Antibacterial air filtering membraneTechnical Field
The invention relates to the technical field of air filtering materials, in particular to an antibacterial air filtering membrane.
Background
In recent years, with the increase of environmental pollution, the content of pollutants such as dust in the air is increasing, which seriously harms the health of people, so that a filtering membrane product which is convenient to use and has obvious purification capability and sterilization performance is urgently needed.
At present, the antibacterial performance of the glass fiber air filter paper is endowed by adding the nano silver on the surface of the glass fiber air filter paper, but the nano silver is granular and can only be gathered at a specific part of the filter paper and cannot be uniformly distributed on the surface of the filter paper, so that the antibacterial effect of the filter paper is influenced, and the nano silver and the glass fiber cannot be tightly combined and are easy to fall off in the use process, so that the service life of the filter paper is influenced. On the other hand, it has been reported in the literature that nano silver and silver ions have potential biotoxicity, exhibit respiratory toxicity and neurotoxicity, exhibit increased mortality and decreased hatchability after exposing zebra fish embryos to nano silver and silver ions, and have a phenomenon of delayed hatching. The nano gold and gold ions which are researched at present and have the effects of bacteriostasis and antibiosis have no nutrition effect on human bodies, but can be smoothly discharged out of the human bodies, and do not generate toxic or side effect, so that the nano gold and gold ions are good antibacterial agents, but are difficult to load on a filtering membrane.
Semiconductor material nano TiO with photocatalysis function2Not only has the advantages of high activity, high antibacterial speed, good thermal stability, low price, NO toxicity to human body and the like, but also can decompose endotoxin, and has the functions of purifying, self-bonding, deodorizing and removing NOxEtc. and thus becomes the most interesting inorganic antibacterial agent, but nano TiO is used singly2As inorganicThe antibacterial agent still has some problems, such as no selective killing property to bacteria and weak antibacterial effect, and the like, so that the application field of the antibacterial agent is limited to a certain extent. The aluminum ions have good bacteria-killing effect on bacteria and mould, and the aluminum ions and the titanium dioxide are compounded to have a wider sterilization range.
Therefore, the development of an antibacterial air filtering membrane with strong antibacterial effect is of great significance.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide an antibacterial air filtering membrane, which loads nano-gold, aluminum oxide and titanium dioxide together so as to solve the problems of weak antibacterial action and narrow antibacterial range of the conventional air filtering membrane, and the prepared antibacterial filtering membrane is not easy to layer in the using process and is tightly combined among layers.
In order to achieve the purpose, the invention adopts the following technical scheme:
the antibacterial air filtering membrane comprises a second adsorption layer, an antibacterial layer and a first adsorption layer from inside to outside, the second adsorption layer is a non-woven filtering membrane formed by weaving two-component hollow fibers, the antibacterial layer is compounded on the outer surface of the second adsorption layer, and the antibacterial layer is a supported nano Au-Al2O3/TiO2The first adsorption layer is compounded on the outer surface of the antibacterial layer and is a polyether sulfone filter membrane.
Furthermore, the non-woven filter membrane is a double-component hollow fiber structure formed by compounding and spinning PTT fibers and PET fibers.
Further, the supported nano Au-Al2O3/TiO2The preparation raw materials of the membrane comprise: alumina, chloroauric acid, butyl titanate, chitosan, methanol and acid solution.
Further, the preparation method of the antibacterial air filtering membrane comprises the following steps:
introducing one end of the non-woven filter membrane into a third heating roller of the composite membrane equipment, pressing the non-woven filter membrane by using a pressing roller, and introducing 160-sand 200 ℃ circulating hot air; loading nano Au-Al2O3/TiO2One end of the film is led into a second roller of the composite film equipment and is compressed by a compression roller; introducing one end of the polyethersulfone filter membrane into a first heating roller of composite membrane equipment, introducing 120-plus 150 ℃ circulating hot air, and pressing by using a pressing roller; opening the composite membrane equipment, setting the linear speed and the tension value, and enabling the non-woven filter membrane and the supported nano Au-Al2O3/TiO2Simultaneously drawing the membrane and the polyether sulfone filter membrane onto a composite roller for compounding, and drawing forwards by using a drawing roller after compounding to obtain a filter membrane blank; and cutting rough edges of the filtering membrane blank to obtain the antibacterial air filtering membrane.
Furthermore, in the preparation of the antibacterial air filter membrane, the set linear speed is 0.1-0.2 m/min, and the tension value is 10-15N.
