A fiber-type microbial platinum adsorbent and its preparation method

Abstract

The present invention discloses a fiber-type microbial platinum adsorbent and a preparation method thereof, and relates to the technical field of metal adsorbents. The fiber-type microbial platinum adsorbent of the present invention is prepared by firstly combining a glycidyl methacrylate-acrylonitrile multi-polymer and composite porous microspheres, followed by wet spinning to obtain a fiber blank, and then successively immersing the fiber blank in a polyethyleneimine solution, a hydroxylamine hydrochloride solution, and an Escherichia coli solution; the glycidyl methacrylate-acrylonitrile multi-polymer is obtained by copolymerizing acrylonitrile, glycidyl methacrylate, and triallylamine; the composite porous microspheres are obtained by compounding nano-hydroxy calcium phosphate, collagen, and bacterial cellulose; the polyethyleneimine solution is obtained by dissolving polyethyleneimine in dioxane; the fiber-type microbial platinum adsorbent prepared by the present invention has good platinum adsorption effect, good mechanical properties, and a long service life.

Description

Technical Field

[0001] The invention relates to the technical field of metal adsorbents, in particular to a fiber-type microbial platinum adsorbent and a preparation method thereof. Background Art

[0002] Currently, platinum recovery methods primarily include traditional methods such as chemical precipitation, electrolysis, ion exchange, and solvent extraction. However, these methods suffer from common issues such as high reagent and energy consumption, the potential for secondary pollution, incomplete reactions, and high operating costs. They are particularly poor at processing low concentrations of platinum group metals.

[0003] In recent years, polymer adsorbent fibers or nonwoven fabrics have shown great potential for the enrichment and recovery of platinum ions due to their high adsorption capacity, simple operation procedures, and excellent mechanical properties. These adsorbents are a new type of functional polymer material developed based on ion exchange resins. Their preparation typically involves chemically modifying a substrate, such as natural or synthetic fibers, to introduce specific functional groups. Due to the substrate's excellent chemical stability and mechanical properties, the adsorbent fibers possess not only high strength and corrosion resistance but also high reusability. Furthermore, the fibers or related fabrics are easy to arrange and recover in water bodies, simplifying the adsorption and desorption steps in practical applications.

[0004] In addition, microbial adsorption materials, as a green, environmentally friendly and low-cost option, have also attracted the attention of researchers. This type of adsorbent can be prepared from living or dead microorganisms and their metabolites, including but not limited to yeast, mold, bacteria and algae. They can effectively convert metal ions in water into accumulative forms through physical adsorption, ion exchange, complexation reaction and even redox reaction. Nevertheless, the effect of microbial adsorbents is easily affected by environmental factors such as solution pH and temperature, and their stability is relatively poor, which is also an area that needs further improvement.

[0005] In summary, exploring a new adsorbent that can effectively adsorb platinum ions and has good stability is of significant value in improving the recovery rate of platinum resources, reducing environmental pollution, and lowering recycling costs. Summary of the Invention

[0006] The purpose of the present invention is to provide a fibrous microbial platinum adsorbent and a preparation method thereof, so as to solve the problems existing in the prior art.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a fiber-type microbial platinum adsorbent, wherein the fiber-type microbial platinum adsorbent is firstly prepared by wet-spinning a composite of glycidyl methacrylate-acrylonitrile multi-polymer and composite porous microspheres to obtain a fiber blank, and then successively immersing the fiber blank in a polyethyleneimine solution, a hydroxylamine hydrochloride solution, and an Escherichia coli solution.

[0008] Furthermore, the glycidyl methacrylate-acrylonitrile multipolymer is obtained by copolymerizing acrylonitrile, glycidyl methacrylate and triallylamine.

[0009] Furthermore, the composite porous microspheres are obtained by compounding nano-hydroxy calcium phosphate, collagen, and oxidized bacterial cellulose.

[0010] Furthermore, the E. coli solution is prepared at a concentration of 10 8 ~10 10 CFU / L E. coli solution.

[0011] A method for preparing the aforementioned fibrous microbial platinum adsorbent comprises the following steps:

[0012] (1) A glycidyl acrylate-acrylonitrile multipolymer solution and a composite porous microsphere dispersion were mixed at a mass ratio of 1:0.9-1.1 to obtain a mixed spinning solution, which was then extruded into an ethyl acetate coagulation bath at a constant speed of 8 mL / h through a microinjection pump equipped with a 22G spinning needle with a diameter of 0.4 mm, and formed in the coagulation bath. The mixed spinning solution was then wound and collected, and then washed and dried with anhydrous ethanol and deionized water to obtain a fiber blank.

[0013] (2) 40-42 parts by weight of the fiber blank was placed in 200 parts by weight of polyethyleneimine solution, and the reaction was carried out under nitrogen protection at 75-85°C for 3.8-4.2 hours. The non-woven fabric was then repeatedly washed with ethanol and deionized water to remove the residual reagent on the surface, and then placed in a vacuum oven at 60°C to dry to constant weight to obtain a once-impregnated fiber;

[0014] (3) placing the primary impregnated fiber obtained in step (2) in 190-210 parts by mass of hydroxylamine hydrochloride solution at 75-85°C for 23.8-24.2 hours, washing it in deionized water after the reaction and drying it in a vacuum oven at 60°C to constant weight to obtain a secondary impregnated fiber;

[0015] (4) Place the secondary impregnated fiber obtained in step (3) at 10 8 ~10 10The mixture was added to a CFU / L Escherichia coli solution, shaken at 37°C and 120 r / min for 2-4 hours, removed, and centrifuged and dehydrated at 37°C for 10-20 minutes to obtain a fibrous microbial platinum adsorbent.

