KR20190012046A - Zeolite-Based Self-Luminous Sensors for removal and detection of the Radioactive Isotopes and preparation method thereof - Google Patents

Abstract

The present invention relates to a self-luminous zeolite sensor for removing and tracking radioactive isotopes, capable of removing radioactive isotopes based on zeolite as well as absorbing and emitting radiation to detect radioactive isotopes, and a preparation method thereof. The self-luminous zeolite sensor includes: a zeolite skeleton; a hafnium chloride complex introduced into a space created by the zeolite skeleton; and thallium (Tl) or cesium (Cs) introduced into the zeolite skeleton as a non-skeleton element and ion-bonded to the hafnium chloride complex. The hafnium chloride complex is ionically coupled with thallium or cesium to form a hafnium-chloride-thallium continuum or a hafnium-chloride-cesium continuum, respectively. The radioactive isotope can be selectively absorbed and efficiently removed through the zeolite skeleton. The gamma rays emitted from thallium or cesium can be absorbed through hafnium serving as a light emitting activator so that light having high intensity can be emitted, thereby effectively detecting the radioactive isotopes.

Description

TECHNICAL FIELD [0001] The present invention relates to a self-emitting zeolite sensor for removing and tracking radioactive isotopes and a method for manufacturing the same,

The present invention relates to a self-emitting zeolite sensor for removing and tracking a radioactive isotope and a method of manufacturing the same, and more particularly, to a zeolite sensor capable of removing a radioactive isotope based on zeolite, Emitting zeolite sensor for radioactive isotope removal and tracking, and a method for producing the same.

With the development of science and technology and industrial activities in the 20th century, research and development has been carried out to utilize nuclear power as a power source to solve energy problems. Therefore, it is necessary to construct and operate a safe nuclear power plant, It has provided economic revival and liveliness of life by receiving and receiving.

Currently, radioactive contaminated water is generated in various nuclear facilities as well as in nuclear power plants. Radioactive contaminated water is generated due to various characteristics in the course of decontamination of nuclear power plants and nuclear facilities, A large amount of highly radioactive contaminated water will be generated.

These radioactive contaminated water should be managed as radioactive waste, unlike general polluted water that does not contain radioactive isotopes. After the contaminated water treatment, the issuer should dispose of the secondary waste as a radioactive waste ranging from low to high level. Or sent to a radioactive waste repository for disposal.

Accordingly, researches on the selective separation and removal of radioactive isotopes using various sorptive agents have been actively conducted, and zeolite is most well known as a sorption agent.

Zeolite is a porous crystalline mineral produced by the action of volcanic ash, which has a very large surface area, has uniformity and molecular selectivity, and has a highly porous structure, which is effective in removing cationic pollutants such as heavy metals and radioactive isotopes have.

On the other hand, a scintillator is a material that emits flash by radiation. In other words, it refers to a substance that can transform high-energy radiation into visible light that can not be seen by human eyes outside the visible light region. It is also used in medical fields such as cancer treatment, luggage retrieval, nondestructive inspection, And particle detection.

However, since the conventional scintillator absorbs the radiation emitted from the surrounding radioisotope and emits light, it can not absorb the radioisotope and can not absorb the radioisotope according to the distance between the scintillator and the radioactive isotope. There is a disadvantage in that the intensity of emitted light is somewhat weak.

Moreover, the zeolite only functions to adsorb and remove radioactive isotopes, which is disadvantageous in that it is difficult to detect radioactive isotopes that emit radiation that can not be seen by human eyes due to high energy.

Therefore, a zeolite sensor capable of efficiently detecting a radioactive isotope by directly introducing a radioactive isotope into a non-skeleton structure and selectively irradiating and removing the radioactive isotope, Development is necessary.

JP 2015017003 A KR 10-2014-0122726 A

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a radioactive isotope capable of selectively picking up and removing radioactive isotopes by directly introducing radioactive isotopes into a skeletal structure, The present invention provides a self-emitting zeolite sensor for radioisotope removal and tracking which can efficiently detect isotopes, and a method for manufacturing the same.

According to an aspect of the present invention, there is provided a self-emitting zeolite sensor for removing and tracking a radioactive isotope, comprising: a zeolite skeleton; A hafnium chloride complex introduced into the space created by the zeolite framework; And thallium (Tl) or cesium (Cs) introduced into the zeolite skeleton as a non-skeleton element and ion-binding with the hafnium chloride complex, wherein the hafnium chloride complex is ion-bonded with thallium or cesium to form hafnium- Continuum or hafnium-chloride-cesium continuum, respectively.

A method for preparing a self-emitting zeolite sensor for removing and tracking a radioactive isotope according to the present invention comprises the steps of flowing an aqueous solution of a thallium (I) precursor into a capillary tube containing sodium-zeolite, A first step of exchanging; Drying the liquid phase ion-exchanged zeolite to form thallium-zeolite having thallium as a non-skeleton element in the zeolite skeleton; A third step in which the thallium-zeolite is heated under a hafnium chloride gas to introduce hafnium chloride into the space formed by the zeolite skeleton, and the hafnium chloride ion-couples with the thallium; And a fourth step of cooling the heated thallium-zeolite to room temperature and then sealing the capillary.

A method for preparing a self-emitting zeolite sensor for removing and tracking radioactive isotopes according to the present invention comprises the steps of flowing an aqueous solution of a cesium (I) precursor into a capillary tube containing sodium-zeolite, (A) replacing; (B) drying the liquid phase ion-exchanged zeolite to form cesium, sodium-zeolite into which cesium is introduced as a non-skeleton element in the zeolite skeleton; (C) heating the cesium, sodium-zeolite under a hafnium chloride gas to introduce hafnium chloride into the space formed by the zeolite skeleton and ionizing the hafnium chloride with the cesium; And (D) cooling the heated cesium, sodium-zeolite to room temperature and then sealing the capillary.

