A sandwich type composite filter material and preparation method thereof

Abstract

The present invention provides a sandwich type composite filter material, characterized in that it comprises a HEPA membrane layer and a composite metal particle layer, wherein the composite metal particle layer is arranged between two layers of the HEPA membrane layers, and the composite metal particle layer comprises manganese dioxide / activated carbon composite particles, wherein the manganese dioxide / activated carbon composite particles comprise the following components by mass percentage: 40-70% activated carbon, 1-4% copper oxide, 0.5-4% iron oxide, and 28.5%-52% manganese dioxide. The sandwich type composite filter material provided by the present invention has good filtering effect and good anti-virus effect.

Description

Technical Field

[0001] The invention belongs to the field of composite filter materials, and in particular relates to a sandwich-type composite filter material and a preparation method thereof. Background Art

[0002] Laparoscopic surgery is a new type of minimally invasive surgical method. Compared with traditional surgical methods, it has less surgical trauma, faster postoperative recovery, and less pain. It has been widely used in most general surgical operations. In laparoscopic surgery, energy instruments are needed to cut human tissues, which will produce a lot of smoke. The smoke contains a large number of tissue particles, dozens of organic substances such as sevoflurane, cyclopentane, ethylbenzene, and even some pathogens, some of which are harmful substances or even carcinogens. When smoke is generated in the abdominal cavity, it will affect the visual field of the endoscope if it is not discharged in time, interfere with surgical judgment, and will be deposited in the patient's body and affect the patient's health. However, if it is discharged directly from the tubular working channel (trocar), it will produce obvious smoke and odor, pollute the surgical environment, and harm the health of patients and medical staff.

[0003] Therefore, it is necessary to take measures to deal with harmful gases during surgery. In the relevant information, there is an external device for filtering, but the particularity of the medical industry is not taken into account. The relevant filter components are simply assembled together. The device is large in size and cumbersome to use. In addition, there is a lack of targeted filter materials for this specific gas (solid tissue particles, organic matter, bacteria and viruses may exist), and the filtration volume and filtration accuracy are low, and it is also difficult to play an effective protective role. At the same time, as an intraoperative use, it lacks the killing effect on possible bacteria or viruses, and it is easy to be retained in the filter body or spread into the air. Therefore, in the current actual laparoscopic surgery, no filtration or external water bottle filtration is still used, which basically has no protective effect on patients and medical staff.

[0004] In the Chinese invention patent application CN106731319A "A new type of graded gas filtration device", a filter membrane with a multi-layer cylindrical structure is disclosed. The filter membrane material is a HEPA membrane (High Efficiency Particulate air Filter) with different filtration rate precision for graded filtration and emission. The technical solution uses a single HEPA membrane as the filter material, and does not consider the filtration of gaseous organic matter and pathogenic cells.

[0005] Chinese invention patent CN103191620B "A disposable laparoscopic surgery exhaust gas filter" discloses the use of a filter material comprising a combination of color-changing silica gel, activated carbon fiber, and HEPA membrane to adsorb and filter smoke particles. However, the filter material can only adsorb gaseous organic matter and organic particles, and cannot filter pathogenic cells.

[0006] The applicant of the present application has conducted in-depth research on the formula and structure of the filter material based on the HEPA membrane, and has produced the sandwich-type composite filter material of the present application, which has excellent effects in the application of laparoscopic surgical gas purification, and also has good performance when used for gases in other fields. Summary of the invention

[0007] In view of the deficiencies in the prior art, the present invention provides a sandwich-type composite filter material with good filtering effect and good anti-virus effect and a preparation method thereof.

[0008] The present invention provides a sandwich-type composite filter material, comprising a HEPA membrane layer and a composite metal particle layer, wherein the composite metal particle layer is arranged between two HEPA membrane layers, and the composite metal particle layer comprises manganese dioxide / activated carbon composite particles. Calculated by mass percentage, the manganese dioxide / activated carbon composite particles comprise the following components: 40-70% activated carbon, 1-4% copper oxide, 0.5-4% iron oxide, and 28.5%-52% manganese dioxide.

[0009] Preferably, the size of the manganese dioxide / activated carbon composite particles is 20-40 mesh.

