Photodynamic heterogeneous composite spiral fiber antibacterial composite film as well as preparation method and application thereof

Abstract

The invention discloses a photodynamic heterogeneous composite spiral fiber antibacterial composite film as well as a preparation method and application thereof, the preparation method comprises the following steps: uniformly mixing a dried polymer raw material with titanium dioxide, and carrying out melt extrusion granulation to obtain PPLA / TiO2 master batch; adding the dried PPLA / TiO2 master batch into melt-blowing equipment, and carrying out melt spinning under the condition of 180-190 DEG C to obtain a PPLA-coated TiO2 melt-blown non-woven fabric; and spinning and spraying an inner channel spinning solution, a middle channel spinning solution and an outer channel spinning solution on the PPLA-coated TiO2 melt-blown non-woven fabric by adopting a three-channel coaxial electrostatic spinning technology, and finishing spinning to obtain the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane. The photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained by the invention has excellent radiation cooling regulation capability, good thermal stability and comfort, and the antibacterial rate of 99.86% under a dark condition.

Description

Technical Field

[0001] This invention belongs to the field of photodynamic antibacterial film technology, specifically relating to a photodynamic heterogeneous composite spiral fiber antibacterial composite film, its preparation method, and its application. Background Technology

[0002] In recent years, public health incidents caused by pathogenic microorganisms such as bacteria and viruses have occurred frequently, especially in densely populated places such as hospitals, schools, and shopping malls, where the risk of cross-infection has increased significantly. Taking respiratory diseases as an example, relevant data shows that more than 60% of cases are caused by cross-infection. Although widespread vaccination and the application of modern protective equipment can reduce the spread of infectious diseases to some extent, it is still difficult to completely block the spread of pathogens. Against this backdrop, photodynamic antibacterial materials, with their advantages of high bactericidal efficiency, low drug resistance, and low biotoxicity, have shown broad application prospects in reducing the risk of cross-transmission of pathogenic microorganisms and have gradually become a research hotspot in the field of protective materials.

[0003] Traditional photodynamic antibacterial materials are highly photodependent, achieving antibacterial rates exceeding 99% under light conditions. However, their antibacterial rate drops below 10% or even becomes completely ineffective in darkness. This is because photosensitizers readily decay and quench in darkness, resulting in low release efficiency of reactive oxygen species (ROS) and poor antibacterial efficacy. Furthermore, traditional photodynamic antibacterial materials struggle to meet comfort requirements under sunlight and exhibit poor reusability, severely limiting their practical application and widespread adoption in personal protective equipment. Therefore, developing a photodynamic antibacterial material that can function under both light and darkness conditions, is reusable, and provides comfort is crucial for addressing current health and hygiene challenges. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane.

[0005] Another object of the present invention is to provide a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained by the above preparation method.

[0006] Another object of the present invention is to provide the application of the above-mentioned photodynamic heterogeneous composite spiral fiber antibacterial composite membrane in antibacterial materials.

[0007] The objective of this invention is achieved through the following technical solution.

[0008] A method for preparing a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane includes the following steps:

[0009] Step 1), the dried polymer raw material is mixed evenly with titanium dioxide (TiO2), and melt extruded and granulated to obtain PPLA / TiO2 masterbatch. The polymer raw material includes polypropylene (PP) and polylactic acid (PLA). By mass fraction, the ratio of polypropylene, polylactic acid and titanium dioxide is (89~90):(8~9):(0.1~0.2).

[0010] In step 1), the drying process includes placing the product at 45-60 °C for 8-14 h.

[0011] In step 1), the melting temperature in melt extrusion granulation is 190~200 ℃.

[0012] Step 2) The dried PPLA / TiO2 masterbatch is added to the meltblown equipment and melt-spun at 180~190 ℃ to obtain PPLA@TiO2 meltblown nonwoven fabric;

[0013] In step 2), the drying temperature is 75~85 ℃ and the drying time is 8~12 h.

[0014] In step 2), the diameter of the spinneret hole in the meltblown equipment is 0.8~0.9 mm.

[0015] Step 3) Using three-channel coaxial electrospinning technology, the inner channel spinning solution, middle channel spinning solution and outer channel spinning solution are spun and sprayed onto the PPLA@TiO2 meltblown nonwoven fabric. After spinning is completed, a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane is obtained. The ratio of the inner channel spinning solution, middle channel spinning solution and outer channel spinning solution by volume is 1:(1~2):(1~3).

[0016] The internal channel spinning solution includes: 4,4'-terephthaloyl phthalic anhydride (TDPA), caffeic acid (CFA), zeolite imidazole ester backbone-8 (ZIF-8), and polycaprolactone (PCL).

[0017] The spinning solution for the middle channel includes: cellulose acetate (CA), lithium chloride (LiCl), N,N-dimethylacetamide (DMAc) and acetone (ACE);

[0018] The external channel spinning solution includes thermoplastic polyurethane (TPU) and N,N-dimethylformamide (DMF).

[0019] In step 3), the method for obtaining the inner channel spinning solution includes: mixing polycaprolactone (PCL) with N,N-dimethylformamide (DMF) and stirring at 60-70 °C for 20-24 h to obtain a PCL solution, wherein the concentration of polycaprolactone in the PCL solution is 18-28 wt%; under light-protected and stirred conditions, adding 4,4'-terephthaloyl phthalic anhydride (TDPA), caffeic acid (CFA), and zeolite imidazole ester skeleton-8 (ZIF-8) to the PCL solution, and maintaining at 50-60 °C for 4-8 h to obtain the inner channel spinning solution, wherein, by mass parts, the ratio of 4,4'-terephthaloyl phthalic anhydride, caffeic acid, and ZIF-8 is 1:(1.5-2):(1.5-2), and the concentration of 4,4'-terephthaloyl phthalic anhydride in the inner channel spinning solution is 0.1-0.5%. wt%.

