WO2018038564A1 - Carbon group-boron non-oxide nanoparticles, radiation shielding composition comprising same, and manufacturing method thereof - Google Patents

Abstract

One embodiment of the present invention provides carbon group-boron non-oxide nanoparticles for radiation shielding, consisting of an alloy of B and at least one element selected from among C, Si, and Ge.

Description

Carbon group-boron non-oxide nanoparticles, radiation shielding composition comprising the same and method for preparing same

The present invention relates to a carbon group-boron non-oxide nanoparticle, a radiation shielding composition comprising the same, and a method of manufacturing the same.

Nanotechnology is a core technology of 21st century science and technology, which is not only used to induce the technological innovation by combining with the traditional manufacturing industry, but also as a foundation technology that can further enhance future core strategic projects by integrating with advanced technologies such as IT, BT, CT, etc. It is recognized as the next generation growth engine. Methods of manufacturing nanomaterials applied to such advanced technologies include laser heating, liquid phase synthesis, solid phase synthesis, and the like. Liquid phase synthesis is basically a batch process, and since contact with various solvents and foreign substances is inevitably followed, impurities are difficult to synthesize high-purity nanoparticles, and in the case of laser heating, There is no contact at all, there is an advantage that can be produced nanoparticles continuously.

Looking at the nanoparticle manufacturing apparatus by the laser heating method, the nanoparticle synthesis apparatus using the CO2 laser pyrolysis method for supplying a raw material gas such as a laser irradiation unit, a reaction chamber, a collecting unit and a vacuum pump and monosilane into the reaction chamber. It is composed of an injection portion provided with a carrier gas supply nozzle for supplying a carrier gas, such as source gas supply nozzle and helium (He) gas. Referring to the manufacturing process of the nanoparticles by the above device, the laser beam irradiated from the laser irradiation unit is irradiated into the reaction chamber through the reflecting mirror and the lens, at this time monosilane injected into the reaction chamber through the source gas supply nozzle of the injection unit, etc. As the same source gas is decomposed by the heat of the laser beam, nanoparticles are formed, and the nanoparticles uniformly grown in the reaction chamber form negative pressure in the reaction chamber by a vacuum pump, thereby moving the nanoparticles out of the reaction chamber. Activated to recover the nanoparticles through the collector.

Looking at the prior art for the method of manufacturing nanoparticles by the laser heating method as described above, the silicon, germanium, silicon-germanium alloy, group 3-5 semiconductor compound to be supplied into the chamber by the nanoparticle manufacturing method using a laser And a method for synthesizing nanoparticles by irradiating laser to a source gas such as a metal oxide compound, and the synthesis method for producing silicon / germanium nanoparticles by laser pyrolysis is known, pulsed in tetramethylgermanium gas Irradiation of the laser, including the step of photolysis, the method for producing germanium nanoparticles is known that the yield of germanium nanoparticles is 70 to 80%, germanium antimony telluride-based, germanium bismuth telluride-based, germanium antimony selenide Germanium Bismuth Selenide, Indium Antimony Telluride, Phosphorus Bismuth telluride, indium antimony selenide, indium bismuth selenide, indium antimony germanide, gallium antimony telluride, gallium bismuth telluride, gallium selenide, gallium antimony selenide, gallium bismuth Irradiating a laser beam to a bulk target including at least one selected from the group consisting of selenide, stannum antimony telluride, stannum bismuth telluride, stannum antimony selenide and stannum bismuth selenide Methods of making particles are known.

The method of manufacturing nanoparticles by the laser heating method has the advantage of manufacturing high purity nanoparticles, but the production yield of nanoparticles is low, and the environment is damaged when raw gas, which is unreacted toxic gas, is discarded as a by-product. In addition, there is a problem in that the system becomes complicated and expensive when the raw material gas that is disposed of is recovered and not reused.

[Preceding technical literature]

[Patent Documents]

(Patent Document 0001) Korean Patent Publication No. 10-2013-0130284

(Patent Document 0002) Korean Patent Registration No. 10-1363478

The present invention is to solve the above problems of the prior art, an object of the present invention is to provide a radioactive shielding composition which is economically advantageous because of excellent radiation shielding performance and a simple manufacturing process.