[0010] Preferably, the sandwich-type composite filter material is used as a gas purification material for laparoscopic surgery.

[0011] HEPA membrane refers to a high-efficiency particulate air filter membrane. The HEPA membrane can filter out various pollutants, allergens and some viruses with a diameter greater than 20nm. Its material is usually various organic fibers and polymer spinning. The HEPA membrane also has the characteristics of large dust holding capacity and good water absorption. The HEPA membrane provided by the present invention can adopt a finished HEPA membrane, that is, a sub-glass fiber membrane. The model of the HEPA membrane is its filtration grade. The filtration grade of the HEPA membrane can reach H14, U15, U16 or U17. The sandwich-type composite filter material provided in this embodiment, the high-precision HEPA membrane can filter solid particles, and the manganese dioxide / activated carbon composite particles in the HEPA membrane interlayer contain a large number of submicron and nanometer pores, which can effectively adsorb organic matter. At the same time, because the manganese dioxide / activated carbon composite particles are doped with a small amount of iron and copper elements, they have the effect of decomposing organic matter and antibacterial and sterilization.

[0012] The present invention also provides a method for preparing the sandwich-type composite filter material, comprising the following steps:

[0013] S1, dissolving iron nitrate, copper nitrate and manganese nitrate as raw materials in water, stirring and mixing to obtain a nitrate mixed solution;

[0014] In this step, the raw materials of iron nitrate, copper nitrate and manganese nitrate need to be put in a fixed ratio. Take the ratio of each metal ion in the mixed solution as an example: in the nitrate mixed solution, the ratio of iron, copper and manganese ions is 0.5-5:1-4:94-98.5 in terms of molar mass. The solution is mainly composed of manganese ions, which are doped with iron ions and ions. After reaction, they become manganese dioxide, copper oxide and iron oxide. In the subsequent preparation of particles, manganese dioxide forms the main skeleton, and iron oxide and copper oxide are doped therein to form a stable structure.

[0015] S2, adding glycine solution to the nitrate mixed solution, maintaining stirring and heating for evaporation and concentration to obtain a precursor salt, calcining the precursor salt at high temperature, and crushing the calcined precursor salt to obtain a precursor powder, wherein the particle size of the precursor powder is -140 mesh;

[0016] Preferably, in step S2, the molar amount of glycine in the added glycine solution is 80% to 120% of the molar amount of nitrate in the nitrate mixed solution, and the heating evaporation temperature is 80 to 120°C.

[0017] In this step, after adding the glycine solution and evaporating and concentrating it, when it is concentrated to a certain extent, the glycine will ignite and cause the solution to burn, which is a self-propagating combustion method. It uses the high temperature generated by the chemical reaction between heterogeneous substances in the powder or powder block to synthesize the compound material of the required composition and structure through self-combustion after ignition. During the combustion process, a large amount of gas will escape, and a precursor salt with a high specific surface area will be obtained after combustion.

[0018] Preferably, in step S2, the high temperature calcination temperature is 300-600°C, and the high temperature calcination time is 1-3 hours.

[0019] In this step, the precursor salt after further high temperature calcination will become a composite manganese oxide with a high specific surface area and a large number of submicron and nanometer pores. The crushing step can be performed by a crusher, a ball mill or a mortar crusher commonly used in the art, as long as the particle size of the precursor powder reaches -140 mesh.

[0020] In the reaction of this step, nitrate serves as an oxide precursor and oxidant, and glycine serves as a fuel and a chelating agent. The oxide mixture obtained after combustion forms a porous body containing a large number of nanoscale pores due to gas escape. At the same time, the oxides in the precursor are evenly distributed, with submicron or even nanoscale particles, so the precursor powder obtained after subsequent crushing also has a large porosity and specific surface area.

[0021] S3, adding granular activated carbon to the precursor powder and mixing them evenly, then adding silica gel and mixing them evenly, granulating the mixture to obtain manganese dioxide / activated carbon composite particles, and drying;

[0022] Preferably, in step S3, the particle size of the added granular activated carbon is less than 100 mesh, and the mass of the added granular activated carbon accounts for 40-70% of the total mass of the mixture, and the mass of the added silicone gel accounts for 3-8% of the total mass of the mixture.

