A doped graphene / iron oxyhydroxide compact and a preparation method and application thereof

Abstract

The present application relates to the field of composite materials, and particularly relates to a kind of doped graphene / hydroxyl iron oxide pressing agent, composition is: graphene+alpha-hydroxyl iron oxide+pressing agent, wherein pressing agent is: 30g PVA1788+4g AM+2mL AA.Preparation method is: step 1: weighing 30g PVA1788, 4g AM and 2mL AA configuration pressing agent;Step 2: 3 ‰ graphene and 5 ‰ alpha-hydroxyl iron oxide are added in the pressing agent of step 1, and a doped graphene / hydroxyl iron oxide pressing agent is prepared.The doped graphene / hydroxyl iron oxide pressing agent prepared by the present application is applied to the purification of radioactive aerosol in cooperation with ion wind.By experiment, it can be seen that the auxiliary effect of ion wind is very obvious, the pressing effect is more than 99% after 5min of sedimentation, and the pressing effect is more than 99.9% after 15min of sedimentation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of composite materials, in particular to a graphene / hydroxyl iron oxide doped pressing agent and a preparation method and application thereof. BACKGROUND

[0002] Aerosol refers to a stable colloidal system formed by dispersing a liquid or solid with small particle size in air. The size of the particulate matter is generally described by the aerodynamic diameter, and the aerodynamic diameter of the dispersed liquid or solid particles in the aerosol system is between 1-105 nm. Aerosols have a wide range of sources, and can be broadly divided into pollution sources caused by human factors and pollution sources caused by natural factors.

[0003] Radioactive aerosol refers to the aerosol in which the particulate matter has a certain radioactivity or the particulate matter is contaminated by external radionuclides to make it radioactive. Radioactive aerosol not only has the characteristics of ordinary aerosol, but also has the characteristics of radionuclide, and can enter the human body through diet, respiration and other behaviors to cause further damage. Therefore, the efficient purification technology of radioactive aerosol is of great significance to human health.

[0004] Currently, there is no report on the application of graphene / hydroxyl iron oxide doped pressing agent. The currently used radioactive aerosol pressing agent has the following technical problems: long pressing agent operation time; the current pressing agent is an organic material, which is expensive and has limitations; a large amount of radioactive waste is generated, and the secondary pollution problem is serious. SUMMARY

[0005] In order to comprehensively solve the above problems, the present application provides a graphene / hydroxyl iron oxide doped pressing agent and a preparation method and application thereof.

[0006] In order to achieve the above purpose, the present application provides a graphene / hydroxyl iron oxide doped pressing agent, which comprises: graphene + alpha-hydroxyl iron oxide + pressing agent, wherein the pressing agent is PVA + AM + AA.

[0007] Preferably, the addition amount of graphene is 3 ‰, and the addition amount of alpha-hydroxyl iron oxide is 5 ‰.

[0008] Preferably, the addition amounts of PVA, AM and AA are 30 g, 4 g and 2 mL respectively.

[0009] The present application provides a preparation method of a graphene / hydroxyl iron oxide doped pressing agent, which comprises:

[0010] Step 1: weigh 30 g of PVA1788, 4 g of AM and 2 mL of AA to prepare a pressing agent;

[0011] Step 2: adding 3 ‰ graphene and 5 ‰ alpha-hydroxyl iron oxide into the pressing agent of step 1 to prepare a graphene / hydroxyl iron oxide doped pressing agent.

[0012] The third aspect of the present application provides a method for purifying radioactive aerosols by using the graphene / hydroxyl iron oxide doped pressing agent in combination with ion wind.

[0013] Compared with the prior art, the present application has the following beneficial effects:

[0014] 1. The graphene / hydroxyl iron oxide doped pressing agent prepared by the present application has high efficiency, and a small amount of the pressing agent can achieve efficient pressing of radioactive aerosols.

[0015] 2. The pressing agent of the present application has simple operation, excellent purification effect, and very obvious effect after ion wind assistance. After 5 min of sedimentation, the pressing effect is more than 99%, and after 15 min of sedimentation, the pressing effect is more than 99.9%.

[0016] 3. The pressing agent of the present application has low cost, which is lower than the current organic polymer pressing material.

[0017] 4. The pressing agent of the present application has no secondary pollution, and the amount of radioactive waste after treatment is less, which is convenient for disposal. DETAILED DESCRIPTION

[0018] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, which together with the embodiments of the present application, serve to explain the present application, and do not constitute a limitation of the present application.

