A polytetrafluoroethylene membrane for air filtration and preparation method thereof
By preparing and modifying the polytetrafluoroethylene membrane, coating the Dendrobium polysaccharide-hyaluronic acid mixture and adding copper chloride, the problem of insufficient antibacterial performance of air filter materials is solved, and a more efficient microbial inhibition effect is achieved.
Patent Information
- Application Number
- CN202411889290.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-08-19
- Estimated Expiration
- 2044-12-20
AI Technical Summary
The existing air filter materials have shortcomings in antibacterial properties and durability, and cannot effectively inhibit the growth of microorganisms in the air.
Polytetrafluoroethylene films were prepared using polytetrafluoroethylene resin and isomer dodecane, and active sites were increased by aminoation treatment, Dendrobium polysaccharide-hyaluronic acid mixture was coated, and copper chloride was added to improve antibacterial properties.
It enhances the antibacterial properties of the polytetrafluoroethylene film, reduces the adhesion and reproduction of microorganisms on the membrane surface, and improves air quality.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of polytetrafluoroethylene membranes, in particular to a polytetrafluoroethylene membrane for air filtration and a preparation method thereof. Background Art
[0002] While traditional air filter materials have achieved certain results in removing particulate matter and harmful gases, they lack antibacterial properties and durability, which makes the demand for new filter materials increasingly urgent.
[0003] Polytetrafluoroethylene (PTFE) is widely used in air filtration due to its excellent chemical stability and anti-pollution properties. However, PTFE membranes themselves lack antimicrobial properties and are unable to effectively inhibit the growth of airborne microorganisms. Therefore, developing a PTFE membrane with antimicrobial properties could not only improve air filtration efficiency but also provide a healthier living environment. This innovation has broad application prospects in air purification, air conditioning systems, and other related fields.
[0004] In order to solve the above problems and improve the antibacterial performance of polytetrafluoroethylene membranes, the present invention provides a polytetrafluoroethylene membrane for air filtration and a preparation method thereof. Summary of the Invention
[0005] The object of the present invention is to provide a polytetrafluoroethylene membrane for air filtration and a preparation method thereof, so as to solve the problems raised in the prior art.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] A method for preparing a polytetrafluoroethylene membrane for air filtration comprises the following steps:
[0008] Step 1: Take polytetrafluoroethylene resin and isododecane, mix them evenly, mature them, extrude, calender, and dry them to obtain polytetrafluoroethylene tape, stretch them, and heat-set them to obtain polytetrafluoroethylene film;
[0009] Step 2: Soaking the polytetrafluoroethylene membrane in an ethanol and deionized water solution for 15-20 minutes, washing with deionized water, and then soaking the treated polytetrafluoroethylene membrane in a 1,3-diaminopropane solution for 1.5-2 hours, washing with deionized water, and drying to obtain an amino polytetrafluoroethylene membrane;
[0010] Step 3: coating the dendrobium polysaccharide-hyaluronic acid mixed solution on the surface of the amino polytetrafluoroethylene membrane and drying it to obtain the polytetrafluoroethylene membrane for air filtration.
[0011] More optimally, the preparation method of the dendrobium polysaccharide-hyaluronic acid mixed solution is: take dendrobium polysaccharide and ethyl acetate, ultrasonically disperse them to obtain a dendrobium polysaccharide solution; take modified hyaluronic acid and phosphate buffer, stir them evenly, add the dendrobium polysaccharide solution, ultrasonically treat for 20-30 minutes, add copper chloride, stir for 3-4 hours, and obtain a dendrobium polysaccharide-hyaluronic acid mixed solution.