[0016] Furthermore, the preparation method of the glycidyl acrylate-acrylonitrile multipolymer solution is as follows: under nitrogen protection, 53-55 parts by mass of triallylamine, 23-24 parts by mass of acrylonitrile, and 4-6 parts by mass of glycidyl methacrylate are mixed and stirred at 300-500 rpm for 1-3 hours, then 10-11 parts by mass of azobisisobutyronitrile and 10-11 parts by mass of tert-dodecyl mercaptan are added, and stirring is continued for 1-3 hours. Then, the mixture is added to a mixed solution of 512.5-544.5 parts by mass of dimethylformamide and 57-61 parts by mass of tetrahydrofuran at 59-61° C., stirred for reaction for 5.5-6.5 hours, and the temperature is raised to 84-86° C. and the reaction is continued for 25-35 minutes to obtain the glycidyl acrylate-acrylonitrile multipolymer solution.

[0017] Furthermore, the composite porous microsphere dispersion is prepared by adding 24 to 26 parts by mass of composite porous microspheres to 100 parts by mass of dimethylformamide and ultrasonically dispersing the mixture for 30 to 50 minutes to obtain the composite porous microsphere dispersion.

[0018] Furthermore, the preparation method of the composite porous microspheres is as follows: collagen and oxidized bacterial cellulose are dissolved in deionized water in equal mass proportions, mixed, filtered, and freeze-dried to prepare a collagen-oxidized bacterial cellulose complex; 4 to 6 parts by mass of 1-allyl-3-methylimidazole chloride from which water has been removed, 0.18 to 0.22 parts by mass of the collagen-oxidized bacterial cellulose complex, 0.7 to 0.8 parts by mass of polystyrene, 0.7 to 0.8 parts by mass of nano-hydroxy calcium phosphate, and 2.4 to 2.6 parts by mass of Tween-8 are added. 0 were mixed evenly to obtain a dispersed phase; n-hexadecane and Span-80 were mixed evenly in a mass ratio of 1:2-4 to obtain a n-hexadecane continuous phase; 0.8-1.2 parts by mass of the dispersed phase were stirred with 10-12 parts by mass of the n-hexadecane continuous phase to form a W / O type emulsion, 90-110 parts by mass of n-butanol as a precipitant were added to the W / O type emulsion, stirred, and then allowed to stand to form a precipitate, and the microsphere precipitate was collected by filtration, washed with ethanol to remove the template agent styrene, and then washed with n-butanol, acetone, and distilled water, repeatedly washed by filtration, and freeze-dried to obtain composite porous microspheres.

[0019] Furthermore, the preparation method of the polyethyleneimine solution is as follows: polyethyleneimine and 1,4-dioxane are mixed and stirred to dissolve in a mass ratio of 1:2-4 to obtain the polyethyleneimine solution.

[0020] Furthermore, the concentration of the hydroxylamine hydrochloride solution is 4-6%, and the solvent is water and dimethyl sulfoxide in a volume ratio of 1:0.8-1.2.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The fiber-type microbial platinum adsorbent of the present invention comprises the following steps: firstly, glycidyl methacrylate-acrylonitrile multi-component copolymer and composite porous microspheres are composited and then wet-spun to obtain a fiber blank; then, the fiber blank is sequentially immersed in a polyethyleneimine solution, a hydroxylamine hydrochloride solution, and an Escherichia coli solution; the glycidyl methacrylate-acrylonitrile multi-component copolymer is obtained by copolymerizing acrylonitrile, glycidyl methacrylate, and triallylamine; the composite porous microspheres are composited by nano-hydroxy calcium phosphate, collagen, and bacterial cellulose; and the polyethyleneimine solution is obtained by dissolving polyethyleneimine in dioxane.

[0023] First, acrylonitrile, glycidyl methacrylate, and triallylamine are copolymerized to obtain a hyperbranched glycidyl methacrylate-acrylonitrile copolymer. While forming a large number of cavities in the glycidyl methacrylate-acrylonitrile copolymer, the crosslinking density of the glycidyl methacrylate-acrylonitrile copolymer is increased, thereby enhancing the mechanical properties of the glycidyl methacrylate-acrylonitrile copolymer.

[0024] Secondly, the glycidyl methacrylate-acrylonitrile multipolymer and the composite porous microspheres are compounded and wet-spun to obtain a fiber blank; the composite porous microspheres are compounded by nano-hydroxy calcium phosphate, collagen, and bacterial cellulose; the composite porous microspheres are quickly dispersed in the glycidyl methacrylate-acrylonitrile multipolymer by the nano-hydroxy calcium phosphate, thereby avoiding the problem of large-scale agglomeration of the composite porous microspheres causing a decrease in the mechanical properties of the fiber blank, and increasing the service life of the fiber-type microbial platinum adsorbent.

[0025] Finally, the fiber blank is immersed in polyethyleneimine solution, hydroxylamine hydrochloride solution and Escherichia coli solution in turn to obtain a fiber-type microbial platinum adsorbent; the polyethyleneimine solution reacts with the epoxy group on the glycidyl methacrylate-acrylonitrile copolymer through part of the amino group to graft the polyethyleneimine molecular chain onto the fiber blank, and introduces amino groups into the fiber blank. The fiber blank is then immersed in hydroxylamine hydrochloride solution to subject the nitrile group in the fiber blank to amine oxime, and further introduces amino groups into the fiber blank, which has good reaction activity and excellent metal ion adsorption effect, thereby enhancing the adsorption effect of the fiber-type microbial platinum adsorbent on platinum metal; further, the fiber blank The composite porous microspheres contain channels and cavities, which can adsorb E. coli solution, allowing E. coli to attach to the secondary impregnated fibers, combining the microbial adsorption material E. coli and the polymer adsorption fiber, thereby enhancing the platinum adsorption effect of the fiber-type microbial platinum adsorbent. At the same time, the collagen and bacterial cellulose in the secondary impregnated fibers can be used as nutrients to feed E. coli, allowing E. coli to reproduce, which can break the technical barrier of the limited content of E. coli in the microbial adsorption material in the polymer adsorption fiber after the microbial adsorption material E. coli and the polymer adsorption fiber are combined with each other, further enhancing the platinum adsorption effect of the fiber-type microbial platinum adsorbent. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] In order to more clearly illustrate the method provided by the present invention, the following examples are provided in detail. The test methods for various indicators of the fiber-type microbial platinum adsorbent prepared in the following examples are as follows:

[0028] Platinum adsorption effect: 50 parts by mass of the fibrous microbial platinum adsorbent prepared in the examples and comparative examples were added to 500 parts by mass of a 100 mg / L chloroplatinic acid solution, the pH was adjusted to 7, and the mixture was shaken at a constant temperature at 25°C for 6 hours. The mixture was filtered, and the filtrate was taken. The concentration of platinum metal ions in the filtrate was measured using an atomic absorption spectrophotometer. Platinum adsorption rate = (100 - concentration of platinum metal ions in the filtrate) * 100% / 100.

