Polymer material for preventing microbial film adhesion to filter bag and preparation method thereof

Abstract

The application relates to a kind of high molecular material of filter bag microbial adhesion resistance bacteria membrane and its preparation method, belong to high molecular material preparation technical field, by silane coupling agent in SiO2 Surface introduction carboxyl and other organic functional groups, obtain the pretreatment SiO2 Filler, then be used to enhance PET, obtain the modified PET fiber with SiO2 Reinforcement.Finally, the fiber is immersed in the protein after acylation treatment, and a amyloid protein layer is constructed on the fiber surface by reducing disulfide bond, to prevent microbial adhesion effect.The anti-bioadhesion material prepared by the application has good mechanical properties, and the advantages of anti-microbial and algal adhesion.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high polymer material preparation, in particular to a high polymer material for preventing microbial film adhesion of a filter bag and a preparation method thereof. BACKGROUND

[0002] As a core component in the fields of industrial dust removal, water treatment and medical protection, the surface anti-microbial adhesion performance of a filter bag directly determines the service life and safety. The adhesion of microorganisms on the surface of the filter material and the formation of the biofilm can cause filter hole blockage, reduced air permeability and increased risk of secondary pollution. Traditional filter materials are prone to become "hot spots" for microbial adhesion due to strong surface hydrophilicity and single charge distribution, and the conventional antibacterial agents have the problem of easy loss. Therefore, it is of great significance to develop a high polymer material with good anti-adhesion ability for improving the filtration efficiency, reducing the maintenance cost and ensuring the public health safety.

[0003] Amyloid is a kind of β-sheet rich structure formed by protein misfolding, but the hydrophobic amino acids exposed on the surface of the amyloid repel the hydration layer through hydrophobic interaction, thereby destroying the wettability between the microorganisms and the material. Meanwhile, the dense network structure formed by the β-sheet can physically block the adhesion, and the self-adaptive conformation can resist the shear force flushing and maintain long-term stability, and it does not pollute the environment. Traditional amyloid needs to be obtained by strong acid hydrolysis or high temperature denaturation, which leads to the loss of protein activity, and it is difficult to realize uniform assembly on the surface of the fiber, and the interfacial bonding force with the base fiber is weak, which is easy to peel off in the filtration process, thereby limiting its application in anti-adhesion materials.

[0004] Based on the above statement, the application provides a high polymer material for preventing microbial film adhesion of a filter bag and a preparation method thereof. SUMMARY

[0005] In order to solve the problems in the background art, the application provides a high polymer material for preventing microbial film adhesion of a filter bag and a preparation method thereof.

[0006] A preparation method of a high polymer material for preventing microbial film adhesion of a filter bag, comprising the following preparation steps:

[0007] S1, pretreated SiO2 filler, terephthalic acid and ethylene glycol are mixed and reacted at 230-240 DEG C for 2-3 hours to obtain an esterification product; then diethylene glycol and an antioxidant are added to the system, and the reaction is continued for 30-40 minutes to obtain modified PET, which is dried and then melt extruded, spun and heat set to obtain modified PET fiber;

[0008] S2, the protein raw material is treated with an acylating agent, and then subjected to reduction modification to obtain a modified protein system; the PET fiber obtained in step S1 is immersed in the modified protein system according to a bath ratio of 1 g:10 mL, and then filtered and dried to obtain a high polymer material with anti-microbial bacterial film adhesion.

[0009] Further, in step S1, the pretreated SiO2 filler is prepared by the following steps:

[0010] The nano-SiO2 powder is added to the xylene solvent, stirred at room temperature for 10-15 minutes, then ultrasonically dispersed, and the silane coupling agent is added to the system, the system temperature is raised to 70-80°C and stirred, filtered and Soxhlet extracted with acetone to remove impurities, and vacuum dried to constant weight to obtain the pretreated SiO2 filler.

[0011] Further preferably, in step S1, the pretreated SiO2 filler is prepared by the following steps:

[0012] The nano-SiO2 powder is added to the xylene solvent according to a mass-volume ratio of 1 g:(10-15) mL, stirred at room temperature at a speed of 30-90 rpm for 10-15 minutes, then ultrasonically dispersed for 30-40 minutes, then the silane coupling agent is added to the system, the system temperature is raised to 70-80°C and stirred at a speed of 30-90 rpm for 4-5 hours, filtered and Soxhlet extracted with acetone for 24 hours to remove unreacted coupling agent, and vacuum dried to constant weight to obtain the pretreated SiO2 filler.