According to the solution of the above problems, the self-emitting zeolite sensor for removing and tracking radioactive isotopes of the present invention and the method for producing the same are capable of selectively removing radioactive isotopes by high cation exchange ability because they contain a zeolite skeleton, There is an effect that can be done.

Since the hafnium-chloride-thallium continuum or the hafnium-chloride-cesium continuum is contained, hafnium, which is a light emitting activator, can absorb gamma rays emitted from thallium or cesium and emit light of high intensity to efficiently detect radioactive isotopes There is an effect that can be done.

1 is a schematic view of a method for manufacturing a self-emitting zeolite sensor for removing and tracking radioactive isotopes according to the present invention.
2 is a diagram showing a composition mapping of SEM-EDX results and crystals of a zeolite sensor according to Example 1 and Example 2 of the present invention.
FIG. 3 is a diagram showing a stereoscopic view of a sodalite cavity of a zeolite sensor according to Example 1 of the present invention. FIG.
4 is a diagram showing a stereoscopic view of a large cavity of the zeolite sensor according to the first embodiment of the present invention.
FIG. 5 is a diagram illustrating the stereochemistry to illustrate the hafnium-chloride-thallium continuum of the present invention. FIG.
6 is a diagram showing a stereoscopic view of a sodalite cavity of a zeolite sensor according to Example 2 of the present invention.
7 is a diagram showing a stereoscopic view of a large cavity of the zeolite sensor according to the second embodiment of the present invention.
8 is a view showing the emission of X-rays of the zeolite sensor according to Example 1 and Example 2 of the present invention.
9 is a diagram showing an X-ray induced emission spectrum of a zeolite sensor according to Example 1 and Example 2 of the present invention.
10 is a graph showing the emission decay time of the zeolite sensor according to Example 1 and Example 2 of the present invention.
11 is a graph showing the yield of emitted light of the zeolite sensor according to Example 1 and Example 2 of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below, but may be embodied in various different forms, and these embodiments are not intended to be exhaustive or to limit the scope of the present invention to the precise form disclosed, It is provided to inform the person completely of the scope of the invention. And the terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. The singular forms herein include plural forms unless the context clearly dictates otherwise.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Brief Description of Drawings FIG. 1 is a block diagram of a computer system according to an embodiment of the present invention; FIG. 2 is a block diagram of a computer system according to an embodiment of the present invention; FIG.

Before describing the present invention in detail, zeolites refer to minerals which are aluminum silicate hydrates of alkali and alkaline earth metals, and are colorless transparent or white translucent. The kind of zeolite can be distinguished by the skeleton which is the crystal structure of zeolite or by the contained components, but there are common in physical and chemical properties.

The zeolite itself referred to as " zeolite framework " in the present invention may be a skeleton of natural zeolite or a skeleton of synthetic zeolite.

The zeolite has a high cation exchange capacity and is capable of exchanging existing cations constituting the skeleton of zeolite with other cations. The exchange of such cations may change the physico-chemical properties in the pores of the zeolite.

Further, the space formed by the zeolite framework means a three-dimensional space of pore dimensions generated when the zeolite framework is arranged in three dimensions. The space formed by the zeolite skeleton may have the same meaning as a cavity, and the pupil may be a sodalite cavity, a large cavity, or the like.

The self-emitting zeolite sensor for removing and tracking radioactive isotopes according to the present invention comprises a zeolite framework; A hafnium chloride complex introduced into the space created by the zeolite framework; And thallium (Tl) or cesium (Cs) which is introduced into the zeolite framework as a non-skeleton element and ionically bonded to the hafnium chloride complex.

The hafnium chloride complex in the present invention may be ion-bonded to thallium or cesium to form a hafnium-chloride-thallium continuum or a hafnium-chloride-cesium continuous, respectively.

Specifically, the zeolite sensor of the present invention is characterized in that the hafnium chloride complex is disposed in the large pore formed by the zeolite framework and interacts with the non-scaffold thallium or cesium ion of the zeolite to form a hafnium- A light-cesium stream can be formed. At this time, the hafnium chloride complex may be located at the central part of the large pore formed by the zeolite framework.

On the other hand, if gamma rays or beta rays are emitted from the thallium or cesium introduced into the non-skeleton of zeolite, the gamma rays are absorbed by the hafnium chloride complex and emitted in the visible light region to determine the presence of thallium or cesium .

At this time, as for a conventional scintillator, a scintillator is a substance that emits a flash of light by radiation. In other words, it refers to a substance that can transform high-energy radiation into visible light that can not be seen by human eyes outside the visible light region.

However, since the conventional scintillator absorbs the radiation emitted from the surrounding radioisotope and emits light, it can not absorb the radioisotope and can not absorb the radioisotope according to the distance between the scintillator and the radioactive isotope. There is a disadvantage in that the intensity of emitted light is somewhat weak.

Conventional zeolites can remove radioactive isotopes by introducing radioactive isotopes into the zeolite skeleton due to their high cation exchange ability, but they are disadvantageous in that it is difficult to detect radioactive isotopes that emit radiation not visible to human eyes due to high energy.

On the other hand, the self-emission zeolite sensor according to the present invention is capable of directly adsorbing radioactive isotopes in the zeolite skeleton and absorbing radiation emitted from the introduced radioactive isotopes to emit light, In addition, the intensity of emitted light is relatively strong, which is advantageous in that the radioactive isotope can be efficiently detected.

Specifically, the zeolite framework in the present invention may be any one selected from the group consisting of zeolite-A, zeolite-X, zeolite-Y, zeolite L, ZSM-5 zeolite, BEA zeolite, mordenite and chabazite.

Further, the zeolite framework may further include an alkali metal introduced into the non-skeleton element. This takes advantage of the high cation exchange ability of zeolites, and zeolites containing specific metal ions in the zeolite skeleton can be represented as " ion-zeolites ". For example, the sodium-zeolite having the skeleton structure of zeolite-A and containing Na ⁺ ion in the zeolite skeleton is Na-zeolite, Na ₁₂ (H ₂ O) _x | [Si ₁₂ Al ₁₂ O ₄₈ ] -LTA, Na ₁₂ -A _x H ₂ O, Na ₁₂ -A, or Na-A. The ions included in the zeolite skeleton may mean ions constituting the zeolite skeleton.