[0029] Mechanical properties: The tensile properties of the fibrous microbial platinum adsorbents prepared in the examples and comparative examples were tested using a universal tensile testing machine; a 50N mechanical sensor, a tensile speed of 1mm / min, a clamping distance of 3cm, each sample was tested 10 times, and the results were averaged.

[0030] Some of the raw materials of the Examples and Comparative Examples of the present invention are as follows:

[0031] The preparation method of the Escherichia coli solution is as follows: Escherichia coli with the strain number CICC 23917 and the Latin name Escherichia coli provided by the China Industrial Microorganism Culture Collection is inoculated into LB medium, and cultured under shaking conditions of 37°C and 120 rpm for 6 hours, during which the bacterial concentration is measured using an ultraviolet spectrophotometer. The sample is centrifuged and freeze-dried overnight, and then dissolved in PBS buffer to obtain 10 8 ~10 10 CFU / L Escherichia coli solution; wherein, LB medium includes 10g of peptone, 5g of yeast extract, and 10g of sodium chloride, and is diluted to 1L with deionized water.

[0032] The preparation method of the collagen is as follows: take fresh pig skin, wash it thoroughly with water, dehair it, remove the fat layer, and cut it into 5mm×5mm leather pieces; weigh 5 parts by mass of the leather pieces and mix them with 10 parts by mass of degreasing agent acetone, stir and soak them at 4°C for 6 hours for degreasing treatment, change the degreasing agent every 2 hours during the degreasing period, wash them with deionized water 3 to 4 times after the treatment, dry them naturally, and store them at 4°C for use to obtain defatted leather pieces; weigh 5 parts by mass of the defatted leather pieces, wash them with 50 to 100 parts by mass of deionized water 4 times, then add 75 parts by mass of hydrochloric acid solution with a pH of 2.3, soak them at 4°C for 14 hours, stir them every 2 hours during the soaking period, wait until the leather pieces expand evenly, take out the leather pieces, add appropriate amount of deionized water to pulp, obtain leather pulp, then add 4.0wt% pepsin to the leather pulp, adjust the pH to 2 with hydrochloric acid solution .3. Enzyme hydrolysis was performed at 4°C for 24 hours, and the mixture was centrifuged at 9000 r / min for 20 minutes. The supernatant was slowly added with 1 mol / L sodium hydroxide solution to adjust the pH to about 7. Solid sodium chloride was slowly added while stirring to a sodium chloride concentration of 1.0 mol / L. After standing for 24 hours, the mixture was centrifuged again. The precipitate was dissolved in 0.1 mol / L acetic acid solution and placed in a dialysis bag with a treated molecular weight cutoff of 11000 kDa. The precipitate was dialyzed in 0.05 mol / L acetic acid solution for 3 days, and the dialysate was replaced every 4 hours during the dialysis. The precipitate was then dialyzed with distilled water, and the dialysate was replaced every 4 hours during the dialysis. No white precipitate was detected in the dialysate using 10% silver nitrate solution. The dialysis was stopped, and the dialyzed solution was freeze-dried to obtain collagen, which was stored at 4°C for later use.

[0033] The preparation method of the oxidized bacterial cellulose is as follows: 0.2 parts by mass of bacterial cellulose is weighed and placed in 50 parts by mass of deionized water for homogenization, the slurry is transferred to a 100 mL round-bottom flask, the round-bottom flask is wrapped with tin foil to avoid light, 0.1 parts by mass of an oxidant, sodium metaperiodate, is added, and the reaction is carried out in an oil bath at 40° C. and a pH of 6 for 14 hours. After the reaction is completed, the precipitate is collected and added with a 0.1 mol / L ethylene glycol solution, and the reaction is continued for 0.8 hours to remove unreacted sodium metaperiodate. After the reaction is completed, the precipitate is collected and filtered, and the precipitate is washed with deionized water 5 times. The filter residue is collected and freeze-dried to obtain the oxidized bacterial cellulose.

[0034] The weight average molecular weight of the polyethyleneimine is 600.

[0035] Example 1

[0036] A method for preparing a fibrous microbial platinum adsorbent comprises the following steps:

[0037] (1) A glycidyl acrylate-acrylonitrile multipolymer solution and a composite porous microsphere dispersion were mixed in a mass ratio of 1:0.9 to obtain a mixed spinning solution, which was then extruded into an ethyl acetate coagulation bath at a constant speed of 8 mL / h through a microinjection pump equipped with a 22G spinning needle with a diameter of 0.4 mm, and formed in the coagulation bath, and then wound and collected, and washed and dried with anhydrous ethanol and deionized water to obtain a fiber blank;

[0038] (2) 40 parts by mass of the fiber blank was placed in 200 parts by mass of polyethyleneimine solution and nitrogen was introduced for 15 minutes, then sealed and reacted at 75°C for 3.8 hours. The non-woven fabric was then repeatedly washed with ethanol and deionized water to remove residual reagents on the surface, and then placed in a vacuum oven at 60°C and dried to constant weight to obtain a once-impregnated fiber;

[0039] (3) placing the primary impregnated fiber obtained in step (2) in 190 parts by mass of hydroxylamine hydrochloride solution at 75°C for reaction for 23.8 hours, washing it in deionized water after the reaction and drying it in a vacuum oven at 60°C to constant weight to obtain a secondary impregnated fiber;

[0040] (4) Place the secondary impregnated fiber obtained in step (3) at 10 8 ~10 10 The mixture was added to a CFU / L Escherichia coli solution, shaken at 37°C and 120 r / min for 2 h, removed, and centrifuged and dehydrated at 37°C for 10 min to obtain a fibrous microbial platinum adsorbent.

