An antibacterial and anticolloid adsorption polyester fiber, its preparation method, and its application in reverse osmosis membrane flow channel fabric.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-14
- Publication Date
- 2026-08-14
AI Technical Summary
然而，传统涤纶流道布在长期运行中存在两个突出问题
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Figure CN122564786A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of high-performance polyester fiber technology, belonging to patent classification number D01F6 / 92, specifically to an antibacterial and anticolloid adsorption polyester fiber, its preparation method, and its application in reverse osmosis membrane flow channel fabric. Background Technology
[0002] Reverse osmosis membrane separation technology has been widely applied in seawater desalination, industrial wastewater reuse, and pure water production. In spiral-wound reverse osmosis membrane elements, the feed-side flow channel fabric (mesh fabric) plays a role in supporting the membrane, constructing the feed channel, and promoting turbulence. The mainstream material for this fabric is polyester (polyethylene terephthalate, PET) monofilament woven fabric. Polyester has advantages such as high mechanical strength, dimensional stability, good hydrolysis resistance, and low cost. However, traditional polyester flow channel fabrics have two prominent problems in long-term operation. Firstly, they are prone to microbial growth: after organic matter and nutrients in the feed water adhere to the surface of the flow channel fabric, microorganisms rapidly multiply and secrete extracellular polymers, forming a dense biofilm, causing biofouling of the membrane element. This manifests as a decrease in permeate flux, an increase in inlet and outlet pressure differential, necessitating frequent chemical cleaning, and shortening membrane life. Secondly, it easily adsorbs charged colloids in the water: Polyester is a hydrophobic and inert polymer with poor surface hydrophilicity and difficult charge state control. Clay particles, humic organic matter and microorganisms in the influent are mostly negatively charged under normal water pH conditions, which easily adhere to and deposit on the flow channel and membrane surface, superimposed with biofouling, further aggravating membrane fouling and increasing operating energy consumption. Summary of the Invention
[0003] The purpose of this invention is to provide an application of antibacterial and anticolloid adsorption polyester fiber in reverse osmosis membrane flow channel fabric, so as to solve the technical problems mentioned in the background art.
[0004] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing antibacterial and anticolloid adsorption polyester fiber includes the following steps: (1) The silver-zinc oxide heterojunction composite antibacterial agent, stabilizer and first polyethylene terephthalate chips were melt-blended and pelletized to obtain antibacterial functional masterbatch; (2) The antibacterial functional masterbatch is mixed with second polyethylene terephthalate chips and then melt-spun, cooled and solidified, stretched and heat-set to obtain antibacterial polyester fiber; (3) The antibacterial polyester fiber is immersed in a buffer solution containing dopamine hydrochloride, zwitterionic polymer and zwitterionic grafted mesoporous silica for surface co-deposition treatment to obtain the product.
[0005] Preferably, the antibacterial masterbatch in step (1) is vacuum dried before entering step (2) for melt spinning so that the moisture content of the antibacterial masterbatch is ≤50ppm.
[0006] Preferably, the stabilizing agent in step (1) includes hindered phenolic primary antioxidant, phosphite secondary antioxidant, and surface passivating agent for passivating active sites on the solid surface of zinc oxide. The surface passivating agent is a phosphate ester compound or a phosphite ester compound.
[0007] Preferably, the silver-zinc oxide heterojunction composite antibacterial agent described in step (1) is prepared by the following photodeposition method: Nano-zinc oxide is dispersed in a solution containing silver ions and a hole sacrificial agent, and photochemical reduction deposition is performed under ultraviolet light irradiation, so that metallic silver nanoparticles are deposited in situ on the surface of the nano-zinc oxide.
[0008] Preferably, the hole sacrificial agent is anhydrous ethanol; The mass ratio of the first polyethylene terephthalate chips, silver-zinc oxide heterojunction composite antibacterial agent, and stabilizing agent is 90:(8-12):(1-2).
[0009] Preferably, in step (2), the mass ratio of the second polyethylene terephthalate chips to the antibacterial masterbatch is 1:(0.2-0.3).
[0010] Preferably, the buffer solution in step (3) is a weakly alkaline buffer solution; The surface co-deposition treatment was performed under oxygen-permeable conditions; The zwitterionic polymer is polysulfobetaine.
[0011] Preferably, the method for preparing zwitterionic grafted mesoporous silica in step (3) is as follows: N,N-dimethyl-3-aminopropyltrimethoxysilane is reacted with 1,3-propanesulfonyl lactone in a ring-opening reaction to obtain sulfobetaine-type silane, which is then grafted onto the inner and outer surfaces of the pores of mesoporous silica.
[0012] The mass ratio of dopamine hydrochloride, zwitterionic polymer, and zwitterionic grafted mesoporous silica is (1-1.5):1:(0.8-1.2).
[0013] An antibacterial and anticolloid-adsorption polyester fiber is prepared by the above method.
[0014] Application of an antibacterial and anticolloid adsorption polyester fiber in reverse osmosis membrane flow channel fabric.
[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. Regarding antibacterial properties, the key to the highly efficient and long-lasting bactericidal effect of the fibers in this invention lies in the silver-zinc oxide heterostructure constructed during the functionalization treatment that endows the fibers with antibacterial capabilities. Unlike a simple mixture of silver and zinc components, this invention allows metallic silver to adhere firmly to the zinc oxide surface in the form of nanoparticles, forming a large-area, tightly contacted interface. The difference in the solubility characteristics of the silver and zinc oxide phases, coupled with the electrochemical coupling formed by the tight contact, jointly influences the dissolution behavior of the active components, causing antibacterial active substances to be slowly and continuously released to the fiber surface in water (with silver ions as the main contributor and zinc ions as a secondary contributor in terms of antibacterial contribution). After these active substances come into contact with microorganisms, they disrupt their cell structure and interfere with their normal metabolism, exhibiting broad-spectrum and highly efficient inhibitory and bactericidal effects against Escherichia coli and Staphylococcus aureus. Because metallic silver is firmly anchored to the zinc oxide surface, inhibiting the aggregation of nanoparticles, the antibacterial rate of the fibers remains at a high level even after repeated acid and alkali washing, and the antibacterial performance does not significantly decrease with time and washing.