[0013] In the above reaction process, the silane coupling agent introduces carboxyl and other organic functional groups on the surface of SiO2 to prepare the pretreated SiO2 filler, which is beneficial to enhance the chemical bonding ability with PET hydroxyl and to regulate the surface charge environment to improve the dispersibility. The pretreated SiO2 filler is chemically bonded to the PET hydroxyl through functional groups such as silicon hydroxyl and carboxyl, forming a nano-scale concave-convex structure with increased surface roughness, which facilitates the subsequent anchoring of protein molecules.

[0014] Further, the mass ratio of nano-SiO2 powder to silane coupling agent is (5-10):(0.4-0.8).

[0015] Preferably, the silane coupling agent is KH570.

[0016] Further, in step S1, the mass ratio of pretreated SiO2 filler, terephthalic acid, ethylene glycol, diethylene glycol and antioxidant is (0.4-2):(30-90):(0.8-1):(0.9-9):(0.12-1.8).

[0017] Further, in the S1 step, the temperature for melt extrusion is 250-280℃, the screw rotation speed is 50-150rpm, and the back pressure is 5-15MPa.

[0018] Further preferably, in the S1 step, the temperature for melt extrusion is 250-280℃, the screw rotation speed is 50-150rpm, and the back pressure is 5-15MPa.

[0019] Further, in the S1 step, the specific operation for spinning and heat setting is as follows:

[0020] The melt for melt extrusion is fed into a spinning assembly, extruded through the micro-holes of a spinneret to form a stream, solidified by air cooling in a spinning duct, and then the solidified yarn is subjected to high draw ratio of 1500-3000m / min and heat setting treatment. The heat setting process is specifically set as: first relaxation at 240℃ for 10 seconds, and then setting at 230℃ for 30 seconds, to obtain the modified PET fiber.

[0021] Further, in the S2 step, the modified protein system is specifically prepared by the following steps:

[0022] S21, the protein raw material is added to deionized water, stirred at room temperature for 10-15 minutes, then the pH value of the system is adjusted to 8.0-8.5, the acylation reagent is added and the system temperature is raised to 45-55℃, and the system is stirred for 1.5-3 hours, during which the pH value of the system is maintained at 8.0-8.5; after the reaction is completed, the pH value of the system is adjusted to 4.0-4.5, the system is centrifuged, the precipitate is collected, washed and dried to obtain the acylated protein;

[0023] S22, the acylated protein is partially reduced using ascorbic acid, and then completely reduced using TCEP solution to obtain the modified protein system.

[0024] Further preferably, in the S2 step, the modified protein system is specifically prepared by the following steps:

[0025] S21, the protein raw material is added to deionized water according to a mass-volume ratio of (6.5-8) g:100 mL, stirred at a speed of 30-90 rpm for 10-15 minutes at room temperature, then the pH value of the system is adjusted to 8.0-8.5 using a 1 mol / L NaOH solution, the acylation reagent is added and the temperature of the system is raised to 45-55℃, and the reaction is stirred at a speed of 30-90 rpm for 1.5-3 hours, and the pH value of the system is maintained at 8.0-8.5 after the process; after the reaction is completed, the pH value of the system is adjusted to 4.0-4.5 using a 1 mol / L HCl solution, the system is centrifuged at a speed of 4000-5000 rpm for 20-30 minutes, the precipitate is collected, and the precipitate is washed with deionized water until the pH value of the washing liquid is neutral, and then dried to a constant weight to obtain an acylated protein;

[0026] S22, the acylated protein obtained in step S21 is added to a 0.1 mol / L sodium bicarbonate buffer with a pH value of 8 according to a mass-volume ratio of (0.01-0.02) g:10 mL, then a 0.1 mol / L ascorbic acid solution with a pH value of 8 is added according to a volume ratio of 1:1, and the reaction is stirred at a speed of 100-300 rpm for 30-60 minutes at room temperature and in the dark, then a 10 mM TCEP solution with a pH value of 7.5 is added to the system according to a volume ratio of 1:1, and the reaction is stirred at a speed of 100-300 rpm for 30-60 minutes at room temperature and in the dark, and the system is dialyzed to obtain a modified protein system.