Further, the supported nano Au-Al2O3/TiO2The membrane was prepared as follows:
(1) adding chitosan to an acid solution with a pH of 1-5 to obtain a chitosan solution; wherein the mass-volume ratio of the chitosan to the acid solution is 1-3 g: 100 mL;
(2) weighing 100gAu-Al2O3/TiO2Putting the powder into a load dish, adding all the chitosan solution obtained in the step (1) into the load dish by using a liquid-transferring gun, performing ultrasonic treatment for 30min after dropwise adding, and aging in the air for 24 h; then placing the obtained powder in an air atmosphere, heating to 350 ℃ at a heating rate of 5 ℃/min to obtain the Au-Al loaded with chitosan2O3/TiO2Powder for standby;
(3) weighing the chitosan-loaded Au-Al prepared in the step (2)2O3/TiO2Placing 10g of the powder in a test tube, adding a methanol solution into the test tube while stirring, and performing ultrasonic dispersion to obtain a suspension;
(4) casting the suspension onto a glass vessel by adopting a casting method, and then placing the glass vessel under a vacuum oven at 80 ℃ for constant temperature for 3 hours to obtain Au-Al2O3/TiO2And (3) a membrane.
Further, the acid solution in step (1) is an organic acid solution and/or an inorganic acid solution, the organic acid comprises acetic acid, formic acid and lactic acid, and the inorganic acid comprises hydrochloric acid, nitric acid or phosphoric acid.
Further, the Au-Al2O3/TiO2The preparation steps of the powder are as follows:
weighing butyl titanate, slowly dropwise adding the butyl titanate into an absolute ethyl alcohol solution, stirring for 10-12min by using a magnetic stirrer to obtain a yellow clear solution, adding a mixed solution of glacial acetic acid and the ethyl alcohol solution into the yellow clear solution, adjusting the pH value to be 3, heating in a water bath at 40 ℃, stirring for 30min, and adding Au-Al2O3Continuously stirring the powder for 1 to 2 hours to form gel, standing and aging for 12 hours, drying at the constant temperature of 150 ℃ for 10 hours, calcining at the temperature of 500 ℃ for 2.5 to 3 hours to obtain Au-Al2O3/TiO2And (3) powder.
Further, the Au-Al2O3The preparation steps of the powder are as follows:
weighing chloroauric acid, dissolving in deionized water to obtain chloroauric acid solution, adding aluminum oxide powder for ultrasonic dispersion, adding 65-70wt% ethanol solution after dispersion to form suspension, performing ultrasonic stirring, heating to 80-90 ℃, and reacting for 0.5-2h to obtain Au-Al2O3And (3) powder.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention uses chitosan to load nano Au-Al2O3/TiO2The antibacterial layer is prepared on the film, and mainly utilizes the strong adsorbability of chitosan, which can adsorb microbe bacteria, and simultaneously, because of the large amount of free ammonia in the molecular structure of the chitosan, the chitosan can react with Au-Al2O3/TiO2Powder forming stable chelate and Au-Al as carrier2O3/TiO2The powder can generate electron-hole pairs under illumination and is adsorbed and dissolved in Au-Al2O3/TiO2Oxygen on the surface obtains electrons to generate superoxide which can react with organic matters in bacteria to achieve the aims of sterilization and antibiosis, and the adsorption effect of chitosan can promote the carrier Au-Al2O3/TiO2The prepared supported nano Au has the functions of sterilization and antibiosis-Al2O3/TiO2When the membrane is used as an antibacterial layer, the antibacterial efficiency is higher, and the antibacterial effect of the antibacterial air filtering membrane is finally improved.
2. The antibacterial air filtering membrane is designed into a three-layer composite structure, so that the filtering membrane can contain and adsorb more substances to be adsorbed, and the working efficiency of the filtering membrane is improved. Wherein, larger particles in the air are firstly filtered by the first adsorption layer, and substances which are not filtered pass through the antibacterial layer and pass through the supported nano Au-Al2O3/TiO2The membrane kills bacteria, and the second adsorbed layer further adsorbs the particulate matter in to the air to reach and both killed the bacterium and can reach the effect of filtering granule in the air again.
3. The first adsorption layer adopts a polyether sulfone filter membrane, and the antibacterial layer adopts supported nano Au-Al2O3/TiO2The membrane and the second adsorption layer are non-woven filter membranes woven by two-component hollow fibers, in the compounding process, the first heating roller is heated to 150 ℃ plus materials, the second roller is not heated, the third roller is heated to 200 ℃ plus materials, the membranes of the first adsorption layer and the second adsorption layer are heated to a micro-melting state, the three layers are tightly compounded together by a hot melting method, the layers are not easy to rise, and the purpose of multi-layer filtration is achieved.