[0020] In step 3), the method for obtaining the central channel spinning solution includes: uniformly dispersing cellulose acetate (CA) and lithium chloride (LiCl) in a mixture of N,N-dimethylacetamide (DMAc) and acetone (ACE), heating and stirring at 60-70 °C for 6-8 h to obtain the central channel spinning solution, wherein, by mass parts, the ratio of cellulose acetate to lithium chloride is (13-14):(1-2), and the concentration of cellulose acetate in the central channel spinning solution is 13-14 wt%; the N,N-dimethylacetamide / acetone mixture includes N,N-dimethylacetamide and acetone, and by mass parts, the ratio of N,N-dimethylacetamide to acetone in the N,N-dimethylacetamide / acetone mixture is (0.14-0.16):1.

[0021] In step 3), the method for obtaining the external channel spinning solution includes: dispersing thermoplastic polyurethane (TPU) in N,N-dimethylformamide (DMF) and stirring at 60~70 ℃ for 6~8 h to obtain the external channel spinning solution, wherein the concentration of thermoplastic polyurethane in the external channel spinning solution is 15~25 wt%.

[0022] In the above technical solution, the thickness of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane is 0.9~1 mm.

[0023] The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained by the above preparation method.

[0024] The above-mentioned photodynamic heterogeneous composite spiral fiber antibacterial composite membrane is used in antibacterial materials.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] 1. The preparation method of this invention employs a three-channel coaxial electrospinning technique, where the three-component co-spinning solution is spun together and sprayed onto the surface of a PPLA / TiO2 meltblown nonwoven fabric to form a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane with a helical fiber structure. TDPA, acting as a photosensitizer, exhibits strong structural rigidity and abundant conjugated and functional group sites, which facilitates synergistic action with the photosensitizer (CFA) to increase ROS concentration, thereby enhancing antibacterial efficiency and stability. The solid titanium dioxide on the surface of the PPLA / TiO2 meltblown nonwoven fabric undergoes heterogeneous composite formation with the photosensitizer and ZIF-8 in the three-component co-spinning solution. This results in the generation of electron-hole pairs in the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane after light irradiation, synergistically promoting the separation and migration of photogenerated charges, thereby promoting redox reactions to generate ROS and enhancing the antibacterial effect.

[0027] 2. The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained by the present invention has excellent radiation cooling regulation capability and good thermal stability. Under sunny conditions, it is 6.1 ℃ lower than commercial PP cloth on average, and under cloudy conditions, it is still 5.5 ℃ lower than commercial PP cloth on average.

[0028] 3. The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained by this invention has good comfort, with air permeability and moisture permeability of 211.2 mm / s and 4723.2 g⋅(m³), respectively. 2 (24h) -1 It exhibits excellent breathability and moisture permeability. Furthermore, it boasts a filtration efficiency of up to 99.99% for airborne particles with a diameter ≥0.76 μm, effectively blocking harmful substances in the air.

[0029] 4. The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane of the present invention has an antibacterial rate of up to 99.86% against E. coli and S. aureus within 10 minutes under both light and dark conditions, and after being washed 25 times with water, it can still maintain an antibacterial rate of 99.45% under dark conditions. Attached Figure Description

[0030] Figure 1 The XRD patterns (a) of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane and titanium dioxide obtained in Example 2 and the XPS pattern (b) of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 are shown.

[0031] Figure 2The images show the morphology and elemental distribution of the PPLA meltblown nonwoven fabric obtained in Example 1, the PPLA / TiO2 meltblown nonwoven fabric obtained in Example 2, the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2, and the photodynamic spiral fiber antibacterial composite film obtained in Example 3. Among them, (a) is a morphology image of the PPLA meltblown nonwoven fabric obtained in Example 1, (b) is a partial enlarged view of (a), (c) is a morphology image of the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2, (d) is a partial enlarged view of (c), (e) is an elemental distribution map of the PPLA / TiO2 meltblown nonwoven fabric obtained in Example 2, and (f) is a morphology image of the photodynamic spiral fiber antibacterial composite film obtained in Example 3.

[0032] Figure 3 This is a diagram illustrating the preparation process of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2.

[0033] Figure 4 This is a diagram of the equipment used to test the radiation cooling performance of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane and commercial PP cloth obtained in Example 2.

[0034] Figure 5 The graph shows the test results of the radiation cooling performance of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane and commercial PP cloth obtained in Example 2.

[0035] Figure 6 Infrared thermal images of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane and commercial PP cloth obtained in Example 2 under direct sunlight;

[0036] Figure 7 The air permeability (a) and moisture permeability (b) of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 and the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3 are shown.

[0037] Figure 8 The air filtration efficiency of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 and the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3;

[0038] Figure 9 The relationship between the release of H2O2 and •OH in the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 and the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3 and the change over time.

[0039] Figure 10 The colony count (a) and antibacterial rate (b) of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 under light conditions, and the colony count (c) and antibacterial rate (d) under dark conditions.

[0040] Figure 11The colony count (a) and antibacterial rate (b) of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 after 25 washes are compared with those under light conditions and under dark conditions. Detailed Implementation

[0041] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0042] The sources of the drugs involved in the following embodiments are as follows:

[0043] Polypropylene (PP) was purchased from Dongguan Xiang Sheng Plastics Co., Ltd. (Mw: 60000).