[0041] The preparation method of the glycidyl acrylate-acrylonitrile multipolymer solution is as follows: under nitrogen protection, 53 parts by mass of triallylamine, 23 parts by mass of acrylonitrile, and 4 parts by mass of glycidyl methacrylate are mixed and stirred at 300 rpm for 1 hour, then 10 parts by mass of azobisisobutyronitrile and 10 parts by mass of tert-dodecyl mercaptan are added, and stirring is continued for 1 hour. Then, the mixture is added to a mixed solution of 512.5 parts by mass of dimethylformamide and 57 parts by mass of tetrahydrofuran at 59° C., stirred and reacted for 5.5 hours, and the temperature is raised to 84° C. and the reaction is continued for 25 minutes to obtain the glycidyl acrylate-acrylonitrile multipolymer solution.

[0042] The preparation method of the composite porous microsphere dispersion is as follows: 24 parts by mass of composite porous microspheres are added to 100 parts by mass of dimethylformamide and ultrasonically dispersed for 30 minutes to obtain the composite porous microsphere dispersion.

[0043] The preparation method of the composite porous microspheres is as follows: weigh 0.2 parts by mass of collagen, add 30 parts by mass of deionized water, bath in 40°C water and stir at 30 rpm until the collagen is uniformly swollen, and keep stirring for 1 hour to obtain solution A; weigh 0.2 parts by mass of oxidized bacterial cellulose and 30 parts by mass of deionized water, mix them in a high-speed homogenizer for homogenization, bath in 40°C water for 1 hour to obtain solution B; mix solution A and solution B, stir at 30 r / min for 20 minutes, then filter at room temperature, and then rinse with 40°C hot water to remove residual collagen, collect the filter residue, and freeze-dry to obtain a collagen-oxidized bacterial cellulose complex; weigh 4 parts by mass of 1-allyl-3-methylimidazole chloride, place it in a blast drying oven, dry it at 105°C for 3 hours to remove moisture, add 0.18 parts by mass of collagen-oxidized bacterial cellulose complex, bath in 90°C oil until the collagen-oxidized bacterial cellulose complex is completely dissolved, and at the same time add 0.7 parts by mass of polystyrene olefins and 0.7 parts by mass of nano-hydroxy calcium phosphate were uniformly dispersed, and then 2.4 parts by mass of Tween-80 were added and mixed to obtain a dispersed phase; n-hexadecane and Span-80 were mixed in a mass ratio of 1:2 to obtain a n-hexadecane continuous phase; 0.8 parts by mass of the dispersed phase was slowly added to 10 parts by mass of the n-hexadecane continuous phase under magnetic stirring, and stirring was continued for 2 hours to form a W / O type emulsion; 90 parts by mass of n-butanol as a precipitant was added to the W / O type emulsion, and magnetic stirring was continued for 3 hours, followed by standing for 2 hours. After precipitation was complete, the microsphere precipitate was collected by suction filtration, and 50 parts by mass of acetone was added to wash the microsphere precipitate to remove the template agent polystyrene. The microsphere precipitate was washed with 50 parts by mass of n-butanol, 50 parts by mass of acetone, and 50 parts by mass of distilled water in sequence under suction filtration. During washing, care should be taken not to drain out the solvent, and the microsphere precipitate should be kept in a solvent-containing state to avoid collapse or damage of the microspheres caused by suction filtration. After washing, the obtained microspheres were transferred to a drying dish covered with tin foil and freeze-dried to obtain composite porous microspheres.

[0044] The preparation method of the polyethyleneimine solution is as follows: polyethyleneimine and 1,4-dioxane are mixed and stirred to dissolve in a mass ratio of 1:2-4 to obtain the polyethyleneimine solution.

[0045] The concentration of the hydroxylamine hydrochloride solution is 5%, and the solvent is a mixture of water and dimethyl sulfoxide in a volume ratio of 1:1.

[0046] Example 2

[0047] A method for preparing a fibrous microbial platinum adsorbent comprises the following steps:

[0048] (1) A glycidyl acrylate-acrylonitrile multipolymer solution and a composite porous microsphere dispersion were mixed in a mass ratio of 1:1 to obtain a mixed spinning solution, which was then extruded into an ethyl acetate coagulation bath at a constant speed of 8 mL / h through a microinjection pump equipped with a 22G spinning needle with a diameter of 0.4 mm, and formed in the coagulation bath, and then wound and collected, and washed and dried with anhydrous ethanol and deionized water to obtain a fiber blank;

[0049] (2) 41 parts by mass of the fiber blank was placed in 200 parts by mass of polyethyleneimine solution and nitrogen was introduced for 15 minutes, then sealed and reacted at 80°C for 4 hours, and then the non-woven fabric was repeatedly washed with ethanol and deionized water to remove the residual reagent on the surface, and then placed in a vacuum oven at 60°C to dry to constant weight to obtain a once-impregnated fiber;

[0050] (3) placing the primary impregnated fiber obtained in step (2) in 200 parts by mass of hydroxylamine hydrochloride solution and reacting at 80°C for 24 hours, washing it in deionized water after the reaction and drying it in a vacuum oven at 60°C to constant weight to obtain a secondary impregnated fiber;

[0051] (4) Place the secondary impregnated fiber obtained in step (3) at 10 8 ~10 10 The mixture was added to a CFU / L Escherichia coli solution, shaken at 37°C and 120 r / min for 3 hours, removed, and centrifuged and dehydrated at 37°C for 15 minutes to obtain a fibrous microbial platinum adsorbent.