The self-emitting zeolite sensor for removing and tracking a radioactive isotope according to the present invention exhibits an emission spectrum in a wavelength range of 300 nm to 720 nm and an emission peak in a wavelength range of 390 nm to 410 nm by radiation.

According to a preferred embodiment of the present invention, a method for manufacturing a self-emitting zeolite sensor for removing and tracking a radioisotope includes steps 1 to 4.

1 is a schematic view of a method for manufacturing a self-emitting zeolite sensor for removing and tracking radioactive isotopes according to the present invention.

Referring to FIG. 1, the first step is a step of flowing an aqueous solution of a thallium (I) precursor into a capillary tube containing sodium-zeolite and liquid-ion-exchanging sodium of the sodium-zeolite with thallium a) → (b) process).

Specifically, a zeolite containing sodium is reacted with a solution containing thallium to liquid ion exchange the sodium ion with thallium ion, wherein the sodium in the zeolite skeleton can be entirely exchanged with thallium.

The thallium (I) precursor may be selected from the group consisting of thallium acetate, thallium acetylacetonate, thallium chloride, thallium chloride tetrahydrate, thallium fluoride, , Thallium formate, Thallium nitrate, and Thallium nitrate trihydrate. [0033] The term " a "

Next, in the second step, the liquid phase ion-exchanged zeolite is vacuum dewatered to form thallium-zeolite into which thallium is introduced as a non-skeleton element in the zeolite skeleton. At this time, the liquid phase ion-exchanged zeolite is completely vacuum-dehydrated to form thallium-zeolite in which zeolite skeleton is completely substituted with sodium ditolium.

Next, in the third step, the thallium-zeolite is heated under a hafnium chloride gas to introduce hafnium chloride into the space formed by the zeolite framework, and the hafnium chloride ion-couples with the thallium (see (b ) → (c) process). At this time, the thallium-zeolite is a zeolite containing dehydrated anhydrous thallium ion (Tl ⁺ ) and has a structure in which thallium is contained as a non-skeleton element in the zeolite skeleton.

Through the gaseous ion exchange in the third step, a part of the thallium ions contained in the thallium-zeolite can be replaced by the ions contained in the vapor of the hafnium chloride. Since thallium-containing materials have high vapor pressures even at low temperatures, thallium ions can be easily and quantitatively removed from thallium-zeolite and can be easily used to produce the zeolite sensor of the present invention. After the thallium ion is partially removed from the thallium-zeolite, the zeolite from which the thallium ion is removed reacts with the Hf ⁺ ions of HfCl ₄ .

Thus, by reacting hafnium chloride with thallium-zeolite, thallium from thallium-zeolite can be placed in the space created by the zeolite framework while hafnium and chlorine ions derived from hafnium chloride can be placed.

In addition, after the third step, further heating the heated thallium-zeolite under a vacuum atmosphere at an absolute temperature of 523K for 24 hours may further include distilling to remove excess hafnium chloride.

Finally, the fourth step is a step of cooling the heated thallium-zeolite to room temperature and then sealing the capillary to produce a zeolite sensor. Specifically, thallium-zeolite heated by introducing hafnium chloride is cooled at room temperature, and then sealed in a vacuum state to block the foreign substance, whereby a pure zeolite sensor into which thallium is introduced can be produced.

1 (c), the zeolite sensor of the present invention does not emit light when ²⁰⁴ Tl, which is a non-radioactive isotope, is introduced and emits light when ²⁰¹ Tl, which is a radioisotope, is introduced as shown in (d) Element can be detected.

According to a preferred embodiment of the present invention, a method for manufacturing a self-emitting zeolite sensor for radioisotope removal and tracking includes steps (A) to (D).

First, in step (A), an aqueous solution of a cesium (I) precursor is flowed through a capillary containing sodium-zeolite, and the sodium of the sodium-zeolite is subjected to liquid ion exchange with the cesium (FIG. 1 (b) process).

Specifically, a zeolite containing sodium is reacted with a solution containing cesium to exchange the sodium ions with cesium ions, wherein the sodium in the zeolite skeleton can be partially replaced with cesium.

The cesium (I) precursor may be selected from the group consisting of cesium acetate, cesium acetylacetonate, cesium chloride, cesium cyclopentadienide, cesium fluoride, , Cesium formate, cesium hexa fluoroacetylacetonate, cesium nitrate, cesium trifluoroacetate and cesium perchlorate hydrate. . ≪ / RTI >

Next, in the step (B), the liquid phase ion-exchanged zeolite is vacuum dewatered to form cesium, sodium-zeolite into which cesium is introduced as a non-skeleton element in the zeolite framework. At this time, the liquid phase ion-exchanged zeolite is completely dehydrated to form thallium-zeolite in which the sodium in the zeolite skeleton is partially substituted with cesium.

Next, in the step (C), hafnium chloride is introduced into the space formed by the zeolite framework by heating the cesium, sodium-zeolite under a hafnium chloride gas, and the hafnium chloride is ion-bonded to the cesium (B) → (c) of FIG.

At this time, cesium, sodium-zeolite is a sodium-zeolite containing dehydrated cesium anhydride (Cs ⁺ ) and has a structure in which cesium is included as a non-skeleton element in the sodium-zeolite skeleton.

Further, through the gas-phase ion exchange in the step (C), a part of the cesium ions contained in the cesium, sodium-zeolite can be replaced by the ions contained in the vapor of the hafnium chloride.

Thus, by reacting hafnium chloride with cesium, sodium-zeolite, thallium derived from cesium, sodium-zeolite is placed in the pores of the zeolite framework and hafnium and chlorine elements derived from hafnium chloride can be placed .