[0016] 2. Regarding the inhibition of colloidal adsorption in water, reverse osmosis feed water, especially seawater and high-salinity wastewater, has high salt content and strong ionic strength. In such cases, relying on the net surface charge to repel colloids becomes largely ineffective due to the intense compression of the double electric layer. Therefore, this invention constructs an antifouling layer on the fiber surface using a hydrophilic amphoteric ionic structure. This layer carries equal amounts of positive and negative charges, is electrically neutral overall, and yet, through the strong interaction between ions and water molecules, firmly binds a dense and orderly water film to the surface. This water film acts like an invisible water cushion, separating colloids such as clay, humus, and microorganisms from the fiber surface. For colloids to adhere, they must first disrupt this hydration structure, making adhesion extremely difficult. Furthermore, the effectiveness of this hydration barrier is independent of the water's salt content, maintaining stable performance even in high-salinity feed water, thus allowing the fiber to achieve reliable and durable anti-colloid adsorption capabilities under real-world operating conditions.
[0017] 3. The polydopamine-zwitterionic coating applied to the fiber surface to prevent fouling will cover the antibacterial particles exposed on the surface and add an extra diffusion path between the particles and the water. If the coating is too thick or too dense, the channel for the surface antibacterial ions to move outward is blocked, and less antibacterial substance can come into contact with the water, thus reducing the antibacterial effect and durability of the fiber. To address this technical problem, this invention introduces zwitterionic-grafted mesoporous silica into the antifouling coating. This silica, filled with water-filled nanopores, is a highly hydrophilic micro-region where ions can easily diffuse. Incorporating it into the coating significantly reduces the overall resistance to silver and zinc ion transport, allowing for smoother release of surface antibacterial substances. The zwitterionic grafts provide hydrophilicity, strongly hydrating and creating a high-bound-water-content local microenvironment on the inner and outer surfaces of the pores. This keeps the pores fully hydrated and strengthens the aqueous pathways upon which ion transport depends (the polydopamine anchoring layer itself is hydrophilic, so water-filled pores are not a problem; the zwitterionic grafts further enhance local hydrophilicity and bound-water content, rather than compensating for the hydrophobicity of the matrix). Simultaneously, the antifouling properties of the pore openings delay the pores from being adsorbed and blocked by pollutants, extending the channel's open time. Together, they form a highly hydrated micro-region that facilitates ion transport, helps block large colloids, and is resistant to fouling and clogging. This is something that neither mesoporous silica nor zwitterion layer alone can achieve at the same time. Attached Figure Description
[0018] Figure 1 This is a SEM image of the antibacterial and anticolloid-adsorbing polyester fiber prepared in Example 1 of the present invention. Detailed Implementation
[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0020] In a specific embodiment, the hindered phenolic primary antioxidant is Irganox 1010, and the phosphite secondary antioxidant is bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (PEP-36).
[0021] Example 1
[0022] A method for preparing antibacterial and anticolloid adsorption polyester fiber includes the following steps: (1) Take 20g of nano zinc oxide with an average particle size of about 30nm, ultrasonically disperse it in a mixture of 4L deionized water and 4L anhydrous ethanol (as a hole sacrificial agent) to make a slurry, add 0.96g of silver nitrate, and magnetically stir in the dark for 30min to fully enrich silver ions on the surface of zinc oxide. Then, under strong stirring, irradiate with a 365nm ultraviolet lamp for about 4h to carry out photochemical reduction deposition, so that photogenerated electrons reduce silver ions in situ to metallic silver nanoparticles and deposit them on the surface of zinc oxide to form a closely contacted heterojunction. After filtration, washing with deionized water, and vacuum drying at 60℃ for 12h, a silver-zinc oxide heterojunction composite antibacterial agent is obtained. Then, take the silver-zinc oxide heterojunction composite antibacterial agent and stabilizing agent (hindered phenolic main antioxidant, phosphite auxiliary antioxidant, and phosphate ester zinc oxide surface passivating agent in a mass ratio of 7:7:1) and mix them with fully dried first polyethylene terephthalate chips (first polyethylene terephthalate chips, silver-zinc oxide heterojunction composite antibacterial agent, and stabilizing agent in a mass ratio of 90:11:1.8). In a twin-screw extruder, melt blend (feeding section 255℃, melting section 268℃, mixing section 276℃, metering section 272℃, die head 272℃), high shear dispersion, extrusion, water cooling, and pelletizing to obtain antibacterial functional masterbatch. The masterbatch is sealed and stored in a moisture-proof environment.
[0023] The above-mentioned antibacterial masterbatch was vacuum dried at 140℃ under nitrogen protection for 10 hours until the moisture content was ≤50ppm and then transferred hot to the hopper to prevent secondary moisture absorption. The dried masterbatch was then thoroughly mixed with the second polyethylene terephthalate chips that had been dried in the same manner (the mass ratio of the second PET chips to the antibacterial masterbatch was 1:0.28). The mixture was then fed into a screw spinning machine for melt spinning (feeding section 260℃, melting section 273℃, metering section 278℃, spinning box and spinneret assembly 280℃). The melt was metered by a metering pump, extruded by a spinneret, and then rapidly cooled and solidified in a 25℃ water bath to obtain nascent monofilaments (winding speed approximately 50m / min). Subsequently, the nascent monofilaments were sequentially stretched by three stages of hot rollers (roller temperatures of 85℃, 110℃, and 130℃, with a total stretching ratio of 3.8 times) to orient the macromolecular chains and induce crystallization. Finally, the structure was fixed by heat setting at 190℃ for 50s, and the antibacterial polyester fiber was obtained by winding.
