Photodynamic antibacterial filter element for automobile air conditioner and preparation method

Abstract

The invention provides a photodynamic antibacterial filter element for an automobile air conditioner and a preparation method of the photodynamic antibacterial filter element, and belongs to the field of automobile air conditioner filter materials. The method comprises the following steps: loading photosensitizer molecules onto polymer fibers to obtain polymer fibers loaded with photosensitive molecules; compounding an activated carbon fiber mat on the polymer fiber loaded with the photosensitive molecules to obtain a compound roll material; and carrying out electrostatic electret treatment on the obtained compound roll material, and then carrying out hot pressing, shaping, folding, cutting and edge sealing according to an air conditioner filter element process to obtain the photodynamic antibacterial filter element for the automobile air conditioner. The photodynamic antibacterial automobile air conditioner filter prepared by the invention can efficiently generate reactive oxygen species (ROS) under the irradiation of green light with the wavelength of 500-530nm, and the ROS can attack various amino acids and ribose bases and cause irreversible oxidative damage of proteins and DNA (deoxyribonucleic acid) (RNA) so as to achieve the antibacterial purpose.

Description

Technical Field

[0001] The present invention belongs to the field of automotive air - conditioning filter materials, and particularly relates to a filter element for automotive air - conditioners with photodynamic antibacterial properties and a preparation method thereof. Background Art

[0002] In - vehicle air - conditioning filter elements play an important role in the automotive air - conditioning system. It is located at the air inlet of the automotive air - conditioning system. Its main function is to filter the air introduced from the outside into the vehicle interior, prevent dust, pollen, bacteria, particulate matter, and other pollutants from entering the vehicle, and at the same time, it can also remove odors, adsorb harmful gases, and improve the cleanliness of the air inside the vehicle. In the post - epidemic era, consumers pay more attention to the cleanliness and hygiene of the automotive interior environment, and the demand for a sterile environment of the air inside the vehicle is also increasing day by day. In this case, the filtering effect and antibacterial effect of the automotive air - conditioning system become particularly important.

[0003] In order to reduce the entry of bacteria and molds into the vehicle, most in - vehicle air - conditioning filter elements add antibacterial materials or coatings. Most antibacterial air - conditioning filter elements on the market choose to add silver - ion antibacterial agents as an antibacterial means. However, silver ions are easily released from the air - conditioning filter element and enter the vehicle with the air flow, which poses a great safety hazard to the passengers in the vehicle. The European Union has now prohibited the use of silver ions as antibacterial agents. Some products have prepared antibacterial coatings containing natural antibacterial peptides, but the stability of antibacterial peptides is poor, resulting in the antibacterial effect of the product not being persistent and the service life being short. In short, the existing antibacterial automotive air - conditioning filter products on the market generally have problems such as different degrees of safety hazards and non - persistent antibacterial effects.

[0004] Photodynamic antibacterial automotive air - conditioning filters have the advantages of rapid sterilization, long - term persistence, no chemical residues, and no generation of bacterial drug resistance. Currently, they have not appeared on the market. Herein, in order to solve the problems existing in this field, we propose a preparation method for an automotive air - conditioning filter element using photodynamic antibacterial properties. Summary of the Invention

[0005] The purpose of the present invention is to provide a filter element for automotive air - conditioners with photodynamic antibacterial properties and a preparation method thereof to solve the problems of non - persistent antibacterial effect and short service life of existing antibacterial automotive air - conditioning filter products.

[0006] To achieve the above - mentioned purpose, the present invention adopts the following technical solutions:

[0007] The present invention first provides a preparation method for a filter element for automotive air - conditioners with photodynamic antibacterial properties, including:

[0008] Step 1: Load photosensitizer molecules onto polymer fibers to obtain polymer fibers loaded with photosensitive molecules;

[0009] Step 2: Composite the activated carbon fiber thin felt on the polymer fiber loaded with photosensitive molecules in Step 1 to obtain a composite coil material;

[0010] Step 3: Perform electrostatic electret treatment on the composite coil material obtained in Step 2, and then carry out hot pressing, shaping, folding, cutting, and edge sealing according to the air-conditioning filter element process to obtain a filter element for automotive air-conditioning with photodynamic antibacterial properties.