[0012] More optimally, the preparation method of the modified hyaluronic acid comprises the following steps:
[0013] S1: Folic acid and dimethyl sulfoxide were mixed, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were added, and the mixture was stirred for 60-70 minutes to obtain a mixed solution A; amino hyaluronic acid and phosphate buffer were mixed, and the mixture was added dropwise to the mixed solution A, and the mixture was stirred for 22-26 hours, dialyzed, and freeze-dried to obtain a mixture A;
[0014] S2: Take thioglycolic acid and phosphate buffer, stir evenly, add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir evenly to obtain a mixed solution B; take mixture A and phosphate buffer, stir evenly, add mixed solution B dropwise, stir for 22-26 hours, dialyze, and lyophilize to obtain modified hyaluronic acid.
[0015] More optimally, in S1, the preparation method of amino hyaluronic acid is: take hyaluronic acid and deionized water, stir evenly, add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir evenly, add cystamine dihydrochloride, stir for 5-7 hours, dialyze, and freeze-dry to obtain amino hyaluronic acid.
[0016] More optimally, the polytetrafluoroethylene membrane comprises the following components, by weight: 100-110 parts of polytetrafluoroethylene resin and 28-32 parts of isododecane.
[0017] More optimally, in step three, the coating thickness of the Dendrobium polysaccharide-hyaluronic acid mixture is 1-1.5µm.
[0018] More optimally, the particle size of the dendrobium polysaccharide is 80-120 mesh.
[0019] Compared with the prior art, the present invention has the following beneficial effects:
[0020] 1. The present invention prepares a polytetrafluoroethylene membrane using polytetrafluoroethylene resin and isomeric dodecane. The polytetrafluoroethylene membrane is then subjected to an amino treatment to increase the number of active sites on the surface of the polytetrafluoroethylene membrane, allowing it to load more dendrobium polysaccharide-hyaluronic acid components.
[0021] 2. The present invention coats the surface of an amino polytetrafluoroethylene membrane with a layer of a dendrobium polysaccharide-hyaluronic acid mixture. The dendrobium polysaccharide has a good antibacterial effect on Staphylococcus aureus and Escherichia coli, thereby improving the antibacterial properties of the polytetrafluoroethylene membrane. Hyaluronic acid is modified and then compounded with the dendrobium polysaccharide to achieve a good sustained-release effect, enhance antibacterial properties, reduce the attachment and reproduction of microorganisms on the membrane surface, and further improve air quality. The present invention also adds copper chloride to the dendrobium polysaccharide-hyaluronic acid mixture. The copper chloride can destroy microbial cell membranes, thereby achieving an antibacterial effect and improving the antibacterial properties of the polytetrafluoroethylene membrane. DETAILED DESCRIPTION
[0022] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.
[0023] There is no particular restriction on the sources and purchase channels of the raw materials involved in the present invention, and illustratively include: polytetrafluoroethylene resin: can be purchased from DuPont, model: 601A; isododecane: can be purchased from ExxonMobil, model: ISOPAR-H; hyaluronic acid: can be purchased from Shandong Freda Biological Co., Ltd., relative molecular mass: 20-40Da; Dendrobium polysaccharide: can be purchased from Shaanxi Lvlai Biotechnology Co., Ltd., particle size: 80 mesh-120 mesh.
[0024] Example 1: A method for preparing a polytetrafluoroethylene membrane for air filtration, comprising the following steps:
[0025] Step 1: Preparation of polytetrafluoroethylene membrane:
[0026] Taking polytetrafluoroethylene resin and isododecane, mixing them evenly, aging, extruding, calendering, and drying to obtain polytetrafluoroethylene tape, stretching, and heat-setting to obtain polytetrafluoroethylene film;
[0027] The polytetrafluoroethylene membrane comprises the following components, by weight: 105 parts of polytetrafluoroethylene resin, 30 parts of isododecane;
[0028] Step 2: Preparation of amino-modified polytetrafluoroethylene membrane:
[0029] The polytetrafluoroethylene membrane was immersed in a solution of ethanol and deionized water with a volume ratio of 1:1 for 18 minutes, and then washed with deionized water. The treated polytetrafluoroethylene membrane was then immersed in a 1,3-diaminopropane solution with a concentration of 1 mg / mL for 1.7 hours, and then washed with deionized water and dried to obtain an amino polytetrafluoroethylene membrane.