[0024] (3) Take 20.7g of N,N-dimethyl-3-aminopropyltrimethoxysilane and dissolve it in 80mL of anhydrous acetonitrile. Under nitrogen protection, slowly add 12.8g of 1,3-propanesulfonyl lactone and stir at 65℃ for 14h. Remove the solvent under reduced pressure to obtain sulfobetaine-type silane. Separately, take 10g of mesoporous silica (particle size 20-50nm) and ultrasonically disperse it in a mixture of 190mL of ethanol and 10mL of deionized water for 20min. Add glacial acetic acid to adjust the pH to 4.5. Add 2g of the above sulfobetaine-type silane slowly over 1.5h under low-speed stirring. After the addition is complete, stir at 65℃ for 12h. After adjusting to neutral, centrifuge, wash with ethanol, and dry under vacuum at 60℃ to obtain zwitterionic grafted mesoporous silica.
[0025] Take 10g of antibacterial polyester fiber and immerse it in 200mL of 0.01mol / L dilute nitric acid and rinse it at room temperature for 2min. After taking it out, rinse it repeatedly with deionized water until the washing solution is neutral. Air dry at room temperature to obtain pretreated fiber. 1.1 g of zwitterionic grafted mesoporous silica was added to 100 mL of deionized water and ultrasonically dispersed at 100 W for 20 min to prepare a uniform pre-dispersion. 6.06 g of tris(hydroxymethyl)aminomethane was weighed and dissolved in 800 mL of deionized water. The pH was adjusted to 8.5 with dilute hydrochloric acid to prepare a Tris buffer solution. The pre-dispersion solution was poured into this buffer solution, and then 1.4 g of dopamine hydrochloride and 1.0 g of polysulfobetaine (weight average molecular weight approximately 30,000 Da) were added sequentially. The solution was brought to a final volume of 1 L with deionized water and stirred for 10 min until homogeneous, yielding a treatment solution. The pretreated fibers were completely immersed in this treatment solution and impregnated at room temperature with open ventilation for 6 h. During impregnation, the fibers were gently stirred at 150 r / min and turned over every h. After impregnation, the fibers were removed and repeatedly rinsed with deionized water until the washing solution was colorless and free of floating color. The fibers were then vacuum dried at 60 °C for 6 h to obtain antibacterial and anticolloid-adsorption polyester fibers.
[0026] Example 2
[0027] A method for preparing antibacterial and anticolloid adsorption polyester fiber includes the following steps: (1) Take 20g of nano zinc oxide with an average particle size of about 30nm, ultrasonically disperse it in a mixture of 4L deionized water and 4L anhydrous ethanol (as a hole sacrificial agent) to make a slurry, add 0.96g of silver nitrate, and magnetically stir in the dark for 30min to fully enrich silver ions on the surface of zinc oxide. Then, under strong stirring, irradiate with a 365nm ultraviolet lamp for about 4h to carry out photochemical reduction deposition, so that photogenerated electrons reduce silver ions in situ to metallic silver nanoparticles and deposit them on the surface of zinc oxide to form a closely contacted heterojunction. After filtration, washing with deionized water, and vacuum drying at 60℃ for 12h, a silver-zinc oxide heterojunction composite antibacterial agent is obtained. Next, take the silver-zinc oxide heterojunction composite antibacterial agent and stabilizing agent (hindered phenolic main antioxidant, phosphite auxiliary antioxidant, and phosphate ester zinc oxide surface passivating agent in a mass ratio of 7:7:1) and mix them with fully dried first polyethylene terephthalate chips (first polyethylene terephthalate chips, silver-zinc oxide heterojunction composite antibacterial agent, and stabilizing agent in a mass ratio of 90:9:1.2). In a twin-screw extruder, melt blend (feeding section 255℃, melting section 268℃, mixing section 276℃, metering section 272℃, die head 272℃), high shear dispersion, extrusion, water cooling, and pelletizing to obtain antibacterial functional masterbatch. The masterbatch is sealed and stored in a moisture-proof environment.
[0028] (2) The above-mentioned antibacterial masterbatch was vacuum dried at 140°C under nitrogen protection for 10 hours until the moisture content was ≤50ppm and then transferred to the hopper in a hot state to prevent secondary moisture absorption. The dried masterbatch was thoroughly mixed with the second polyethylene terephthalate chips that had been dried in the same way (the mass ratio of the second PET chips to the antibacterial masterbatch was 1:0.23). The mixture was fed into a screw spinning machine for melt spinning (feeding section 260°C, melting section 273°C, metering section 278°C, spinning box and spinneret assembly 280°C). The melt was metered by a metering pump, extruded by a spinneret, and then rapidly cooled and solidified in a 25°C water bath to obtain nascent monofilament (winding speed about 50m / min). Then, it was stretched by three hot rollers in sequence (roller temperatures were 85°C, 110°C, and 130°C, with a total stretching ratio of 3.8 times) to orient the macromolecular chains and induce crystallization. Finally, it was heat-set at 190°C for 50s to fix the structure. The antibacterial polyester fiber was then obtained by winding.
[0029] (3) Take 20.7g of N,N-dimethyl-3-aminopropyltrimethoxysilane and dissolve it in 80mL of anhydrous acetonitrile. Under nitrogen protection, slowly add 12.8g of 1,3-propanesulfonyl lactone and stir at 65℃ for 14h. Remove the solvent under reduced pressure to obtain sulfobetaine-type silane. Separately, take 10g of mesoporous silica (particle size 20-50nm) and ultrasonically disperse it in a mixture of 190mL of ethanol and 10mL of deionized water for 20min. Add glacial acetic acid to adjust the pH to 4.5. Add 2g of the above sulfobetaine-type silane slowly over 1.5h under low-speed stirring. After the addition is complete, stir at 65℃ for 12h. After adjusting to neutral, centrifuge, wash with ethanol, and dry under vacuum at 60℃ to obtain zwitterionic grafted mesoporous silica.