[0044] Polylactic acid (PLA) was purchased from Dongguan Qingheng Plastic Raw Materials Co., Ltd. (Mw: 100000).

[0045] Polycaprolactone (PCL) was purchased from Solvay, Inc., USA (Mw: 80000).

[0046] Thermoplastic polyurethane (TPU, granules) was purchased from Suzhou Shengxi Plastic Technology Co., Ltd. (Mw: 200000).

[0047] Zeolite imidazole ester skeleton-8 (ZIF-8), titanium dioxide (TiO2, particles, average particle size 50 nm, analytical grade), N,N-dimethylformamide (DMF, analytical grade), caffeic acid (CFA, analytical grade), cellulose acetate (CA, analytical grade), acetone (ACE, analytical grade), and lithium chloride (LiCl, analytical grade) were all purchased from Kmart Chemical Technology Co., Ltd.

[0048] Gram-negative bacteria: Escherichia coli (ATCC-25922) TM Gram-positive bacteria: Staphylococcus aureus (ATCC-25923) TM Both the PBS buffer (0.01 M, pH 7.2-7.4, sterile) and PBS were purchased from Beijing Aoboxing Biotechnology Co., Ltd.

[0049] In the following embodiments, the instrument model and source are as follows:

[0050] Desktop scanning electron microscope, model: Phenom XL, purchased from Phenom-World, Netherlands;

[0051] X-ray diffractometer, model: D8 Discover, purchased from Bruker GmbH, Germany;

[0052] Xenon lamp (light source), model: SSC-PCX300UV-K21, purchased from Shandong Xinshike Instrument Co., Ltd.

[0053] Example 1 (for comparison)

[0054] A method for preparing PPLA meltblown nonwoven fabric includes the following steps:

[0055] Step 1): Place the polymer raw material in a vacuum drying oven (model: 101-4, purchased from Taizhou Mengyi Automation Equipment Co., Ltd.) and dry it at 50 ℃ for 12 h. Then, add the dried polymer raw material to a single-screw granulator (model: SJ45X36, purchased from Qingdao Keshengda Plastic Machinery Co., Ltd., China) and sequentially perform melting at 200 ℃ (the polymer raw material melts into a liquid state at 200 ℃), extrusion, and pelletizing to complete melt extrusion granulation and obtain PPLA mixed masterbatch. Then, add the PPLA mixed masterbatch to the single-screw granulator and repeat the melt extrusion granulation process 4 times to obtain PPLA masterbatch with uniform particles. The polymer raw materials include polypropylene (PP) and polylactic acid (PLA), with a mass ratio of 90:9. The process parameters of the single-screw granulator during melt extrusion granulation include: Zone 1 of the barrel, temperature 185 ℃; Zone 2 of the barrel, temperature 190 ℃; Zone 3 of the barrel, temperature 200 ℃. ℃ (melting temperature); die head zone 1 temperature is 205 ℃ (discharge temperature); pelletizing speed is 70 r·min -1 The screw speed is 6 r·min -1 .

[0056] Step 2) The PPLA masterbatch is dried in a vacuum drying oven at 80 ℃ for 12 h. After the meltblown equipment is preheated and stabilized at the preset temperature, the dried PPLA masterbatch is added to the feed cylinder of the meltblown equipment (single-screw meltblown machine, purchased from Tianjin Shengruiyuan Machinery Technology Co., Ltd.) and melt-spun at 185 ℃ to obtain PPLA meltblown nonwoven fabric (the dimensions of the PPLA meltblown nonwoven fabric are: length 10 cm, width 5 cm, thickness 0.8 mm). The meltblown equipment has 7 preset temperature zones, namely screw zone 1, screw zone 2, screw zone 3, pipeline, metering pump, meltblown die head and hot air pipe, with corresponding temperatures of 195 ℃, 200 ℃, 205 ℃, 205 ℃, 185 ℃ and 185 ℃ respectively; the diameter of the spinneret of the meltblown die head is 0.9 mm.

[0057] Example 2

[0058] A method for preparing a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane (PPLA / TiO2 / ZIF-8 composite membrane) includes the following steps:

[0059] Step 1): Place the polymer raw material in a vacuum drying oven and dry it at 50 ℃ for 12 h. Then, mix the dried polymer raw material with titanium dioxide (TiO2) evenly and add it to a single-screw granulator. Perform melting at 200 ℃ (the polymer raw material melts into a liquid state at 200 ℃), extrusion, and pelletizing sequentially to complete melt extrusion granulation and obtain PPLA / TiO2 mixed masterbatch. Then, add the PPLA / TiO2 mixed masterbatch back into the single-screw granulator and repeat the melt extrusion granulation process four times to obtain PPLA / TiO2 masterbatch with uniform particles. The polymer raw materials include polypropylene (PP) and polylactic acid (PLA), with a mass ratio of 90:9:0.2 for polypropylene, polylactic acid, and titanium dioxide. The process parameters of the single-screw granulator during melt extrusion granulation include: Zone 1 of the barrel, temperature 185 ℃; Zone 2 of the barrel, temperature 190 ℃; Zone 3 of the barrel, temperature 200 ℃. ℃; Die head zone 1 temperature is 205 ℃; Pelletizing speed is 70 r·min -1 The screw speed is 6 r·min -1 .

