371 results about "Aqueous sodium hydroxide" patented technology

The invention discloses an alkali-washable aluminum foil etching gravure printing UV ink. The gravure UV ink comprises the following components in parts by weight: 30-50 parts of a UV prepolymer, 20-30 parts of a UV monomer, 6-20 parts of an initiator, 10-30 parts of an inorganic filler, 1-5 parts of a pigment, 0.1-3 parts of a dispersant, 0.1-2 parts of a leveling agent, 0.1-2 parts of a defoaming agent and 0.1-2 parts of an adhesion aid. According to the gravure UV etching protection ink, the special UV prepolymer and the UV monomer are matched with the filler, so that the prepared gravure UV etching protection ink not only has excellent aluminum foil adhesive force, but also has excellent corrosion resistance of hot hydrochloric acid, particularly provides effective protection for circuit edges, and meanwhile, the gravure UV etching protection ink can rapidly retreat a film in a sodium hydroxide aqueous solution with the concentration of 1% or above and the temperature of 40 DEG C, so that the service life of the gravure UV etching protection ink is prolonged. When the prepared gravure UV ink is used for gravure printing, diffusion of knife lines and printing lines cannot be generated, and possibility is brought to cost reduction and efficiency improvement of the industry.

The invention belongs to the field of egg by-product processing, and particularly relates to a preparation method and application of eggshell membrane peptides, the preparation method of the eggshell membrane peptides comprises the following steps: S1, drying and crushing cleaned eggshells, and then separating eggshell membranes; s2, putting the eggshell membrane into a steam explosion machine, carrying out pressure maintaining treatment for 1-5 minutes under the pressure of 1.0-1.5 MPa, then instantly releasing the pressure, and collecting a steam explosion sample; s3, adding the eggshell membrane subjected to steam explosion treatment into a sodium hydroxide aqueous solution with the pH value of 7-9 according to the solid-liquid ratio of 1: (20-30), then adding alkaline protease according to the enzyme addition amount of 5000-15000U / g, carrying out enzymolysis for 5-10 hours at the temperature of 35-65 DEG C, then inactivating for 3-5 minutes at the temperature of 100 DEG C, filtering enzymatic hydrolysate, taking filtrate, centrifuging, taking supernate, and freeze-drying to obtain polypeptide; s4, polypeptide obtained in S3 is dissolved in an activation solution to be activated for 8-10 h at the temperature of 4-8 DEG C; and S5, separating the sample activated in the step S4 through a Sephadex G-15 chromatographic column to obtain the activated eggshell membrane peptide. Based on the method, the preparation efficiency is high, and the prepared eggshell membrane peptide is high in antioxidant activity.

The invention belongs to the technical field of preparation and application of nano materials, and relates to a preparation method and application of amino-functionalized cerium oxide nano enzyme, and the preparation method comprises the following steps: adding 3-aminophenylboronic acid into a cerous nitrate hexahydrate aqueous solution to obtain a mixed solution; dropwise adding a sodium hydroxide aqueous solution into the mixed solution, carrying out hydrothermal reaction, cooling after the reaction is finished, centrifuging, washing and drying to obtain milk white powder, namely the amino-functionalized cerium oxide nano-enzyme. The boron element is introduced in the preparation of the cerium oxide nano-enzyme, and the amino-functionalized cerium oxide nano-enzyme is prepared by adopting a simple one-step hydrothermal synthesis method, so that the nano-enzyme has good phosphatase-like activity, has high selectivity and sensitivity to LPS, and is short in detection time, high in sensitivity, low in detection limit, simple in preparation process and high in preparation efficiency; the product is good in quality, high in stability, environment-friendly and extremely wide in market prospect.

The invention provides a method for continuously synthesizing 2-thiophenecarboxaldehyde by using a continuous flow reactor, and relates to the technical field of organic synthesis, and the method comprises the following steps: mixing thiophene and N, N-dimethylformamide (DMF) to form a material A; continuously inputting the material A and phosphorus oxychloride (POCl3) into a micro-channel continuous flow reactor through a high-pressure feeding pump, and controlling the reaction temperature to be 60-150 DEG C and the retention time to be 0.5-5 minutes; synchronously inputting the reaction liquid output by the micro-channel reactor and a sodium hydroxide aqueous solution into a dynamic tubular reactor, and carrying out hydrolysis reaction at 10-70 DEG C for 0.5-5 minutes; according to the method, the 2-thiophenecarboxaldehyde is obtained by extracting the 2-thiophenecarboxaldehyde by using dichloromethane (DCM), and a continuous flow reactor technology is adopted, so that the reaction efficiency is remarkably improved. Compared with the traditional batch reaction, the continuous flow reactor has higher mass transfer and heat transfer efficiency, can realize rapid reaction, shortens the reaction time, and improves the product yield at the same time.