One aspect of the present invention provides a radiation shielding carbon group-boron non-oxide nanoparticle consisting of an alloy of one or more elements selected from C, Si and Ge and B.

The carbon-boron non-oxide nanoparticles may have a particle size of 5 to 400 nm.

On the other hand, another aspect of the present invention provides a radioactive shielding composition comprising the carbon group-boron non-oxide nanoparticles for radiation shielding, and a binder resin.

As used herein, the term "carbon-boron non-oxide nanoparticle" refers to a particle further comprising B and at least one carbon group (Group 14) element of C, Si, and Ge, and a heterogeneous carbon group element. It may be understood as a concept including a particle alloyed with boron (B) in at least one carbon group element and a compound composed of carbon group element and boron.

As used herein, the term "non-oxide nanoparticle" refers to a particle that substantially does not contain an element of oxygen (O), the reaction of the non-oxide nanoparticles by reaction with trace amounts of moisture and oxygen that are difficult to exclude during the manufacture of the particles It can be understood as a concept including an oxide layer formed on the surface.

Hereinafter, for convenience, silicon-boron non-oxide nanoparticles will be described as representative examples, but the nanoparticles constituting the radiation shielding composition according to the embodiment of the present invention are not limited thereto. For example, BC (boron carbide), SiB alloy, GeB, CSiB, SiGeB, CGeB, CSiGeB non-oxide nanoparticles and the like can be included in the carbon-boron non-oxide nanoparticles according to an embodiment of the present invention.

While supplying the mixed gas together with the carrier gas into the reaction chamber, the wavelength of the CO ₂ laser is matched with the absorption cross-sectional area of the source gas such as monosilane, silicon tetrachloride, etc., so that the energy is easily absorbed by the raw material molecules and the intense vibration of the molecules This breaks the Si-H bonds of the monosilane molecules and breaks them down into their respective radical forms.

The silicon radicals thus generated develop into silicon nanoparticle nuclei by homogeneous nucleation and grow gradually by combining with surrounding silicon radicals. Thus, the surrounding environment of silicon radicals In addition, the residence time in which the silicon nanoparticle nucleus stays in the reaction part is an important factor controlling the size and characteristics of the silicon nanoparticles. In this case, the diborane gas is mixed during the pyrolysis of monosilane, which is a raw material gas. It can transfer energy from collision of molecules to increase the conversion rate from source gas to nanoparticles.

The laser is generated and irradiated by a CO ₂ laser generator, and is irradiated in the form of a line beam of continuous waves having a wavelength of 10.6 μm. The CO ₂ laser generator preferably uses a maximum output of 50 to 60 W. However, depending on the size of the nanoparticle manufacturing apparatus or the amount of nanoparticles to be produced, a maximum output of about 6,000W laser can be used.

The reaction chamber may have an internal pressure of 100 to 500 torr, but is not limited thereto. If the internal pressure of the reaction chamber is less than 100torr, raw material gas decomposition may not be performed smoothly, and thus the production yield of nanoparticles may be lowered.

Diborane gas is excellent in absorbing the wavelength of 10.6㎛, so the energy is more efficiently transferred to monosilane as monosilane gas meets the laser and decomposes into nanoparticles, which is a large amount of Si-H bond. By cutting to increase the yield of the silicon nanoparticles.

If the majority of the monosilane gas used as the source gas is thrown away and cannot participate in the reaction, there is a problem of environmental pollution with toxic gas, and it is not preferable in terms of cost. This complicates the system and adds cost.

Monosilane gas and diborane gas may have an explosive reaction when it receives energy from the outside and is excited. The reaction process is shown in Scheme 1 below.

<Scheme 1>

nSiH ₄ + mB ₂ H ₆ → Si _n B _m + (2n + 3m) H ₂

The carbon group non-oxide nanoparticles may have a size of 5 to 400 nm, preferably 10 to 100 nm, but are not limited thereto. If the size of the carbon-based non-oxide nanoparticles is less than 5nm, the production of nanometer-based particles may not be easy, and if the size of more than 400nm, the surface area of the particles may be small, a problem of performance degradation may occur.

