Nano composite material with radiation protection characteristic as well as preparation method and application of nano composite material

Abstract

The invention relates to a nano composite material with a radiation protection characteristic and a preparation method and application thereof, the method comprises the following steps: 1) weighing graphene oxide (GO), adding deionized water, carrying out ultrasonic treatment until the graphene oxide is dissolved, adding N, N-dimethylformamide (DMF), stirring and heating, slowly adding NbCl5, heating and stirring, reacting for more than or equal to 5 hours, centrifuging, washing, drying and grinding to obtain an Nb2O5 / GO nano composite material; and 2) taking a proper amount of the Nb2O5 / GO nano composite material, uniformly mixing the Nb2O5 / GO nano composite material with an ethylene-vinyl acetate copolymer (EVA), carrying out melt blending at 150 DEG C, and pressing into a sample sheet to obtain the Nb2O5 / GO / ethylene-vinyl acetate copolymer nano composite material. The nano composite material disclosed by the invention has a remarkable shielding effect on X rays and gamma rays, has the advantages of light weight, simple preparation method and the like, and can be used for manufacturing radiation protection articles such as radiation protection clothing and the like.

Description

Technical Field

[0001] The present invention belongs to the research field of radiation protection materials, specifically to a preparation method and application of a nano-composite material with radiation protection properties, and particularly to a Nb2O5 / GO / ethylene-vinyl acetate copolymer nano-composite material and a preparation method and application thereof. Background Art

[0002] With the development of modern science, various high-energy rays are widely used in various fields such as military, communication, medicine, and daily life, which directly leads to the increase of the annual collective effective dose of radiation dose worldwide. Common high-energy rays include X-rays, gamma rays, and rays generated by neutrons. Among them, X-rays and gamma rays are radiation damage caused by radiation sources outside the body to the human body, which belongs to external radiation. The wavelength of X-rays is 0.1 to 1nm, and it has strong penetrating power. It produces ionization when it enters the human body, causing biological effects on the human body. Gamma rays have higher energy and extremely strong penetrating ability. When the human body is irradiated by gamma rays, it causes ionization of internal cells and even cell death.

[0003] Radiation protection materials refer to materials that can absorb or dissipate radiation energy and protect the human body or equipment. Traditional radiation protection materials are difficult to meet people's protection needs due to their heavy weight, toxicity and insufficient protection performance. Therefore, it is necessary to continuously improve and develop new protection materials. The nano-scale shielding materials and the ability to be used in complex environments with multiple rays (multifunctionality) are important development trends of radiation protection materials.

[0004] Niobium (Nb) occupies an important position in the nuclear industry due to its low capture cross section for thermal neutrons, good chemical stability and corrosion resistance, and stability at high temperatures. It is widely used in various nuclear energy equipment and systems that require high stability and safety.

[0005] Graphene is a two-dimensional crystal composed of carbon atoms in the form of sp 2 Hybrid orbitals form a two-dimensional carbon nanomaterial with a hexagonal honeycomb lattice. Its unique structure gives it excellent electrical, mechanical, thermal and optical properties. As an ideal two-dimensional crystal material, graphene has an electron movement speed of 1 / 300 of the speed of light and an electrical conductivity of 10 -6 The internal carrier mobility of graphene can reach 2×10 -5 cm -2 / Vs, which is 140 times that of silicon. Most methods for preparing metal and metal oxide / graphene oxide nanocomposites are high-temperature calcination under alkaline conditions.

[0006] Ethylene-vinyl acetate copolymer (EVA) is a general-purpose polymer with the molecular formula (C2H4)x.(C4H6O2)y. It is a non-toxic, odorless, transparent thermoplastic. EVA material has excellent elasticity, flexibility, transparency, insulation, low-temperature flexibility, weather resistance, and chemical corrosion resistance. It is widely used in the manufacture of wire and cable materials, films and other molded products and mixtures, automotive industry parts, adhesives, coatings, etc.

[0007] Traditional radiation protection materials mainly contain lead, which is heavy, toxic and has insufficient protective performance.

[0008] So far, there has been no report on EVA and metal oxide / graphene oxide nanocomposite copolymer protective materials. Summary of the invention

[0009] The purpose of the present invention is to provide a preparation method and application of a nanocomposite material with radiation protection properties, and in particular to a Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material and a preparation method and application thereof. The method of the present invention has simple reaction conditions, does not require the addition of a catalyst, is green and environmentally friendly, and controls the generation of nanoparticles only by heating and refluxing. The prepared Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material has a shielding effect on X-rays and gamma rays, and can be used to make radiation protection clothing, radiation protection gloves, radiation protection vests and other radiation protection products.