[0030] Step 3: Preparation of amino-modified hyaluronic acid:
[0031] Take 1 g of hyaluronic acid and 100 mL of deionized water, stir evenly, add 1 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.2 g of N-hydroxysuccinimide, stir evenly, add 3 g of cystamine dihydrochloride, stir for 6 h, dialyze, and lyophilize to obtain amino hyaluronic acid;
[0032] Step 4: Preparation of modified hyaluronic acid:
[0033] 0.1 g of folic acid and 100 mL of dimethyl sulfoxide were mixed and stirred evenly, and 0.05 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysuccinimide were added and stirred for 65 min to obtain a mixed solution A. 1 g of amino-modified hyaluronic acid and 50 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly, and then added dropwise to the mixed solution A. The mixture was stirred for 24 h, dialyzed, and lyophilized to obtain a mixture A.
[0034] 0.1 g of thioglycolic acid and 10 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. 0.4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.25 g of N-hydroxysuccinimide were added and stirred evenly to obtain a mixed solution B. 0.2 g of mixture A and 20 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. The mixed solution B was added dropwise and stirred for 24 h. The mixture was dialyzed and freeze-dried to obtain modified hyaluronic acid.
[0035] Step 5: Preparation of Dendrobium polysaccharide-hyaluronic acid mixture:
[0036] Take 0.1g of dendrobium polysaccharide and 20mL of ethyl acetate, and ultrasonically disperse them to obtain a dendrobium polysaccharide solution; take 1g of modified hyaluronic acid and 100mL of phosphate buffer with a pH value of 7.4, stir evenly, add the dendrobium polysaccharide solution, ultrasonically treat for 25min, add 0.1g of copper chloride, and stir for 3.5h to obtain a dendrobium polysaccharide-hyaluronic acid mixed solution;
[0037] Step 6: Preparation of polytetrafluoroethylene membrane for air filtration:
[0038] The dendrobium polysaccharide-hyaluronic acid mixed solution was coated on the surface of a 250µm thick amino-modified polytetrafluoroethylene membrane to a thickness of 1µm, and then dried to obtain a polytetrafluoroethylene membrane for air filtration.
[0039] Example 2: A method for preparing a polytetrafluoroethylene membrane for air filtration, comprising the following steps:
[0040] Step 1: Preparation of polytetrafluoroethylene membrane:
[0041] Taking polytetrafluoroethylene resin and isododecane, mixing them evenly, aging, extruding, calendering, and drying to obtain polytetrafluoroethylene tape, stretching, and heat-setting to obtain polytetrafluoroethylene film;
[0042] The polytetrafluoroethylene membrane comprises the following components, by weight: 100 parts of polytetrafluoroethylene resin, 28 parts of isododecane;
[0043] Step 2: Preparation of amino-modified polytetrafluoroethylene membrane:
[0044] The polytetrafluoroethylene membrane was immersed in a solution of ethanol and deionized water with a volume ratio of 1:1 for 15 minutes, and then washed with deionized water. The treated polytetrafluoroethylene membrane was then immersed in a 1,3-diaminopropane solution with a concentration of 1 mg / mL for 1.5 hours, and then washed with deionized water and dried to obtain an amino polytetrafluoroethylene membrane.
[0045] Step 3: Preparation of amino-modified hyaluronic acid:
[0046] Take 1 g of hyaluronic acid and 100 mL of deionized water, stir evenly, add 1 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.2 g of N-hydroxysuccinimide, stir evenly, add 3 g of cystamine dihydrochloride, stir for 5 h, dialyze, and lyophilize to obtain amino hyaluronic acid;
[0047] Step 4: Preparation of modified hyaluronic acid:
[0048] 0.1 g of folic acid and 100 mL of dimethyl sulfoxide were mixed and stirred evenly, and 0.05 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysuccinimide were added and stirred for 60 min to obtain a mixed solution A. 1 g of amino hyaluronic acid and 50 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly, and then added dropwise to the mixed solution A. The mixture was stirred for 22 h, dialyzed, and lyophilized to obtain a mixture A.