[0060] Step 2): The PPLA / TiO2 masterbatch is dried in a vacuum drying oven at 80 ℃ for 12 h. After the meltblown equipment is preheated and stabilized at the preset temperature, the dried PPLA / TiO2 masterbatch is added to the feed cylinder of the meltblown equipment (single-screw meltblown machine) and melt-spun at 185 ℃ to obtain PPLA / TiO2 meltblown nonwoven fabric (the dimensions of the PPLA / TiO2 meltblown nonwoven fabric are: length 10 cm, width 5 cm, thickness 0.8 mm). The meltblown equipment has 7 preset temperature zones, namely screw zone 1, screw zone 2, screw zone 3, pipeline, metering pump, meltblown die head, and hot air pipe, with corresponding temperatures of 195 ℃, 200 ℃, 205 ℃, 205 ℃, 185 ℃, and 185 ℃ respectively; the diameter of the spinneret orifice of the meltblown die head is 0.9 mm.

[0061] Step 3): Inject the inner channel spinning solution, middle channel spinning solution, and outer channel spinning solution (volumes of 4 mL, 6 mL, and 10 mL respectively) into one syringe. The syringes for the inner, middle, and outer channel spinning solutions are different. Connect the three syringes to the three-channel coaxial electrospinning needle of the electrospinning machine (model: JDF105, purchased from Changsha Nayi Instrument Technology Co., Ltd.) to allow the inner, middle, and outer channel spinning solutions to converge, obtaining a three-component co-spun solution. Set the flow rates of the inner, middle, and outer channel spinning solutions to 0.4 mL / h, 0.6 mL / h, and 1 mL / h respectively. Then connect the three-channel coaxial electrospinning needle to the positive terminal of a high-voltage power supply, with a receiving device connected to the negative terminal. Adjust the voltage to 25V. kV, the three-component co-spinning solution was spun and sprayed onto PPLA@TiO2 meltblown nonwoven fabric, and the spinning was completed to obtain a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane. The ratio of the inner channel spinning solution, the middle channel spinning solution and the outer channel spinning solution by volume was 1:1.5:2.5, and the spinning time was 10 h.

[0062] A method for obtaining an internal channel spinning solution includes: mixing polycaprolactone (PCL) with N,N-dimethylformamide (DMF) and stirring at 70 °C for 20 h until the polycaprolactone is completely dissolved to obtain a PCL solution, wherein the concentration of polycaprolactone in the PCL solution is 20 wt%; under light-protected and stirred conditions, adding 4,4'-terephthaloyl phthalic anhydride (TDPA, photosensitizer), caffeic acid (CFA), and zeolite imidazole ester skeleton-8 (ZIF-8) sequentially to the PCL solution, and maintaining at 50 °C for 4 h to obtain an internal channel spinning solution (TDPA / CFA / PCL / ZIF-8 mixture), wherein the concentrations of 4,4'-terephthaloyl phthalic anhydride, caffeic acid, and ZIF-8 in the internal channel spinning solution are 0.1 wt%, 0.2 wt%, and 0.2 wt%, respectively. The structural formula of 4,4'-terephthaloyl phthalic anhydride (TDPA, photosensitizer) is:

[0063] .

[0064] A method for obtaining a mid-channel spinning solution includes: uniformly dispersing cellulose acetate (CA) and lithium chloride (LiCl) in a mixture of N,N-dimethylacetamide (DMAc) and acetone (ACE), heating and stirring at 70 °C for 6 h to obtain a mid-channel spinning solution, wherein, by mass parts, the ratio of cellulose acetate to lithium chloride is 13.89:1.39, and the concentration of cellulose acetate in the mid-channel spinning solution is 13.89 wt%; the N,N-dimethylacetamide / acetone mixture is a mixture of N,N-dimethylacetamide and acetone, and by mass parts, the ratio of N,N-dimethylacetamide to acetone in the N,N-dimethylacetamide / acetone mixture is 0.147:1.

[0065] A method for obtaining an external channel spinning solution includes: dispersing thermoplastic polyurethane (TPU, particles) in N,N-dimethylformamide (DMF) and stirring at 70 °C for 6 h to obtain an external channel spinning solution, wherein the concentration of thermoplastic polyurethane in the external channel spinning solution is 20 wt%.

[0066] The dimensions of the aforementioned photodynamic heterogeneous composite spiral fiber antibacterial composite membrane are: 10 cm in length, 5 cm in width, and 1 mm in thickness.

[0067] X-ray diffraction analysis was performed on the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane and titanium dioxide (particles) obtained in Example 2. XPS testing was also performed on the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2. The results are as follows: Figure 1 As shown, (a) is the XRD spectrum and (b) is the XPS spectrum. Figure 1 As shown in (a), the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 exhibits a characteristic peak at 20°~40°, indicating that titanium dioxide was successfully composited in the PPLA / TiO2 masterbatch, and the process of mixing with polypropylene (PP) and polylactic acid (PLA) and then performing melt extrusion granulation did not destroy the anatase crystal form of titanium dioxide (TiO2). During the melt extrusion granulation process, the polymer raw material melts into a liquid state, coats the solid TiO2, and then synergistically constructs the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane with ZIF-8. Figure 1 As can be seen from (b), the XPS full spectrum of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 contains a Ti2p characteristic peak, indicating that titanium dioxide (TiO2) was successfully composited on PPLA / TiO2 meltblown nonwoven fabric through chemical action.

[0068] Example 3 (for comparison)

[0069] The preparation method of a photodynamic spiral fiber antibacterial composite membrane (PPLA / ZIF-8 composite membrane) is basically the same as step 3) of Example 2, except that "PPLA@TiO2 meltblown nonwoven fabric" is replaced with PPLA meltblown nonwoven fabric of Example 1.