[0030] Take 10g of antibacterial polyester fiber and immerse it in 200mL of 0.01mol / L dilute nitric acid and rinse it at room temperature for 2min. After taking it out, rinse it repeatedly with deionized water until the washing solution is neutral. Air dry at room temperature to obtain pretreated fiber. 0.9 g of zwitterionic grafted mesoporous silica was added to 100 mL of deionized water and ultrasonically dispersed at 100 W for 20 min to prepare a uniform pre-dispersion. 6.06 g of tris(hydroxymethyl)aminomethane was weighed and dissolved in 800 mL of deionized water. The pH was adjusted to 8.5 with dilute hydrochloric acid to prepare a Tris buffer solution. The pre-dispersion solution was poured into this buffer solution, and then 1.2 g of dopamine hydrochloride and 1.0 g of polysulfobetaine (weight average molecular weight approximately 30,000 Da) were added sequentially. The solution was then diluted to 1 L with deionized water and stirred for 10 min until homogeneous, yielding a treatment solution. The pretreated fibers were completely immersed in this treatment solution and impregnated at room temperature with open ventilation for 6 h. During impregnation, the fibers were gently stirred at 150 r / min and turned over every h. After impregnation, the fibers were removed and repeatedly rinsed with deionized water until the washing solution was colorless and free of floating color. The fibers were then vacuum dried at 60 °C for 6 h to obtain antibacterial and anticolloid-adsorption polyester fibers.
[0031] Example 3
[0032] A method for preparing antibacterial and anticolloid adsorption polyester fiber includes the following steps: (1) Take 20g of nano zinc oxide with an average particle size of about 30nm, ultrasonically disperse it in a mixture of 4L deionized water and 4L anhydrous ethanol (as a hole sacrificial agent) to make a slurry, add 0.96g of silver nitrate, and magnetically stir in the dark for 30min to fully enrich silver ions on the surface of zinc oxide. Then, under strong stirring, irradiate with a 365nm ultraviolet lamp for about 4h to carry out photochemical reduction deposition, so that photogenerated electrons reduce silver ions in situ to metallic silver nanoparticles and deposit them on the surface of zinc oxide to form a closely contacted heterojunction. After filtration, washing with deionized water, and vacuum drying at 60℃ for 12h, a silver-zinc oxide heterojunction composite antibacterial agent is obtained. Then, take the silver-zinc oxide heterojunction composite antibacterial agent and stabilizing agent (hindered phenolic main antioxidant, phosphite auxiliary antioxidant, and phosphate ester zinc oxide surface passivating agent in a mass ratio of 7:7:1) and mix them with fully dried first polyethylene terephthalate chips (first polyethylene terephthalate chips, silver-zinc oxide heterojunction composite antibacterial agent, and stabilizing agent in a mass ratio of 90:10:1.5). In a twin-screw extruder, melt blend (feeding section 255℃, melting section 268℃, mixing section 276℃, metering section 272℃, die head 272℃), high shear dispersion, extrusion, water cooling, and pelletizing to obtain antibacterial functional masterbatch. The masterbatch is sealed and stored in a moisture-proof environment.
[0033] (2) The above-mentioned antibacterial masterbatch was vacuum dried at 140°C under nitrogen protection for 10 hours until the moisture content was ≤50ppm and then transferred to the hopper in a hot state to prevent secondary moisture absorption. The dried masterbatch was thoroughly mixed with the second polyethylene terephthalate chips that had been dried in the same way (the mass ratio of the second PET chips to the antibacterial masterbatch was 1:0.25). The mixture was fed into a screw spinning machine for melt spinning (feeding section 260°C, melting section 273°C, metering section 278°C, spinning box and spinneret assembly 280°C). The melt was metered by a metering pump, extruded by a spinneret, and then rapidly cooled and solidified in a 25°C water bath to obtain nascent monofilaments (winding speed about 50m / min). Then, it was stretched by three hot rollers in sequence (roller temperatures were 85°C, 110°C, and 130°C, with a total stretching ratio of 3.8 times) to orient the macromolecular chains and induce crystallization. Finally, it was heat-set at 190°C for 50s to fix the structure. The antibacterial polyester fiber was then obtained by winding.
[0034] (3) Take 20.7g of N,N-dimethyl-3-aminopropyltrimethoxysilane and dissolve it in 80mL of anhydrous acetonitrile. Under nitrogen protection, slowly add 12.8g of 1,3-propanesulfonyl lactone and stir at 65℃ for 14h. Remove the solvent under reduced pressure to obtain sulfobetaine-type silane. Separately, take 10g of mesoporous silica (particle size 20-50nm) and ultrasonically disperse it in a mixture of 190mL of ethanol and 10mL of deionized water for 20min. Add glacial acetic acid to adjust the pH to 4.5. Add 2g of the above sulfobetaine-type silane slowly over 1.5h under low-speed stirring. After the addition is complete, stir at 65℃ for 12h. After adjusting to neutral, centrifuge, wash with ethanol, and dry under vacuum at 60℃ to obtain zwitterionic grafted mesoporous silica.
[0035] Take 10g of antibacterial polyester fiber and immerse it in 200mL of 0.01mol / L dilute nitric acid and rinse it at room temperature for 2min. After taking it out, rinse it repeatedly with deionized water until the washing solution is neutral. Air dry at room temperature to obtain pretreated fiber. 1.0 g of zwitterionic grafted mesoporous silica was added to 100 mL of deionized water and ultrasonically dispersed at 100 W for 20 min to prepare a uniform pre-dispersion. 6.06 g of tris(hydroxymethyl)aminomethane was weighed and dissolved in 800 mL of deionized water. The pH was adjusted to 8.5 with dilute hydrochloric acid to prepare a Tris buffer solution. The pre-dispersion solution was poured into this buffer solution, and then 1.3 g of dopamine hydrochloride and 1.0 g of polysulfobetaine (weight average molecular weight approximately 30,000 Da) were added sequentially. The solution was then diluted to 1 L with deionized water and stirred for 10 min until homogeneous, yielding a treatment solution. The pretreated fibers were completely immersed in this treatment solution and impregnated at room temperature with open ventilation for 6 h. During impregnation, the fibers were gently stirred at 150 r / min and turned over every h. After impregnation, the fibers were removed and repeatedly rinsed with deionized water until the washing solution was colorless and free of floating color. The fibers were then vacuum dried at 60 °C for 6 h to obtain antibacterial and anticolloid-adsorption polyester fibers.