[0011] Preferably, the photosensitizer molecule described in Step 1 is a BODIPY derivative, curcumin, porphyrin and its derivatives, or Chlorin e6.

[0012] Preferably, the polymer fiber is a polypropylene fiber or PET.

[0013] Preferably, the loading in Step 1 is loaded onto the polymer fiber by impregnation.

[0014] Preferably, the thickness of the activated carbon fiber thin felt is 3 mm.

[0015] Preferably, the voltage in the electrostatic electret treatment described in Step 3 is 15 - 50 KV.

[0016] The present invention also provides a filter element for automotive air-conditioning obtained by the above preparation method.

[0017] Advantages of the present invention

[0018] The present invention provides a filter element for automotive air-conditioning with photodynamic antibacterial properties and a preparation method thereof. The method is to load photosensitizer molecules onto polymer fibers to obtain polymer fibers loaded with photosensitive molecules; composite the activated carbon fiber thin felt on the polymer fibers loaded with photosensitive molecules to obtain a composite coil material; finally, perform electrostatic electret treatment on the composite coil material and then process it according to the air-conditioning filter element process to obtain a filter element for automotive air-conditioning with photodynamic antibacterial properties. The photodynamic antibacterial automotive air-conditioning filter prepared by the present invention can efficiently generate reactive oxygen species (ROS) under the irradiation of green light with a wavelength of 500 - 530 nm. ROS can attack various amino acids and ribonucleotide bases and cause irreversible oxidative damage to proteins and DNA (RNA) to achieve the purpose of antibacterial. Specific embodiments

[0019] The present invention first provides a preparation method for a filter element for automotive air-conditioning with photodynamic antibacterial properties, including:

[0020] Step 1: Load photosensitizer molecules onto polymer fibers to obtain polymer fibers loaded with photosensitive molecules; the photosensitizer molecules are preferably BODIPY derivatives, curcumin, porphyrin and its derivatives, or Chlorin e6, more preferably BODIPY derivatives; the polymer fibers are preferably polypropylene fibers or PET, more preferably polypropylene fibers; there are no special restrictions on the loading method, and in the present invention, it is preferably loaded onto polymer fibers by impregnation. Preferably, the photosensitizer molecules are dissolved in a solvent to obtain a photosensitizer solution, and then the above-mentioned polymer fiber blocks are impregnated in the photosensitizer solution. The impregnation time is preferably 10 min - 60 min, and the impregnated sample is preferably dried in a blast dryer at 40°C - 80°C for 30 min - 300 min to obtain polymer fibers loaded with photosensitizers.

[0021] Step 2: Composite activated carbon fiber felts on the polymer fibers loaded with photosensitive molecules in Step 1 to obtain a composite roll material; the thickness of the activated carbon fiber felt is preferably 3 mm. The composite method is preferably by hot pressing with hot melt adhesive;

[0022] Step 3: Perform electrostatic electret treatment on the composite roll material obtained in Step 2. Preferably, the composite roll material is laid flat in a high-voltage electric field electret device, and the electret device charges the meltblown material by means of corona discharge with the voltage of the needle-shaped electrode of the electrostatic generator, one group or multiple groups. The voltage is preferably 15 - 50 KV. Finally, hot pressing, shaping, folding, cutting, and edge sealing are carried out according to the air-conditioning filter element process to obtain a filter element for automotive air conditioners with photodynamic antibacterial properties.