[0023] In this step, activated carbon is added to make the composite particles have a stronger adsorption capacity, and the added silica gel is used as a binder to bond the activated carbon and the precursor powder. Preferably, in step S3, the drying temperature of the manganese dioxide / activated carbon composite particles is 60-90°C and the drying time is 2-4 hours.

[0024] Preferably, in step S3, the size of the manganese dioxide / activated carbon composite particles obtained by granulation is 20-40 meshes.

[0025] S4, taking a HEPA membrane, spraying polyacrylic acid glue on the HEPA membrane, then evenly spreading the manganese dioxide / activated carbon composite particles, spraying another layer of the polyacrylic acid glue, and finally spreading a layer of the HEPA membrane to obtain a sandwich-type composite filter material.

[0026] Preferably, in step S4, the filtration grade of the HEPA membrane is H14, U15, U16 or U17, and the loading amount of the manganese dioxide / activated carbon composite particles is 200-300 g / m 2 Low loadings will result in poor purification, while high loadings will reduce throughput.

[0027] Beneficial effects of the present invention: The present invention uses manganese nitrate, iron nitrate and copper nitrate as raw materials, dissolves to form a mixed nitrate solution, then adds glycine, evaporates and concentrates under stirring, burns to obtain a high specific surface area precursor salt, and further performs high-temperature calcination to obtain a high specific surface area composite manganese oxide with a large number of submicron and nanometer pores. It is crushed into a composite manganese oxide fine granular powder and then added with granular activated carbon, and granulated with silica gel as a molding agent to obtain coarse particles of a certain size and dry to obtain manganese dioxide / activated carbon composite particles. Two layers of high filtration accuracy HEPA membrane are used as a carrier, polyacrylic acid glue is evenly sprayed on the membrane, and then the composite manganese oxide particles are evenly spread, and then covered with a layer of HEPA membrane to form a sandwich structure. The sandwich-type composite filter material has high filtration accuracy, large filtration volume, and good disinfection effect. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0029] In order to have a further understanding and recognition of the technical solution of the present invention, several preferred embodiments are listed and described in further detail.

[0030] Example 1

[0031] Preparation of composite manganese dioxide powder

[0032] Take iron nitrate, copper nitrate and manganese nitrate as raw materials and dissolve them in water, stir and mix to obtain a nitrate mixed solution; wherein in the nitrate mixed solution, the ratio of iron, copper and manganese ions is 0.5:1:98.5 in terms of molar mass. Add glycine solution to the nitrate mixed solution, the molar amount of glycine in the added glycine solution is 100% of the molar amount of nitrate in the nitrate mixed solution, keep stirring and heat to evaporate and concentrate, the heating evaporation temperature is 120°C, and the precursor salt is obtained. The precursor salt is calcined at high temperature, the high temperature calcination temperature is 500°C, the high temperature calcination time is 3 hours, and the calcined precursor salt is crushed to obtain a precursor powder, and the particle size of the precursor powder is -140 mesh.

[0033] Preparation of manganese dioxide / activated carbon composite particles

[0034] Granular activated carbon is added to the precursor powder and mixed evenly, and then silica gel is added and mixed evenly, and the mixture is granulated to obtain manganese dioxide / activated carbon composite particles, and dried at 80°C for 4 hours. The particle size of the added granular activated carbon is less than 100 meshes, and the mass of the added granular activated carbon accounts for 50% of the total mass of the mixture, and the mass of the added silica gel accounts for 5% of the total mass of the mixture.

[0035] Preparation of Sandwich Structure Filter Material

[0036] Take a HEPA membrane with a filtration grade of U16, spray polyacrylic acid glue on the HEPA membrane, then evenly spread manganese dioxide / activated carbon composite particles, spray another layer of polyacrylic acid glue, and finally spread a layer of HEPA membrane to obtain a sandwich-type composite filter material.