[0036] Example 4
[0037] A method for preparing antibacterial and anticolloid adsorption polyester fiber includes the following steps: (1) Take 20g of nano zinc oxide with an average particle size of about 30nm, ultrasonically disperse it in a mixture of 4L deionized water and 4L anhydrous ethanol (as a hole sacrificial agent) to make a slurry, add 0.96g of silver nitrate, and magnetically stir in the dark for 30min to fully enrich silver ions on the surface of zinc oxide. Then, under strong stirring, irradiate with a 365nm ultraviolet lamp for about 4h to carry out photochemical reduction deposition, so that photogenerated electrons reduce silver ions in situ to metallic silver nanoparticles and deposit them on the surface of zinc oxide to form a closely contacted heterojunction. After filtration, washing with deionized water, and vacuum drying at 60℃ for 12h, a silver-zinc oxide heterojunction composite antibacterial agent is obtained. Then, take the silver-zinc oxide heterojunction composite antibacterial agent and stabilizing agent (hindered phenolic main antioxidant, phosphite auxiliary antioxidant, and phosphate ester zinc oxide surface passivating agent in a mass ratio of 7:7:1) and mix them with fully dried first polyethylene terephthalate chips (first polyethylene terephthalate chips, silver-zinc oxide heterojunction composite antibacterial agent, and stabilizing agent in a mass ratio of 90:12:2). In a twin-screw extruder, melt blend (feeding section 255℃, melting section 268℃, mixing section 276℃, metering section 272℃, die head 272℃), high-shear dispersion, extrusion, water cooling, and pelletizing to obtain antibacterial functional masterbatch. The masterbatch is sealed and stored in a moisture-proof environment.
[0038] (2) The above-mentioned antibacterial masterbatch was vacuum dried at 140°C under nitrogen protection for 10 hours until the moisture content was ≤50ppm and then transferred to the hopper in a hot state to prevent secondary moisture absorption. The dried masterbatch was thoroughly mixed with the second polyethylene terephthalate chips that had been dried in the same way (the mass ratio of the second PET chips to the antibacterial masterbatch was 1:0.3). The mixture was fed into a screw spinning machine for melt spinning (feeding section 260°C, melting section 273°C, metering section 278°C, spinning box and spinneret assembly 280°C). The melt was metered by a metering pump, extruded by a spinneret, and then rapidly cooled and solidified in a 25°C water bath to obtain nascent monofilament (winding speed about 50m / min). Then, it was stretched by three hot rollers in sequence (roller temperatures were 85°C, 110°C, and 130°C, with a total stretching ratio of 3.8 times) to orient the macromolecular chains and induce crystallization. Finally, it was heat-set at 190°C for 50s to fix the structure. The antibacterial polyester fiber was then obtained by winding.
[0039] (3) Take 20.7g of N,N-dimethyl-3-aminopropyltrimethoxysilane and dissolve it in 80mL of anhydrous acetonitrile. Under nitrogen protection, slowly add 12.8g of 1,3-propanesulfonyl lactone and stir at 65℃ for 14h. Remove the solvent under reduced pressure to obtain sulfobetaine-type silane. Separately, take 10g of mesoporous silica (particle size 20-50nm) and ultrasonically disperse it in a mixture of 190mL of ethanol and 10mL of deionized water for 20min. Add glacial acetic acid to adjust the pH to 4.5. Add 2g of the above sulfobetaine-type silane slowly over 1.5h under low-speed stirring. After the addition is complete, stir at 65℃ for 12h. After adjusting to neutral, centrifuge, wash with ethanol, and dry under vacuum at 60℃ to obtain zwitterionic grafted mesoporous silica.
[0040] Take 10g of antibacterial polyester fiber and immerse it in 200mL of 0.01mol / L dilute nitric acid and rinse it at room temperature for 2min. After taking it out, rinse it repeatedly with deionized water until the washing solution is neutral. Air dry at room temperature to obtain pretreated fiber. 1.2 g of zwitterionic grafted mesoporous silica was added to 100 mL of deionized water and ultrasonically dispersed at 100 W for 20 min to prepare a uniform pre-dispersion. 6.06 g of tris(hydroxymethyl)aminomethane was weighed and dissolved in 800 mL of deionized water. The pH was adjusted to 8.5 with dilute hydrochloric acid to prepare a Tris buffer solution. The pre-dispersion solution was poured into this buffer solution, and then 1.5 g of dopamine hydrochloride and 1.0 g of polysulfobetaine (weight average molecular weight approximately 30,000 Da) were added sequentially. The solution was then diluted to 1 L with deionized water and stirred for 10 min until homogeneous, yielding a treatment solution. The pretreated fibers were completely immersed in this treatment solution and impregnated at room temperature with open ventilation for 6 h. During impregnation, the fibers were gently stirred at 150 r / min and turned over every h. After impregnation, the fibers were removed and repeatedly rinsed with deionized water until the washing solution was colorless and free of floating color. The fibers were then vacuum dried at 60 °C for 6 h to obtain antibacterial and anticolloid-adsorption polyester fibers.
[0041] Example 5
[0042] A method for preparing antibacterial and anticolloid adsorption polyester fiber includes the following steps: (1) Take 20g of nano zinc oxide with an average particle size of about 30nm, ultrasonically disperse it in a mixture of 4L deionized water and 4L anhydrous ethanol (as a hole sacrificial agent) to make a slurry, add 0.96g of silver nitrate, and magnetically stir in the dark for 30min to fully enrich silver ions on the surface of zinc oxide. Then, under strong stirring, irradiate with a 365nm ultraviolet lamp for about 4h to carry out photochemical reduction deposition, so that photogenerated electrons reduce silver ions in situ to metallic silver nanoparticles and deposit them on the surface of zinc oxide to form a closely contacted heterojunction. After filtration, washing with deionized water, and vacuum drying at 60℃ for 12h, a silver-zinc oxide heterojunction composite antibacterial agent is obtained. Then, take the silver-zinc oxide heterojunction composite antibacterial agent and stabilizing agent (hindered phenolic main antioxidant, phosphite auxiliary antioxidant, and phosphate ester zinc oxide surface passivating agent in a mass ratio of 7:7:1) and mix them with fully dried first polyethylene terephthalate chips (first polyethylene terephthalate chips, silver-zinc oxide heterojunction composite antibacterial agent, and stabilizing agent in a mass ratio of 90:8:1). In a twin-screw extruder, melt blend (feeding section 255℃, melting section 268℃, mixing section 276℃, metering section 272℃, die head 272℃), high-shear dispersion, extrusion, water cooling, and pelletizing to obtain antibacterial functional masterbatch. The masterbatch is sealed and stored in a moisture-proof environment.