In addition, the step (C) may further include further heating the heated cesium, sodium-zeolite under a vacuum atmosphere at an absolute temperature of 523K for 24 hours so as to remove excessive hafnium chloride.

Finally, step (D) is a step of cooling the heated cesium, sodium-zeolite to room temperature, and then sealing the capillary. Specifically, cesium and sodium-zeolite heated by introducing hafnium chloride are cooled at room temperature and sealed in a vacuum state to block foreign substances, whereby a pure zeolite sensor into which cesium is introduced can be produced.

As shown in FIG. 1 (c), the zeolite sensor of the present invention does not emit light when the non-radioactive isotope ¹³³ Cs is introduced. When the radioactive isotope ¹³⁷ Cs is introduced as shown in FIG. 1 (d) Element can be detected.

Hereinafter, the present invention will be described in more detail by way of examples, but the scope of the present invention is not limited by the examples.

<Examples>

1. (Example 1) Synthesis of Hf, Cl, Tl-A

(1) Production of Tl-A (| Tl ₁₂ (H ₂ O) _y | [Si ₁₂ Al ₁₂ O ₄₈ ] -LTA, Tl ₁₂ -A)

0.1 M TlC ₂ H ₃ O ₂ aqueous solution (Strem Chemicals, 99.999) with Pyrex capillaries containing 1.0 g of Na ⁺ ion exchanged zeolite-A (Aldrich, less than 5 micron, Na-A) %) Was flowed at a constant rate for 24 hours under the condition of an absolute temperature of 294K, and the same procedure was repeated three times with a fresh solution. At this time, Na-A is a colorless transparent crystal synthesized by J. Kharnell method in GT Kokotailo's laboratory.

Then, aqueous Tl-A was filtered and dehydrated by vacuum dehydration for 48 hours under the conditions of an absolute temperature of 673 K and a pressure of 1 x 10 &lt; ^-4 &gt; Pa. After cooling to room temperature, zeolite (Tl- .

(2) Preparation of Hf, Cl, Tl-A

Placing a Tl-A powder 40mg of the side walls of the Pyrex capillary diameter 2mm, was heated for 48 hours at 523K under the hafnium chloride (HfCl ₄₎ gas (Aldrich, 99.9%). At this time, HfCl ₄ (g) was maintained at 7.9 × 10 ³ Pa at 523K.

Then, in order to distill off the unreacted HfCl ₄ , it was further heated at 523 K for 24 hours and then cooled to room temperature to obtain a zeolite sensor (Hf, Cl, Tl-A crystal) according to Example 1 of the present invention .

2. (Example 2) Synthesis of Hf, Cl, Cs, Na-A

(1) Preparation of Cs, Na-A (| Cs ₇ Na ₅ | [Si ₁₂ Al ₁₂ O ₄₈ ] -LTA, Cs ₁₂ , Na ₅ -A)

100 ml of a 0.M CsC ₂ H ₃ O ₂ aqueous solution (Sigma-Aldrich, 99.999%) was flowed at 294 K for 24 hours at a constant rate with a Pyrex capillary tube containing 1.0 g of Na-A (Aldrich, less than 5 microns) The same procedure was repeated three times with fresh solution. At this time, Na-A is a colorless transparent crystal synthesized by J. Kharnell method in GT Kokotailo's laboratory.

Then, aqueous Cs and Na-A were filtered and dehydrated by vacuum dehydration for 48 hours under the conditions of 673 K and 1 × 10 ^-4 Pa. After cooling to room temperature, cesium-ion exchanged sodium-zeolite (Cs, Na-A).

(2) Preparation of Hf, Cl, Cs, Na-A

40 mg of Cs, Na-A powder was placed on the side wall of a Pyrex capillary tube 2 mm in diameter and heated at 523 K for 48 hours under hafnium chloride (HfCl ₄ ) gas (Aldrich, 99.9%). At this time, HfCl ₄ (g) was maintained at 7.9 × 10 ³ Pa at 523K.

Next, to further distill off the unreacted HfCl ₄ , it was further heated at 523 K for 24 hours and then cooled to room temperature to obtain a zeolite sensor (Hf, Cl, Cs, Na-A crystal ).

<Analysis>

1. Crystal structure analysis

The crystal structure and characteristics of the zeolite sensor according to Example 1 and Example 2 of the present invention were analyzed.

First, X-ray diffraction (XRD) of the zeolite sensor according to Example 1 and Example 2 was performed. The X-ray diffraction intensity was measured with a synchrotron X-ray through a silicon (Ⅲ) double crystal monochromator. The BL2D-SMDC program was used to collect data by an omega scanning method. High redundancy data set was obtained by collecting each set of 72 frames for one second to determine the exposure time and ⁵⁰ scans per frame (frame). The underlying data files used the HKL3000 (PLS) program and the reflections were indexed by the automatic indexing routine of the DENZO program.

The space group pmm, which is the standard for zeolites, was determined by the XPREP program. The results and additional experimental data are shown in Table 1.

In Table 1, the ^a particle accelerator is a Pohang radiation accelerator in Korea, 2D-SMC. The reflection (F _o ) of F _o > 4σ is given by ^b R ₁ = Σ | F _o - | F _c || / ΣF _o and all the specific reflections measured are ^c R ₂ = [Σw (F _o ² -F _c ² ) ² / Σw (F _o ² ) ² ] ^1/2 and ^d fit was calculated using fit = (Σw (F _o ² -F _c ² ) ² / (ms)) ^1/2 .

After X-ray diffraction analysis, scanning electron microscopy energy-dispersive X-ray (SEM-EDX) analysis was carried out for in-crystal analysis. To perform the SEM-EDX analysis, the zeolite sensors according to Examples 1 and 2 were removed from the capillaries and exposed to the atmosphere.

The compositions of the zeolite sensors according to Examples 1 and 2 were measured using a Horiba X-MAX N50 EDX spectrometer in a Hitachi SU8820-SR FE (Field Emission) scanning electron microscope and measuring a current of 2 μA and a beam of 20 keV The energy was determined at 294 K and 9 × 10 ^-4 Pa, and the results are shown in Table 2.