The invention provides a method for separating boron isotopes by using ferroferric oxide / resin microspheres, which comprises the following steps: in a chromatographic column, taking a boric acid-monosodium borate aqueous solution with the pH value of 6-7 as an adsorption solution, and taking a sodium hydroxide aqueous solution with the pH value of 10-11 as a desorption solution to obtain a 10B-rich boric acid aqueous solution; the preparation method of the microspheres comprises the following steps: (1) adding dimethyl sulfoxide to swell polystyrene-divinylbenzene resin microspheres, adding concentrated sulfuric acid to treat until the sulfonation rate is 0.3-0.4 mmol / g, washing with water, treating with an ammonium chloride aqueous solution, washing with water, drying in vacuum, spraying with a ferric chloride-ferrous chloride aqueous solution, evaporating in vacuum to remove part of water, and introducing ammonia-containing nitrogen flow to treat to obtain polystyrene-divinylbenzene resin microspheres; and washing with water, grinding the surface, treating with a sodium hydroxide aqueous solution and washing with water. The method is simple in separation operation, easy to implement and high in efficiency, and has a certain application prospect; the chromatographic column is relatively stable in performance, reproducible and relatively long in service life.

The invention relates to the technical field of water-based binders, in particular to a preparation method of a high-flexibility positive electrode water-based binder and a product of the high-flexibility positive electrode water-based binder, and the preparation method at least comprises the following steps: dissolving acrylamide in deionized water, and sequentially adding carboxylic acid monomers, acrylonitrile and acrylate monomers to obtain a mixture A; heating the mixture A to 50-60 DEG C under the protection of inert gas, dropwise adding an initiator, filtering, and washing to obtain a solid precipitate; and adding a sodium hydroxide aqueous solution into the solid precipitate to obtain the high-flexibility positive aqueous binder. A polymerization precipitation process is adopted, the solid content of the mixture A is controlled to be 45-60 wt%, the reaction temperature is controlled to be 50-60 DEG C, and the synthesized water-based adhesive has good flexibility and peel strength while maintaining the viscosity of 5000-20000 mPa.s.

The invention discloses a synthesis method of 2, 4, 5-trifluorophenylacetic acid, which comprises the following steps: by taking cheap and easily available o-chloronitrobenzene as a raw material, reacting with sodium nitrate in a sulfuric acid and trifluoroacetic acid system, separating generated 2, 4-dinitrochlorobenzene through melt crystallization, and continuing to synthesize 2, 4-dinitrochlorobenzene in methyl chloroacetate to obtain 2, 4, 5-trifluorophenylacetic acid. The method comprises the following steps: carrying out indirect aromatic nucleophilic substitution reaction on 2, 4-dinitrophenylacetic acid under the condition of sodium hydride to generate 5-chloro-2, 4-dinitrophenylacetic acid methyl ester, separating, carrying out fluorination reaction on the 5-chloro-2, 4-dinitrophenylacetic acid methyl ester and potassium fluoride under the action of a phase transfer catalyst, carrying out rectification separation to obtain 2, 4, 5-trifluorophenylacetic acid, and carrying out hydrolytic acidification on the 2, 4, 5-trifluorophenylacetic acid in a sodium hydroxide aqueous solution to obtain 2, 4, 5-trifluorophenylacetic acid. And the process route is safer, more environment-friendly, more efficient and lower in cost.

The invention provides a method for synthesizing carboxymethyl cellulose by a slurry method based on a novel etherifying agent and an application, the method comprises the following steps: adding crushed cellulose into a reaction container filled with an organic solvent, stirring, continuously introducing nitrogen into the reaction container, and when the temperature of the reaction container reaches 25-35 DEG C, stirring for 2-3 hours; slowly dropwise adding a sodium hydroxide aqueous solution into the reaction container, keeping the temperature for a period of time, rapidly raising the temperature of the reaction container to 55 DEG C, slowly adding a novel etherifying agent into the reaction container, controlling the temperature of the reaction container to be kept at 55-75 DEG C, placing the reaction container at 65 DEG C after dropwise adding, and keeping the temperature for a period of time; wherein the novel etherifying agent is low-carbon alcohol chloroacetate or chloroacetamide, an acidic material is added into a reaction container to adjust the pH value of a reaction system to 6.5-7.5, washing liquid is used for multiple times to obtain carboxymethyl cellulose, and the novel etherifying agent is adopted to solve the problems of a traditional etherifying agent. And the high-quality and high-substitution-degree carboxymethyl cellulose is prepared.