[0019] In the drawings:

[0020] Figure 1 The flow chart of the method of the present application is shown in the figure;

[0021] Figure 2 The natural sedimentation effect of PM5 in the reaction chamber is shown in the figure;

[0022] Figure 3 The pressing effect of 12 g PVA1788 + 3 g AM + 3 mL AA sprayed for different times is shown in the figure;

[0023] Figure 4 The pressing effect of 24 g PVA1788 + 3 g AM + 3 mL AA sprayed for different times is shown in the figure;

[0024] Figure 5 The pressing effect of 30 g PVA1788 + 4 g AM + 2 mL AA sprayed for different times is shown in the figure;

[0025] Figure 6 Comparison of pressing effect of different formula pressing agent

[0026] Figure 7 Comparison of pressing effect of different formula pressing agent

[0027] Figure 8 Comparison of pressing effect of different formula pressing agent

[0028] Figure 9 Comparison of pressing effect of different formula pressing agent

[0029] Figure 10 Comparison of pressing effect of different formula pressing agent

[0030] Figure 11 Comparison of pressing effect of different formula pressing agent

[0031] Fig. 12(a) and Fig. 12(b) are the synergistic effect of ion wind on aerosol deposition: Fig. 12(a) is the pressing effect of 10.7 mg / m 3 Initial aerosol concentration in a 1m 3 closed cabin; Fig. 12(b) is the pressing effect of 12.5 mg / m 3 Initial aerosol concentration in a 1m 3 closed cabin.

[0032] Figure 13 Comparison of pressing effect under different conditions. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present application are described below with reference to the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. Figures 1-13

[0034] Example 1:

[0035] A graphene / hydroxyl iron doped pressing agent, comprising: graphene + α-hydroxyl iron oxide + pressing agent, wherein the pressing agent is: 30 g PVA + 4 g AM + 2 mL AA.

[0036] The addition amount of graphene is 3‰, and the addition amount of α-hydroxyl iron oxide is 5‰.

[0037] Example 2:

[0038] A graphene / hydroxyl iron doped pressing agent preparation method, comprising:

[0039] ​Step 1: 30 g of PVA (polyvinyl alcohol 1788), 4 g of AM (acrylamide) and 2 mL of AA (acrylic acid) were weighed to prepare a pressing agent;

[0040] Step 2: 3 ‰ graphene and 5 ‰ α-hydroxyl iron oxide were added to the pressing agent of step 1 (based on the mass of the pressing agent) to prepare a graphene / hydroxyl iron oxide doped pressing agent.

[0041] Example 3:

[0042] A method for purifying radioactive aerosols by using a graphene / hydroxyl iron oxide doped pressing agent in combination with ion wind.

[0043] The ion wind is generated by an ion wind generator. An Optimal Voyage negative ion generator and a 12V6W duct fan are selected to combine into an ion wind generator. A non-polar speed controller is used to control the air volume, and different negative ion wind volumes can be adjusted according to the requirements.

[0044]

[0045] Experiment:

[0046] 1 m 3 of the environment warehouse and the simulation prototype developed according to the aerosol settling mechanism were used as experimental platforms. In the closed environment warehouse, wormwood smoke was used as a simulation aerosol, and the initial concentration was controlled at 20-25 μg / m 3 , and the aerosol pressing effect under different application conditions was studied.

[0047] Experimental results

[0048] (1) Natural settling

[0049] Figure 2 As shown in the figure, under the condition of natural settling, the settling effect within 80 min is very poor, and there are phenomena such as coagulation between particles, which leads to changes in particle size. For PM5, not only is there no aerosol settling removal effect within 80 min, but it also leads to an increase in the concentration of PM5 in the reaction chamber. After 80 min, the particles tend to be stable and gradually begin to show natural settling effect. Within 360 min, natural settling can remove about 37% of the particles in the reaction chamber.