[0010] The technical solution of the present invention is:

[0011] Nanocomposite material with radiation protection properties The material is prepared by melt blending the following components in parts by weight: 5-3 parts by weight of ethylene-vinyl acetate copolymer, 5-7 parts by weight of Nb2O5 / GO nanocomposite material;

[0012] The Nb2O5 / GO nanocomposite material is obtained by reflux reaction of graphene oxide and NbCl5 at 130°C-135°C, and the mass ratio of graphene oxide to NbCl5 is 1:2.

[0013] The method for preparing the nanocomposite material is characterized by comprising the following steps:

[0014] 1) Preparation of Nb2O5 / GO nanocomposites

[0015] Take graphene oxide (GO), add deionized water, ultrasonicate until dissolved, GO concentration is 20g / L, add N,N dimethylformamide (DMF), stir and heat to 120°C, slowly add NbCl5, heat to 130°C-135°C, reflux, stir, react for ≥5 hours, centrifuge, wash, dry and grind to obtain Nb2O5 / GO nanocomposite material;

[0016] The mass ratio of graphene oxide to NbCl5 is 1:2;

[0017] 2) Preparation of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposites

[0018] After mixing Nb2O5 / GO nanocomposite material and ethylene-vinyl acetate copolymer, the mixture was melt-blended at 150°C, and then pressed into a plate to prepare a sample, thereby obtaining Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material;

[0019] The mass ratio of the Nb2O5 / GO nanocomposite material to the ethylene-vinyl acetate copolymer is 5-3:5-7.

[0020] In step 1), the volume ratio of deionized water to N,N-dimethylformamide is 1:1.

[0021] The ultrasonic treatment time in step 1) is 1-2 hours.

[0022] The time of melt blending in step 2) is 8 minutes.

[0023] Application of the above-mentioned Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material in the preparation of products for protecting against high-energy radiation.

[0024] The high energy rays are X-rays and gamma rays.

[0025] The articles described are radiation protection clothing, radiation protection gloves, radiation protection vests and other protective articles.

[0026] The technical effects of the present invention are:

[0027] In the method of the present invention, DMF can be recycled and the reaction is pollution-free, so it is green and environmentally friendly; the reaction conditions are simple and no catalyst needs to be added; the generation of nanoparticles is controlled only by heating and reflux, and the obtained nanoparticles are mixed with EVA and hot-pressed to form a densely structured radiation-proof material.

[0028] The Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite prepared by the present invention overcomes the problems of traditional radiation protection materials mainly containing lead, being heavy, toxic and insufficient in protection performance, and the Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite can have a strong protection effect on X-rays, and utilize the excellent performance of graphene to have a protection effect on gamma rays. In addition, the material itself is light and thin, and the weight per unit area is significantly lighter than commercially available lead cloth, and it has no toxic side effects, and has good practicality and safety.

[0029] The present invention utilizes the low capture cross section of niobium (Nb) for thermal neutrons to reduce the absorption of neutrons in the reactor, and also reduces the absorption of X-rays and gamma rays, and utilizes the high conductivity of graphene to quickly conduct the captured energy to have a radiation protection effect. EVA can be used as an adhesive to bond and shape the prepared nano radiation protection material, and it is non-toxic, odorless, elastic and flexible, and can be used to make radiation protection clothing, radiation protection gloves, radiation protection vests and other radiation protection products.

[0030] The applicant's cell experiments and animal experiments verified that the Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material has a shielding effect on X-rays and gamma rays. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 HAADF diagram of Nb2O5 / GO nanocomposite;

[0032] Figure 2 It is the radiation protection effect evaluation process of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite;

[0033] Figure 3 The radiation protection effect of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite against 9Gy irradiation by X-ray irradiator of IEC-6 cells;

[0034] Figure 4 The radiation protection effect of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposites against IEC-6 cells irradiated with 15Gy of cobalt source gamma rays;

[0035] Figure 5 The radiation protection effect of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite on Balb / c mice irradiated by 7Gy X-ray irradiator;

[0036] Figure 6 The radiation protection effect of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material on Balb / c mice irradiated with 7Gy cobalt source γ-rays. Specific implementation plan

[0037] Reagent Source

[0038] Graphene oxide was prepared by a modified Hummers method, see reference [1];

[0039] NbCl5, NN-dimethylformamide, and ethylene-vinyl acetate copolymer were purchased from Aladdin;

[0040] IEC-6 cells were purchased from Nanjing Kebai Biotechnology Co., Ltd.;

[0041] PBS, trypsin, 1640 medium and FBS were purchased from Gibce.

[0042] Other reagents were commercially available.