[0043] (2) The above-mentioned antibacterial masterbatch was vacuum dried at 140°C under nitrogen protection for 10 hours until the moisture content was ≤50ppm and then transferred to the hopper in a hot state to prevent secondary moisture absorption. The dried masterbatch was thoroughly mixed with the second polyethylene terephthalate chips that had been dried in the same way (the mass ratio of the second PET chips to the antibacterial masterbatch was 1:0.2). The mixture was fed into a screw spinning machine for melt spinning (feeding section 260°C, melting section 273°C, metering section 278°C, spinning box and spinneret assembly 280°C). The melt was metered by a metering pump, extruded by a spinneret, and then rapidly cooled and solidified in a 25°C water bath to obtain nascent monofilament (winding speed about 50m / min). Then, it was stretched by three hot rollers in sequence (roller temperatures were 85°C, 110°C, and 130°C, with a total stretching ratio of 3.8 times) to orient the macromolecular chains and induce crystallization. Finally, it was heat-set at 190°C for 50s to fix the structure. The antibacterial polyester fiber was then obtained by winding.
[0044] (3) Take 20.7g of N,N-dimethyl-3-aminopropyltrimethoxysilane and dissolve it in 80mL of anhydrous acetonitrile. Under nitrogen protection, slowly add 12.8g of 1,3-propanesulfonyl lactone and stir at 65℃ for 14h. Remove the solvent under reduced pressure to obtain sulfobetaine-type silane. Separately, take 10g of mesoporous silica (particle size 20-50nm) and ultrasonically disperse it in a mixture of 190mL of ethanol and 10mL of deionized water for 20min. Add glacial acetic acid to adjust the pH to 4.5. Add 2g of the above sulfobetaine-type silane slowly over 1.5h under low-speed stirring. After the addition is complete, stir at 65℃ for 12h. After adjusting to neutral, centrifuge, wash with ethanol, and dry under vacuum at 60℃ to obtain zwitterionic grafted mesoporous silica.
[0045] Take 10g of antibacterial polyester fiber and immerse it in 200mL of 0.01mol / L dilute nitric acid and rinse it at room temperature for 2min. After taking it out, rinse it repeatedly with deionized water until the washing solution is neutral. Air dry at room temperature to obtain pretreated fiber. 0.8 g of zwitterionic grafted mesoporous silica was added to 100 mL of deionized water and ultrasonically dispersed at 100 W for 20 min to prepare a uniform pre-dispersion. 6.06 g of tris(hydroxymethyl)aminomethane was weighed and dissolved in 800 mL of deionized water. The pH was adjusted to 8.5 with dilute hydrochloric acid to prepare a Tris buffer solution. The pre-dispersion solution was poured into this buffer solution, and then 1 g of dopamine hydrochloride and 1.0 g of polysulfobetaine (weight average molecular weight approximately 30,000 Da) were added sequentially. The solution was brought to a final volume of 1 L with deionized water and stirred for 10 min until homogeneous, yielding a treatment solution. The pretreated fibers were completely immersed in this treatment solution and impregnated at room temperature with open ventilation for 6 h. During impregnation, the fibers were gently stirred at 150 r / min and turned over every h. After impregnation, the fibers were removed and repeatedly rinsed with deionized water until the washing solution was colorless and free of floating color. The fibers were then vacuum dried at 60 °C for 6 h to obtain antibacterial and anticolloid-adsorption polyester fibers.
[0046] Comparative Example 1: Compared with Example 4, UV photochemical reduction deposition was not performed. Equal amounts of nano-silver and nano-zinc oxide were directly mixed mechanically to replace the silver-zinc oxide heterojunction composite antibacterial agent. All other steps and parameters were the same.
[0047] Comparative Example 2: Compared with Example 4, silver nitrate was not added when preparing the antibacterial agent. Instead, an equal mass of nano zinc oxide was used to replace the silver-zinc oxide heterojunction composite antibacterial agent. All other steps and parameters were the same.
[0048] Comparative Example 3: Compared with Example 4, no stabilizing agents (hindered phenolic primary antioxidant, phosphite secondary antioxidant, and phosphate ester zinc oxide surface passivating agent) were added when preparing the antibacterial functional masterbatch, and all other steps and parameters were the same.
[0049] Comparative Example 4: Compared with Example 4, the antibacterial masterbatch was not vacuum dried before melt spinning (moisture content > 50 ppm), and all other steps and parameters were the same.
[0050] Comparative Example 5: Compared with Example 4, the surface co-deposition treatment in step (3) was omitted, and antibacterial polyester fiber was used directly as the finished product. The remaining steps and parameters were the same.
[0051] Comparative Example 6: Compared with Example 4, no polysulfobetaine was added to the surface co-deposition treatment solution, and all other steps and parameters were the same.
[0052] Comparative Example 7: Compared with Example 4, zwitterionic grafted mesoporous silica was not added to the surface co-deposition treatment solution, and all other steps and parameters were the same.
[0053] Comparative Example 8: Compared with Example 4, the surface co-deposition treatment solution was prepared by replacing the zwitterionic-grafted mesoporous silica with an equal amount of ungrafted zwitterionic ordinary mesoporous silica, while the remaining steps and parameters were the same.