[0037] Example 2

[0038] Preparation of composite manganese dioxide powder

[0039] Take iron nitrate, copper nitrate and manganese nitrate as raw materials and dissolve them in water, stir and mix to obtain a nitrate mixed solution; wherein in the nitrate mixed solution, the ratio of iron, copper and manganese ions is 5:4:94 in terms of molar mass. Add glycine solution to the nitrate mixed solution, the molar amount of glycine in the added glycine solution is 100% of the molar amount of nitrate in the nitrate mixed solution, keep stirring and heat to evaporate and concentrate, the heating evaporation temperature is 120°C, and the precursor salt is obtained. The precursor salt is calcined at high temperature, the high temperature calcination temperature is 500°C, the high temperature calcination time is 3 hours, and the calcined precursor salt is crushed to obtain a precursor powder, and the particle size of the precursor powder is -140 mesh.

[0040] Preparation of manganese dioxide / activated carbon composite particles

[0041] Granular activated carbon is added to the precursor powder and mixed evenly, and then silica gel is added and mixed evenly, and the mixture is granulated to obtain manganese dioxide / activated carbon composite particles, and dried at 80°C for 4 hours. The particle size of the added granular activated carbon is less than 100 meshes, and the mass of the added granular activated carbon accounts for 50% of the total mass of the mixture, and the mass of the added silica gel accounts for 5% of the total mass of the mixture.

[0042] Preparation of Sandwich Structure Filter Material

[0043] Take a HEPA membrane with a filtration grade of U16, spray polyacrylic acid glue on the HEPA membrane, then evenly spread manganese dioxide / activated carbon composite particles, spray another layer of polyacrylic acid glue, and finally spread a layer of HEPA membrane to obtain a sandwich-type composite filter material.

[0044] Comparative Example 1

[0045] Compared with Example 1, in Comparative Example 1, copper nitrate and ferric nitrate were not added, and only manganese nitrate was used as the raw material, and the remaining proportions and operation steps were the same as those in Example 1. Only manganese oxide, the bactericidal ability decreased

[0046] Comparative Example 2

[0047] In the sandwich structure of Comparative Example 2, all three layers are made of HEPA membranes, that is, three layers of HEPA membranes are bonded together by polyacrylic acid glue to form a sandwich-type composite filter material.

[0048] (1) The composite filter materials prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were applied to the smoke filtration process in simulated laparoscopic surgery, and the smoke filtration duration was 4 hours. Then, PM2.5 filtration effect test, formaldehyde, and TVOC (Total Volatile Organic Compound) filtration effect test were performed. The test results are shown in Table 1.

[0049] Table 1

[0050]

[0051]

[0052] When the filtered gas meets the following standard value, it is considered effective filtration. When the filtered gas pollutants exceed the standard value, it is considered ineffective. The standard value is: PM2.5<35μg·m -3 , TVOC content <0.6mg·m -3 , formaldehyde content <0.1mg·m -3 .

[0053] It can be seen from the data in Table 1 that after 4 hours of continuous flue gas filtration test, the PM2.5 content, formaldehyde content and TVOC content of Examples 1 and 2 are all lower than the standard values, reaching the effective filtration standard; while the PM2.5 content of Comparative Example 1 is lower than the standard value, while the formaldehyde content and TVOC content are slightly higher than the standard value, and the filtration effect does not meet the requirements of effective filtration, because in Comparative Example 1 there is only manganese oxide, and the bactericidal ability is reduced; while in Comparative Example 2, only the PM2.5 content meets the standard requirements, and the gas odor after filtration is obvious and pungent, and there is no bactericidal and filtration effect of organic matter.

[0054] (2) The composite filter materials prepared in Example 1, Example 2, Comparative Example 1 and Comparative Example 2 were subjected to an antibacterial rate test. The test was conducted in accordance with the national standard GB 21551.2-2010: Bacteria were quantitatively inoculated on the composite filter materials of each embodiment, and after 24 hours of cultivation, the number of surviving bacteria in the sample was measured, and the antibacterial rate of the filter material was compared and calculated.

[0055] Group 1: Staphylococcus aureus was quantitatively inoculated on the filter material prepared in Example 1 and cultured for 24 hours;

[0056] Group 2: Staphylococcus aureus was quantitatively inoculated on the filter material prepared in Example 2 and cultured for 24 hours;

[0057] Group 3: Staphylococcus aureus was quantitatively inoculated on the filter material prepared in Comparative Example 1 and cultured for 24 hours;

[0058] Group 4: Staphylococcus aureus was quantitatively inoculated on the filter material prepared in Comparative Example 2 and cultured for 24 hours;

[0059] Control group: Staphylococcus aureus was quantitatively inoculated into clean water and cultured for 24 hours.