[0043] Example 1 Preparation of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite

[0044] Weigh 4 g of graphene oxide (GO), add deionized water, ultrasonicate for 2 h until dissolved, so that the GO concentration is 20 g / L, add N, N dimethylformamide (DMF) (water:DMF = volume ratio of 1:1), stir and heat to 120 ° C, slowly add NbCl5 (mass ratio of GO:NbCl5 = 1:2), heat to 130 ° C-135 ° C, reflux and stir, react for ≥ 5 hours, after the reaction is completed, filter the black suspension, wash the precipitate with deionized water 3 times, dry at 60 ° C, grind, and obtain Nb2O5 / GO nanocomposite material, see Figure 1 The particles of Nb2O5 / GO nanocomposite materials are all smaller than 5nm and can be evenly dispersed in the material to exert a better protective effect.

[0045] Take 3 parts by weight of Nb2O5 / GO nanocomposite material and 7 parts by weight of EVA and mix them evenly, place them in a precision mixer for melt blending at 150°C, melt blending for 8 minutes, and place them in an automatic tablet press heated to 160°C to press into a plate to obtain Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material.

[0046] The nanocomposite material was cut with a universal sample making machine to prepare 1 mm×12 cm×15 cm samples and 3 mm×12 cm×15 cm samples for later use.

[0047] Example 2 Evaluation of radiation resistance of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite (cells)

[0048] a. Take IEC-6 cells frozen in liquid nitrogen, thaw quickly in a 40℃ water bath, and centrifuge at 1000rpm for 5 minutes at room temperature.

[0049] b. Discard the supernatant, resuspend with 1 mL 1640 medium, and transfer to a sterilized cell culture flask containing 4 mL 1640 medium. Culture in a 37°C, 5% CO2 cell culture incubator. When the cells have grown to the bottom of the culture flask, subculture.

[0050] c. After the cells adhered to the wall and grew to about 80% of the culture flask, wash the cells with 5 mL of PBS and add 1 mL of trypsin to digest the cells. After the cells are completely digested, add 5 mL of 1640 culture medium containing 10% fetal bovine serum (FBS) to terminate the reaction and centrifuge at 1000 rpm for 5 min.

[0051] e. Count the cells on a cell counting plate and dilute to 4×10 4 , add 100 μl of the above diluted cells to each well of the 96-well plate and culture at 37°C overnight until the cells adhere.

[0052] f. Add fresh culture medium to the cells, irradiate with 9Gy in an X-ray irradiator and 15Gy in a cobalt source gamma ray, and culture in a cell culture incubator at 37°C and 5% CO2.

[0053] g. After 24 h or 48 h, the 96-well plate was taken out, washed twice with PBS, and 90 μL of serum-free culture medium and 10 μL of CCK-8 solution were added to each well of the 96-well plate.

[0054] h. Place the 96-well plate in an incubator at 37°C and 5% CO2 for 2 hours.

[0055] i. Measure the absorbance of the sample at 450nm using an ELISA reader. Figure 2-Figure 4 .in:

[0056] See also Figure 3 ② X-ray 9Gy irradiation group, X-ray irradiator irradiated IEC-6 cells with 9Gy, and the cell survival rate was 73.1%. When protected by Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite, among which, ③ X-ray 9Gy irradiation + 1mm material group (1mm×12cm×15cm sample) protection, the IEC-6 cell survival rate was 90.8%, and when protected by ④ X-ray 9Gy irradiation + 3mm material group (3mm×12cm×15cm sample), the IEC-6 cell survival rate rose to 100%, and the nanocomposite group had a significant protective effect.

[0057] See also Figure 4 ②γ-ray 15Gy irradiation group, cobalt source γ-ray 15Gy irradiation IEC-6 cells, cell survival rate is 54.3%. When protected by Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite, among which, group ③γ-ray 15Gy irradiation + 1mm material group (1mm×12cm×15cm sample) protection, IEC-6 cell survival rate is 62.7%, and group ④γ-ray 15Gy irradiation + 3mm material group (3mm×12cm×15cm sample) protection, IEC-6 cell survival rate is 75.6%, the nanocomposite group has obvious protection effect.

[0058] Example 3

[0059] Evaluation of X-ray Radiation Resistance of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposites

[0060] 40 Balb / c mice were randomly divided into four groups, 10 mice in each group: ① control group, ② X-ray 7Gy irradiation group, ③ X-ray 7Gy irradiation + 1mm material group, ④ X-ray 7Gy irradiation + 3mm material group. The weight of each group was weighed and recorded before irradiation. ① The control group did not receive any treatment, ② X-ray 7Gy irradiation group, ③ X-ray 7Gy irradiation + 1mm material group and ④ X-ray 7Gy irradiation + 3mm material group were irradiated with 7Gy in the X-ray irradiator, and their weight was weighed and recorded 24 hours after irradiation, and weighed continuously for 15 days. The survival rate of mice was observed and recorded every day.