[0054] Performance testing Except for tensile strength, all the following performance tests were conducted using the flow channel fabric as the test specimen: the polyester monofilaments obtained in each example and comparative example were woven into a diamond mesh flow channel fabric according to the conventional specifications of the flow channel fabric on the feed water side of the reverse osmosis membrane element (the mesh size and monofilament diameter were controlled according to the same specifications to ensure comparability of each sample), washed with deionized water, and dried at 60°C for later use, so that the antibacterial, wash-resistant, hydrophilic and anti-colloid adsorption properties were evaluated in the actual application form of the fiber (flow channel fabric).
[0055] (1) Antibacterial performance test* The antimicrobial properties of textiles were evaluated according to GB / T 20944.3—2008, "Evaluation of antimicrobial properties of textiles—Part 3: Shaking method". *Escherichia coli* (ATCC 8099) and *Staphylococcus aureus* (ATCC 6538) were used as test bacteria. Each sample's flow channel fabric was cut into approximately 0.5cm × 0.5cm pieces, and 0.75g was weighed and placed in an Erlenmeyer flask. 70mL of a 1×10⁻⁶ solution was added. 5 ~4×10 5 The bacterial suspension of CFU / mL was shaken at 24℃ and 150r / min for 18h, with a blank bottle without sample as a control. The bacterial suspension before and after shaking was diluted, plated, and incubated at 37℃ for 24h. The number of viable bacteria was counted, and the antibacterial rate (%) of the sample against the two bacteria was calculated according to the antibacterial rate formula. Each group was measured in parallel 3 times and the average value was taken.
[0056] (2) Washability and antibacterial durability test The acid-base chemical cleaning process of reverse osmosis membrane elements was simulated. Citric acid solution with pH=2 and sodium hydroxide solution with pH=11 were prepared. The sample flow channel was alternately soaked and shaken in the two solutions (35℃, 30min per solution for one cycle, for a total of 50 cycles). The sample was thoroughly rinsed with deionized water in between. After cleaning, the sample was dried at 60℃. The antibacterial rate of the cleaned sample against Escherichia coli was re-determined according to method (1). The antibacterial rate retention rate after 50 cleaning cycles was calculated as "antibacterial rate after cleaning / antibacterial rate before cleaning × 100%".
[0057] (3) Surface hydrophilicity (water contact angle) test The contact angle was measured at room temperature using an optical contact angle meter via the seated drop method. The sample flow channel fabric was flattened, stretched taut, and fixed on the stage. 5 μL of deionized water was dropped onto the fabric surface using a microsyringe. Images were acquired within 5 seconds of the droplet contacting the surface, and the static water contact angle was calculated by fitting. Five points were measured at different locations for each sample, and the average value was taken. The smaller the contact angle, the better the surface hydrophilicity.
[0058] (4) Test of static protein adsorption capacity under high salt conditions Bovine serum albumin (BSA) was used to simulate proteinaceous organic colloids in the influent. A high-salt protein solution containing 1.0 g / L BSA and 0.5 mol / L NaCl was prepared (simulating the ionic strength of high-salt influent). A sample flow channel cloth cut to a known surface area was immersed in 50 mL of this solution and allowed to stand at 25°C in the dark for 24 h for adsorption. The absorbance of the solution before and after adsorption was measured at 280 nm using a UV spectrophotometer. The change in BSA concentration was calculated based on the standard curve, and the protein adsorption capacity per unit area (μg / cm²) was calculated according to the sample surface area. 2 The lower the value, the better the anti-colloid adsorption performance.
[0059] (5) Humic acid adsorption capacity test under high salinity conditions Humic acid (HA) was used to simulate charged colloids of humic substances in the influent. A high-salt humic acid solution containing 20 mg / L humic acid and 0.5 mol / L NaCl was prepared. A sample flow channel cloth, cut to a known surface area, was immersed in 50 mL of this solution and allowed to stand at 25°C for 24 h for adsorption. The absorbance before and after adsorption was measured at 254 nm using a UV spectrophotometer. The change in humic acid concentration was calculated based on the standard curve, and the amount of humic acid adsorbed per unit area (μg / cm²) was calculated. 2 ).
[0060] (6) Fracture strength test The test was conducted according to GB / T 14344—2022 "Test Method for Tensile Properties of Chemical Fiber Filaments". Breaking strength is used to characterize the mechanical properties of the fiber itself; therefore, polyester monofilaments were directly tested before weaving. After conditioning for 24 hours at 20℃ and 65% relative humidity, the fibers were tested using an electronic single-fiber tensile tester with a clamping distance of 250mm and a tensile speed of 250mm / min. Twenty fibers were tested for each sample, and the average value was taken. The breaking strength (cN / dtex) was used to characterize the fiber.
[0061] (7) Antibacterial ion release test 1.0 g of sample was immersed in 100 mL of deionized water and kept at a constant temperature of 37 °C for 72 h. The immersion solution was then filtered through a 0.22 μm filter membrane, and the cumulative release of silver ions (μg / L) was determined by inductively coupled plasma mass spectrometry (ICP-MS). This index is used to characterize the ability of surface antibacterial ions to be transported and released into the water through the coating, and can reflect the density of the surface coating and the effect of mesoporous silica on reducing the resistance to ion transport.
[0062] Table 1:
[0063] The breaking strength of Examples 1-5 decreased slightly with increasing antibacterial agent addition (3.65-3.96 cN / dtex), but remained at a usable level. The breaking strength of Comparative Example 3 (without stabilizing agent) and Comparative Example 4 (masterbatch not dried before spinning) decreased to 3.15 and 3.02 cN / dtex, respectively, which was significantly lower than that of Example 4 (3.65). This indicates that the passivation of zinc oxide catalytic sites by the stabilizing agent and the control of moisture content by sufficient drying before spinning are indispensable for inhibiting high-temperature degradation of PET and ensuring fiber mechanical properties.