[0052] The preparation method of the glycidyl acrylate-acrylonitrile multipolymer solution is as follows: under nitrogen protection, 54 parts by mass of triallylamine, 23.5 parts by mass of acrylonitrile, and 5 parts by mass of glycidyl methacrylate are mixed and stirred at 400 rpm for 2 hours, then 10.5 parts by mass of azobisisobutyronitrile and 10.5 parts by mass of tert-dodecyl mercaptan are added, and stirring is continued for 2 hours. Then, the mixture is added to a mixed solution of 529.5 parts by mass of dimethylformamide and 59 parts by mass of tetrahydrofuran at 60° C., stirred and reacted for 6 hours, and the temperature is raised to 85° C. and the reaction is continued for 30 minutes to obtain the glycidyl acrylate-acrylonitrile multipolymer solution.

[0053] The preparation method of the composite porous microsphere dispersion is as follows: 25 parts by mass of composite porous microspheres are added to 100 parts by mass of dimethylformamide and ultrasonically dispersed for 40 minutes to obtain the composite porous microsphere dispersion.

[0054] The preparation method of the composite porous microspheres is as follows: weigh 0.2 parts by mass of collagen, add 30 parts by mass of deionized water, bath in 40°C water and stir at 40 rpm until the collagen is uniformly swollen, and keep stirring for 1 hour to obtain solution A; weigh 0.2 parts by mass of oxidized bacterial cellulose and 30 parts by mass of deionized water, mix them in a high-speed homogenizer for homogenization, bath in 40°C water for 1 hour to obtain solution B; mix solution A and solution B, stir at 40 r / min for 20 minutes, then filter at room temperature, and then rinse with 40°C hot water to remove residual collagen, collect the filter residue, and freeze-dry to obtain a collagen-oxidized bacterial cellulose complex; weigh 5 parts by mass of 1-allyl-3-methylimidazole chloride, place it in a blast drying oven, dry it at 105°C for 3 hours to remove moisture, add 0.2 parts by mass of collagen-oxidized bacterial cellulose complex, bath in 90°C oil until the collagen-oxidized bacterial cellulose complex is completely dissolved, and at the same time add 0.75 parts by mass of polystyrene olefins and 0.75 parts by mass of nano-calcium hydroxyphosphate were uniformly dispersed, and then 2.5 parts by mass of Tween-80 were added and mixed to obtain a dispersed phase; n-hexadecane and Span-80 were mixed in a mass ratio of 1:3 to obtain a n-hexadecane continuous phase; 1 part by mass of the dispersed phase was slowly added to 11 parts by mass of the n-hexadecane continuous phase under magnetic stirring, and stirring was continued for 2 hours to form a W / O type emulsion; 100 parts by mass of n-butanol as a precipitant was added to the W / O type emulsion, and magnetic stirring was carried out for 3 hours, followed by standing for 2 hours. After precipitation was complete, the microsphere precipitate was collected by suction filtration, and 50 parts by mass of acetone was added to wash the microsphere precipitate to remove the template agent polystyrene. The microsphere precipitate was washed with 50 parts by mass of n-butanol, 50 parts by mass of acetone, and 50 parts by mass of distilled water in sequence under suction filtration. During washing, care should be taken not to drain out the solvent, and the microsphere precipitate should be kept in a solvent-containing state to avoid collapse or damage of the microspheres caused by suction filtration. After washing, the obtained microspheres were transferred to a drying dish covered with tin foil and freeze-dried to obtain composite porous microspheres.

[0055] The preparation method of the polyethyleneimine solution is as follows: polyethyleneimine and 1,4-dioxane are mixed and stirred to dissolve in a mass ratio of 1:3 to obtain the polyethyleneimine solution.

[0056] The concentration of the hydroxylamine hydrochloride solution is 5%, and the solvent is water and dimethyl sulfoxide in a volume ratio of 1:1.

[0057] Example 3

[0058] A method for preparing a fibrous microbial platinum adsorbent comprises the following steps:

[0059] (1) A glycidyl acrylate-acrylonitrile multipolymer solution and a composite porous microsphere dispersion were mixed in a mass ratio of 1:1.1 to obtain a mixed spinning solution, which was then extruded into an ethyl acetate coagulation bath at a constant speed of 8 mL / h through a microinjection pump equipped with a 22G spinning needle with a diameter of 0.4 mm, and formed in the coagulation bath, and then wound and collected, and then washed and dried with anhydrous ethanol and deionized water to obtain a fiber blank;

[0060] (2) 42 parts by mass of the fiber blank was placed in 200 parts by mass of polyethyleneimine solution and nitrogen was introduced for 15 minutes, then sealed and reacted at 85°C for 4.2 hours. The non-woven fabric was then repeatedly washed with ethanol and deionized water to remove residual reagents on the surface, and then placed in a vacuum oven at 60°C and dried to constant weight to obtain a once-impregnated fiber;

[0061] (3) placing the primary impregnated fiber obtained in step (2) in 210 parts by mass of hydroxylamine hydrochloride solution at 85°C for 24.2 hours, washing it in deionized water after the reaction and drying it in a vacuum oven at 60°C to constant weight to obtain a secondary impregnated fiber;

[0062] (4) Place the secondary impregnated fiber obtained in step (3) at 10 8 ~10 10 The mixture was added to a CFU / L Escherichia coli solution, shaken at 37°C and 120 r / min for 4 hours, removed, and centrifuged and dehydrated at 37°C for 20 minutes to obtain a fibrous microbial platinum adsorbent.

[0063] The preparation method of the glycidyl acrylate-acrylonitrile multipolymer solution is as follows: under nitrogen protection, 55 parts by mass of triallylamine, 24 parts by mass of acrylonitrile, and 6 parts by mass of glycidyl methacrylate are mixed and stirred at 500 rpm for 3 hours, then 11 parts by mass of azobisisobutyronitrile and 11 parts by mass of tert-dodecyl mercaptan are added, and stirring is continued for 3 hours. Then, the mixture is added to a mixed solution of 544.5 parts by mass of dimethylformamide and 61 parts by mass of tetrahydrofuran at 61° C., stirred for reaction for 6.5 hours, and then the temperature is raised to 86° C. and the reaction is continued for 35 minutes to obtain the glycidyl acrylate-acrylonitrile multipolymer solution.

