in the hydrate of the crate, and thus the mechanical strength is rather decreased and the electrochemical There is a problem of decreasing the characteristics.

The nanocomposite according to the present invention is characterized in that the hydrophilic clay particles are dispersed inside the ionic cluster hydrate, so that the clathrate hydrate penetrates with high compatibility between the inner layers of the clay particles, and the mechanical properties thereof are significantly improved.

In addition, the present invention comprises the steps of preparing a homogeneous solution formed by dispersing 1.5-2.5% by weight of clay particles in the ionic cluster hydrate penetrated into the inner layer of the clay particles (step 1); And

It provides a method for producing a nanocomposite with improved mechanical properties, including the step (step 2) of preparing a solid nanocomposite by crystallizing the homogeneous solution prepared in step 1 at room temperature.

Hereinafter, the manufacturing method according to the present invention will be described step by step.

In the manufacturing method according to the present invention, the step 1 is to prepare a homogeneous solution formed by dispersing 1.5-2.5% by weight of clay particles in the ionic cluster hydrate penetrated between the inner layer of the clay particles It's a step.

Specifically, 1.5-2.5% by weight of clay is added to the ionic cluster hydrate, and agitated at 50-90 ° C and sonicated under conditions of 20-60 kHz, 120-180 W to prepare a homogeneous solution.

At this time, the ionic cluster hydrate may be used Me ₄ NOH · 5H ₂ O, Me ₄ NOH · 7.5H ₂ O, Me ₄ NOH · 10H ₂ O, etc., Me ₄ in terms of having an operating melting point It is preferable to use NOH 5H ₂ O.

In addition, the clay may be a clay containing a hydrophilic cation such as sodium montmorillonite (Na-MMT), montmorillonite magnesium, montmorillonite calcium, montmorillonite potassium.

At this time, from the viewpoint of improving the mechanical properties of the nanocomposite, the content of clay is preferably 1.5-2.5% by weight. More preferably, the clay content is 1.8-2.2% by weight. Even more preferably, the clay content is 1.9-2.1% by weight.

If the content of the clay is less than 1.5% by weight, there is a problem that the mechanical strength does not increase. If the content of the clay is more than 2.5% by weight, the clay does not disperse well in the hydrate of the crate, and thus the mechanical strength is rather decreased and the electrochemical There is a problem of decreasing the characteristics.

In the preparation method according to the present invention, step 2 is a step of preparing a solid nanocomposite by crystallizing the homogeneous solution prepared in step 1 at room temperature.

Specifically, the homogeneous liquid prepared in step 1 is poured into a mold of a desired shape, cooled to room temperature, and left to stand for 1-10 hours to induce crystallization, thereby preparing a solid nanocomposite.

Furthermore, the present invention comprises the steps of slowly adding a platinum powder (Pt black) to distilled water and completely wet, then adding a Nafionperfluorinated resin solution and stirring to disperse (step 1);

Adding isopropyl alcohol to the dispersion, dispersing the catalyst particles well by repeating stirring and sonication (step 2);

Uniformly loading the dispersion onto the surface of the electroconductive carbon electrode, evaporating the organic solvent loaded together in the air, and then loading platinum on the carbon electrode to obtain an anode (step 3);

Placing the anode thus obtained on one side of a cell made of Teflon, and connecting the anode and the cathode with an ammeter using a carbon electrode which has not been loaded on the other side of the anode as a cathode (step 4); And

Preparation of a hydrogen sensing sensor comprising the step of injecting the nanocomposite in a liquid state at a temperature above the melting point between the anode and the cathode in the Teflon cell and crystallizing at room temperature for at least one night to produce a hydrogen ion conductor (step 5). Provide a method.

The present invention also provides a hydrogen electrochemical sensor, characterized in that the nanocomposite is located as a solid electrolyte between the anode and the cathode.

Nanocomposites in which clay particles are dispersed in ionic hydrate hydrates according to the present invention maintain high ionic conductivity inherent in the hydrate hydrate, while infiltrating the hydrate of the clay hydrate between layers within the clay particles with high compatibility. Not only is the mechanical properties significantly improved, but also has a melting point that is sufficiently usable at room temperature, and thus may be useful as a solid electrolyte in an electrochemical system as a proton conductor.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

< Example  1> ionic Cluster  Preparation of Nanocomposites Dispersed Clay Particles in Hydrates 1

Tetramethylammonium hydroxide pentahydrate (Me ₄ NOH ₃ · 5H ₂ O) was used as an ionic cholate hydrate from Aldrich and was used as clay montmorillonite sodium. Na-MMT) was used from the Source Clays Repository of the Clay Minerals Society at Purdue University.