[0061] The results are as follows Figure 5 As shown in: Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite has a certain radiation protection effect. Without material protection, X-ray irradiator irradiated Balb / c mice with 7Gy, and the mice in the ②X-ray 7Gy irradiation group began to die from the 6th day until all died on the 11th day. When Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite (1mm×12cm×15cm sample) was used for protection, the mortality rate of mice in the ③X-ray 7Gy irradiation + 1mm material group and the ④X-ray 7Gy irradiation + 3mm material group was 0, and the protection effect was 100%.

[0062] Example 4

[0063] Evaluation of the γ-ray radiation resistance of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposites

[0064] 40 Balb / c mice were randomly divided into three groups, 10 mice in each group: ① control group, ② γ-ray 7Gy irradiation group, ③ γ-ray 7Gy irradiation + 1mm material group and ④ γ-ray 7Gy irradiation + 1mm material group. The weight of each group was weighed and recorded before irradiation. ① The control group did not receive any treatment, ② γ-ray 7Gy irradiation group, ③ γ-ray 7Gy irradiation + 1mm material group and ④ γ-ray 7Gy irradiation + 3mm material group were irradiated with 7Gy in the γ-ray irradiator, and their weight was weighed and recorded 24 hours after irradiation, and weighed continuously for 15 days. The survival rate of mice was observed and recorded every day.

[0065] The results are as follows Figure 6As shown in: Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite has a certain radiation protection effect. Without material protection, Balb / c mice were irradiated with cobalt source γ-rays at 7Gy. The mice in the 2γ-ray 7Gy irradiation group began to die from the 6th day until the 11th day. When Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite (1mm×12cm×15cm sample) was used for protection, the protective effect of the 3γ-ray 7Gy irradiation + 1mm material group was more obvious. By the 15th day, the survival rate of mice in the 3γ-ray 7Gy irradiation + 1mm material group was 30%, while the survival rate of mice in the 4γ-ray 7Gy irradiation + 3mm material group increased to 50%. Due to the increase in the amount of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite added, its protective effect was significantly improved.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

[0067] Reference 1 W. SH Jr, RE Offeman, Preparation of graphitic oxide, J. Am. Chem. Soc. 80 (6) (1958).

Claims

1. A nanocomposite material having radiation protection properties, characterized in that: The material is prepared by melt blending the following components in weight: 5-3 weight parts of ethylene-vinyl acetate copolymer and 5-7 weight parts of Nb2O5 / GO nanocomposite material; The Nb2O5 / GO nanocomposite material is obtained by reflux reaction of graphene oxide and NbCl5 at 130°C-135°C, and the mass ratio of graphene oxide to NbCl5 is 1:

2.

2. The method for preparing the nanocomposite material according to claim 1, characterized in that: The following steps are involved: 1) Preparation of Nb2O5 / GO nanocomposites Take graphene oxide (GO), add deionized water, ultrasonicate until dissolved, GO concentration is 20g / L, add N,N dimethylformamide (DMF), stir and heat to 120°C, slowly add NbCl5, heat to 130°C-135°C, reflux, stir, react for ≥5 hours, centrifuge, wash, dry and grind to obtain Nb2O5 / GO nanocomposite material; The mass ratio of graphene oxide to NbCl5 is 1:2; 2) Preparation of Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposites After mixing Nb2O5 / GO nanocomposite material and ethylene-vinyl acetate copolymer, the mixture was melt-blended at 150°C, and then pressed into a plate to prepare a sample, thereby obtaining Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material; The mass ratio of the Nb2O5 / GO nanocomposite material to the ethylene-vinyl acetate copolymer is 5-3:5-7.

3. The preparation method according to claim 2, characterized in that: In step 1), the volume ratio of deionized water to N,N-dimethylformamide is 1:

1.

4. The preparation method according to claim 2, characterized in that: The ultrasonic treatment time in step 1) is 1-2 hours.

5. The preparation method according to claim 2, characterized in that: The time of melt blending in step 2) is 8 minutes.

6. Use of the Nb2O5 / GO / ethylene-vinyl acetate copolymer nanocomposite material according to claim 1 in the preparation of products for protecting against high-energy radiation.

7. The use according to claim 6, wherein the high-energy rays are X-rays and gamma rays.

8. The use according to claim 6, characterized in that: The articles are radiation protection clothing, radiation protection gloves, and radiation protection vests.

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