[0064] The preparation method of the composite porous microsphere dispersion is as follows: 26 parts by mass of composite porous microspheres are added to 100 parts by mass of dimethylformamide and ultrasonically dispersed for 50 minutes to obtain the composite porous microsphere dispersion.

[0065] The preparation method of the composite porous microspheres is as follows: weigh 0.2 parts by mass of collagen, add 30 parts by mass of deionized water, place in a 40°C water bath and stir at 50 rpm until the collagen is uniformly swollen, and keep stirring for 1 hour to obtain solution A; weigh 0.2 parts by mass of oxidized bacterial cellulose and 30 parts by mass of deionized water, mix them in a high-speed homogenizer for homogenization, and place in a 40°C water bath for 1 hour to obtain solution B; mix solution A and solution B, stir at 50 r / min for 20 minutes, then filter at room temperature, and then rinse with 40°C hot water to remove the remaining collagen, collect the filter residue, and freeze-dry to obtain a collagen-oxidized bacterial cellulose complex; weigh 6 parts by mass of 1-allyl-3-methylimidazole chloride, place it in a blast drying oven, dry it at 105°C for 3 hours to remove moisture, add 0.22 parts by mass of collagen-oxidized bacterial cellulose complex, place in a 90°C oil bath until the collagen-oxidized bacterial cellulose complex is completely dissolved, and at the same time add 0.8 parts by mass of polystyrene. , 0.8 parts by mass of nano-calcium hydroxyphosphate to make it evenly dispersed, then 2.6 parts by mass of Tween-80 was added and mixed evenly to obtain a dispersed phase; n-hexadecane and Span-80 were mixed evenly in a mass ratio of 1:4 to obtain a n-hexadecane continuous phase; 1.2 parts by mass of the dispersed phase was slowly added to 12 parts by mass of the n-hexadecane continuous phase under magnetic stirring, and stirring was continued for 2 hours to form a W / O type emulsion, 110 parts by mass of precipitant n-butanol was added to the W / O type emulsion, magnetic stirring was performed for 3 hours, and then the mixture was allowed to stand for 2 hours. After precipitation was complete, the microsphere precipitate was collected by suction filtration, 50 parts by mass of acetone was added to wash the microsphere precipitate to remove the template agent polystyrene, and the microsphere precipitate was washed with 50 parts by mass of n-butanol, 50 parts by mass of acetone, and 50 parts by mass of distilled water in sequence under suction filtration. During washing, care should be taken not to drain the solvent, and the microsphere precipitate should be kept in a solvent-containing state to avoid collapse or damage of the microspheres caused by suction filtration. After washing, the obtained microspheres were transferred to a drying dish covered with tin foil and freeze-dried to obtain composite porous microspheres.

[0066] The preparation method of the polyethyleneimine solution is as follows: polyethyleneimine and 1,4-dioxane are mixed and stirred to dissolve in a mass ratio of 1:4 to obtain the polyethyleneimine solution.

[0067] The concentration of the hydroxylamine hydrochloride solution is 6%, and the solvent is water and dimethyl sulfoxide in a volume ratio of 1:1.2.

[0068] Comparative Example 1

[0069] The difference between Comparative Example 1 and Example 2 lies only in the preparation method of the glycidyl acrylate-acrylonitrile multipolymer solution. The preparation method of the glycidyl acrylate-acrylonitrile multipolymer solution in Comparative Example 1 is as follows: under nitrogen protection, 54 parts by mass of butadiene, 23.5 parts by mass of acrylonitrile, and 5 parts by mass of glycidyl methacrylate are mixed and stirred at 400 rpm for 2 hours, followed by adding 10.5 parts by mass of azobisisobutyronitrile and 10.5 parts by mass of tert-dodecyl mercaptan, and stirring is continued for 2 hours. The mixture is then added to a mixed solution of 529.5 parts by mass of dimethylformamide and 59 parts by mass of tetrahydrofuran at 60° C., stirred for 6 hours, and then heated to 85° C. and reacted for 30 minutes to obtain a glycidyl acrylate-acrylonitrile multipolymer solution. The remaining components, proportions, and processes are the same as those in Example 2.

[0070] Comparative Example 2

[0071] The difference between Comparative Example 2 and Example 2 is only the preparation of composite porous microspheres. The preparation method of composite porous microspheres in Comparative Example 2 is as follows: weigh 0.2 parts by mass of collagen, add 30 parts by mass of deionized water, bath in 40°C water and stir at 40 rpm until the collagen is evenly swollen, and keep stirring for 1 hour to obtain solution A; weigh 0.2 parts by mass of oxidized bacterial cellulose and 30 parts by mass of deionized water, mix them in a high-speed homogenizer, bath in 40°C water for 1 hour to obtain solution B; mix solution A with solution B, stir at 40r / min for 20 minutes, then filter at room temperature, and then rinse with 40°C hot water to remove the remaining collagen, collect the filter residue, and freeze-dry to obtain a collagen-oxidized bacterial cellulose complex; weigh 5 parts by mass of 1-allyl-3-methylimidazole chloride, place it in a blast drying oven, dry it at 105°C for 3 hours to remove moisture, add 0.2 parts by mass of collagen-oxidized bacterial cellulose complex, bath in 90°C oil until the collagen-oxidized bacterial cellulose complex is completely dissolved, and add 0.75 parts by mass of polystyrene was added to disperse it evenly, and then 2.5 parts by mass of Tween-80 was added and mixed evenly to obtain a dispersed phase; n-hexadecane and Span-80 were mixed evenly in a mass ratio of 1:3 to obtain a n-hexadecane continuous phase; 1 part by mass of the dispersed phase was slowly added to 11 parts by mass of the n-hexadecane continuous phase under magnetic stirring, and stirring was continued for 2 hours to form a W / O type emulsion, 100 parts by mass of n-butanol as a precipitant was added to the W / O type emulsion, and magnetic stirring was carried out for 3 hours, and then the mixture was allowed to stand for 2 hours until precipitation was complete. The microsphere precipitate was collected by filtration, and 50 parts by mass of acetone was added to wash the microsphere precipitate to remove the template polystyrene. The microsphere precipitate was washed with 50 parts by mass of n-butanol, 50 parts by mass of acetone, and 50 parts by mass of distilled water in sequence under filtration. During washing, care should be taken not to drain the solvent and keep the microsphere precipitate in a solvent-containing state to avoid collapse or damage of the microspheres caused by filtration. After washing, the obtained microspheres were transferred to a drying dish lined with tin foil and freeze-dried to obtain composite porous microspheres. The remaining components, proportions, and processes were the same as those in Example 2.