[0023] According to the present invention, the preparation of the BODIPY derivative adopts the prior art, and the preferred method is:

[0024] First, dissolve benzoyl chloride (5 mmol) in dry CH 2 Cl 2 and then add 2,4-dimethylpyrrole (11 mmol) under N 2 atmosphere. After stirring overnight in the dark at room temperature, slowly add triethylamine (5 mL) and BF 3 ·Et 2 O (6 mL) and stir for 2 h. After the reaction, concentrate on a rotary evaporator, and finally purify through a chromatographic silica gel column (CH 2 Cl 2 : n-hexane = 1:1) to obtain an orange solid. Dissolve this product (2 mmol) and N-iodosuccinimide (8 mmol) in CH 2 Cl 2 (50 mL) and stir at room temperature for 5 h. Through a chromatographic silica gel column (CH 2 Cl 2: n-Hexane = 1:1) to isolate and purify I-BDP.

[0025] The present invention will be further described in detail below with reference to specific embodiments. All raw materials involved in the embodiments are commercially available.

[0026] Example 1

[0027] 1. Cut the selected polypropylene fiber into pieces of 10 mm × 10 mm, wash and dry, and set aside.

[0028] 2. Synthesis of iodinated BODIPY:

[0029] First, dissolve benzoyl chloride (5 mmol) in dry CH 2 Cl 2 , and then add 2,4-dimethylpyrrole (11 mmol) under N 2 atmosphere. After stirring overnight at room temperature in the dark, slowly add triethylamine (5 mL) and BF 3 ·Et 2 O (6 mL), and stir the reaction for 2 h. After the reaction, concentrate on a rotary evaporator, and finally purify through a chromatographic silica gel column (CH 2 Cl 2 : n-Hexane = 1:1) to obtain an orange solid. Dissolve the product (2 mmol) and N-iodosuccinimide (8 mmol) in CH 2 Cl 2 (50 mL), and stir at room temperature for 5 h. Isolate and purify through a chromatographic silica gel column (CH 2 Cl 2 : n-Hexane = 1:1) to obtain I-BDP.

[0030] 3. Prepare the photosensitizer solution: Add 0.001 g of the photosensitizer to 1 g of the alcohol solution, and ultrasonicate in an ultrasonic machine for 1 h to obtain the photosensitizer solution.

[0031] 4. Immerse the above polymer fiber block sample in 1 ml of the photosensitizer solution for 60 min.

[0032] 5. Dry the impregnated sample in a 40 °C drying oven with forced air for 60 min to obtain the polymer fiber loaded with the photosensitizer, called Fiber One.

[0033] 6. Uniformly coat the activated carbon fiber felt with hot melt adhesive and bond it to Fiber One. Feed the bonded fibers into a hot press, and process at 150 °C and 0.5 MPa for 40 s. After hot pressing, naturally cool to room temperature to obtain a composite roll material.

[0034] 7. Apply a high voltage of 20 kV to the surface of the composite roll material using a corona discharge device, and let it stand after treatment to make the charge distribution uniform to obtain the electret product.

[0035] 8. Carry out cold air shaping, folding, cutting, and edge sealing according to the conventional process of the automotive air conditioner filter element, and the bacteria-inhibiting filter element for automotive air conditioners is obtained.

[0036] Example 2

[0037] 1. Cut the selected polypropylene fibers into pieces of 10 mm×10 mm, clean and dry them, and set aside.

[0038] 2. Synthesize iodinated BODIPY:

[0039] First, dissolve benzoyl chloride (5 mmol) in dry CH 2 Cl 2 , and then add 2,4-dimethylpyrrole (11 mmol) under an N 2 atmosphere. After stirring overnight at room temperature in the dark, slowly add triethylamine (5 mL) and BF 3 ·Et 2 O (6 mL), and stir for 2 h. After the reaction, concentrate on a rotary evaporator, and finally purify through a chromatographic silica gel column (CH 2 Cl 2 : n-hexane = 1:1) to obtain an orange solid. Dissolve the product (2 mmol) and N-iodosuccinimide (8 mmol) in CH 2 Cl 2 (50 mL), and stir at room temperature for 5 h. Separate and purify through a chromatographic silica gel column (CH 2 Cl 2 : n-hexane = 1:1) to obtain I-BDP.