[0060] The number of surviving bacteria in the first, second, third and fourth groups of samples was compared with the number of viable bacteria in the control group, and the antibacterial rates of the first, second, third and fourth groups were calculated, respectively. The calculation results are shown in Table 2.

[0061] Table 2

[0062] Group Group 1 Group 2 Group 3 Group 4 Antibacterial rate 99.93％ 99.98％ 90.5％ 15.45％

[0063] It can be seen from the data in Table 2 that the antibacterial rate of the sandwich-type composite filter materials prepared in Examples 1 and 2 against Staphylococcus aureus can reach more than 99.93% within 24 hours, and have a good antibacterial effect; the sandwich-type composite filter material of Comparative Example 1 is not doped with copper oxide and iron oxide, and its antibacterial rate is only about 90%; and the antibacterial rate of Comparative Example 2 with only three layers of HEPA membrane is lower, and the effect is poor.

[0064] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A sandwich type composite filter material, characterized in that: It comprises a HEPA membrane layer and a composite metal particle layer, wherein the composite metal particle layer is arranged between two layers of the HEPA membrane layers, and the composite metal particle layer comprises manganese dioxide / activated carbon composite particles, wherein the manganese dioxide / activated carbon composite particles comprise the following components by mass percentage: 40-70% activated carbon, 1-4% copper oxide, 0.5-4% iron oxide, and 28.5%-52% manganese dioxide; The preparation method of the sandwich type composite filter material comprises the following steps: S1, dissolving iron nitrate, copper nitrate and manganese nitrate as raw materials in water, stirring and mixing to obtain a nitrate mixed solution; S2, adding glycine solution to the nitrate mixed solution, maintaining stirring and heating for evaporation and concentration to obtain a precursor salt, calcining the precursor salt at high temperature, and crushing the calcined precursor salt to obtain a precursor powder, wherein the particle size of the precursor powder is -140 mesh; S3, adding granular activated carbon to the precursor powder and mixing them evenly, then adding silica gel and mixing them evenly, granulating the mixture to obtain manganese dioxide / activated carbon composite particles, and drying; S4, taking a HEPA membrane, spraying polyacrylic acid glue on the HEPA membrane, then evenly spreading the manganese dioxide / activated carbon composite particles, spraying another layer of the polyacrylic acid glue, and finally spreading a layer of the HEPA membrane to obtain a sandwich-type composite filter material.

2. The sandwich type composite filter material according to claim 1, characterized in that: The size of the manganese dioxide / activated carbon composite particles is 20-40 meshes.

3. The sandwich type composite filter material according to any one of claims 1 to 2, characterized in that: The sandwich-type composite filter material is used as a gas purification material for laparoscopic surgery.

4. The sandwich type composite filter material according to claim 1, characterized in that: In step S1, in the nitrate mixed solution, the ratio of iron, copper and manganese ions is 0.5-5:1-4:94-98.5 in terms of molar mass.

5. The sandwich type composite filter material according to claim 1, characterized in that: In step S2, the molar amount of glycine in the added glycine solution is 80% to 120% of the molar amount of nitrate in the nitrate mixed solution, and the heating evaporation temperature is 80 to 120°C.

6. The sandwich type composite filter material according to claim 1, characterized in that: In step S2, the high temperature calcination temperature is 300-600°C, and the high temperature calcination time is 1-3 hours.

7. The sandwich type composite filter material according to claim 1, characterized in that: In step S3, the particle size of the added granular activated carbon is less than 100 mesh, and the mass of the added granular activated carbon accounts for 40-70% of the total mass of the mixture, and the mass of the added silica gel accounts for 3-8% of the total mass of the mixture.

8. The sandwich type composite filter material according to claim 1, characterized in that: In step S3, the drying temperature of the manganese dioxide / activated carbon composite particles is 60-90° C., and the drying time is 2-4 hours.

9. The sandwich type composite filter material according to claim 1, characterized in that: In step S4, the filtration grade of the HEPA membrane is H14, U15, U16 or U17, and the loading amount of the manganese dioxide / activated carbon composite particles is 200-300 g / m 2 .

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