[0049] 0.1 g of thioglycolic acid and 10 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. 0.4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.25 g of N-hydroxysuccinimide were added and stirred evenly to obtain a mixed solution B. 0.2 g of mixture A and 20 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. Mixed solution B was added dropwise and stirred for 22 h. The mixture was dialyzed and freeze-dried to obtain modified hyaluronic acid.
[0050] Step 5: Preparation of Dendrobium polysaccharide-hyaluronic acid mixture:
[0051] 0.1 g of dendrobium polysaccharide and 20 mL of ethyl acetate were ultrasonically dispersed to obtain a dendrobium polysaccharide solution; 1 g of modified hyaluronic acid and 100 mL of phosphate buffer with a pH value of 7.4 were stirred evenly, and the dendrobium polysaccharide solution was added. The mixture was ultrasonically treated for 20 min, and 0.1 g of copper chloride was added and stirred for 3 h to obtain a dendrobium polysaccharide-hyaluronic acid mixed solution;
[0052] Step 6: Preparation of polytetrafluoroethylene membrane for air filtration:
[0053] The dendrobium polysaccharide-hyaluronic acid mixed solution was coated on the surface of a 250µm thick amino-modified polytetrafluoroethylene membrane to a thickness of 1µm, and then dried to obtain a polytetrafluoroethylene membrane for air filtration.
[0054] Example 3: A method for preparing a polytetrafluoroethylene membrane for air filtration, comprising the following steps:
[0055] Step 1: Preparation of polytetrafluoroethylene membrane:
[0056] Taking polytetrafluoroethylene resin and isododecane, mixing them evenly, aging, extruding, calendering, and drying to obtain polytetrafluoroethylene tape, stretching, and heat-setting to obtain polytetrafluoroethylene film;
[0057] The polytetrafluoroethylene membrane comprises the following components, by weight: 110 parts of polytetrafluoroethylene resin, 32 parts of isododecane;
[0058] Step 2: Preparation of amino-modified polytetrafluoroethylene membrane:
[0059] The polytetrafluoroethylene membrane was immersed in a solution of ethanol and deionized water with a volume ratio of 1:1 for 20 minutes, and then washed with deionized water. The treated polytetrafluoroethylene membrane was then immersed in a 1,3-diaminopropane solution with a concentration of 1 mg / mL for 2 hours, and then washed with deionized water and dried to obtain an amino polytetrafluoroethylene membrane.
[0060] Step 3: Preparation of amino-modified hyaluronic acid:
[0061] Take 1 g of hyaluronic acid and 100 mL of deionized water, stir evenly, add 1 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.2 g of N-hydroxysuccinimide, stir evenly, add 3 g of cystamine dihydrochloride, stir for 7 h, dialyze, and lyophilize to obtain amino hyaluronic acid;
[0062] Step 4: Preparation of modified hyaluronic acid:
[0063] 0.1 g of folic acid and 100 mL of dimethyl sulfoxide were mixed and stirred evenly, and 0.05 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysuccinimide were added and stirred for 70 min to obtain a mixed solution A. 1 g of amino hyaluronic acid and 50 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly, and then added dropwise to the mixed solution A. The mixture was stirred for 26 h, dialyzed, and lyophilized to obtain a mixture A.
[0064] 0.1 g of thioglycolic acid and 10 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. 0.4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.25 g of N-hydroxysuccinimide were added and stirred evenly to obtain a mixed solution B. 0.2 g of mixture A and 20 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. The mixed solution B was added dropwise and stirred for 26 h. The mixture was dialyzed and freeze-dried to obtain modified hyaluronic acid.