[0040] 3. Prepare a photosensitizer solution: Add 0.05 g of the photosensitizer to 50 g of an alcohol solution, and ultrasonicate for 1 h in an ultrasonic machine to obtain a photosensitizer solution.

[0041] 4. Immerse the above polymer fiber block sample in 1 ml of the photosensitizer solution for 30 min.

[0042] 5. Dry the impregnated sample in a drying oven at 60 °C with air blowing for 100 min to obtain a polymer fiber loaded with a photosensitizer, called Fiber One.

[0043] 6. Uniformly coat the activated carbon fiber felt with hot melt adhesive and bond it to Fiber One. Feed the bonded fibers into a hot press, process them at 150 °C and a pressure of 0.5 MPa for 40 s, and naturally cool to room temperature after hot pressing to obtain a composite roll material.

[0044] 7. Apply a high voltage of 30 kV to the surface of the composite roll material using a corona discharge device, and let it stand for a period of time after treatment to make the charge distribution uniform, obtaining an electret product.

[0045] 8. Perform cold air setting, folding, cutting, and edge sealing on the automotive air conditioning filter element according to the conventional process, and the bacteria-inhibiting filter element for automotive air conditioning is obtained.

[0046] Example 3

[0047] 1. Cut the selected polypropylene fibers into pieces of 10 mm × 10 mm, wash and dry them for later use.

[0048] 2. Synthesize iodinated BODIPY:

[0049] First, dissolve benzoyl chloride (5 mmol) in dry CH 2 Cl 2 and then add 2,4-dimethylpyrrole (11 mmol) under N 2 atmosphere. After stirring overnight at room temperature in the dark, slowly add triethylamine (5 mL) and BF 3 ·Et 2 O (6 mL) and stir for 2 h. After the reaction, concentrate on a rotary evaporator and finally purify through a chromatographic silica gel column (CH 2 Cl 2 : n-hexane = 1:1) to obtain an orange solid. Dissolve the product (2 mmol) and N-iodosuccinimide (8 mmol) in CH 2 Cl 2 (50 mL) and stir at room temperature for 5 h. Separate and purify through a chromatographic silica gel column (CH 2 Cl 2 : n-hexane = 1:1) to obtain I-BDP.

[0050] 3. Prepare a photosensitizer solution: Add 0.1 g of the photosensitizer to 100 g of an alcohol solution and ultrasonicate in an ultrasonic machine for 1 h to obtain a photosensitizer solution.

[0051] 4. Immerse the above polymer fiber block sample in 10 mL of the photosensitizer solution for 30 min.

[0052] 5. Dry the impregnated sample in a 60 °C drying oven with forced air for 100 min to obtain a polymer fiber loaded with the photosensitizer, called Fiber One.

[0053] 6. Uniformly coat the activated carbon fiber felt with hot melt adhesive and bond it to Fiber One. Feed the bonded fibers into a hot press and process them at 150 °C and a pressure of 0.5 MPa for 30 s. After hot pressing, naturally cool to room temperature to obtain a composite roll material.

[0054] 7. Apply a high voltage of 25 kV to the surface of the composite roll material using a corona discharge device, and let it stand for a period of time after treatment to make the charge distribution uniform, obtaining an electret product.

[0055] 8. The conventional process of automobile air conditioning filter element is followed by cold air shaping, folding, cutting and edge sealing to obtain the automobile air conditioning filter element that inhibits bacteria.