[0027] In the above reaction process, by using the acylation reagent to treat the protein raw material, on the one hand, the acylation reagent reacts with the epsilon-amino group on the protein to introduce a negatively charged group on the protein, interfere with the surface charge distribution of the protein, reduce the effect of amino cations, and promote the combination of protein components with modified PET fibers. On the other hand, the acylated protein weakens the intermolecular electrostatic attraction, promotes the unfolding of alpha-helix, and promotes the formation of beta-fold through hydrogen bond network, which can better open the internal structure, expose the disulfide bond buried in the internal structure, so that the reducing agent can better act, promote the reduction of disulfide bond in the protein, and form amyloid protein layer on the surface of the modified PET fiber.

[0028] Further, the protein raw material is at least one of soybean protein isolate, egg white protein and wheat gluten protein.

[0029] Further, the acylation reagent is succinic anhydride.

[0030] Further, the heat setting is specifically operated as follows: first relaxation at 240℃ for 10 seconds, and then setting at 230℃ for 30 seconds.

[0031] Further, the mass ratio of the protein raw material and the acylation reagent is 100:(5-12).

[0032] In summary, the present application has the following beneficial effects:

[0033] In the technical scheme of the present application, carboxyl and other organic functional groups are introduced on the surface of SiO2 by using a silane coupling agent to prepare a pretreated SiO2 filler, which is then used to reinforce PET to obtain a modified PET fiber reinforced with SiO2. Finally, the fiber is immersed in acylated protein, and a amyloid protein layer is constructed on the surface of the fiber by reducing disulfide bonds, thereby achieving the effect of preventing microbial adhesion.

[0034] During the process, the protein raw material is treated by using an acylating agent. On the one hand, the acylating agent reacts with the ε-amino group on the protein to introduce a negatively charged group on the protein, thereby interfering with the surface charge distribution of the protein, reducing the effect of amino cations, and promoting the combination of the protein component and the modified PET fiber. On the other hand, the acylated protein weakens the intermolecular electrostatic attraction, promotes the unfolding of α-helix, and promotes the formation of β-sheet through hydrogen bond network, which can better open the internal structure, expose the buried disulfide bonds inside, and make the reducing agent act better, promote the reduction of disulfide bonds in the protein, and form a self-assembled protein layer on the surface of the modified PET fiber. During the process, the process parameters are optimized to overcome the influence of modification on the reduction of disulfide bonds and self-assembly. Specifically, a step-by-step reduction method is used to reduce disulfide bonds. First, a weak reducing agent is used for partial reduction, ascorbic acid is used to selectively reduce non-essential disulfide bonds in the acylated protein, the integrity of the intrachain disulfide bond is preserved, and excessive reduction is avoided to prevent protein aggregation. Then, a reducing agent is used for complete reduction to further promote the conversion of protein structure to β-sheet, thereby forming an amyloid protein layer. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] The reagents involved in the specific embodiments of the present application are all chemically pure.

[0037] The silane coupling agent used is KH570.

[0038] The antioxidant used is antioxidant 1010.

[0039] The average particle size of the nano-SiO2 powder used is 20 nm.

[0040] Wheat gluten protein: CAS No. 93384-22-6, purity 99%.

[0041] Soy protein isolate: CAS No. 9010-10-0, 99% purity.

[0042] Example 1

[0043] A method for preparing a high molecular material for filtering bag anti-microbial bacteria film adhesion, comprising the following preparation steps:

[0044] S1, pretreated SiO2filler, terephthalic acid and ethylene glycol were mixed and reacted at 230℃ for 2 hours to obtain an esterification product; then diethylene glycol and an antioxidant were added to the system, and the reaction was continued for 30 minutes to obtain modified PET, which was dried to constant weight and then melt extruded; the temperature of the first zone of the melt extruder cylinder was set to 240℃, the temperature of the second zone of the melt extruder cylinder was set to 250℃, the temperature of the third zone of the melt extruder cylinder was set to 260℃, the temperature of the connecting body was set to 260℃, the temperature of the first zone of the die head was set to 250℃, the screw rotation speed was set to 50rpm, and the back pressure was set to 5MPa; then the melt extruded melt was sent into a spinning assembly, extruded through the micropores of a spinneret to form a fine stream, the spinneret hole diameter was 0.45mm, the length-diameter ratio was 8:1, the fine stream was cooled and solidified in a spinning duct by air, then the solidified yarn was treated by 1000m / min spinning rate, 4 times post-drawing and heat setting; the heat setting process was specifically set as: first relaxation at 240℃ for 10 seconds, then setting at 230℃ for 30 seconds, to obtain modified PET fiber; the mass ratio of pretreated SiO2filler, terephthalic acid, ethylene glycol, diethylene glycol and antioxidant was 0.4:30:0.8:0.9:0.12.