Table 2 shows the element composition of the zeolite sensor (Hf, Cl, Tl-A crystal) according to Example 1 and the zeolite sensor (Hf, Cl, Cs, Na-A crystal) according to Example 2.

After SEM-EDX analysis, the zeolite sensors according to Examples 1 and 2 were destroyed and the compositional map of the new surface of the zeolite sensor was confirmed using the EDX software function Trumap. The SEM-EDX results and the mapping results of the crystal composition are shown in Fig.

2 is a diagram showing a composition mapping of SEM-EDX results and crystals of a zeolite sensor according to Example 1 and Example 2 of the present invention. 2 (a) shows Hf, Cl and Tl-A crystals according to Example 1, (b) shows SEM-EDX results of Hf, Cl, Cs and Na- Fig.

Referring to FIG. 2 together with Table 1 and Table 2, hafnium (Hf), chloride (Cl) and thallium (Tl) ions are present in the zeolite sensor (Hf, Cl, (Hf), chloride (Cl), cesium (Cs) and sodium (Na) ions are present in the zeolite sensor according to Example 2 (Hf, Cl, Cs and Na-A crystals).

From Table 2, it can be seen that Hf, Cl, Tl-A according to Example 1 of the present invention and Hf, Cl, Cs and Na-A according to Example 2 are generally in conformity with the crystallographically determined composition have.

Tables 3 and 4 are tables showing the positions and final structural parameters of the non-skeletal atoms of the zeolite sensor according to Example 1 and Example 2 of the present invention, respectively.

Hereinafter, the crystal structure of the zeolite sensor according to the first and second embodiments of the present invention will be described in more detail with reference to FIGS. 3 to 7 together with Tables 3 to 4 above.

FIG. 3 is a diagram showing a stereoscopic view of a sodalite cavity of a zeolite sensor according to Embodiment 1 of the present invention. FIG. 3 (a) is a plan view of a sidalite cavity adjacent to a large pore having Tl ₁₂ HfCl ₆ ¹²⁺ ions (B) shows the others. In Figure 3, the zeolite-A skeleton is represented by open bonds and the non-skeletal ions are represented by solid bonds.

FIG. 4 is a diagram showing a stereoscopic view of a large cavity of a zeolite sensor according to Example 1 of the present invention, wherein FIG. 4 (a) shows a diagram including Tl ₁₄ HfCl ₆ ¹²⁺ ions, b) represents the others.

5 is hafnium of the invention chloride- a view showing a three-dimensional road in order to explain the thallium continuum, (a) of Figure 5 is HfCl ₆ ^2-, (b) is a ^{_{Tl 6 HfCl 6 4+, (c}} ) is Tl ₁₄ HfCl ₆ ¹²⁺ ion.

FIG. 6 is a diagram showing a stereoscopic view of a sodalite cavity of a zeolite sensor according to Embodiment 2 of the present invention, wherein FIG. 6 (a) shows a diagram adjacent to a large pore having HfCl ₆ ^2- ion , and (b) show others.

Figure 7 (a), a diagram showing a three-dimensional view of the large cavity (large cavity) of the zeolite sensor according to a second embodiment of the invention, Figure 7 shows a drawing that contains the HfCl ₆ ^2- ions, (b) Indicates others.

Referring to FIGS. 3 to 5, the crystal structure of Hf, Cl, and Tl-A according to Example 1 will be described with reference to Tables 3 and 4, wherein about seven Tl ⁺ Position.

It can be seen that the Tl ⁺ ions are located in the interior of sodalite, the large cavity opposite to the 6-ring and the 8-ring. These positions are similar to the structure of Tl-A.

Referring to FIG. 3 and Table 3, the Hf ^{4 +} ions of Hf 11 are located in the 3-fold axes near the 6-ring. Hf ^{4 +} ions extend from the plane of three 6-ring oxygen atoms to 0.49 Å from the sodalite pupil, respectively. Furthermore, 0.22 (3) Hf ^{4 +} ions per unit cell of Hf 12 in the 3-fold axis near the 6-ring extend 0.58 Å from the plane to the larger pupil.

These Hf ⁴⁺ ions are all 3-coordinated and are bound to the oxygen atoms of the skeleton. At this time, Hf11 and O3 of the coupling length is 2.153 (21) Å, Hf12 and O3 of the coupling length is 2.177 (10) Å, and a combination thereof length Hf ⁴⁺ and O ^2- sum of the ionic radius, 0.78 + 1.32 = Lt; / RTI &gt;

4 and 5, the 0.073 (6) Hf ^{4 +} ions of Hf per unit cell in HfCl ₆ ^2- are located in the center of a large pupil, not the zeolite skeleton, occupying 7.3% of the large pupil can confirm.

It can be confirmed that these Hf ^{4 +} ions do not bind to the zeolite skeleton, but are bonded to the six Cl ^- ions at 2.63 (13) Å in octahedral form. That is, HfCl ₆ ^2- is formed, and their bond lengths are similar to 0.78 + 1.81 = 2.59 Å, which is the sum of the ionic radii of Hf ⁴⁺ and Cl ^- .

Referring to Figure 5 again, Tl ₁₄ in HfCl ₆ ¹²⁺ Cl of HfCl ₆ ^{2- -} ions in combination with Tl ⁺ ions (Tl22) located near 8-ring to form a Tl ₆ HfCl ₆ ^4+. The bond length of Tl22 and Cl, 2.95 (14) Å, is close to the sum of Tl ⁺ and Cl ^- ion radii 1.47 + 1.81 = 3.28 Å.

In addition, each of the six Cl ^- ions is further combined with eight Tl ⁺ ion cubes in a large pore to form the Tl ₁₄ HfCl ₆ ¹²⁺ continuum. Each of these Cl ^- ions can be at y = z = 1/2 because it is associated with the four Tl ⁺ ion planes at Tl13.