Radiation generally consists of alpha rays, beta rays and gamma rays. In this case, the carbon group-boron non-oxide nanoparticles are materials capable of shielding gamma rays, and are generally compounded in a binder resin through a biaxial extruder and manufactured in a sheet form to be used as a radiation shielding material.

The binder resin is low density polyethylene (LDPE), high density polyethylene (HDPE), polyvinyl alcohol (polyvinylalcohol, PVA), PET (polyethylene terephthalate), EPM (copolymer of ethylene and propylene), polyurethane (polyurethane) ), Polyurea, silicone resin, epoxy resin and a mixture of two or more thereof, and may be one selected from the group consisting of, preferably a silicone resin, but is not limited thereto. no.

The silicone resin has excellent resilience, chemical resistance, heat resistance, flame retardancy, weather resistance, chemical resistance, hot water resistance, oil resistance, insulation, non-toxicity, strength, low temperature elasticity, and when the composition containing the silicone resin is used as a radiation shielding material. Since the tensile strength, elongation, friction fastness and the like is excellent, there is an advantage that the coated portion is not peeled off arbitrarily. In addition, the silicone resin is not only harmful to the human body, but also has a long life of the shielding material.

The silicone resin may be, for example, one selected from the group consisting of dimethylsiloxane, polydimethylsiloxane, polyether modified polydimethylsiloxane, oligosiloxane, and mixtures of two or more thereof.

The radiation shielding composition may further include one selected from the group consisting of alkaline earth metal compounds, tourmalines, metals, transition metals, lanthanides, actinides, and mixtures of two or more thereof, and more particularly, tin (Sn). ), Antimony (Sb), tellurium (Te), iodine (I), xenon (Xe), cesium (Cs), barium (Ba), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd) ), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Tolium (Tm), Ytterbium (Yb) ), Lutetium (Lu), Hafnium (Hf), Tantalum (Ta), Tungsten (W), Rhenium (Re), Osmium (Os), Iridium (Ir), Platinum (Pt), Gold (Au), Mercury (Hg) ), Thallium (Tl), lead (Pb), polonium (Po), astaxin (At), radon (Rn), francium (Fr), radium (Ra), actinium (Ac), thorium (Th), protactinium ( Pa), Uranium (U), Neptunium (Np), Plutonium (Pu), Americium (Am), Curium (Cm), Berkelium (Bk), Californium (Cf), Eincitanium (Es) ), Fermium (Fm), Mendelebium (Md), Nobelium (No), Lawrencium (Lr), Rutherfordium (Rf), Dubnium (Db), Siboum (Sg), Bolium (Bh), Hassium (Hs), Methane may further include one selected from the group consisting of Mt and mixtures of two or more thereof, but is not limited thereto.

The radiation shielding composition according to an embodiment may further increase the shielding efficiency of beta rays, alpha rays, as well as gamma rays by further comprising one of the metals or mixtures of the metals listed in the carbon-boron non-oxide nanoparticles.

In the radiation shielding composition, the carbon group non-oxide nanoparticles may be included in the form of a diluted solution and powder in a concentration of 1 to 50,000 ppm, and the content of the solution and powder may be 1 to 100 parts by weight of the binder resin. It may be 20 parts by weight.

According to another aspect of the invention, preparing a carbon group-boron non-oxide nanoparticle consisting of an alloy of one or more elements selected from C, Si and Ge and B; And mixing the carbon group-boron nonoxide nanoparticles, liquid binder resin, and a resin cured material.

Radioactive shielding composition according to an aspect of the present invention, by controlling the particle size of the carbon-based non-oxide nanoparticles to a certain range and including a binder resin is excellent in radioactivity shielding performance, simple manufacturing process is advantageous in terms of productivity and economics. .

It is to be understood that the effects of the present invention are not limited to the above effects, and include all effects deduced from the configuration of the invention described in the detailed description or claims of the present invention.