[0050] (2) Pressing effect of pressing agents with different formulations

[0051] (1) 12 g PVA1788 + 3 g AM + 3 mL AA sprayed for different times

[0052] A pressurized formulation was prepared using 12 g PVA1788 + 3 g AM + 3 mL AA and sprayed into the reaction chamber. Figure 3 When spraying for 10 min, 20 min, and 30 min respectively, it was found that although the suppression effect varied with different spraying times, the suppression effect was significantly improved compared to natural sedimentation. Even with only 10 s of spraying, the aerosol removal efficiency reached 73.5% after 300 min of sedimentation, which was about twice that of natural sedimentation. When the spraying time reached 20 s, the aerosol sedimentation rate reached 93.8% after 300 min; however, the effect decreased as the spraying time continued to increase.

[0053] (2) 24 g PVA1788 + 3 g AM + 3 mL AA sprayed at different times

[0054] When adjusting the formulation of the compression preparation to use 24 g PVA1788 + 3 g AM + 3 mL AA, as follows: Figure 4 It can also be seen that there is a significant suppression effect. The suppression effect of this formula increases with the increase of spraying time. When the spraying time reaches 30 seconds, the removal efficiency of aerosols in 360 minutes reaches 92.5%.

[0055] (3) 30 g PVA1788 + 4 g AM + 2 mL AA sprayed at different times

[0056] When 30 g PVA1788 + 4 g AM + 2 mL AA is used as the compression formulation, the compression effect is further improved, such as... Figure 5 Although the suppression effect of spraying for 10 seconds was not significantly different from the previous two suppression formulations, the suppression effect on aerosols was significantly improved when the spraying time was increased. When the spraying time was 30 seconds and 360 minutes, the aerosol settling effect could reach 95.4%.

[0057] (III) Comparison of the compression effects of the three compression formulations

[0058] like Figure 6 Comparing the compression effects of the three formulations with an injection time of 30 seconds reveals that while all formulations showed good results, the effects varied depending on the formulation. The formulation of 30 g PVA1788 + 4 g AM + 2 mL AA demonstrated the best aerosol compression effect. Therefore, this formulation will be used as the basis for subsequent formulation improvements.

[0059] (iv) The pressing effect of graphene doping in the pressing agent

[0060] As Figure 7 30 g PVA1788 + 4 g AM + 2 mL AA as the base formula of the pressing agent, adding graphene in the pressing agent. When the addition amount is 1 ‰, 2 ‰ and 3 ‰ respectively, the pressing effect of the pressing agent on aerosol has different changes. It can be seen that when a small amount of graphene is added to the pressing agent, not only does it not improve the pressing effect on aerosol, but it also leads to a decrease in the pressing effect. But when the amount of graphene gradually increases, the pressing effect on aerosol has a rising trend. In terms of the amount of graphene added, the order of the pressing ability on aerosol is 1 ‰ < 2 ‰ < 3 ‰, and when the amount of graphene added reaches 3 ‰, the removal rate of PM5.0 aerosol within 300 min can reach 98.1%.

[0061] (V) Changes in the pressing effect of the pressing agent after adding hydroxyl iron oxide

[0062] (1) Pressing effect of the pressing agent after adding γ-hydroxyl iron oxide

[0063] 30 g PVA1788 + 4 g AM + 2 mL AA as the base formula of the pressing agent, adding γ-hydroxyl iron oxide in the pressing agent. As Figure 8 It can be seen that after adding γ-hydroxyl iron oxide, the removal effect on PM5 in the early stage of sedimentation will decrease. Only when the amount of γ-hydroxyl iron oxide added increases to 3 ‰, the effect in the late stage of sedimentation will be higher than that of the pure pressing agent without adding, and the aerosol sedimentation efficiency can reach 97.5% after 360 min.

[0064] (2) Pressing effect of the pressing agent after adding α-hydroxyl iron oxide

[0065] α-hydroxyl iron oxide is used to replace γ-hydroxyl iron oxide and is added to the base formula of 30 g PVA1788 + 4 g AM + 2 mL AA pressing agent. As Figure 9 It can be found that compared with γ-hydroxyl iron oxide, the effect of α-hydroxyl iron oxide on the pressing agent in the early stage is significantly weakened, especially when the amount of addition increases to 5 ‰, the removal effect on aerosol in the early stage of sedimentation has already approached that of the pure pressing agent; the removal rate of aerosol after sedimentation can reach 95.5% after 360 min.

[0066] Compared with γ-hydroxyl iron oxide, α-hydroxyl iron oxide has better effect, so α-hydroxyl iron oxide is selected as the additive.