[0064] Examples 1-5, after surface co-deposition treatment, showed water contact angles reduced to 18-26°, and BSA and humic acid adsorption amounts under high-salt conditions were significantly lower than the control. Comparative Example 5, without surface treatment, exhibited excellent antibacterial properties, but had a high water contact angle of 76°, high high-salt adsorption, and poor anti-colloidal adsorption capacity. Comparative Example 6, without zwitterionic polymers and relying solely on a polydopamine layer, showed moderate hydrophilicity and anti-adsorption capacity (contact angle 42°, BSA 128 μg / cm). 2 The result was significantly inferior to Example 4, indicating that the zwitterionic hydration layer is the core of anti-colloid adsorption in a high-salt environment.
[0065] Comparative Example 7, without grafted mesoporous silica, had a dense coating, and the cumulative release of silver ions over 72 hours decreased to 24 μg / L (lower than 38 μg / L in Example 4). The initial antibacterial rate also decreased slightly, confirming that mesoporous silica can alleviate the obstruction of antibacterial ion transport on the surface of the coating. Comparative Example 8, with ungrafted ordinary mesoporous silica as a substitute, saw a recovery in silver ion release (32 μg / L). However, due to the lack of zwitterionic grafting, its hydrophilicity and anti-adsorption capacity (contact angle 22°, BSA 30 μg / cm²) were weaker than those of Example 4. This indicates that zwitterionic grafting makes an additional contribution to improving the local hydrophilicity and bound water content of the coating. Only through the synergy of both can antibacterial ion release and anti-colloidal adsorption be achieved.
[0066] It should be noted that the initial antibacterial rates of Comparative Examples 7 and 8 (99.1% and 99.4%, respectively) were similar to those of Example 4 (99.9%), and did not decrease proportionally with the decrease in silver ion release. This is because silver ions themselves have extremely strong bactericidal ability, and the antibacterial rate, as an indicator of the killing ratio measured under 18-hour contact conditions, has a significant saturation effect. As long as the release flux of silver ions per unit time is high enough to kill more than 99% of the viable bacteria in the bacterial solution, the increase or decrease in the release amount within a certain range will not be proportionally reflected in the antibacterial rate. Even though the coating of Comparative Example 7 was relatively dense, reducing the silver ion release amount to 24 μg / L, this release level was still sufficient to maintain an antibacterial rate of about 99% in the oscillating contact system, so the antibacterial rate only decreased slightly. Therefore, the effect of mesoporous silica and its zwitterionic grafts on the ion transport of coatings is mainly reflected in the more sensitive indicator of the cumulative release of silver ions, and the long-term sustained antibacterial durability ensured by the unobstructed release channels, rather than in the antibacterial rate value measured in a single test.
[0067] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the essence and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for preparing antibacterial and anticolloid adsorption polyester fibers, characterized in that, Includes the following steps: (1) The silver-zinc oxide heterojunction composite antibacterial agent, stabilizer and first polyethylene terephthalate chips were melt-blended and pelletized to obtain antibacterial functional masterbatch; (2) The antibacterial functional masterbatch is mixed with second polyethylene terephthalate chips and then melt-spun, cooled and solidified, stretched and heat-set to obtain antibacterial polyester fiber; (3) The antibacterial polyester fiber is immersed in a buffer solution containing dopamine hydrochloride, zwitterionic polymer and zwitterionic grafted mesoporous silica for surface co-deposition treatment to obtain the product.
2. The method for preparing antibacterial and anticolloid adsorption polyester fiber according to claim 1, characterized in that, Before entering step (2) for melt spinning, the antibacterial masterbatch described in step (1) is vacuum dried to ensure that the moisture content of the antibacterial masterbatch is ≤50ppm.
3. The method for preparing antibacterial and anticolloid adsorption polyester fiber according to claim 1, characterized in that, The stabilizing agents mentioned in step (1) include hindered phenolic primary antioxidants, phosphite secondary antioxidants, and surface passivating agents for passivating the active sites on the solid surface of zinc oxide; The surface passivating agent is a phosphate ester compound or a phosphite ester compound.
4. The method for preparing antibacterial and anticolloid adsorption polyester fiber according to claim 1, characterized in that, The silver-zinc oxide heterojunction composite antibacterial agent described in step (1) was prepared by the following photodeposition method: Nano-zinc oxide is dispersed in a solution containing silver ions and a hole sacrificial agent, and photochemical reduction deposition is performed under ultraviolet light irradiation, so that metallic silver nanoparticles are deposited in situ on the surface of the nano-zinc oxide.
5. The method for preparing antibacterial and anticolloid adsorption polyester fiber according to claim 4, characterized in that, The hole sacrificial agent is anhydrous ethanol; The mass ratio of the first polyethylene terephthalate chips, silver-zinc oxide heterojunction composite antibacterial agent, and stabilizing agent is 90:(8-12):(1-2).
6. The method for preparing antibacterial and anticolloid adsorption polyester fiber according to claim 1, characterized in that, In step (2), the mass ratio of the second polyethylene terephthalate chips to the antibacterial masterbatch is 1:(0.2-0.3).
7. The method for preparing antibacterial and anticolloid adsorption polyester fiber according to claim 1, characterized in that, The buffer solution mentioned in step (3) is a weakly alkaline buffer solution; The surface co-deposition treatment was performed under oxygen-permeable conditions; The zwitterionic polymer is polysulfobetaine.
8. The method for preparing antibacterial and anticolloid adsorption polyester fiber according to claim 1, characterized in that, The method for preparing zwitterionic grafted mesoporous silica in step (3) is as follows: N,N-dimethyl-3-aminopropyltrimethoxysilane is reacted with 1,3-propanesulfonyl lactone in a ring-opening reaction to obtain sulfobetaine-type silane, and then the sulfobetaine-type silane is grafted onto the inner and outer surfaces of the pores of mesoporous silica. The mass ratio of dopamine hydrochloride, zwitterionic polymer, and zwitterionic grafted mesoporous silica is (1-1.5):1:(0.8-1.2).
9. An antibacterial and anticolloid adsorption polyester fiber, characterized in that, It is prepared by the method described in any one of claims 1 to 8.
10. Application of an antibacterial and anticolloid adsorption polyester fiber in reverse osmosis membrane flow channel fabric.