[0065] Step 5: Preparation of Dendrobium polysaccharide-hyaluronic acid mixture:
[0066] Take 0.1g of dendrobium polysaccharide and 20mL of ethyl acetate, and ultrasonically disperse them to obtain a dendrobium polysaccharide solution; take 1g of modified hyaluronic acid and 100mL of phosphate buffer with a pH value of 7.4, stir evenly, add the dendrobium polysaccharide solution, ultrasonically treat for 30min, add 0.1g of copper chloride, and stir for 4h to obtain a dendrobium polysaccharide-hyaluronic acid mixed solution;
[0067] Step 6: Preparation of polytetrafluoroethylene membrane for air filtration:
[0068] The dendrobium polysaccharide-hyaluronic acid mixed solution was coated on the surface of a 250µm thick amino-modified polytetrafluoroethylene membrane to a thickness of 1µm, and then dried to obtain a polytetrafluoroethylene membrane for air filtration.
[0069] Comparative Example 1: The polytetrafluoroethylene membrane was not subjected to amination treatment, and the rest was the same as in Example 1:
[0070] Step 1: Preparation of polytetrafluoroethylene membrane:
[0071] Taking polytetrafluoroethylene resin and isododecane, mixing them evenly, aging, extruding, calendering, and drying to obtain polytetrafluoroethylene tape, stretching, and heat-setting to obtain polytetrafluoroethylene film;
[0072] The polytetrafluoroethylene membrane comprises the following components, by weight: 105 parts of polytetrafluoroethylene resin, 30 parts of isododecane;
[0073] Step 2: Preparation of amino-modified hyaluronic acid:
[0074] Take 1 g of hyaluronic acid and 100 mL of deionized water, stir evenly, add 1 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.2 g of N-hydroxysuccinimide, stir evenly, add 3 g of cystamine dihydrochloride, stir for 6 h, dialyze, and lyophilize to obtain amino hyaluronic acid;
[0075] Step 3: Preparation of modified hyaluronic acid:
[0076] 0.1 g of folic acid and 100 mL of dimethyl sulfoxide were mixed and stirred evenly, and 0.05 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysuccinimide were added and stirred for 65 min to obtain a mixed solution A. 1 g of amino-modified hyaluronic acid and 50 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly, and then added dropwise to the mixed solution A. The mixture was stirred for 24 h, dialyzed, and lyophilized to obtain a mixture A.
[0077] 0.1 g of thioglycolic acid and 10 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. 0.4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.25 g of N-hydroxysuccinimide were added and stirred evenly to obtain a mixed solution B. 0.2 g of mixture A and 20 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. The mixed solution B was added dropwise and stirred for 24 h. The mixture was dialyzed and freeze-dried to obtain modified hyaluronic acid.
[0078] Step 4: Preparation of Dendrobium polysaccharide-hyaluronic acid mixture:
[0079] Take 0.1g of dendrobium polysaccharide and 20mL of ethyl acetate, and ultrasonically disperse them to obtain a dendrobium polysaccharide solution; take 1g of modified hyaluronic acid and 100mL of phosphate buffer with a pH value of 7.4, stir evenly, add the dendrobium polysaccharide solution, ultrasonically treat for 25min, add 0.1g of copper chloride, and stir for 3.5h to obtain a dendrobium polysaccharide-hyaluronic acid mixed solution;
[0080] Step 5: Preparation of polytetrafluoroethylene membrane for air filtration:
[0081] The dendrobium polysaccharide-hyaluronic acid mixed solution was coated on the surface of a 250µm thick polytetrafluoroethylene membrane to a coating thickness of 1µm, and then dried to obtain a polytetrafluoroethylene membrane for air filtration.