6 and 7 show crystal structures of Hf, Cl, Cs and Na-A according to Example 2 with reference to Tables 3 and 4, about 6 Cs ⁺ ions per unit cell are represented by 8-rings (Cs1 (Cs3 and Cs4) opposite to the 6-ring (Cs2) opposite the sodalite pupil and the large pore (Fig. 6 (a) and (b)).

These Cs ⁺ ions combine with the oxygen atoms of the zeolite skeleton at 3.391 (4) A in Cs1, 3.131 (5) A in Cs2, 2.888 (4) A in Cs3 and 3.124 (8) A in Cs4 . The approach distance is the sum of all the Cs ⁺ and O ^2- ionic radii, except for the fact that it generally contains the longer 8-ring Cs ⁺ ions (Cs1) in the structure of the Cs ⁺ -containing zeolite-A, 1.32 = 2.99A.

In addition, the Na ⁺ ions of five per unit cell are located near the six-ring planes. Each of the Na ⁺ ions is 3-coordinated and bonds to the oxygen atoms of the zeolite framework at a length of 2.277 (3) Å in the 6-ring, which is the sum of the Na ⁺ and O ^2- ionic radius, 0.97 + 1.32 = 2.29 ANGSTROM.

Referring back to FIG. 7, it can be seen that 0.066 (6) Hf ^{4 +} ions per unit cell in HfCl ₆ ^2- are located at the center of the large pupil far from the zeolite framework and occupy 6.6% of the large pupil have.

The Hf ⁴⁺ ions of Hf, Cl, Cs and Na-A in each of the Hf, Cl, and Tl-A according to Example 1 had 6. Cl ^- ions and octahedral forms of 2.25 (13) , Which is shorter than 0.78 + 1.81 = 2.59 Å, which is the sum of Hf ⁴⁺ and Cl ^- ion radii.

In addition, the HfCl ₆ ^2- ion in Cs ₈ HfCl ₆ ⁶⁺ mainly retains 24 bonds between 6 Cl ^- ions and 8 Cs ⁺ ions (Cl - Cs4 = 3.655 (24) Å). At this time, the eight Cs ⁺ ions have a structure similar to the Tl ⁺ ions of Hf, Cl, and Tl-A according to Example 1, because Cl ^- ion is located at exactly y = z = 1/2 to be.

In addition, Cs ₁₁ HfCl ₆ ⁹⁺ continuum Cs ₈ HfCl ₆ ⁶⁺ of Cl ^- through the Cs ⁺ ions at the center of the ion and the ^8-ring-Cl ions of the ion different Cs ₈ HfCl ₆ ⁶⁺ adjacent each large cavity while being connected to form a unit cell formula is Cs ₁₁ HfCl ₆ ⁹⁺ 3-dimensional continuum. The bond length of Cs1 and Cl, 3.88 (13) Å, is somewhat longer than 1.67 + 1.81 = 3.48 Å, which is the sum of Cs ⁺ and Cl ^- ion diameters.

Therefore, the structure of the hafnium-chloride-thallium continuum in the Hf, Cl, and Tl-A crystals of the zeolite sensor according to Example 1 is as follows. Hf ⁴⁺ ions combine with _six Cl ^- ions in octahedral form to form HfCl ₆ ^{2 -} ions, and the six Cl ^- ions of the HfCl ₆ ^2- combine with the eight Tl ⁺ ions to form the Tl ₁₄ HfCl ₆ ¹²⁺ continuum. At this time, in the Tl ₁₂ HfCl ₆ ¹²⁺ continuum, HfCl ₆ ^2- ions account for 7.3% of the large pupil.

Example 2 Hafnium zeolite sensor, Hf, Cl, Cs, Na-A crystal according to-chlorite-look at the structure of the cesium continuum Example 1 6 Cl in HfCl ₆ ^2- ions formed as ^ion 8 in combination with one of the Cs ⁺ ions to form an ion CS ₈ HfCl ₆ ^6+, Cl ^- ions are other Cl in position adjacent via the Cs ^{+ ion} by combining with the ions, Cs ₁₁ HfCl ₆ ⁹⁺ continuum . At this time, in the Cs ₁₁ HfCl ₆ ⁹⁺ continuum, HfCl ₆ ^2- ions account for 6.6% of the large pores.

On the other hand, in the structures of Example 1 and Example 2, HfCl ₆ ^2- ions are located in the center of the large pores of A-zeolite having complete symmetry.

However, their Hf ⁴⁺ and Cl ^- bond lengths are 2.63 (13) Å in the Hf, Cl, Tl-A structures of Example 1 and 2.25 (13) Å in the Hf, Cl, Cs and Na- ) A, it is confirmed that there is a slight difference. Specifically, in the structure of Example 2, since the covalent bonding force of Cs ⁺ and Cl ^- bonds is low, Hf ⁴⁺ and Cl ^- bond lengths are short, and the covalent bonding force of Tl ⁺ and Cl ^- is relatively high in the structure of Example 1 , Hf ⁴⁺ and Cl ^- were found to be longer.

2. Luminescence analysis

Next, the luminescence according to the X-ray of the zeolite sensor according to Example 1 and Example 2 of the present invention was confirmed. A CCD image of Hf, Cl, Tl-A and Hf, Cl, Cs and Na-A obtained by irradiating the synchrotron X-ray is shown in Fig.

FIG. 8 is a graph showing the emission of X-rays from the zeolite sensor according to the first and second embodiments of the present invention. FIG. 8 (a) (B) is a CCD image of Hf, Cl, Cs, Na-A according to Example 2. Fig.

8, it can be seen that Hf, Cl, Tl-A according to Example 1 and Hf, Cl, Cs and Na-A according to Example 2 exhibit bright sky blue color upon X-ray irradiation have. This means that Hf, Cl, Tl-A according to Example 1 of the present invention and Hf, Cl, Cs and Na-A according to Example 2 exhibit light emission according to irradiation with radiation.