Step 1: Ionic Cluster  Dispersion of Clay Particles in Hydrates

1 weight% of Na-MMT was added to the liquid Me ₄ NOH · 5H ₂ O, and stirring and sound wave treatment (40 kHz, 150 W) using a magnetic stirrer at 74 ° C. were repeated, followed by Me ₄ NOH · 5H ₂ O. A homogeneous liquid phase in which Na-MMT was dispersed was prepared. The procedure was performed until no aggregated mass of clay was visually observed at the bottom of the vessel.

Step 2: Crystallization of Nanocomposites

The homogeneous liquid prepared in step 1 is poured into a Teflon mold (internal diameter 1.0 cm, height 4.0 cm), cooled to room temperature and left to stand for 1 hour to induce crystallization, and solid nano containing ionic cluster hydrate and clay The complex was prepared.

< Example  2> ionic Cluster  Preparation of Nanocomposites Dispersed Clay Particles in Hydrates 2

A nanocomposite comprising ionic cluster hydrate and clay was prepared in the same manner as in Example 1 except that 2 wt% of Na-MMT was used instead of 1 wt% of Na-MMT in Step 1 of Example 1.

< Example  3> ionic Cluster  Preparation of Nanocomposites Dispersed Clay Particles in Hydrates 3

A nanocomposite comprising ionic cluster hydrate and clay was prepared in the same manner as in Example 1 except that 3% by weight instead of 1% by weight of Na-MMT was used in Step 1 of Example 1.

< Example  4> ionic Cluster  Preparation of Nanocomposites Dispersed Clay Particles in Hydrates 4

A nanocomposite including ionic cluster hydrate and clay was prepared in the same manner as in Example 1 except that 4 wt% was used instead of 1 wt% Na-MMT in Step 1 of Example 1.

< Comparative example  1> Clathrate compound  Preparation of the sample

An ionic cholate hydrate sample was prepared in the same manner as in Example 1 except that Na-MMT was not used in Step 1 of Example 1.

Table 1 shows the composition ratios of the nanocomposites of Examples 1-4 and the ionic cluster hydrate (Me ₄ NOH ₃ · 5H ₂ O) and clay (Na-MMT) of Comparative Example 1.

Me ₄ NOH ₃ · 5H ₂ O (% by weight) Na-MMT (% by weight) Example 1
99 One Example 2
98 2 Example 3
97 3 Example 4
96 4 Comparative Example 1
100 0

< Experimental Example  1> Mechanical property evaluation

In order to determine the mechanical properties of the ionic cluster hydrate prepared in Comparative Example 1 and the nanocomposite prepared in Examples 1-4, the following experiment was performed.

Specifically, the heights of the samples prepared in Comparative Example 1 and Examples 1-4 were prepared in a size of 18.5 ± 1.0 mm, and then loaded using an Instron 4206 compression test system (Instron Series IX Automated Materials Tester, version 8.28.00). Load-displacement was measured.

The load-displacement evaluation was performed by setting a crosshead speed of 0.5 mm / min under a preload of 0.1 kN under a condition of -20 ° C and a relative humidity of 50%. In order to reduce the error range, six samples each prepared above were prepared and evaluated six times, and the results were converted into stress-strain curve data, and the results are shown in FIG. 1.

The maximum stress of each sample in the stress-strain curve is shown in FIG. 2 as a result of compressive strength.

1 is a graph showing a stress-strain curve of a nanocomposite according to an embodiment of the present invention.

2 is a graph showing the compressive strength of the nanocomposite according to an embodiment of the present invention.

In addition, Table 2 below shows the compressive strength of each sample, the Young's modulus, the maximum strain, which is the slope of the stress-strain curve shown in FIG. 1.

Compressive strength (MPa) Young's modulus (10 ² MPa) % Deflection Comparative Example 1
7.95 ± 1.17 8.98 ± 2.44 1.74 ± 0.42 Example 1
11.58 ± 1.08 7.04 ± 2.36 2.50 ± 0.59 Example 2
18.25 ± 1.34 14.63 ± 5.20 2.74 ± 0.40 Example 3
11.89 ± 0.64 8.55 ± 0.99 3.18 ± 1.43 Example 4
9.74 ± 0.44 10.54 ± 2.18 2.26 ± 0.39

As shown in Table 2 and Figures 1-2, the maximum compressive strength is 7.95 MPa for the ionic cluster hydrate sample of Comparative Example 1, whereas the maximum compressive strength is 18.25 MPa for the nanocomposite sample of Example 2. It can be seen that about 130% improvement. In addition, it was found that the Young's modulus of Example 2 was improved by about 63% compared to Comparative Example 1. Furthermore, it was found that the maximum strain of Example 3 was improved by about 83% compared to Comparative Example 1.

The improvement in mechanical properties indicated above is due to the fact that the clay particles have Na ⁺ ions, exhibit hydrophilicity, and are highly compatible with ionic cluster hydrates and thus are well dispersed in the interior.