[0082] Comparative Example 2: No dendrobium polysaccharide was added, and the rest was the same as Example 1:
[0083] Step 1: Preparation of polytetrafluoroethylene membrane:
[0084] Taking polytetrafluoroethylene resin and isododecane, mixing them evenly, aging, extruding, calendering, and drying to obtain polytetrafluoroethylene tape, stretching, and heat-setting to obtain polytetrafluoroethylene film;
[0085] The polytetrafluoroethylene membrane comprises the following components, by weight: 105 parts of polytetrafluoroethylene resin, 30 parts of isododecane;
[0086] Step 2: Preparation of amino-modified polytetrafluoroethylene membrane:
[0087] The polytetrafluoroethylene membrane was immersed in a solution of ethanol and deionized water with a volume ratio of 1:1 for 18 minutes, and then washed with deionized water. The treated polytetrafluoroethylene membrane was then immersed in a 1,3-diaminopropane solution with a concentration of 1 mg / mL for 1.7 hours, and then washed with deionized water and dried to obtain an amino polytetrafluoroethylene membrane.
[0088] Step 3: Preparation of amino-modified hyaluronic acid:
[0089] Take 1 g of hyaluronic acid and 100 mL of deionized water, stir evenly, add 1 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.2 g of N-hydroxysuccinimide, stir evenly, add 3 g of cystamine dihydrochloride, stir for 6 h, dialyze, and lyophilize to obtain amino hyaluronic acid;
[0090] Step 4: Preparation of modified hyaluronic acid:
[0091] 0.1 g of folic acid and 100 mL of dimethyl sulfoxide were mixed and stirred evenly, and 0.05 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysuccinimide were added and stirred for 65 min to obtain a mixed solution A. 1 g of amino-modified hyaluronic acid and 50 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly, and then added dropwise to the mixed solution A. The mixture was stirred for 24 h, dialyzed, and lyophilized to obtain a mixture A.
[0092] 0.1 g of thioglycolic acid and 10 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. 0.4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.25 g of N-hydroxysuccinimide were added and stirred evenly to obtain a mixed solution B. 0.2 g of mixture A and 20 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. The mixed solution B was added dropwise and stirred for 24 h. The mixture was dialyzed and freeze-dried to obtain modified hyaluronic acid.
[0093] Step 5: Preparation of modified hyaluronic acid mixture:
[0094] Take 1 g of modified hyaluronic acid and 100 mL of phosphate buffer with a pH of 7.4, stir evenly, add 0.1 g of copper chloride, and stir for 3.5 hours to obtain a modified hyaluronic acid mixture;
[0095] Step 6: Preparation of polytetrafluoroethylene membrane for air filtration:
[0096] The modified hyaluronic acid mixture was coated on the surface of a 250µm thick amino polytetrafluoroethylene membrane to a coating thickness of 1µm, and dried to obtain a polytetrafluoroethylene membrane for air filtration.
[0097] Comparative Example 3: No copper chloride was added, and the rest was the same as in Example 1:
[0098] Step 1: Preparation of polytetrafluoroethylene membrane:
[0099] Taking polytetrafluoroethylene resin and isododecane, mixing them evenly, aging, extruding, calendering, and drying to obtain polytetrafluoroethylene tape, stretching, and heat-setting to obtain polytetrafluoroethylene film;
[0100] The polytetrafluoroethylene membrane comprises the following components, by weight: 105 parts of polytetrafluoroethylene resin, 30 parts of isododecane;
[0101] Step 2: Preparation of amino-modified polytetrafluoroethylene membrane:
[0102] The polytetrafluoroethylene membrane was immersed in a solution of ethanol and deionized water with a volume ratio of 1:1 for 18 minutes, and then washed with deionized water. The treated polytetrafluoroethylene membrane was then immersed in a 1,3-diaminopropane solution with a concentration of 1 mg / mL for 1.7 hours, and then washed with deionized water and dried to obtain an amino polytetrafluoroethylene membrane.