Specifically, X-ray induced luminescence (XIL) was measured to confirm the luminescence characteristics of the zeolite sensor according to Example 1 and Example 2 of the present invention. X-ray induced emission was measured using a Flame-T spectrometer (Ocean Optics, 50 kV, 30 mA) at an absolute temperature of 298K, and the results are shown in FIG.

9 is a graph showing the X-ray induced emission spectrum of the zeolite sensor according to Example 1 and Example 2 of the present invention, wherein FIG. 9 (a) shows the emission of Hf, Cl and Tl- (B) is the emission spectrum of Hf, Cl, Cs and Na-A according to Example 2. Fig.

9, the X-ray induced emission spectra of Hf, Cl, Tl-A and Hf, Cl, Cs and Na-A powders show a broad emission spectrum between 300 nm and 720 nm, and emission peaks at 390 nm and 410 nm, . Each spectrum has a secondary maximum at 490 nm, which means that it has two types of emission centers or two different relaxation processes.

Specifically, the first emission peak of Hf, Cl, Tl-A and Hf, Cl, Cs and Na-A appeared at 390 nm and 410 nm, respectively. Both zeolites contain HfCl ₆ ^2- ions. In contrast, A-Tl, Cs, Na-A, HfCl ₄ (g) and a mixture of Tl-A or Cs, Na-A in HfCl ₄ (s) and does not contain a HfCl ₆ ^2- ions, or No light was emitted upon X-ray irradiation.

Thus, it can be seen that the HfCl ₆ ^2- ion plays a main peak in the X-ray induced emission spectra of Hf, Cl, Tl-A and Hf, Cl, Cs and Na-A.

Looking at the emission mechanism of HfCl ₆ ^2- , ionizing radiation causes the electrons to move to the t _2g level of the Hf ⁴⁺ 5d orbitals in the Cl ^- 3p orbitals. This is called ligand-to-metal charge transfer (LMCT). This transfer of electrons causes the Cl ^- ion to be transformed into Cl ⁰ , and the Cl ⁰ state can polarize the environment.

Then, Cl ⁰ is the conduction band electron to restore self from (conduction band) of Hf ⁴⁺ 5d orbital - to form an exciton (self-trapped exciton, STE) , Cl ^{neighboring-traps} in conjunction with the ion Cl ₂ ^- ions.

That is, the zeolite sensor according to Example 1 and Example 2 of the present invention absorbs the radiation photons by irradiation, and the absorption of the radiation photons is carried out in the ligand (Cl ^- ) of the zeolite sensors by the high charged metal ion of HfCl ₆ ^2- (Charge transfer) to Hf ⁴⁺ , and when these electrons return to Cl, the zeolite sensors can emit light.

In addition, the second emission peak of Hf, Cl, and Tl-A appeared at 490 nm. At this time, Tl ⁺ ion serves as a light emitting activator.

In general, the Tl ⁺ ion is used as an activator in an alkali halide scintillator such as CsI and NaI doped with Tl ⁺ ions. This effectively combines Tl ⁺ ions with hot electrons (e ^- ) and holes (h ⁺ ) generated by the interaction of ionizing radiation with all parts of the target, thereby reducing Tl ⁰ and &lt; RTI ID = ^0.0 &gt; Tl2 ⁺ . &Lt; / RTI &gt;

Since the number of atoms of hafnium (Hf) is larger than the number of atoms of the zeolite framework, the stop energy and the ability to generate thermal electrons and holes must be large. At this time, the zeolite can act as a medium so that the thermal electrons and the holes can move to Tl ⁺ ions, and can cause luminescence.

In addition, the second emission peak of Hf, Cl, Cs and Na-A appeared at 490 nm.

At this time, Cs ⁺ ion and Na ⁺ ion are located in the non-skeletal structure of zeolite like Tl ⁺ ion.

In general, Na ⁺ ions are used as activators, such as CsI (Na) doped with Na ⁺ ions in CsI. The light emission by the Na ⁺ ions are Na ⁰ - referred to as a disturbance exciton ^{(Na 0 -perturbed excitons, NPE)} .

For example, electron-ray irradiation when the X-, CsI (Na) to CsI (Na) are mainly surrounding the Na ⁺ ion is V _k It is located in a central form. After this Na ⁺ ion becomes the Na ⁰ center, heat transfer from the V _k center to the Na ⁰ center takes place. Finally, the NPE (V _k eNa ⁰ ) emits luminescence.

Similarly, the second emission peak of Hf, Cl, Cs, Na-A may also be due to NPE. Cl ₂ ^- ions, which are the V _k centers of HfCl ₆ ^2- ions, can participate in the energy transfer process to Hf, Cl, Cs and Na-A around the Na ⁺ ions. NPE (Cl ₂ ^- eNa ⁰ ) can be relaxed to release light at 490 nm.

Next, the optical attenuation time of the zeolite sensor according to Example 1 and Example 2 of the present invention was measured at a window entrance of a photomultiplier tube (PMT, H6610) through an acrylic block using Hf, Cl, Tl-A and Hf , Cl, Cs, Na-A powder were directly connected to each other. An XR200 pulse X-ray beam (cold cathode X-ray tube, 0.026 to 0.040 mSv / pulse) with a pulse duration of 60 ns was used for excitation of each powder.

The pulse shape of the PMT output was directly registered in a 1 GHz digital oscilloscope (WaveRunner 610z) and the decay time was calculated from it. The optical decay time of the Zr, Cs, Na, Cl-A powders was determined according to the pulse shape information recorded with the two-component exponential function, and the heterogeneous exponential function was y = A ₁ exp (-t / τ ₁ ) + A ₂ exp (-t / τ ₂ ) + y ₀ , where y and y ₀ are the emission intensities, A ₁ and A ₂ are constants, t is time and τ ₁ and τ ₂ are the decay times . The results are shown in Fig.