Detailed Description
The present invention will be described in detail with reference to specific examples below:
example 1: load type nano Au-Al2O3/TiO2Preparation of film 1
The supported nano Au-Al prepared in the embodiment2O3/TiO2Film, first Au-Al should be prepared2O3/TiO2The powder is prepared by the following steps:
weighing 20g of chloroauric acid, dissolving in 2L of deionized water to prepare a chloroauric acid solution, adding 30g of alumina powder, performing ultrasonic dispersion for 10min, adding 65 wt% ethanol solution after dispersion to form a suspension, performing ultrasonic stirring, heating to 80 ℃, and reacting for 2h to obtain Au-Al2O3Powder;
weighing 100ml of butyl titanate, slowly dripping the butyl titanate into 200ml of absolute ethanol solution, stirring the solution for 12min by using a magnetic stirrer to obtain yellow clear solution, adding a mixed solution of 150ml of glacial acetic acid and 10ml of ethanol solution into the yellow clear solution, adjusting the pH value to 3 by using hydrochloric acid, heating the solution in a water bath at 40 ℃ and stirring the solution for 30min, and adding Au-Al2O3Continuously stirring the powder for 1h to form a gel, standing and aging for 12h, drying at the constant temperature of 150 ℃ for 10h, and calcining at the temperature of 500 ℃ for 2.5h to obtain Au-Al2O3/TiO2And (3) powder.
Au-Al was prepared according to the above method2O3/TiO2After the powder is prepared, the supported nano Au-Al is carried out2O3/TiO2Membrane preparation, the procedure was as follows:
(1) adding 30g of chitosan to 3000ml of an inorganic acid hydrochloric acid solution having a pH of 1 to obtain a chitosan solution; wherein the mass-volume ratio of the chitosan to the hydrochloric acid solution is 1-3 g: 100 mL;
(2) 100g of Au-Al are weighed2O3/TiO2Putting the powder into a load dish, adding all the chitosan solution obtained in the step (1) into the load dish by using a liquid-transferring gun, performing ultrasonic treatment for 30min after dropwise adding, and aging in the air for 24 h; then placing the obtained powder in an air atmosphere, heating to 350 ℃ at a heating rate of 5 ℃/min to obtain the Au-Al loaded with chitosan2O3/TiO2Powder for standby;
(3) weighing the chitosan-loaded Au-Al prepared in the step (2)2O3/TiO2Placing 10g of the powder in a test tube, adding a methanol solution into the test tube while stirring, and performing ultrasonic dispersion to obtain 65 wt% suspension;
(4) casting the suspension onto a glass vessel by adopting a casting method, and then placing the glass vessel under a vacuum oven at 80 ℃ for constant temperature for 3 hours to obtain Au-Al2O3/TiO2And (3) a membrane.
Wherein, the hydrochloric acid solution adopted in the step (1) can also be one or more of acetic acid, formic acid, lactic acid, nitric acid or phosphoric acid.
Example 2: load type nano Au-Al2O3/TiO2Preparation of the Membrane
The supported nano Au-Al prepared in the embodiment2O3/TiO2Film, first Au-Al should be prepared2O3/TiO2The powder is prepared by the following steps:
weighing 10g of chloroauric acid, dissolving in 1L of deionized water to prepare a chloroauric acid solution, adding 15g of alumina powder, performing ultrasonic dispersion for 6min, adding 70wt% of ethanol solution after dispersion to form a suspension, performing ultrasonic stirring, heating to 90 ℃, and reacting at 0.5 to obtain Au-Al2O3Powder;
weighing 50ml of butyl titanate, slowly dripping the butyl titanate into 150ml of absolute ethanol solution, stirring the solution for 10min by using a magnetic stirrer to obtain yellow clear solution, adding a mixed solution of 75ml of glacial acetic acid and 5ml of ethanol solution into the yellow clear solution, adjusting the pH value to 3 by using hydrochloric acid, heating the solution in a water bath at 40 ℃ and stirring the solution for 30min, and adding Au-Al2O3Continuously stirring the powder for 2h to form gel, standing and aging for 12h, drying at constant temperature of 150 ℃ for 10h, and calcining at 500 ℃ for 3h to obtain Au-Al2O3/TiO2And (3) powder.