[0045] The pretreated SiO2filler is specifically prepared by the following steps:

[0046] Nano-SiO2powder was added to a dimethylbenzene solvent at a mass-volume ratio of 1g:10mL, stirred at room temperature at a speed of 60rpm for 15 minutes, then ultrasonic dispersion treated for 30 minutes, then silane coupling agent was added to the system, the system temperature was raised to 70℃ and stirred at a speed of 90rpm for 4 hours, then filtered and Soxhlet extracted with acetone for 24 hours to remove unreacted coupling agent, and then vacuum dried to constant weight to obtain the pretreated SiO2filler; the mass ratio of nano-SiO2powder and silane coupling agent was 5:0.4.

[0047] S2, after the protein raw material was treated with acylation reagent, reduction modification was performed to obtain a modified protein system; the PET fiber obtained in step S1 was immersed in the modified protein system at a bath ratio of 1g:10mL, then filtered and dried at 50℃ to constant weight to obtain a high molecular material for filtering bag anti-microbial bacteria film adhesion;

[0048] The modified protein system is prepared by the following steps:

[0049] S21, protein raw material is added into deionized water according to a mass-volume ratio of 6.5 g:100 mL, stirred at a speed of 60 rpm for 15 minutes at room temperature, then the pH value of the system is adjusted to 8.0 using a 1 mol / L NaOH solution, an acylation reagent is added and the temperature of the system is raised to 45 DEG C, the reaction is stirred at a speed of 90 rpm for 1.5 hours, and the pH value of the system is maintained at 8.0 during the process; after the reaction is completed, the pH value of the system is adjusted to 4.0 using a 1 mol / L HCl solution, the system is centrifuged at a speed of 4000 rpm for 20 minutes, the precipitate is collected, the precipitate is washed with deionized water until the pH value of the washing liquid is neutral, and then dried to a constant weight to obtain an acylated protein; the protein raw material is soybean protein isolate, the acylation reagent is succinic anhydride, and the mass ratio of the protein raw material to the acylation reagent is 100:5;

[0050] S22, the acylated protein obtained in step S21 is added into a 0.1 mol / L sodium bicarbonate buffer solution with a pH value of 8 according to a mass-volume ratio of 0.01 g:10 mL, then 0.1 mol / L ascorbic acid solution with a pH value of 8 is added according to a volume ratio of 1:1, the reaction is stirred at a speed of 100 rpm for 30 minutes at room temperature and in the dark, then 10 mM TCEP solution with a pH value of 7.5 is added into the system according to a volume ratio of 1:1, the reaction is stirred at a speed of 100 rpm for 30 minutes at room temperature and in the dark, and the system is subjected to dialysis treatment with a molecular weight cut-off of 3 kDa to obtain a modified protein system.

[0051] Example 2

[0052] A method for preparing a high molecular material for filtering bag anti-microbial bacteria membrane adhesion, comprising the following preparation steps:

[0053] S1, pretreated SiO2 filler, terephthalic acid and ethylene glycol are mixed and reacted at 235 DEG C for 2.5 hours to obtain an esterification product; then diethylene glycol and an antioxidant are added into the system, and the reaction is continued for 35 minutes to obtain modified PET, which is dried to a constant weight and then melt extruded; the temperature of the first zone of the melt extruder cylinder is set to 250 DEG C, the temperature of the second zone of the cylinder is set to 260 DEG C, the temperature of the third zone of the cylinder is set to 270 DEG C, the temperature of the connecting body is set to 270 DEG C, the temperature of the first zone of the die head is set to 260 DEG C, the screw rotation speed is set to 100 rpm, and the back pressure is set to 10 MPa; then the melt extruded melt is sent into a spinning assembly, extruded through the micropores of a spinneret to form a fine stream, the spinneret hole diameter is 0.45 mm, and the length-diameter ratio is 8:1; the solidified filaments are cooled and solidified by air in a spinning duct, then the solidified filaments are subjected to 4 times post-drawing and heat setting treatment at a spinning speed of 1000 m / min; the heat setting process is specifically set as: first relaxation at 240 DEG C for 10 seconds, and then setting at 230 DEG C for 30 seconds to obtain modified PET fibers; the mass ratio of the pretreated SiO2 filler, terephthalic acid, ethylene glycol, diethylene glycol and antioxidant is 1.2:60:0.9:5:0.5.