[0070] The PPLA meltblown nonwoven fabric obtained in Example 1, the PPLA / TiO2 meltblown nonwoven fabric obtained in Example 2, the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2, and the photodynamic spiral fiber antibacterial composite film obtained in Example 3 were subjected to SEM and EDS tests. Their morphology and elemental distribution diagrams are shown below. Figure 2 As shown in Figure 2, (a) is a morphological image of the PPLA meltblown nonwoven fabric obtained in Example 1, (b) is a partial magnified view of (a), (c) is a morphological image of the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2, (d) is a partial magnified view of (c), (e) is an elemental distribution diagram of the PPLA / TiO2 meltblown nonwoven fabric obtained in Example 2, and (f) is a morphological image of the photodynamic spiral fiber antibacterial composite film obtained in Example 3. From (a) and (b) of Figure 2, it can be seen that the PPLA meltblown nonwoven fabric obtained in Example 1 exhibits a three-dimensional network structure formed by intertwined fibers, which maintains mechanical stability and provides abundant pore space. Figure 2 As shown in (c) and (d), the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 using the three-channel coaxial electrospinning technology has densely distributed spiral fibers with a uniform distribution. Its surface is coated with dense TiO2 particles, thus forming a heterogeneous structure. Figure 2 As can be seen from (e), Ti elements are uniformly distributed on the PPLA / TiO2 meltblown nonwoven fabric obtained in Example 2. Figure 2 As can be seen from (f), the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3 also showed spiral structure fibers, but no obvious heterogeneous structure was observed.

[0071] Figure 3 The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 ( Figure 3 The diagram shows the preparation process of the "antibacterial composite membrane" shown in the image. Figure 3 It can be seen that the present invention combines the inner channel spinning solution, the middle channel spinning solution, and the outer channel spinning solution at the three-channel coaxial electrospinning needle to obtain a three-component co-spinning solution. Figure 3 The dots in the first image on the right), and then through three-channel coaxial electrospinning technology, the three-component co-spun solution is spun together and sprayed onto PPLA@TiO2 meltblown nonwoven fabric. Figure 3On meltblown nonwoven fabric, a double-layer composite membrane with helical fiber structure and multiple synergistic antibacterial functions is constructed, providing a feasible design idea for photodynamic antibacterial materials.

[0072] Outdoor radiative cooling performance test: Outdoors, a polystyrene foam board with heat insulation and uniform thickness was used as the sample stage. Four identical and symmetrically positioned cubic grooves were cut from the center of the sample stage (the dimensions of the cubic grooves are: length 4 cm, width 4 cm, depth 1 cm). The surface of the sample stage (including the cubic grooves) was tightly wrapped with aluminum foil to accurately record and reflect the heat generated by solar radiation in the surrounding environment. A K-type thermocouple (model: DM6801, purchased from Shengli Company) temperature probe was placed inside the cubic groove. Then, a sample cut to 5 cm long × 5 cm wide × 1 mm thick was placed on top of the cubic groove, ensuring that the sample did not directly contact the temperature probe and that the samples did not interfere with each other. A layer of PE film was then covered on the surface of the sample to ensure that the sample and the temperature probe were completely sealed (according to the zeroth law of thermodynamics: the temperature probe and the sample surface will reach radiative thermal equilibrium, that is, the temperature of the temperature probe is equal to the temperature of the sample surface). The sample stage was then constructed, and the outdoor radiative cooling performance test was conducted. Among them, the samples were either test samples or control samples. The test sample was the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2, and the control sample was commercial PP cloth. The test location was Tianjin University of Technology, and the test time was September 5, 2025 (cloudy, temperature: 20~27 ℃) and September 6, 2025 (sunny, temperature: 22~30 ℃). Figure 4 The "portable DC power supply" provides power to the solar radiometer, K-type thermocouples, and data acquisition equipment. When setting up the sample stage, place one sample to be tested on each of two randomly selected cubic recesses. Figure 4 The "sample" was placed in one of the two remaining cubic recesses, and a control sample was placed in each of the two remaining recesses. Changes in solar power in the environment were monitored in real time using a solar radiometer (photoelectric total solar radiation sensor, model: RS485, purchased from Prison). A K-type thermocouple ( Figure 4 The thermocouple (as shown in the image) detects the temperature change on the surface of the test sample or control sample, and the test results are as follows: Figure 5 As shown.

[0073] Figure 5 The graph shows the radiation cooling performance test results of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane and commercial PP cloth obtained in Example 2. In the graph, (a) represents the real-time temperature change (T) during the cloudy day test, and (b) represents the temperature difference (ΔT, i.e., temperature difference = ...) during the cloudy day test. Figure 5(a) The real-time temperature change of the commercial PP fabric minus the real-time temperature of the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2; (c) The real-time temperature change (T) of the sunny day test; (d) The temperature difference (ΔT, i.e., temperature difference = Figure 5 The change in temperature of the commercial PP cloth in (c) minus the change in temperature of the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2. Figure 5 The "solar energy" in this context corresponds to changes in the power of sunlight in the environment. Figure 5 In (a) and (c), "commercial PP fabric" corresponds to the average surface temperature of two commercial PP fabrics. Figure 5 In (a) and (c), “Example 2” corresponds to the average surface temperature of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in two Examples 2. Figure 5 In (b) and (d), “temperature difference” corresponds to the temperature difference between commercial PP cloth and the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2.