Therefore, the nanocomposite in which clay particles are dispersed in the ionic hydrate hydrate according to the present invention can be useful as a solid electrolyte in an electrochemical system as a proton conductor because its mechanical properties are remarkably improved depending on the content of the optimized clay particles. .

< Experimental Example  2> Clathrate compound  Dispersion Assessment of Clay Particles Inside

To determine whether the clay particles were well dispersed in the nanocomposite prepared in Example 1-4, the following experiment was performed.

Specifically, in order to analyze the inside of the nanocomposite with a transmission electron microscope, the nanocomposite sample prepared in Example 1-4 and the ionic cluster hydrate sample prepared in Comparative Example 1 were cooled with nitrogen at -120 ° C.- A 90 nm ultrathin section was prepared using a diamond knife with an ultramicrotome (model: EM UC7 / FC7, manufactured by Leica).

The ultrathin sections of the samples prepared above were placed on a carbon coated grid and dried and observed with a transmission electron microscope (TEM, model name: G2 Sprit Twin TEM, manufacturer: Technai) combined with an anti-contaminator. The result of observing the sample of Example 2 by TEM is shown in FIG. 3, and the result of observing the sample of Example 4 by TEM is shown in FIG.

3 is an image observed in a TEM by preparing a sample according to Example 2 of the present invention in ultrathin sections (in FIG. 3, the term "Intercalation" refers to the "insertion" of an ionic clathrate hydrate penetrating into the interlayer structure of clay particles). The term "Exfoliation" refers to a phenomenon in which the clay particles are "peeled" by the dispersion process).

4 is an image observed in a TEM by preparing a sample according to Example 4 of the present invention in ultrathin slices.

As shown in Figure 3-4, in the case of the sample containing 2% by weight of the clay particles prepared in Example 2 that the delaminated layer of ionic hydrate hydrate and the clay particles inserted in the clay particles are evenly dispersed It appeared clearly. In the case of the sample containing 4% by weight of the clay particles prepared in Example 4, it was confirmed that the clay particles agglomerated with each other. As described above, it was found that the degree of dispersion of the clay particles was different depending on the content of the clay particles, and when it contained 2% by weight, it was expected to be most evenly dispersed, which would have a positive effect on the improvement of mechanical properties. .

Next, in order to investigate the interlayer structure formation of the clay particles dispersed in the nanocomposite prepared in Example 1-4, the powder X-ray diffraction (PXRD) was inserted into the clay particles. The distance between the clay particle layers according to the ionic cholate hydrates was analyzed.

Specifically, the nanocomposites prepared in Examples 1-4 were prepared in powder having a size of 200 μm or less, and then analyzed by a powder X-ray diffractometer (model name: D / MAX-2500, manufacturer: Rigaku), and then clay particles. After measuring the distance between the clay particle layers according to the ionic hydrate hydrate inserted therein, pure clay particles were prepared in the same powder as above, and analyzed by powder X-ray diffractometer. Measured and compared. The powder X-ray diffraction analysis results of the samples prepared in Example 1-4 are shown in FIG. 5, and the powder X-ray diffraction analysis results of the pure clay particles are shown in FIG. 6.

5 is a graph analyzing the distance between the clay particle layer by PXRD prepared with a powder according to an embodiment of the present invention.

Figure 6 is a graph of the clay particle interlayer distance analysis by PXRD prepared with pure clay particles as a powder.

As shown in Fig. 5-6, the interlayer distance of the pure clay particles is 10.05 비, whereas the interlayer distances of the clay particles are 14.16 실시, 14.13 Å, 13.98 Å and 13.90 각각 in the samples prepared in Example 1-4, respectively. It was found that the ionic cholate hydrate penetrated well between the layers of clay particles.

Therefore, the nanocomposite according to the present invention can be useful as a solid electrolyte in an electrochemical system as a proton conductor because the clay particles are well dispersed in ionic cluster hydrate with high compatibility.

< Experimental Example  3> Melting point evaluation of nanocomposites

In order to determine the melting point of the nanocomposites prepared in Examples 1-4, the phase shift was observed using a differential scanning calorimetry (DSC, model name: DSC 204 F1, manufacturer: NETZSCH), and the results are shown in FIG. It was.

Figure 7 is a graph measuring the phase shift temperature of the samples according to an embodiment of the present invention by differential scanning calorimetry (DSC) (in Figure 7 tetramethylammonium hydroxide pentahydrate (Me ₄ NOH.5H ₂ O) Is a solid-solid phase transition depending on the temperature, where "α phase" is a phase in which some hydrogen bonds are broken, "β phase" is a phase in which hydrogen bonds are broken, and "I" and "II" are "α phase". Between " and " β phase &quot;

As shown in FIG. 7, multiple solid-solid transitions and solid-liquid transitions can be identified through the observed endothermic peaks of the y-axis. At this time, it can be seen that the samples of Example 1-3 remained intact solid phase at 40 ° C. On average, the samples prepared in Examples 1-4 have a melting point of about 43 ℃ or less.