[0056] Test example:

[0057] The present invention tests the antibacterial rate of the automobile air conditioning filter element obtained in the production process of Example 1. The test bacteria are Escherichia coli (E.coli) and methicillin-resistant Staphylococcus aureus (MRSA). The concentration of the prepared sample bacterial solution is 10 6 CFU / mL. Six filter elements produced in Example 1 were taken out for testing, with three pieces forming a group, and a group of control samples was set up, the control group being three ordinary polypropylene fiber samples; the test data was averaged, and the experimental steps were as follows:

[0058] (1) Sterilization and inoculation

[0059] Place the test samples and control group samples in appropriate small glass bottles and then put them into a high-pressure sterilizer at 121°C, 103kPa for sterilization for 15 minutes. Then, place them on a clean workbench to dry for 60 minutes and then place them at the bottom of each well of a 24-well plate; use a pipette to accurately take 0.1mL of the test bacterial solution and disperse it on each sample.

[0060] (2) Cultivation

[0061] Turn on the green light and keep it stable for more than 0.5h. Then adjust the light intensity by adjusting the height or power of the light. Use a UV illuminometer to measure the light intensity reaching the surface of the sample under bright conditions to be 0.01mW / cm 2 -0.1mW / cm 2 The three standard blank control samples and the three test samples prepared above were placed under the above bright conditions, and the bright conditions were controlled as follows: temperature 35°C, relative humidity not less than 85%, and culture conditions for 24 hours.

[0062] (3) Elution after culture

[0063] The samples were added with 20 ml of phosphate buffered saline eluent and eluted thoroughly.

[0064] (4) Determination of colony count

[0065] After incubation, count the number of colonies (CFU) on the plate with 30 to 300 colonies. If the colony count at the minimum dilution is <30, record the actual number; if no colonies grow, record the colony count as "<1". Record the colony counts of the test sample and the 3 control samples after incubation.

[0066] (6) Calculation of antibacterial rate

[0067] Bacteriostatic rate = (Ct - Tt) / Ct × 100

[0068] In the formula:

[0069] Ct is the average number of bacteria measured after inoculating and culturing the control sample for 24 h;

[0070] Tt is the average number of bacteria measured after inoculating and culturing the test sample for 24 h;

[0071] The results are as follows: the antibacterial rate against Escherichia coli under light is 86.3%, and the antibacterial rate against methicillin-resistant Staphylococcus aureus is 95.4%.

Claims

1. A method for preparing a photodynamic antibacterial filter element for automobile air conditioning, characterized in that: include: Step 1: Loading photosensitizer molecules onto polymer fibers to obtain polymer fibers loaded with photosensitizer molecules; Step 2: Compounding the activated carbon fiber felt on the polymer fiber loaded with photosensitive molecules in step 1 to obtain a composite roll; Step 3: subjecting the composite roll obtained in step 2 to an electrostatic charging treatment, and then subjecting the composite roll to hot pressing, shaping, folding, cutting and edge sealing according to the air conditioning filter element process, thereby obtaining a photodynamic antibacterial automobile air conditioning filter element.

2. The method for preparing a photodynamic antibacterial filter element for automobile air conditioning according to claim 1, characterized in that: The photosensitizer molecule in step 1 is a BODIPY derivative, curcumin, porphyrin and its derivatives or Chlorin e6.

3. The method for preparing a photodynamic antibacterial filter element for automobile air conditioning according to claim 1, characterized in that: The polymer fiber is polypropylene fiber or PET.

4. The method for preparing a photodynamic antibacterial filter element for automobile air conditioning according to claim 1, characterized in that: The loading in step 1 is carried out by impregnation onto the polymer fiber.

5. The method for preparing a photodynamic antibacterial filter element for automobile air conditioning according to claim 1, characterized in that: The thickness of the activated carbon fiber felt is 3 mm.

6. The method for preparing a photodynamic antibacterial filter element for automobile air conditioning according to claim 1, characterized in that: The voltage in the electrostatic charging treatment described in step 3 is 15-50KV.

7. The filter element for automobile air conditioning obtained by the preparation method according to claim 1.