10 is a graph showing the emission decay time of the zeolite sensor according to Example 1 and Example 2 of the present invention. FIG. 10 (a) is a graph showing the emission decay time of Hf, Cl, and Tl- (B) is a graph showing the emission decay times of Hf, Cl, Cs and Na-A according to Example 2. Fig.

As described above, it was found that the shape and emission peak position of the Hf, Cl, Tl-A and Hf, Cl, Cs and Na-A were similar in the X-ray induced emission spectrum.

10, τ ₁ is similar to 0.34 μs and 0.24 μs, respectively, but τ ₂ is different from 1.96 μs and 22.7 μs, respectively. Hf, Cl, Tl-A and Hf, Cl, Cs, Na It can be seen that the attenuation pattern of -A is somewhat different. The content of A ₂ was 97.1% in Hf, Cl, Tl-A and 97.1% in Hf, Cl, Cs and Na-A. In other words, it can be seen that most luminescence occurs in a slow collapse process.

The light yield of the zeolite sensor according to the first and second embodiments of the present invention was calculated by X-ray irradiation and compared with other samples.

At this time, X-rays were irradiated at an absolute temperature of 293K, relative light yields were measured using a scintillator bismuth germanate (BGO) and six zeolite samples as a sample, and the results are shown in FIG.

11 is a graph showing the yield of emitted light of the zeolite sensor according to Example 1 and Example 2 of the present invention.

11, the integrated light yields observed for Hf, Cl, Tl-A and Hf, Cl, Cs and Na-A were about 93% and 40%, respectively, at the time of X- Is about 8,000 photons / MeV.

Specifically, the combined light yield of Hf, Cl, and Tl-A was 93% (7,440 photons / MeV), and the combined light yield of Hf, Cl, Cs, and Na-A was 40% (3,200 photons / MeV) The luminous efficiency of Hf, Cl, Tl-A was higher than that of BGO, while the light yield of BGO was lower than that of 100% (8,000 photons / MeV) (see CCD image in FIG. 11).

That is, the zeolite sensors Hf, Cl and Tl-A according to Example 1 and the zeolite sensors Hf, Cl, Cs and Na-A according to Example 2 were Zr, Cl, Tl-A And Hf, Cl, and Tl-A of Example 1 exhibit a higher luminous efficiency than conventional scintillators.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the claims of the invention to be described below may be better understood. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing detailed description, and all changes or modifications derived from the appended claims and their equivalents should be construed as being included within the scope of the present invention.

Claims (8)

Zeolite skeleton;
A hafnium chloride complex introduced into the space created by the zeolite framework; And
Thallium (Tl) or cesium (Cs) introduced into the zeolite framework as a non-skeleton element and ion-bonded to the hafnium chloride complex,
Wherein the hafnium chloride complex ion-binds with thallium or cesium to form a hafnium-chloride-thallium continuum or a hafnium-chloride-cesium continuum, respectively. The method according to claim 1,
Characterized in that when the radiation is emitted from the thallium or cesium introduced into the zeolite skeleton, the gamma ray is absorbed by the hafnium chloride complex and the presence of thallium or cesium is determined by emitting light in the visible ray region Self-emitting zeolite sensor for removal and tracking. The method according to claim 1,
Wherein the zeolite skeleton is any one selected from the group consisting of zeolite-A, zeolite-X, zeolite-Y, zeolite L, ZSM-5 zeolite, BEA zeolite, zeolite RHO, mordenite and chabazite. Self - emitting zeolite sensor for element removal and tracking. The method according to claim 1,
Shows an emission spectrum in a wavelength range of 300 nm to 720 nm by radiation,
And exhibits an emission peak in the wavelength range of 390nm to 410nm. &Lt; RTI ID = 0.0 &gt; 15. &lt; / RTI &gt; A first step of flowing an aqueous solution of a thallium (I) precursor into a capillary tube containing sodium-zeolite and liquid-ion-exchanging the sodium of the sodium-zeolite with the thallium;
A second step of dehydrating the liquid ion-exchanged zeolite by vacuum to form thallium-zeolite into which thallium is introduced as a non-skeleton element in a space formed by the zeolite skeleton;
A third step in which the thallium-zeolite is heated under a hafnium chloride gas to introduce hafnium chloride into the space formed by the zeolite skeleton, and the hafnium chloride ion-couples with the thallium; And
And cooling the heated thallium-zeolite to room temperature, and then sealing the capillary. The method for manufacturing a self-emitting zeolite sensor for radioactive isotope removal and tracking according to claim 1, 6. The method of claim 5,
The thallium (I)
Thallium acetate, thallium acetylacetonate, thallium chloride, thallium chloride tetrahydrate, thallium fluoride, thallium formate, thallium chloride, Characterized in that the method is any one selected from the group consisting of nitrate, nitrate, thallium nitrate and thallium nitrate trihydrate. (A) flowing an aqueous solution of a cesium (I) precursor to a capillary containing sodium-zeolite and liquid-ion-exchanging sodium of the sodium-zeolite with the cesium;
(B) dehydrating the liquid phase ion-exchanged zeolite by vacuum to form cesium, sodium-zeolite into which cesium is introduced as a non-skeleton element in a space formed by the zeolite skeleton;
(C) heating the cesium, sodium-zeolite under a hafnium chloride gas to introduce hafnium chloride into the space formed by the zeolite skeleton and ionizing the hafnium chloride with the cesium; And
(D) cooling the heated cesium, sodium-zeolite to room temperature, and then sealing the capillary. &Lt; Desc / Clms Page number 19 &gt; 8. The method of claim 7,
The cesium (I)
It is also possible to use cesium acetate, cesium acetylacetonate, cesium chloride, cesium cyclopentadienide, cesium fluoride, cesium formate, cesium acetylacetonate, Wherein the aqueous solution is any one selected from the group consisting of Cesium hexa fluoroacetylacetonate, Cesium nitrate, Cesium trifluoroacetate and Cesium perchlorate hydrate. Method of manufacturing self - emitting zeolite sensor for radioactive isotope removal and tracking.

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