[0072] Comparative Example 3

[0073] The only difference between Comparative Example 3 and Example 2 is the preparation method of the fiber blank: the glycidyl acrylate-acrylonitrile copolymer solution is extruded into an ethyl acetate coagulation bath at a uniform speed of 8 mL / h through a microinjection pump equipped with a 22G spinning needle with a diameter of 0.4 mm, and formed in the coagulation bath, and then wound and collected, and the fiber blank is obtained after washing and drying with anhydrous ethanol and deionized water; the remaining components, proportions and processes are the same as those in Example 2.

[0074] Comparative Example 4

[0075] The difference between Comparative Example 4 and Example 2 is only the preparation steps of the fibrous microbial platinum adsorbent:

[0076] (1) A glycidyl acrylate-acrylonitrile multipolymer solution and a composite porous microsphere dispersion were mixed in a mass ratio of 1:1 to obtain a mixed spinning solution, which was then extruded into an ethyl acetate coagulation bath at a constant speed of 8 mL / h through a microinjection pump equipped with a 22G spinning needle with a diameter of 0.4 mm, and formed in the coagulation bath, and then wound and collected, and washed and dried with anhydrous ethanol and deionized water to obtain a fiber blank;

[0077] (2) 41 parts by mass of the fiber blank were placed in 200 parts by mass of hydroxylamine hydrochloride solution and reacted at 80°C for 24 hours. After the reaction, the fiber blank was washed with deionized water and dried in a vacuum oven at 60°C to constant weight to obtain a fiber-type microbial platinum adsorbent; the remaining components, proportions and processes were the same as those in Example 2.

[0078] Comparative Example 5

[0079] The only difference between Comparative Example 5 and Example 2 is that the fiber blank is immersed in the polyethyleneimine solution to obtain the fiber-type microbial platinum adsorbent; the remaining components, proportions and processes are the same as those in Example 2.

[0080] Comparative Example 6

[0081] The only difference between Comparative Example 6 and Example 2 is that the fiber blank is immersed in polyethyleneimine solution and hydroxylamine hydrochloride solution in sequence to obtain a fiber-type microbial platinum adsorbent; the remaining components, proportions and processes are the same as those in Example 2.

[0082] Comparative Example 7

[0083] Comparative Example 7 uses E. coli solution as the platinum adsorbent.

[0084] Effect Examples

[0085] Table 1 below shows the performance analysis results of the fibrous microbial platinum adsorbents of Examples 1 to 3 of the present invention and Comparative Examples 1 to 7.

[0086] Table 1

[0087]

[0088] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 6 in Table 1, it can be found that the fibrous microbial platinum adsorbent prepared in the examples has better platinum adsorption effect and better mechanical properties; from the comparison of the experimental data of Examples 1 to 3 and Comparative Example 1, it can be found that the fibrous microbial platinum adsorbent prepared by copolymerizing acrylonitrile, glycidyl methacrylate, and triallylamine to obtain a glycidyl methacrylate-acrylonitrile multipolymer has better platinum adsorption effect and better mechanical properties, and acrylonitrile, glycidyl methacrylate, and triallylamine are copolymerized to obtain a glycidyl methacrylate-acrylonitrile multipolymer with a hyperbranched structure, while forming a large number of cavities in the glycidyl methacrylate-acrylonitrile multipolymer, increasing the glycidyl methacrylate-acrylonitrile multipolymer. The cross-linking density of the multi-polymer is increased, thereby enhancing the mechanical properties of the glycidyl methacrylate-acrylonitrile multi-polymer. When the fiber blank prepared from the glycidyl methacrylate-acrylonitrile multi-polymer is subsequently immersed in a polyethyleneimine solution, a hydroxylamine hydrochloride solution, and an Escherichia coli solution, the polyethyleneimine solution reacts with the epoxy groups on the glycidyl methacrylate-acrylonitrile multi-polymer through part of the amino groups, grafting the polyethyleneimine molecular chains onto the fiber blank, introducing amino groups into the fiber blank. The fiber blank is then immersed in a hydroxylamine hydrochloride solution, and the nitrile groups in the fiber blank are subjected to amine oxime, further introducing amino groups into the fiber blank. The fiber blank has good reaction activity and excellent metal ion adsorption effect, thereby enhancing the adsorption effect of the fiber-type microbial platinum adsorbent on platinum metal.

[0089] Comparison of the experimental data of Examples 1 to 3 and Comparative Examples 2 to 3 shows that the fiber blank prepared by composite porous microspheres obtained by composite nano-hydroxy calcium phosphate, collagen, and bacterial cellulose has good platinum adsorption effect and mechanical properties for the prepared fiber-type microbial platinum adsorbent. It can be seen that the addition of nano-hydroxy calcium phosphate can improve the platinum adsorption effect of the fiber-type microbial platinum adsorbent;

[0090] Comparison of the experimental data of Examples 1 to 3 and Comparative Examples 4 to 6 shows that the fiber-type microbial platinum adsorbent prepared by sequentially immersing the fiber blank in a polyethyleneimine solution, a hydroxylamine hydrochloride solution, and an E. coli solution has a good platinum adsorption effect; wherein, the polyethyleneimine solution reacts with the epoxy groups on the glycidyl methacrylate-acrylonitrile multipolymer in the fiber blank through some amino groups to graft the polyethyleneimine molecular chains onto the fiber blank, introducing amino groups into the fiber blank, and then immersing the fiber blank in a hydroxylamine hydrochloride solution to amine oxime the nitrile groups in the fiber blank, further introducing amino groups into the fiber blank, having good reactivity and excellent metal ion adsorption effect, thereby enhancing the adsorption effect of the fiber-type microbial platinum adsorbent on platinum metal;

[0091] Compared with Example 7, the fibrous microbial platinum adsorbent prepared in Examples 1 to 3 has a better platinum adsorption effect than the traditional platinum adsorption using Escherichia coli.