[0074] By Figure 5 The average of the temperature differences (ΔT) across all time periods in (b) was calculated, and it was found that the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2 under cloudy conditions had an average temperature reduction of 5.5 ℃ compared to commercial PP fabric. Figure 5 The average of the temperature differences (ΔT) across all time periods in (d) was calculated, revealing that the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2 under sunny conditions had an average temperature reduction of 6.1 ℃ compared to commercial PP fabric. Figure 5 As shown in (d), under sunny conditions, with increased solar radiation and higher solar power, the real-time temperature difference dynamics of the commercial PP fabric and the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2 exhibit a similar regularity to those under cloudy conditions, with only slight variations in the absolute value of the temperature difference. Therefore, compared with existing commercial PP fabrics, the photodynamic heterogeneous composite spiral fiber antibacterial composite film obtained in Example 2 demonstrates superior radiative cooling regulation capabilities and exhibits good applicability and thermal stability in environments with varying temperatures.

[0075] Outdoor Human Comfort Test: Outdoors, a sample measuring 10 cm long × 5 cm wide × 0.1 cm thick and a commercial PP cloth were respectively attached to the left and right forearms of a human body. Under direct sunlight (the temperature of direct sunlight was 32 ℃), the temperature change of the human body was measured over 25 minutes using an infrared thermal imager (model: PCE-TC 33N, purchased from Beijing Shidaishanfeng Technology Co., Ltd.). Infrared thermal images were captured at different time points of direct sunlight (0 min, 5 min, 10 min, 15 min, 20 min, and 25 min) to evaluate the radiative cooling regulation capability of the sample. The sample was the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2. The test location was outdoors at Tianjin University of Technology; the test date was September 8, 2025, and the test temperature was 32 ℃. A comparison of the radiative cooling regulation capabilities of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 (left) and the commercial PP cloth (right) under direct sunlight is shown in the figure. Figure 6 As shown. By Figure 6 It can be seen that the surface temperature of commercial PP fabric gradually increased from 27.5 ℃ at min 0 to 29.9 ℃, and reached a stable temperature (29.9 ℃) at min 25; while the surface temperature of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 gradually increased from 25.4 ℃ at min 0 to 27.8 ℃ and tended to stabilize (at min 25). Compared with commercial PP fabric, the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 can effectively maintain a temperature difference of 2.1 ℃. This indicates that the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 has better radiative cooling regulation capability and better meets the comfort requirements of antibacterial materials under sunlight conditions.

[0076] The photodynamic heterogeneous composite spiral fiber antibacterial composite membranes obtained in Example 2 and Example 3 were subjected to air permeability and moisture permeability tests. The air permeability test was conducted according to standard ISO 9237:1995, with the photodynamic heterogeneous composite spiral fiber antibacterial composite membranes obtained in Example 2 and Example 3 serving as the "sample" in "Step 9" of standard ISO 9237:1995. The moisture permeability test was conducted according to standard ASTM E96, with the photodynamic heterogeneous composite spiral fiber antibacterial composite membranes obtained in Example 2 and Example 3 serving as the "sample" in "Step 9" of standard ASTM E96. The results of the air permeability and moisture permeability tests are as follows: Figure 7 As shown, (a) represents the air permeability test results, and (b) represents the moisture permeability test results. Figure 7As shown in (a), the air permeability of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 and the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3 are 211.2 mm / s and 189.7 mm / s, respectively. Figure 7 As shown in (b), the moisture permeability of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 and the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3 are 4723.2 g⋅(m²). 2 (24h) -1 and 4383.6 g⋅(m 2 (24h) -1 The air permeability and moisture permeability of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 are significantly better than those in Example 3. This indicates that in the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2, the dispersion effect of particulate TiO2 reduces the crystallinity of PPLA masterbatch, increases the inter-chain gaps in PPLA masterbatch, effectively increases the free volume for air and water molecule permeation, and achieves better air permeability and moisture permeability, thus better meeting comfort requirements.

[0077] A membrane sample measuring 10 cm in length, 5 cm in width, and 1 mm in thickness was sealed in the fixture of an automatic filter media tester (model: TSI-8127, purchased from Suzhou Huayu Purification Equipment Co., Ltd.). DEHS aerosol-based graded filtration efficiency testing was performed. The membrane sample was either the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 or the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3. The obtained air filtration efficiency is as follows: Figure 8 As shown, by Figure 8 It can be seen that when the diameter of airborne particles is 0.76 μm, the filtration efficiency of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 can reach 99.99%; while the filtration efficiency of the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3 can only reach 99.99% when the diameter of airborne particles is 2.26 μm. This indicates that the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 exhibits better air filtration performance, which can be attributed to the addition of TiO2 optimizing the multi-level pore size distribution of the micro-nano fiber membrane, improving the membrane's interception efficiency for small molecules, and further enhancing its filtration performance. In addition, it also enhances its filtration effect on airborne particulate matter and harmful substances (such as PM2.5, bacteria, etc.).

[0078] To quantify the photoactive storage capacity of the composite membrane, it was irradiated with a xenon lamp simulating sunlight for 1 hour inside a light-shielding enclosure to activate the release of reactive oxygen species (ROS). The xenon lamp was then turned off, and the membrane was kept in darkness for 100 minutes. The concentrations of •OH and H2O2 inside the light-shielding enclosure under dark conditions were measured using a UV-Vis spectrophotometer (model: Evolution™ One Plus, purchased from Thermo Fisher Scientific, USA). The composite membrane was either the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 or the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3. The relationship between the release of H2O2 and •OH of the composite membrane under dark conditions and time is shown below. Figure 9 Figures (a) and (c) show the relationship between H2O2 release and time, where (a) represents the relationship between •OH release and time. As can be seen from the figures, in the first 15 minutes, the release of both H2O2 and •OH from the composite membrane increases sharply. With further extension of time, the release of ROS (ROS) from the composite membrane... total The amount of H2O2 (≈H2O2 + •OH) increases slowly and reaches saturation at 100 min. At this point, the amount of H2O2 and •OH released by the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 is 0.609 mg / g and 14.245 mg / g, respectively, which is higher than that of the photodynamic spiral fiber antibacterial composite membrane obtained in Example 3 (the release amounts of H2O2 and •OH are 0.572 mg / g and 13.569 mg / g, respectively). This indicates that the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 has a higher ROS release rate.