[0054] The pretreated SiO2 filler is prepared by the following steps:

[0055] The nanometer SiO2 powder is added into the xylene solvent at a mass-volume ratio of 1 g:12 mL, stirred at a speed of 60 rpm for 15 minutes at room temperature, then subjected to ultrasonic dispersion treatment for 35 minutes, then the silane coupling agent is added into the system, the system temperature is raised to 75 DEG C and stirred at a speed of 90 rpm for 4.5 hours, then the unreacted coupling agent is removed by filtration and Soxhlet extraction with acetone for 24 hours, and then vacuum dried to constant weight to obtain the pretreated SiO2 filler; the mass ratio of the nanometer SiO2 powder and the silane coupling agent is 7:0.6.

[0056] S2, after the protein raw material is treated with an acylation reagent, a reduction modification is performed to prepare a modified protein system; the PET fiber obtained in the step S1 is immersed in the modified protein system according to a bath ratio of 1 g:10 mL, then filtered and dried at 50 DEG C to constant weight to obtain a high molecular material with anti-microbial bacterial film adhesion;

[0057] The modified protein system is prepared by the following steps:

[0058] S21, the protein raw material is added into deionized water at a mass-volume ratio of 7.2 g:100 mL, stirred at a speed of 60 rpm for 15 minutes at room temperature, then the pH value of the system is adjusted to 8.2 by using a 1 mol / L NaOH solution, an acylation reagent is added and the system temperature is raised to 50 DEG C, and then stirred at a speed of 90 rpm for 2 hours, and the pH value of the system is maintained at 8.2 during the process; after the reaction is completed, the pH value of the system is adjusted to 4.2 by using a 1 mol / L HCl solution, the system is centrifuged at a speed of 4500 rpm for 25 minutes, the precipitate is collected, and the precipitate is washed with deionized water until the pH value of the washing liquid is neutral, and then dried to constant weight to obtain the acylated protein; the protein raw material is soybean protein isolate, the acylation reagent is succinic anhydride, and the mass ratio of the protein raw material and the acylation reagent is 100:8;

[0059] S22, the acylated protein obtained in the step S21 is added into a 0.1 mol / L sodium bicarbonate buffer solution with a pH value of 8 at a mass-volume ratio of 0.015 g:10 mL, then a 0.1 mol / L ascorbic acid solution with a pH value of 8 is added at a volume ratio of 1:1, stirred at a speed of 200 rpm for 45 minutes at room temperature and in the dark, then a 10 mM TCEP solution with a pH value of 7.5 is added into the system at a volume ratio of 1:1, stirred at a speed of 200 rpm for 45 minutes at room temperature and in the dark, and then the system is subjected to dialysis treatment with a molecular weight cut-off of 3 kDa to obtain the modified protein system.

[0060] Example 3

[0061] The application discloses a preparation method of a high polymer material for resisting microbial film adhesion of a filter bag.

[0062] S1, pretreated SiO2 filler, terephthalic acid and ethylene glycol are mixed and reacted at 240 DEG C for 3 hours to obtain an esterification product; then diethylene glycol and an antioxidant are added to the system, and the reaction is continued for 40 minutes to obtain modified PET; after drying to constant weight, the modified PET is melt extruded; the temperature of the first zone of the melt extruder cylinder is 260 DEG C, the temperature of the second zone of the cylinder is 270 DEG C, the temperature of the third zone of the cylinder is 280 DEG C, the temperature of the connecting body is 280 DEG C, the temperature of the first zone of the head is 270 DEG C, the screw rotation speed is 150 rpm, and the back pressure is 15 MPa; then the melt extruded melt is sent into a spinning assembly, extruded through the micropores of a spinneret to form a fine stream, the spinneret hole diameter is 0.45 mm, and the length-diameter ratio is 8:1; the fine stream is solidified by air cooling in a spinning duct; then the solidified yarn is subjected to 4 times of post-drawing at a spinning speed of 1000 m / min and heat setting treatment; the heat setting process is specifically set as: first relaxation at 240 DEG C for 10 seconds, and then setting at 230 DEG C for 30 seconds to obtain modified PET fiber; the mass ratio of the pretreated SiO2 filler, terephthalic acid, ethylene glycol, diethylene glycol and antioxidant is 2:90:1:9:1.8.