[0103] Step 3: Preparation of amino-modified hyaluronic acid:
[0104] Take 1 g of hyaluronic acid and 100 mL of deionized water, stir evenly, add 1 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 1.2 g of N-hydroxysuccinimide, stir evenly, add 3 g of cystamine dihydrochloride, stir for 6 h, dialyze, and lyophilize to obtain amino hyaluronic acid;
[0105] Step 4: Preparation of modified hyaluronic acid:
[0106] 0.1 g of folic acid and 100 mL of dimethyl sulfoxide were mixed and stirred evenly, and 0.05 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.1 g of N-hydroxysuccinimide were added and stirred for 65 min to obtain a mixed solution A. 1 g of amino-modified hyaluronic acid and 50 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly, and then added dropwise to the mixed solution A. The mixture was stirred for 24 h, dialyzed, and lyophilized to obtain a mixture A.
[0107] 0.1 g of thioglycolic acid and 10 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. 0.4 g of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and 0.25 g of N-hydroxysuccinimide were added and stirred evenly to obtain a mixed solution B. 0.2 g of mixture A and 20 mL of phosphate buffer (pH 7.4) were mixed and stirred evenly. The mixed solution B was added dropwise and stirred for 24 h. The mixture was dialyzed and freeze-dried to obtain modified hyaluronic acid.
[0108] Step 5: Preparation of Dendrobium polysaccharide-hyaluronic acid mixture:
[0109] 0.1 g of dendrobium polysaccharide and 20 mL of ethyl acetate were ultrasonically dispersed to obtain a dendrobium polysaccharide solution; 1 g of modified hyaluronic acid and 100 mL of phosphate buffer with a pH value of 7.4 were mixed evenly, and the dendrobium polysaccharide solution was added, and ultrasonic treatment was performed for 25 minutes to obtain a dendrobium polysaccharide-hyaluronic acid mixed solution;
[0110] Step 6: Preparation of polytetrafluoroethylene membrane for air filtration:
[0111] The dendrobium polysaccharide-hyaluronic acid mixed solution was coated on the surface of a 250µm thick amino-modified polytetrafluoroethylene membrane to a thickness of 1µm, and then dried to obtain a polytetrafluoroethylene membrane for air filtration.
[0112] experiment:
[0113] The performance test of the polytetrafluoroethylene membranes for air filtration prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was carried out. The sterilized polytetrafluoroethylene membranes for air filtration were placed in a culture dish, and 200 μL of a 10% ethanol solution was added to the center of the polytetrafluoroethylene membranes. 6 The E. coli solution with a CFU / mL was cultured in a 37°C constant temperature incubator for 18 hours, and its antibacterial rate was tested. The filter was used to test the filtration efficiency of particles with a particle size of 0.1-0.2µm. The data obtained are shown in the following table:
[0114]
[0115] Conclusion: From the data comparison in the table, it can be seen that in Comparative Example 1, the polytetrafluoroethylene membrane is not subjected to an amination treatment, the active sites on the surface of the polytetrafluoroethylene membrane decrease, the amount of dendrobium polysaccharide-hyaluronic acid component that can be loaded decreases, and the antibacterial performance of the polytetrafluoroethylene membrane decreases. Comparative Example 2 does not add dendrobium polysaccharide, and the antibacterial performance of the polytetrafluoroethylene membrane decreases. Comparative Example 3 does not add copper chloride, the inhibition rate decreases, and the antibacterial performance of the polytetrafluoroethylene membrane decreases. Examples 1 to 3 of the present invention were prepared using polytetrafluoroethylene resin and isomeric dodecane to prepare a polytetrafluoroethylene membrane. The polytetrafluoroethylene membrane was then subjected to an amination treatment, so that the active sites on the surface of the polytetrafluoroethylene membrane increased, and more dendrobium polysaccharide-hyaluronic acid components could be loaded. In Examples 1 to 3 of the present invention, a layer of dendrobium polysaccharide-hyaluronic acid mixed solution is coated on the surface of an amino polytetrafluoroethylene film. Dendrobium polysaccharide has a good antibacterial effect on Staphylococcus aureus and Escherichia coli, and can improve the antibacterial properties of the polytetrafluoroethylene film. Hyaluronic acid is modified and then compounded with dendrobium polysaccharide, which can achieve a good sustained-release effect, enhance antibacterial properties, reduce the attachment and reproduction of microorganisms on the film surface, and further improve air quality. The present invention also adds copper chloride to the dendrobium polysaccharide-hyaluronic acid mixed solution. Copper chloride can destroy microbial cell membranes, thereby achieving an antibacterial effect and improving the antibacterial properties of the polytetrafluoroethylene film.