[0079] The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 was subjected to a light-dark fatigue cyclic irradiation test. The specific conditions were as follows: Inside a light-shielding enclosure, the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 was first irradiated under simulated sunlight conditions with a xenon lamp for 100 min, then the xenon lamp was turned off, and the membrane was kept in darkness for 100 min to conduct a light-dark alternating experiment. The concentrations of •OH and H2O2 within the light-shielding enclosure under xenon lamp irradiation (light conditions) and darkness conditions for 200 min were measured using a UV-Vis spectrophotometer (model: Evolution™ One Plus, purchased from Thermo Fisher Scientific, USA). The results are as follows: Figure 9Figures (b) and (d) show the relationship between the release of H2O2 and time, and (d) shows the relationship between the release of •OH and time. As can be seen from the figures, •OH and H2O2 are generated in the photodynamic heterogeneous spiral fiber antibacterial composite membrane obtained in Example 2 during xenon lamp irradiation, and increase slowly within 100 min under dark conditions. This indicates that the photodynamic heterogeneous spiral fiber antibacterial composite membrane obtained in Example 2 can still stably release •OH and H2O2 under dark conditions, and the release of H2O2 and •OH reaches saturation at 200 min, at 0.733 mg / g and 20.523 mg / g, respectively. This suggests that the antibacterial activity of the photodynamic heterogeneous spiral fiber antibacterial composite membrane obtained in Example 2 is not significantly reduced under dark conditions.

[0080] Method for testing antibacterial effect: Take 1 mL of bacterial culture (incubated overnight beforehand, with a viable count of 10⁻⁶). 6 ~10 7 CFU / mL was inoculated into sterilized soybean broth (composed of 1.5 g tryptone, 0.5 g soybean peptone, 0.5 g sodium chloride, and 100 mL deionized water) and incubated at 37±2 ℃ in a constant temperature shaking incubator (110 rpm) for 25 h to obtain bacterial suspension. The bacteria were either Escherichia coli or Staphylococcus aureus. 1 mL of the bacterial suspension was then added to 9 mL of soybean broth to obtain the first dilution; 1 mL of the first dilution was then added to 9 mL of soybean broth to obtain the second dilution. The second dilution was diluted twice with PBS buffer to obtain a final viable count of 10-1. 5 The third dilution solution (CFU / mL) was prepared by first adding 18.6 mL of PBS buffer to an Erlenmeyer flask, then adding 0.1 g of sample and 1.35 mL of the third dilution solution. The flask was placed in a 25 °C constant temperature shaking incubator (150 rpm) and incubated under light for 10 min. At the 1, 5, and 10 mins of incubation, 1 mL of culture was collected and diluted twice with PBS buffer to obtain a viable count of 10⁻⁶ CFU / mL. 3 The fourth dilution (CFU / mL) was used. The fourth dilution was tested for antibacterial activity under light or dark conditions. The sample was the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2, which had undergone UV sterilization treatment in a clean bench.

[0081] Antibacterial test under light conditions: Under xenon lamp simulated sunlight, 0.2 mL of the fourth dilution was spread onto agar medium and then placed in a constant temperature shaking incubator at 37 ℃ for 25 h. The number of bacteria in the agar medium was counted to calculate the antibacterial rate.

[0082] Antibacterial test under dark conditions: 0.2 mL of the fourth dilution was spread onto agar medium inside a light-proof enclosure and then incubated in a constant temperature shaking incubator at 37 ℃ for 25 h. The number of bacteria in the agar medium was counted to calculate the antibacterial rate. The fourth dilution corresponding to the culture medium taken at 1 min of incubation was designated as fourth dilution-1 min, the fourth dilution corresponding to the culture medium taken at 5 min of incubation was designated as fourth dilution-5 min, and the fourth dilution corresponding to the culture medium taken at 10 min of incubation was designated as fourth dilution-10 min.

[0083] The antibacterial test results of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 under light conditions showed the colony count and antibacterial rate against E. coli and S. aureus as follows: Figure 10 As shown in (a) and (b), the colony counts and antibacterial rates of the strains against E. coli and S. aureus obtained under dark conditions are as follows: Figure 10 As shown in (c) and (d). By Figure 10 As shown in (a) and (b), the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 can achieve an antibacterial rate of 99.99% against E. coli and S. aureus within 10 minutes under light conditions; and it can achieve an antibacterial rate of 99.99% against E. coli and S. aureus within 10 minutes under dark conditions (such as...). Figure 10 As shown in (c) and (d), the antibacterial rates against E. coli and S. aureus were 99.86% and 99.99%, respectively. This indicates that the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 has excellent antibacterial efficiency, which is attributed to the synergistic effect of the photosensitizer (TDPA) and the photosactive agent (CFA) to achieve excellent antibacterial effects. When TiO2 is further added and heterogeneously composited with the liquid photosensitizer and photosactive agent, the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 generates electron-hole pairs after light irradiation, which synergistically promotes the separation and migration of photogenerated charges, thereby promoting the redox reaction to generate ROS and enhance the antibacterial effect.