[0063] The pretreated SiO2 filler is specifically prepared by the following steps:

[0064] The nano SiO2 powder is added into a dimethylbenzene solvent in a mass-volume ratio of 1g:15mL, stirred at a speed of 60 rpm for 15 minutes at room temperature, then subjected to ultrasonic dispersion treatment for 40 minutes, then the silane coupling agent is added to the system, the system temperature is increased to 80 DEG C, and stirring is carried out at a speed of 90 rpm for 5 hours; the unreacted coupling agent is removed by filtration and Soxhlet extraction with acetone for 24 hours, and vacuum drying is carried out to constant weight to obtain the pretreated SiO2 filler; the mass ratio of the nano SiO2 powder and the silane coupling agent is 10:0.8.

[0065] S2, after the protein raw material is treated by using an acylation reagent, the protein raw material is subjected to reduction modification to obtain a modified protein system; the PET fiber obtained in the step S1 is immersed in the modified protein system in a bath ratio of 1g:10mL, then filtered and dried at 50 DEG C to constant weight to obtain a high polymer material for resisting microbial film adhesion of a filter bag.

[0066] The modified protein system is prepared by the following steps:

[0067] S21, protein raw material was added into deionized water at a mass-volume ratio of 8 g:100 mL, stirred at a speed of 60 rpm for 15 minutes at room temperature, then the pH value of the system was adjusted to 8.5 using a 1 mol / L NaOH solution, an acylation reagent was added and the temperature of the system was raised to 55℃, the reaction was stirred at a speed of 90 rpm for 3 hours, and the pH value of the system was maintained at 8.5 after the process; after the reaction was completed, the pH value of the system was adjusted to 4.5 using a 1 mol / L HCl solution, the system was centrifuged at a speed of 5000 rpm for 30 minutes, the precipitate was collected, the precipitate was washed with deionized water until the pH value of the washing liquid was neutral, and then dried to a constant weight to obtain an acylated protein; the protein raw material was soybean protein isolate, the acylation reagent was succinic anhydride, and the mass ratio of the protein raw material to the acylation reagent was 100:12;

[0068] S22, the acylated protein obtained in step S21 was added into a 0.1 mol / L sodium bicarbonate buffer with a pH value of 8 at a mass-volume ratio of 0.02 g:10 mL, then a 0.1 mol / L ascorbic acid solution with a pH value of 8 was added at a volume ratio of 1:1, the reaction was stirred at a speed of 300 rpm for 60 minutes at room temperature and in the dark, then a 10 mM TCEP solution with a pH value of 7.5 was added to the system at a volume ratio of 1:1, the reaction was stirred at a speed of 300 rpm for 60 minutes at room temperature and in the dark, and the system was dialyzed with a molecular weight cut-off of 3 kDa to obtain a modified protein system.

[0069] Comparative Example 1

[0070] The difference between this comparative example and Example 1 is that in step S1, the amount of silane coupling agent used in the preparation of the pretreated SiO2 powder is increased. Specifically, in the preparation of the pretreated SiO2 powder in this comparative example, the mass ratio of nano-SiO2 powder to silane coupling agent is 5:0.8.

[0071] Comparative Example 2

[0072] The difference between this comparative example and Example 1 is that in step S1, no silane coupling agent is used in the preparation of the pretreated SiO2 powder. Specifically, the pretreated SiO2 powder in this comparative example is prepared by the following steps:

[0073] Nano-SiO2 powder was added into a xylene solvent at a mass-volume ratio of 1 g:10 mL, stirred at a speed of 60 rpm for 15 minutes at room temperature, then ultrasonic dispersion treatment was performed for 30 minutes, then the temperature of the system was raised to 70℃ and stirred at a speed of 30 rpm for 4 hours, filtered and vacuum dried to a constant weight to obtain the pretreated SiO2 filler.