Therefore, the nanocomposite according to the present invention has a melting point sufficient for use as a solid electrolyte, and thus may be useful as a solid electrolyte in an electrochemical system as a proton conductor.

< Experimental Example  4> Evaluation of ion conductivity of nanocomposites

In order to determine the ionic conductivity of the nanocomposite prepared in Example 1-4, the experiment was carried out as follows.

Specifically, in Example 1-4, the liquid state samples before crystallization are introduced into a cell made of Teflon composed of two SUS electrodes, and in order to prevent electrochemical reaction by oxygen, argon gas is electrolyte for about 10 minutes. Blowed into the crystallization.

Next, the bulk resistance of the impedance spectrum was measured at different temperatures using Solartron's "1260 impedance / gain-phase" analyzer and "1287 electrochemical interface", and then the ion conductivity was calculated from this. This is shown in FIG. 8.

8 is a graph showing the ion conductivity according to the temperature change of the samples according to an embodiment of the present invention.

As shown in FIG. 8, in the case of the ionic cluster hydrate containing no clay particles, the ionic conductivity was about 10 ⁻³ −10 ⁻¹ S · cm ⁻¹ at −30 to 65 ° C. As shown in FIG. Similarly, the samples prepared in Example 1-4 also showed high ion conductivity of about 10 ^−3.3 −10 ^−1.3 S · cm ⁻¹ at ^−20˜40 ° C.

Therefore, nanocomposites in which clay particles are dispersed in ionic hydrate hydrates according to the present invention exhibit similar ionic conductivity as compared to ionic hydrate hydrates having excellent ionic conductivity, and thus are useful as solid electrolytes in electrochemical systems as proton conductors. can do.

Claims (10)

A nanocomposite having 1.5-2.5% by weight of clay particles dispersed in an ionic cluster hydrate, whereby the ionic cluster hydrate penetrates into the inner layers of the clay particles, thereby improving mechanical properties.
The method of claim 1,
The ionic cluster hydrate is Me ₄ NOH · 5H ₂ O characterized in that the nanocomposite.
The method of claim 1,
And wherein said clay is one kind selected from the group consisting of montmorillonite sodium, montmorillonite magnesium, montmorillonite calcium and montmorillonite potassium.
Dispersing 1.5-2.5% by weight of clay particles in the ionic cluster hydrate to prepare a homogeneous solution formed by the penetration of the ionic cluster hydrate into the inner layers of the clay particles (step 1); And
Method for producing a nanocomposite with improved mechanical properties comprising the step (step 2) of preparing a solid nanocomposite by crystallizing the homogeneous solution prepared in step 1 at room temperature.
5. The method of claim 4,
The ionic cluster hydrate is a method for producing a nanocomposite, characterized in that Me ₄ NOH.5H ₂ O.
5. The method of claim 4,
The clay is a method for producing a nanocomposite, characterized in that one kind selected from the group consisting of montmorillonite sodium, montmorillonite magnesium, montmorillonite calcium and montmorillonite potassium.
5. The method of claim 4,
Step 1 is a method for producing a nanocomposite, characterized in that 1.5-2.5% by weight of clay is added to the ionic cluster hydrate, and the stirring and sonication is repeated at 50-90 ℃.
The method of claim 7, wherein
The sound wave treatment method of the nanocomposite, characterized in that carried out under the conditions of 20-60 kHz, 120-180 W.
Platinum powder (Pt black) was slowly added to distilled water and completely wetted, then Nafionperfluorinated resin solution was added and stirred to disperse (step 1);
Adding isopropyl alcohol to the dispersion, dispersing the catalyst particles well by repeating stirring and sonication (step 2);
Uniformly loading the dispersion onto the surface of the electroconductive carbon electrode, evaporating the organic solvent loaded together in the air, and then loading platinum on the carbon electrode to obtain an anode (step 3);
Placing the anode thus obtained on one side of a cell made of Teflon, and connecting the anode and the cathode with an ammeter using a carbon electrode which has not been loaded on the other side of the anode as a cathode (step 4); And
Hydrogen electrochemistry comprising the step of injecting the nanocomposite of claim 1 in a liquid state at a temperature above the melting point between the anode and the cathode in the Teflon cell and crystallizing at room temperature at least overnight to produce a hydrogen ion conductor (step 5). Method of manufacturing the sensor.
Hydrogen electrochemical sensor, characterized in that the nanocomposite of claim 1 is located between the anode and the cathode as a solid electrolyte.

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