Au-Al was prepared according to the above method2O3/TiO2After the powder is prepared, the supported nano Au-Al is carried out2O3/TiO2Membrane preparation, the procedure was as follows:
(1) adding 30g of chitosan to 1000ml of an organic acid formic acid solution with pH of 3 to obtain a chitosan solution; wherein the mass-volume ratio of the chitosan to the formic acid solution is 1-3 g: 100 mL;
(2) 100g of Au-Al are weighed2O3/TiO2Putting the powder into a load dish, adding all the chitosan solution obtained in the step (1) into the load dish by using a liquid-transferring gun, performing ultrasonic treatment for 30min after dropwise adding, and aging in the air for 24 h; then placing the obtained powder in an air atmosphere, heating to 350 ℃ at a heating rate of 5 ℃/min to obtain the Au-Al loaded with chitosan2O3/TiO2Powder for standby;
(3) weighing the chitosan-loaded Au-Al prepared in the step (2)2O3/TiO2Placing 10g of the powder in a test tube, adding a methanol solution into the test tube while stirring, and performing ultrasonic dispersion to obtain a 70wt% suspension;
(4) casting the suspension onto a glass vessel by adopting a casting method, and then placing the glass vessel under a vacuum oven at 80 ℃ for constant temperature for 3 hours to obtain Au-Al2O3/TiO2And (3) a membrane.
Wherein, the formic acid solution adopted in the step (1) can also be one or more of acetic acid, hydrochloric acid, lactic acid, nitric acid or phosphoric acid.
Example 4: antibacterial air filtering membrane I
The method for preparing the antibacterial air filtering membrane comprises the following steps:
introducing one end of a non-woven filter membrane formed by compounding and spinning PTT fibers and PET fibers onto a third heating roller of the composite membrane equipment, pressing the non-woven filter membrane by using a pressing roller, and introducing 160 ℃ circulating hot air; the supported nano Au-Al prepared in the first example2O3/TiO2One end of the film is led into a second roller of the composite film equipment and is compressed by a compression roller; introducing one end of a polyether sulfone filter membrane into a first heating roller of composite membrane equipment, introducing 150 ℃ circulating hot air, and pressing by using a pressing roller; opening the composite membrane equipment, setting the linear speed of 0.1m/min and the tension value of 10N, and enabling the non-woven filter membrane and the supported nano Au-Al to be in contact with each other2O3/TiO2Simultaneously drawing the membrane and the polyether sulfone filter membrane onto a composite roller for compounding, and drawing forwards by using a drawing roller after compounding, wherein the drawing ratio is 1.1 times, so as to obtain a filter membrane blank; and cutting rough edges of the filtering membrane blank to obtain the antibacterial air filtering membrane.
Wherein, the bicomponent hollow fiber non-woven filter membrane and the polyether sulfone filter membrane formed by PTT fiber and PET fiber through composite spinning can be directly purchased from the chemical fiber market.
Example 5: antibacterial air filtering membrane II
The method for preparing the antibacterial air filtering membrane comprises the following steps:
introducing one end of a non-woven filter membrane formed by compounding and spinning PTT fibers and PET fibers onto a third heating roller of a composite membrane device, pressing the non-woven filter membrane by using a pressing roller, and introducing circulating hot air at 200 ℃; will carry outExample two preparation of Supported Nano Au-Al2O3/TiO2One end of the film is led into a second roller of the composite film equipment and is compressed by a compression roller; introducing one end of a polyether sulfone filter membrane into a first heating roller of composite membrane equipment, introducing circulating hot air at 120 ℃, and pressing by using a pressing roller; opening the composite membrane equipment, setting the linear speed of 0.2m/min and the tension value of 15N, and enabling the non-woven filter membrane and the supported nano Au-Al to be in contact with each other2O3/TiO2Simultaneously drawing the membrane and the polyether sulfone filter membrane onto a composite roller for compounding, and drawing forwards by using a drawing roller after compounding, wherein the drawing ratio is 1.3 times, so as to obtain a filter membrane blank; and cutting rough edges of the filtering membrane blank to obtain the antibacterial air filtering membrane.
Wherein, the bicomponent hollow fiber non-woven filter membrane and the polyether sulfone filter membrane formed by PTT fiber and PET fiber through composite spinning can be directly purchased from the chemical fiber market.
Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims. The techniques, shapes, and configurations not described in detail in the present invention are all known techniques.