[0074] Comparative Example 3

[0075] The difference between the present comparative example and Example 1 is that the protein raw material in the present comparative example is not treated with an acylating agent, and specifically, the modified protein system is prepared by the following steps:

[0076] The protein raw material was added to a 0.1 mol / L sodium bicarbonate buffer with a pH of 8 at a mass-volume ratio of 0.01 g:10 mL, then 10 mM TCEP solution with a pH of 7.5 was added at a volume ratio of 1:1, and the system was stirred at room temperature and in the dark at a speed of 100 rpm for 30 minutes. After dialysis treatment of the system with a molecular weight cut-off of 3 kDa, a modified protein system was obtained.

[0077] Comparative Example 4

[0078] The difference between the present comparative example and Example 1 is that the protein raw material in the present comparative example is not treated with an acylating agent, and specifically, the modified protein system is prepared by the following steps:

[0079] S21, the protein raw material was added to deionized water at a mass-volume ratio of 6.5 g:100 mL, and stirred at room temperature at a speed of 60 rpm for 15 minutes. Then, the pH of the system was adjusted to 8.0 using a 1 mol / L NaOH solution, an acylating agent was added, and the temperature of the system was increased to 45°C. The reaction was stirred at a speed of 90 rpm for 1.5 hours, and the pH of the system was maintained at 8.0 after the process. After the reaction was completed, the pH of the system was adjusted to 4.0 using a 1 mol / L HCl solution, the system was centrifuged at a speed of 4000 rpm for 20 minutes, the precipitate was collected, and the precipitate was washed with deionized water until the pH of the washing liquid was neutral. After drying to a constant weight, an acylated protein was obtained. The protein raw material was soybean protein isolate, the acylating agent was succinic anhydride, and the mass ratio of the protein raw material to the acylating agent was 100:5.

[0080] S22, the acylated protein obtained in step S21 was added to a 0.1 mol / L sodium bicarbonate buffer with a pH of 8 at a mass-volume ratio of 0.01 g:20 mL, then 10 mM TCEP solution with a pH of 7.5 was added at a volume ratio of 1:1, and the system was stirred at room temperature and in the dark at a speed of 100 rpm for 30 minutes. After dialysis treatment of the system with a molecular weight cut-off of 3 kDa, a modified protein system was obtained.

[0081] Performance test

[0082] The materials prepared in Examples 1-3 and Comparative Examples 1-4 of the present application were subjected to performance tests.

[0083] Mechanical property test: The mechanical properties of the materials were tested using a universal material testing machine. The tensile strength and elongation at break of different samples were measured at a tensile rate of 100 mm / min. Each group of samples was measured 5 times, and the average value was recorded.

[0084] The specific performance test results are shown in Table 1 below:

[0085] Table 1

[0086] Group Tensile strength (MPa) Elongation at break (%) Example 1 82.6 15.8 Example 2 84.2 16.3 Example 3 84.2 15.4 Comparative Example 1 82.3 16.0 Comparative Example 2 75.1 14.2 Comparative Example 3 78.4 15.3 Comparative Example 4 81.0 15.6

[0087] From the results shown in Table 1 above:

[0088] The samples prepared in Example 2 had the best mechanical properties such as tensile strength and elongation at break among several groups of samples. From the results in Comparative Examples 1 and 2, it can be seen that the use of silane coupling agent can improve the enhancement of the SiO2 component on the elongation at break of the fibers. From the data in Comparative Example 3, it can be seen that acylated protein is also beneficial to improving the mechanical properties of the samples.

[0089] Anti-bioadhesion test:

[0090] The anti-bioadhesion properties of the samples in different groups were tested using the immersion method.

[0091] Microbial adhesion: 10 cm long samples were immersed in E. coli (CMCC 44817) and S. aureus (CMCC(B)26003) bacterial solutions, respectively. After 12 and 24 hours of culture, the samples were taken out, washed with PBS buffer for 30 seconds, and then the bacterial adhesion rate (%) on the surface of the samples was measured by colony counting method. The adhesion rate = the number of adherent bacteria / the initial number of bacteria x 100%. Each group of samples was measured 5 times, and the average value was recorded.