[0084] The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 was washed 25 times with water according to standard GB / T 8629-2017, followed by an antibacterial effect test. The antibacterial effect test after 25 washes was basically the same as the "antibacterial effect test," the only difference being that the sample was the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 after 25 washes. After washing 25 times with water, the antibacterial test under light conditions yielded the following results regarding the colony count and antibacterial rate against *E. coli* and *S. aureus*: Figure 11As shown in (a) and (b), the colony counts and antibacterial rates of the strains against E. coli and S. aureus obtained under dark conditions are as follows: Figure 11 As shown in (c) and (d).

[0085] Depend on Figure 11 As shown in (a) and (b), the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2, after being washed 25 times, still maintains an antibacterial rate of 99.99% against E. coli and S. aureus after 10 minutes under light conditions. Its antibacterial rate after 10 minutes under dark conditions (such as...) is significantly higher. Figure 11 As shown in (c) and (d), the antibacterial rates against E. coli and S. aureus were 99.55% and 99.99%, respectively. This indicates that the ZIF-8 embedded in the spiral fiber successfully protected the photoactive agent (CFA), and the heterostructure formed by adding TiO2 can effectively promote the generation of ROS, so that the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained in Example 2 still maintains a high level of antibacterial performance after 25 water washes.

[0086] The present invention has been described above by way of example. It should be noted that any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort without departing from the core of the present invention fall within the protection scope of the present invention.

Claims

1. A method for preparing a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane, characterized in that, Includes the following steps: Step 1) The dried polymer raw material is mixed evenly with titanium dioxide, and then melt-extruded and granulated to obtain PPLA / TiO2 masterbatch. The polymer raw material includes polypropylene and polylactic acid. The ratio of polypropylene, polylactic acid and titanium dioxide by mass is (89~90):(8~9):(0.1~0.2). Step 2) The dried PPLA / TiO2 masterbatch is added to the meltblown equipment and melt-spun at 180~190 ℃ to obtain PPLA@TiO2 meltblown nonwoven fabric; Step 3) Using three-channel coaxial electrospinning technology, the inner channel spinning solution, middle channel spinning solution and outer channel spinning solution are spun and sprayed onto the PPLA@TiO2 meltblown nonwoven fabric. After spinning is completed, a photodynamic heterogeneous composite spiral fiber antibacterial composite membrane is obtained. The ratio of the inner channel spinning solution, middle channel spinning solution and outer channel spinning solution by volume is 1:(1~2):(1~3). The internal channel spinning solution includes: 4,4'-terephthaloyl phthalic anhydride, caffeic acid, zeolite imidazole ester backbone-8 and polycaprolactone; The medium-channel spinning solution includes: cellulose acetate, lithium chloride, N,N-dimethylacetamide, and acetone; The external channel spinning solution includes thermoplastic polyurethane and N,N-dimethylformamide.

2. The preparation method according to claim 1, characterized in that, In step 1), the drying process includes: placing the container at 45-60 °C for 8-14 h; In step 2), the drying temperature is 75~85 ℃ and the drying time is 8~12 h.

3. The preparation method according to claim 1, characterized in that, In step 1), the melting temperature in melt extrusion granulation is 190~200 ℃.

4. The preparation method according to claim 1, characterized in that, In step 2), the diameter of the spinneret hole in the meltblown equipment is 0.8~0.9 mm.

5. The preparation method according to claim 1, characterized in that, In step 3), the method for obtaining the inner channel spinning solution includes: mixing polycaprolactone with N,N-dimethylformamide and stirring at 60-70 °C for 20-24 h to obtain a PCL solution, wherein the concentration of polycaprolactone in the PCL solution is 18-28 wt%; under light-protected and stirred conditions, adding 4,4'-terephthalic anhydride, caffeic acid, and zeolite imidazole ester skeleton-8 to the PCL solution and maintaining at 50-60 °C for 4-8 h to obtain the inner channel spinning solution, wherein, by mass fraction, the ratio of 4,4'-terephthalic anhydride, caffeic acid, and ZIF-8 is 1:(1.5-2):(1.5-2), and the concentration of 4,4'-terephthalic anhydride in the inner channel spinning solution is 0.1-0.5 wt%.

6. The preparation method according to claim 1, characterized in that, In step 3), the method for obtaining the medium-channel spinning solution includes: uniformly dispersing cellulose acetate and lithium chloride in a mixture of N,N-dimethylacetamide and acetone, heating and stirring at 60-70 °C for 6-8 h to obtain the medium-channel spinning solution, wherein, by mass parts, the ratio of cellulose acetate to lithium chloride is (13-14):(1-2), and the concentration of cellulose acetate in the medium-channel spinning solution is 13-14 wt%; the N,N-dimethylacetamide / acetone mixture includes N,N-dimethylacetamide and acetone, and by mass parts, the ratio of N,N-dimethylacetamide to acetone in the N,N-dimethylacetamide / acetone mixture is (0.14-0.16):

1.

7. The preparation method according to claim 1, characterized in that, In step 3), the method for obtaining the external channel spinning solution includes: dispersing thermoplastic polyurethane in N,N-dimethylformamide and stirring at 60~70 °C for 6~8 h to obtain the external channel spinning solution, wherein the concentration of thermoplastic polyurethane in the external channel spinning solution is 15~25 wt%.

8. The photodynamic heterogeneous composite spiral fiber antibacterial composite membrane obtained by the preparation method according to any one of claims 1 to 7.

9. The thickness of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane as described in claim 8 is 0.9~1 mm.

10. The application of the photodynamic heterogeneous composite spiral fiber antibacterial composite membrane as described in claim 8 in antibacterial materials.

Images