Hereinafter, the present invention will be described. However, the present invention can be embodied in many different forms and thus is not limited to the embodiments described herein.

Throughout the specification, when a part is "connected" to another part, it includes not only "directly connected" but also "indirectly connected" with another member in between. In addition, when a part is said to "include" a certain component, it means that it may further include other components, without excluding the other components unless otherwise stated.

Hereinafter, embodiments of the present invention will be described in detail.

Example  One: SiB  Nano particle manufacturing

Silicon-boron alloy nanoparticles can be prepared according to the following Scheme 2.

<Scheme 2>

2SiH ₄ + 2B ₂ H ₆ + N ₂ SiB ₄ + 8H ₂ + N ₂

Monosilane gas (SiH ₄ ), diborane gas (B ₂ H ₆ ), and nitrogen are mixed and injected into the reaction chamber to irradiate a CO ₂ laser beam. At this time, the diborane gas acts as a catalyst gas and a source gas. In addition, the energy absorbed at the wavelength of 10.6㎛ is efficiently transferred to the silane gas, and the Si-H bond of the silane gas is well broken to generate silicon-boron alloy nanoparticles (SiB _x -NPs).

In addition, diborinase is decomposed into boron and hydrogen atoms, boron alloys with silicon nanoparticles, and serves to prevent the oxidation of silicon. 90% of the catalyst gas, and the catalyst gas is adjusted to the range of 10% or less of the total volume. In addition, the carrier gas nitrogen is not more than 400 parts by volume compared to the raw material gas silane gas. The gas flow rate is in sccm. The process pressure inside the reaction chamber is set in the range of 100 to 400 Torr. In this range, silicon-boron alloy nanoparticles (SiB _x -NPs) having a size of 5 to 400 nm are prepared.

division	Example 1-1	Example 1-2	Example 1-3	Example 1-4	Example 1-5
Raw material gas (sccm)	300	500	700	1000	1500
Catalyst gas (sccm)	15	36	60	80	105
Carrier gas (sccm)	400	400	400	500	500
Process pressure (Torr)	350-200	350-200	250-100	250-100	200-100
Particle size (nm)	20-30	20-30	20-30	20-30	20-30
B content (wt%)	2.5	6	9.6	12.5	16
Si content (wt%)	97.5	94	90.4	87.5	84
Atomic ratio	1:15	1: 6	1: 4	1: 3	1: 2
SiBx	SiB 15	SiB 6	SiB 4	SiB 3	SiB 2

Example  2: SiGeB  Nano particle manufacturing

Silicon-germanium-boron alloy nanoparticles may be prepared according to Scheme 3 below.

<Scheme 3>

2SiH ₄ + 2GeH ₄ + B ₂ H ₆ → 2SiGeB + 11H ₂

100 parts of monosilane (SiH ₄ ), 100 parts of Germane (GeH ₄ ), diborane (B ₂ H ₆ ) and 40 to 80 parts of the source gas through the source gas supply nozzle and carrier gas phosphorus nitrogen ( N ₂ ) The mixed gas containing 400 parts by volume is supplied into the reaction chamber having an internal pressure of 80 to 400 torr, and the laser generated by the CO ₂ laser generator is supplied to the mixed gas supplied into the reaction chamber through the irradiation unit. The silicon-germanium-boron alloy nanoparticles (SiGeB-NPs) were prepared by irradiating for 3 hours in the form of a line beam of continuous waves of 10.6 μm. The particle size of SiGeB-NPs is 5 to 400 nm.

Example 3 Preparation of a Radioactive Shielding Composition Comprising CB Nanoparticles

Carbon-boron alloy nanoparticles can be prepared according to Scheme 4 below.