[0092] Microalgae adhesion: 0.2 g of Chlorella vulgaris seeds and 0.5 g of glucose were mixed in 250 mL of deionized water, stirred uniformly, and then 10 g of samples prepared in different groups were added. After 3 and 7 days of culture, the samples were taken out, rinsed with running water for 1 minute, and then dried at 80°C to constant weight. The microalgae adhesion rate was determined. The adhesion rate = the increase in sample mass after culture / the initial weight x 100%. Each group of samples was measured 5 times, and the average value was recorded.

[0093] The specific test results are shown in Table 2 below.

[0094] Table 2

[0095]

[0096] From the results in Table 2, it can be seen that the several samples prepared in different groups are more sensitive to Staphylococcus aureus for the modified materials, and the anti-adhesion effect is better. Several groups of samples show anti-adhesion effect to microorganisms and algae, among which the sample in Example 2 has the best anti-adhesion effect on the three biological materials compared with other groups of samples. It can also be observed that the adhesion of microorganisms has a certain time dependence, and the microorganism activity is strong at 12 hours, the adhesion rate is fast, but the subsequent adhesion is less, showing effective barrier effect.

[0097] From the results in Tables 1 and 2, it can be seen that the increase of the amount of silane coupling agent in Comparative Example 1 can improve the dispersion of the reinforcing material and increase the mechanical properties, but the surface roughness also decreases, resulting in poor protein loading effect, and the anti-adhesion effect of the protein film formed on microorganisms and microalgae decreases. The results in Comparative Example 2 also verify that the use of silane coupling agent leads to a decrease in the mechanical properties of the material, an increase in the surface roughness, but a decrease in the uniformity of the assembly of the protein film and a decrease in the anti-adhesion effect. The results in Comparative Examples 3 and 4 can verify that the acylation modification step and the step-by-step reduction treatment can reduce the aggregation of proteins during the formation of the protein film, promote the transformation of the protein structure, and improve the anti-adhesion effect of the protein film.

[0098] In the description of the specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0099] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as they do not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A method for preparing a polymeric material for filtering bags resistant to microbial biofilm adhesion, characterized by, The preparation steps include: S1, mixing pretreated SiO2 filler, terephthalic acid and ethylene glycol at 230-240℃ for 2-3 hours to obtain an esterification product; then adding diethylene glycol and an antioxidant to the system and continuing to react for 30-40 minutes to obtain modified PET, which is dried and then melt extruded, spun and heat set to obtain modified PET fibers; wherein the pretreated SiO2 filler is prepared by the following steps: The nano-SiO2 powder is added to a solvent and stirred at room temperature for 10-15 minutes, then ultrasonically dispersed, and a silane coupling agent is added to the system, the system temperature is raised to 70-80℃ and stirred, filtered and impurities are removed, and dried to obtain the pretreated SiO2 filler; S2, the protein raw material is treated with an acylation reagent and then reduced to obtain a modified protein system; the PET fibers obtained in step S1 are immersed in the modified protein system, then filtered and dried to obtain a high polymer material with antibacterial film adhesion for filter bags; the acylation reagent is succinic anhydride; The modified protein system is prepared by the following steps: S21, the protein raw material is added to deionized water and stirred, then the pH value of the system is adjusted to 8.0-8.5, an acylation reagent is added and the system temperature is raised to 45-55℃, and stirred for 1.5-3 hours while maintaining the pH value of the system at 8.0-8.5; after the reaction is completed, the pH value of the system is adjusted to 4.0-4.5, the system is centrifuged, the precipitate is collected, washed and dried to obtain acylated protein; S22, the acylated protein is partially reduced using ascorbic acid and then completely reduced using a TCEP solution to obtain a modified protein system.

2. The method of claim 1, wherein the method is characterized by: The mass ratio of nano-SiO2 powder to silane coupling agent is (5-10):(0.4-0.8).

3. The method of claim 1, wherein the method is characterized by: In step S1, the melt extrusion temperature is 250-280℃, the screw rotation speed is 50-150 rpm, and the back pressure is 5-15 MPa.

4. The method of claim 1, wherein the method is characterized by: The protein raw material is at least one of soybean protein isolate, egg white protein and wheat gluten protein.

5. The method of claim 1, wherein the method is characterized by: The heat setting is specifically performed by first relaxing at 240℃ for 10 seconds and then setting at 230℃ for 30 seconds.

6. A high polymer material prepared by the method of any one of claims 1-5.

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