[0067] The amount of graphene added is 3 ‰, and the amount of α-hydroxyl iron oxide added is 1 ‰, 3 ‰ and 5 ‰ respectively. As Figure 10As can be seen, when the composite is added, on the basis of the addition of 3‰ graphene, the addition of α-hydroxy iron oxide is increased to 3‰ and above, and its effect on the removal of aerosol is better than that of pure compression agent from the beginning.

[0068] After the composite modification of 3‰ graphene + 5‰ α-hydroxy iron oxide, the settling time is higher than 90% at 90 min, and the compression effect on aerosol can reach 98.6% at 360 min.

[0069] (VI) Long-term compression effect of doped compression agent

[0070] The above experimental conditions are tested for 24 hours. Figure 11 As can be seen, when the settling time reaches 4 hours, the compression effect can reach about 99%, when the settling time reaches more than 5 hours, the compression effect can reach 99.5%, when the settling time reaches more than 10 hours, the compression effect can reach 99.9%. After 24 hours of settling, the compression effect is 99.99%.

[0071] (VII) Compression effect of doped compression agent with ion wind

[0072] After the aerosol is generated, the ion wind is blown into the environment chamber, and the removal rate of the aerosol under different action times is investigated.

[0073] As shown in FIG. 12(a) and FIG. 12(b), the ion wind has a synergistic effect on the settling of aerosol. In a 1 m 3 closed square cabin, the compression effect of 10.7 mg / m 3 and 12.5 mg / m 3 initial aerosol concentration is shown in FIG. 12(a) and FIG. 12(b), respectively, and the compression efficiency reaches 99.5% in about 12 minutes, and no rebound phenomenon occurs in 24 hours. It is shown that the effect of electric coagulation on the synergistic effect of aerosol settling is significant.

[0074] As Figure 13 shown, on the basis of 30 g PVA1788 + 4 g AM + 2 mL AA compression agent added with 3‰ graphene and 5‰ α-hydroxy iron oxide composite material, ion wind assisted. As can be seen, the ion wind assisted effect is very obvious, the compression effect is more than 99% after 5 min of settling, and the compression effect is more than 99.9% after 15 min of settling.

[0075] (VIII) Removal effect of "cloud solvent" on cesium element

[0076] Cesium nitrate solution is used to simulate cesium element in air. Cesium nitrate is dissolved in water and added to the reaction chamber by ultrasonic atomization; an air sampler is used to set a sampling flow of 0.5 L / min, and sampling is performed for 5 min; the cesium nitrate salt in the reaction chamber is absorbed into a 50 ml absorption bottle for detection. After 3‰ graphene and 5‰ α-hydroxy iron oxide composite material is added to the initial state and the composite material pressed by 30 g PVA1788 + 4 g AM + 2 mL AA for 360 min, the concentration of cesium in the absorption liquid before and after pressing is 1.01×104 and 85.2 μg / m3 (attached third-party test report), and the pressing efficiency of cesium element for 360 min is 99.16%.

[0077] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A pressed preparation of doped graphene / iron oxyhydroxide, characterized in that: Composition: graphene + alpha-hydroxyl iron oxide + pressing agent, wherein the pressing agent is: PVA + AM + AA, wherein PVA is polyvinyl alcohol, AM is acrylamide, and AA is acrylic acid.

2. The compacted graphene / iron oxyhydroxide doped formulation according to claim 1, characterized in that: The addition amount of graphene is 3 ‰, and the addition amount of alpha-hydroxyl iron oxide is 5 ‰.

3. A pressed formulation of doped graphene / ferric oxyhydroxide according to claim 2, characterised in that: The addition amounts of PVA, AM and AA are respectively: 30 g, 4 g and 2 mL, wherein PVA is polyvinyl alcohol, AM is acrylamide, and AA is acrylic acid.

4. A method for preparing a graphene / hydroxyl iron oxide doped pressing agent, characterized in that: Step 1: weigh 30 g of PVA1788, 4 g of AM and 2 mL of AA to prepare a pressing agent, wherein PVA is polyvinyl alcohol, AM is acrylamide, and AA is acrylic acid; Step 2: add 3 ‰ graphene and 5 ‰ alpha-hydroxyl iron oxide to the pressing agent prepared in step 1 to prepare a graphene / hydroxyl iron oxide doped pressing agent.

5. A graphene / hydroxyl iron oxide doped pressing agent prepared by the method of claim 4 is applied to the purification of radioactive aerosols in cooperation with ionic wind.

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