<Scheme 4>

C ₂ H ₂ + ₄ B ₂ H ₆ + N _{2 2} B ₄ C + ₁₃ H ₂ + N ₂

100 parts by volume of acetylene (C ₂ H ₂ ), diborane (B ₂ H ₆ ) 40-80 parts by volume, and 400 parts by volume of carrier gaseous nitrogen (N ₂ ) are mixed through the source gas supply nozzle. A mixed gas is supplied into a reaction chamber having an internal pressure of 100 to 400 torr, and a laser beam generated by a CO ₂ laser generator is supplied to the mixed gas supplied into the reaction chamber through a radiator to produce a continuous wave line beam having a wavelength of 10.6 μm. Line boron) was irradiated for 3 hours to prepare carbon-boron alloy nanoparticles (CB _x -NPs). The particle size of CB _x -NPs is 5-400 nm.

Example 4 GeB Nanoparticles Preparation

Germanium-boron alloy nanoparticles can be prepared according to Scheme 5 below.

Scheme 5

2GeH ₄ + 2B ₂ H ₆ + N ₂ GeB ₄ + 8H ₂ + N ₂

A mixture of 100 parts of germane (GeH ₄ ), diborane (B ₂ H ₆ ) 40 to 80 parts of raw material gas and 400 parts by volume of carrier gaseous nitrogen (N ₂ ) through a source gas supply nozzle Gas is supplied into the reaction chamber with an internal pressure of 100 to 400 torr, and the laser beam generated by the CO ₂ laser generator is supplied to the mixed gas supplied into the reaction chamber. 3 hours of irradiation in the form of germanium-boron alloy nanoparticles (GeB _x -NPs) was prepared. The particle size of GeB _x -NPs is 5 to 400 nm.

Experimental Example 1

A radioactive shielding composition comprising (85% by weight of dimethylsiloxane, 5% by weight of nanoparticles, and 10% by weight of a silicone resin hardener) containing the carbon group-boron non-oxide nanoparticles for radioactive shielding prepared in Examples 1, 2, 3, and 4. %) Was applied to the substrate with a thickness of 1.5 mm, and then semi-dried, and placed on a belt of the drying section, and dried at 120 to 180 ° C. for about 3 to 5 minutes to completely dry the substrate. Blowing cold air to harden completely and then peeling off the substrate to obtain a film type radiation shielding material (Production Examples 1-1 to 1-4).

Samples having different thicknesses of the radioactive shielding film were cut into 20 cm x 20 cm, and the radioactivity of 100kvp voltage was examined to measure shielding rate (%). At this time, the shielding rate of the radioactive shielding film was measured 10 times at different positions each time, and the average shielding rate (%) was obtained.

Production Example	1-1	1-2	1-3	1-4
Particle Types (-NPs)	SiB 4	SiGeB	CB	GeB
Particle Concentration (%)	5	5	5	5
Silicone resin (wt%)	80	80	80	80
Curing agent (% by weight)	10	10	10	10
Thickness (mm)	1.5	1.5	1.5	1.5
Voltage (kvp)	100	100	100	100
Shielding rate (%)	99.7	99.5	89.2	89.4

Experimental Example 2

A radioactive shielding composition (nanoparticles (10%)) comprising a comparative example (B ₂ O ₃ particles purchased from Aldrich) and carbon group-boron non-oxide nanoparticles for radiological shielding prepared in Examples 1, 2, 3 and 4 1mm thick 250mm x 250mm sheet was produced by hot pressing the HDPE and the chip compounded in a twin-screw extruder at 170oC (Production Examples 2-1 to 4) to shield radiation (gamma) from Cs-137 and Co-60. Performance was analyzed.

Experimental Example 3

A radiation shielding composition (nanoparticles (10%)) comprising a comparative example (B ₂ O ₃ particles purchased from Aldrich) and carbon group-boron non-oxide nanoparticles for radiation shielding prepared in Examples 1, 2, 3 and 4 1mm thick 250mm x 250mm sheet was produced by hot pressing the PET and the chip compounded in a twin screw extruder at 280oC (Manufacturing Examples 3-1 ~ 4) to shield radiation (gamma) from Cs-137 and Co-60. Performance was analyzed.

Tables 3 and 4 below show the results of radiological shielding analysis for Comparative Examples, Preparation Examples 2-1 to 2-4, and Preparation Examples 3-1 to 3-4. In Table 8 and Table 9, the Radiation Quality is Cs-137 and Co-60, respectively.