[0116] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.
Claims
1. A method for preparing a polytetrafluoroethylene membrane for air filtration, characterized in that: The following steps are involved: Step 1: Take polytetrafluoroethylene resin and isododecane, mix them evenly, mature them, extrude, calender, and dry them to obtain polytetrafluoroethylene tape, stretch them, and heat-set them to obtain polytetrafluoroethylene film; Step 2: Soaking the polytetrafluoroethylene membrane in an ethanol and deionized water solution for 15-20 minutes, washing with deionized water, and then soaking the treated polytetrafluoroethylene membrane in a 1,3-diaminopropane solution for 1.5-2 hours, washing with deionized water, and drying to obtain an amino polytetrafluoroethylene membrane; Step 3: coating the dendrobium polysaccharide-hyaluronic acid mixture on the surface of the amino polytetrafluoroethylene membrane and drying it to obtain the polytetrafluoroethylene membrane for air filtration; The preparation method of the dendrobium polysaccharide-hyaluronic acid mixed solution comprises: taking dendrobium polysaccharide and ethyl acetate, ultrasonically dispersing to obtain a dendrobium polysaccharide solution; taking modified hyaluronic acid and phosphate buffer, stirring evenly, adding the dendrobium polysaccharide solution, ultrasonically treating for 20-30 minutes, adding copper chloride, and stirring for 3-4 hours to obtain a dendrobium polysaccharide-hyaluronic acid mixed solution; The preparation method of the modified hyaluronic acid comprises the following steps: S1: Folic acid and dimethyl sulfoxide were mixed, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide were added, and the mixture was stirred for 60-70 minutes to obtain a mixed solution A; amino hyaluronic acid and phosphate buffer were mixed, and the mixture was added dropwise to the mixed solution A, and the mixture was stirred for 22-26 hours, dialyzed, and freeze-dried to obtain a mixture A; S2: Take thioglycolic acid and phosphate buffer, stir evenly, add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir evenly to obtain a mixed solution B; take mixture A and phosphate buffer, stir evenly, add mixed solution B dropwise, stir for 22-26 hours, dialyze, and lyophilize to obtain modified hyaluronic acid.
2. The method for preparing a polytetrafluoroethylene membrane for air filtration according to claim 1, wherein: In S1, the preparation method of amino hyaluronic acid is as follows: take hyaluronic acid and deionized water, stir evenly, add 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide, stir evenly, add cystamine dihydrochloride, stir for 5-7 hours, dialyze, and freeze-dry to obtain amino hyaluronic acid.
3. The method for preparing a polytetrafluoroethylene membrane for air filtration according to claim 1, wherein: The particle size of the dendrobium polysaccharide is 80-120 meshes.
4. The method for preparing a polytetrafluoroethylene membrane for air filtration according to claim 1, wherein: The polytetrafluoroethylene film comprises the following components, by weight: 100-110 parts of polytetrafluoroethylene resin and 28-32 parts of isododecane.
5. The method for preparing a polytetrafluoroethylene membrane for air filtration according to claim 1, wherein: In step 3, the coating thickness of the Dendrobium polysaccharide-hyaluronic acid mixture is 1-1.5µm.
6. A polytetrafluoroethylene membrane for air filtration prepared according to the method for preparing a polytetrafluoroethylene membrane for air filtration according to any one of claims 1 to 5.
Citation Information
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