[0092] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A fibrous microbial platinum adsorbent, characterized in that: The fiber-type microbial platinum adsorbent is obtained by firstly combining glycidyl methacrylate-acrylonitrile multi-polymer and composite porous microspheres and then wet-spinning them to obtain a fiber blank, and then successively immersing the fiber blank in a polyethyleneimine solution, a hydroxylamine hydrochloride solution, and an Escherichia coli solution. The glycidyl methacrylate-acrylonitrile multipolymer is obtained by copolymerizing acrylonitrile, glycidyl methacrylate and triallylamine; The composite porous microspheres are obtained by compounding nanometer calcium hydroxyphosphate, collagen and oxidized bacterial cellulose.

2. The fiber-type microbial platinum adsorbent according to claim 1, characterized in that The E. coli solution has a concentration of 10 8 ~10 10 CFU / L of E. coli solution.

3. A method for preparing a fibrous microbial platinum adsorbent according to claim 1 or 2, characterized in that: The method comprises the following preparation steps: (1) A glycidyl acrylate-acrylonitrile multi-polymer solution and a composite porous microsphere dispersion are mixed in a mass ratio of 1:0.9-1.1 to obtain a mixed spinning solution, and then the mixed spinning solution is uniformly extruded into an ethyl acetate coagulation bath, and formed in the coagulation bath, and then wound and collected, and washed and dried with anhydrous ethanol and deionized water to obtain a fiber blank; (2) 40-42 parts by weight of the fiber blank was placed in 200 parts by weight of polyethyleneimine solution, and the reaction was carried out under nitrogen protection at 75-85°C for 3.8-4.2 hours. The non-woven fabric was then repeatedly washed with ethanol and deionized water to remove the residual reagent on the surface, and dried to a constant weight to obtain a once-impregnated fiber; (3) placing the primary impregnated fiber obtained in step (2) in 190-210 parts by mass of hydroxylamine hydrochloride solution at 75-85° C. for 23.8-24.2 hours, and washing in deionized water and drying to constant weight after the reaction to obtain a secondary impregnated fiber; (4) Place the secondary impregnated fiber obtained in step (3) at 10 8 ~10 10 coli solution with a concentration of 0.1477 CFU / L, shaken, fished out, and centrifuged for dehydration to obtain a fibrous microbial platinum adsorbent.

4. The method for preparing the fiber-type microbial platinum adsorbent according to claim 3, wherein: The preparation method of the glycidyl acrylate-acrylonitrile multipolymer solution is as follows: under nitrogen protection, 53-55 parts by mass of triallylamine, 23-24 parts by mass of acrylonitrile, and 4-6 parts by mass of glycidyl methacrylate are mixed and stirred at 300-500 rpm for 1-3 hours, then 10-11 parts by mass of azobisisobutyronitrile and 10-11 parts by mass of tert-dodecyl mercaptan are added, stirring is continued for 1-3 hours, and then the mixture is added to a mixed solution of 512.5-544.5 parts by mass of dimethylformamide and 57-61 parts by mass of tetrahydrofuran at 59-61° C., stirred for reaction for 5.5-6.5 hours, and then the mixture is heated to 84-86° C. and reacted for 25-35 minutes to obtain the glycidyl acrylate-acrylonitrile multipolymer solution.

5. The method for preparing the fiber-type microbial platinum adsorbent according to claim 3, characterized in that: The preparation method of the composite porous microsphere dispersion is as follows: 24 to 26 parts by mass of composite porous microspheres are added to 100 parts by mass of dimethylformamide and ultrasonically dispersed for 30 to 50 minutes to obtain the composite porous microsphere dispersion.

6. The method for preparing the fiber-type microbial platinum adsorbent according to claim 5, characterized in that: The preparation method of the composite porous microspheres is as follows: collagen and oxidized bacterial cellulose are dissolved in deionized water in equal weight proportions, mixed, filtered, and freeze-dried to prepare a collagen-oxidized bacterial cellulose composite; 4-6 weight parts of 1-allyl-3-methylimidazole chloride from which water has been removed are mixed with 0.18-0.22 weight parts of the collagen-oxidized bacterial cellulose composite, 0.7-0.8 weight parts of polystyrene, 0.7-0.8 weight parts of nano-hydroxy calcium phosphate, and 2.4-2.6 weight parts of Tween-80. The dispersion phase was obtained by uniformly mixing n-hexadecane and Span-80 in a mass ratio of 1:2-4 to obtain a n-hexadecane continuous phase; 0.8-1.2 parts by mass of the dispersed phase and 10-12 parts by mass of the n-hexadecane continuous phase were stirred to form a W / O type emulsion, 90-110 parts by mass of n-butanol as a precipitant was added to the W / O type emulsion, stirred, and then allowed to stand to form a precipitate, and the microsphere precipitate was collected by filtration, washed with ethanol to remove the template agent styrene, and then washed with n-butanol, acetone, distilled water, filtered, and freeze-dried in sequence to obtain composite porous microspheres.

7. The method for preparing the fiber-type microbial platinum adsorbent according to claim 3, characterized in that: The preparation method of the polyethyleneimine solution is as follows: polyethyleneimine and 1,4-dioxane are mixed and stirred to dissolve in a mass ratio of 1:2-4 to obtain the polyethyleneimine solution.

8. The method for preparing the fiber-type microbial platinum adsorbent according to claim 3, characterized in that: The concentration of the hydroxylamine hydrochloride solution is 4-6%, and the solvent is water and dimethyl sulfoxide in a volume ratio of 1:0.8-1.2.

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