Sample classification	Dose rate without sample (mGy / h), Co	Dose rate with sample (mGy / h), Ci	Attenuation Ratio (Ci / Co)	% Uncertainty
Comparative Example ((250 × 250 × 1 (T) mm 3 )	125.2	104.6	0.84	4.2
Preparation Example 2-1 ((250 × 250 × 1 (T) mm 3 )	125.2	90.5	0.74	4.1
Preparation Example 2-2 ((250 × 250 × 1 (T) mm 3 )	125.2	85.6	0.70	4.1
Preparation Example 2-3 ((250 × 250 × 1 (T) mm 3 )	125.2	86.8	0.69	3.8
Preparation Example 2-4 ((250 × 250 × 1 (T) mm 3 )	125.2	85.9	0.69	3.9
Preparation Example 3-1 ((250 × 250 × 1 (T) mm 3 )	125.2	88.4	0.70	4.0
Manufacturing Example 3-2 ((250 × 250 × 1 (T) mm 3 )	125.2	89.4	0.71	4.0
Manufacturing Example 3-3 ((250 × 250 × 1 (T) mm 3 )	125.2	88.2	0.70	4.0
Manufacturing Example 3-4 ((250 × 250 × 1 (T) mm 3 )	125.2	89.8	0.72	4.0

Sample classification	Dose rate without sample (mGy / h), Co	Dose rate with sample (mGy / h), Ci	Attenuation Ratio (Ci / Co)	% Uncertainty
Comparative Example ((250 × 250 × 1 (T) mm 3 )	384.8	355.6	0.92	6.0
Preparation Example 2-1 ((250 × 250 × 1 (T) mm 3 )	384.8	305.5	0.79	6.2
Preparation Example 2-2 ((250 × 250 × 1 (T) mm 3 )	384.8	310.4	0.81	5.8
Preparation Example 2-3 ((250 × 250 × 1 (T) mm 3 )	384.8	303.6	0.79	5.8
Preparation Example 2-4 ((250 × 250 × 1 (T) mm 3 )	384.8	322.4	0.83	5.6
Preparation Example 3-1 ((250 × 250 × 1 (T) mm 3 )	384.8	308.9	0.80	5.8
Manufacturing Example 3-2 ((250 × 250 × 1 (T) mm 3 )	384.8	313.7	0.81	5.6
Manufacturing Example 3-3 ((250 × 250 × 1 (T) mm 3 )	384.8	314.7	0.81	5.6
Manufacturing Example 3-4 ((250 × 250 × 1 (T) mm 3 )	384.8	318.7	0.83	5.6

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it is to be understood that the embodiments described above are illustrative in all respects and are not restrictive. The components present can also be implemented in a combined form.

Claims (6)

1. A carbon group-boron non-oxide nanoparticle for radioactive shielding, comprising an alloy of B with at least one element selected from C, Si, and Ge.
2. The method of claim 1,

   The particle size of the carbon-boron non-oxide nanoparticles is 5 to 400 nm, the radiation shielding composition.
3. A radiation shielding composition comprising carbon group-boron non-oxide nanoparticles for radiation shielding, comprising a alloy of B and at least one element selected from C, Si, and Ge.
4. The method of claim 3,

   The binder resin is low density polyethylene (LDPE), high density polyethylene (HDPE), polyvinyl alcohol (polyvinylalcohol, PVA), PET (polyethylene terephthalate), EPM (copolymer of ethylene and propylene), polyurethane (polyurethane) ), Polyurea, silicone resin, epoxy resin and one or more selected from the group consisting of a mixture of two or more, the radiation shielding composition.
5. The method of claim 3,

   The radiation shielding composition further comprises one selected from the group consisting of alkaline earth metal compounds, tourmaline, metals, transition metals, lanthanides, actinides and mixtures of two or more thereof.
6. Preparing carbon-boron non-oxide nanoparticles composed of an alloy of B and at least one element selected from C, Si, and Ge; And

   Comprising the step of mixing the carbon-boron non-oxide nanoparticles, a liquid binder resin and a resin cured material, a method of producing a radiation shielding composition.