The invention discloses a preparation method and application of a functional nano-pesticide based on a random combinatorial library of polyhexamethylene biguanide hydrochloride analogues and phenolic hydroxyl group-containing natural small molecules. A PHMB analogue containing a mono-guanidyl or biguanidyl structure and a natural small molecule compound with 1-3 phenolic hydroxyl structures are selected, nano-particles with good dispersion coefficients can be formed in a sodium hydroxide aqueous solution with the pH value of 9-11 without additional carriers or stabilizers, and the limitation that traditional nano-pesticides depend on macromolecular carriers is broken through. The obtained nano-particles can be enriched on the surface of a plant pathogenic fungus cell membrane by utilizing the electrostatic adsorption effect of guanidyl, and the delivery effect of natural small molecules is enhanced, so that the antifungal activity of the nano-particles is improved. An antibacterial experiment result shows that part of the composition has a synergistic antibacterial effect on fusarium graminearum, and the diameter of an inhibition zone is superior to that of a single component. The method is high in construction efficiency, has good expansibility, can form a nano pesticide preparation library, and is suitable for plant disease prevention and control and environment-friendly material development.

The invention discloses an antibacterial and deodorant functional fabric and a preparation method thereof, and relates to the technical field of textile fibers. When the antibacterial and deodorant functional fabric is prepared, pre-modified titanium dioxide reacts with diallyl chlorophosphate to prepare modified titanium dioxide; the preparation method comprises the following steps: carrying out polycondensation on hydroxypropyl-terminated polydimethylsiloxane, ethylene glycol, 3, 5-pyridinedicarboxylic acid and terephthalic acid to prepare polyester, and reacting with 4-chloromethylstyrene to prepare modified polyester; carrying out melt spinning on the modified polyester and the modified titanium dioxide to obtain polyester fibers; spinning polyester fibers to obtain a fiber fabric; carrying out coprecipitation on the carboxylated beta-cyclodextrin and tea polyphenol to prepare a carboxylated beta-cyclodextrin inclusion compound; the preparation method comprises the following steps: mixing a polyester fabric with a sodium hydroxide aqueous solution to prepare an alkali-treated polyester fabric, and immersing the alkali-treated polyester fabric into a carboxylated beta-cyclodextrin inclusion compound aqueous solution to prepare the antibacterial and deodorant functional fabric. The antibacterial and deodorant functional fabric prepared by the invention has good antibacterial, deodorant, flame-retardant and mechanical properties.

The invention discloses a bismuth vanadate material for carbon dioxide electroreduction and a preparation method and application, and belongs to the technical field of carbon dioxide electroreduction.The method comprises the steps that bismuth salt is dissolved in a nitric acid aqueous solution, a surfactant is added, and a mixed solution A is obtained through a stirring reaction; dissolving ammonium metavanadate in a sodium hydroxide aqueous solution, adding a surfactant, and carrying out a stirring reaction to obtain a mixed solution B; and mixing the mixed solution A and the mixed solution B, adjusting the pH value to be neutral, and carrying out stirring reaction, hydrothermal reaction, washing, drying and calcination reaction to obtain the bismuth vanadate material for carbon dioxide electroreduction. The preparation method comprises the following steps: uniformly mixing bismuth salt and ammonium metavanadate with a surfactant respectively, and roasting through a hydrothermal method and a template effect of the surfactant to prepare the bismuth vanadate material with high specific surface area for electroreduction of carbon dioxide. In carbon dioxide electroreduction, the catalyst has catalytic performance of high activity, good stability and high selectivity and electrochemical performance of low overpotential and high current density.

The invention provides a carbon-supported platinum-cobalt-copper multifunctional alloy catalyst and a preparation method and application thereof, and belongs to the technical field of energy materials. Wherein the nanocarbon carrier solution is mixed with a chloroplatinic acid solution, a cobalt chloride solution and a copper chloride solution, a sodium hydroxide aqueous solution is added to adjust the pH value, ultrasonic dispersion and stirring are performed to obtain turbid liquid, and the molar ratio of platinum ions to cobalt ions to copper ions is 2: (0.5-1): (0.5-1); then, putting the turbid liquid into a reaction kettle, and reacting at 120-250 DEG C for 1-6 hours to obtain a black colloidal solution; then filtering, washing and drying the black colloidal solution to obtain black powder; and finally, carrying out acid treatment on the black powder, and grinding to obtain the carbon-loaded platinum-cobalt-copper multifunctional alloy catalyst. The catalyst is used for catalyzing an oxygen reduction reaction of a cathode in a hydrogen fuel cell and / or a methanol fuel cell, and / or catalyzing a methanol oxidation reaction of an anode in a direct methanol fuel cell.

The invention discloses a zinc oxide modified silicon dioxide catalyst, a preparation method and application of the zinc oxide modified silicon dioxide catalyst in catalytic alcoholysis of waste PET (polyethylene terephthalate), zinc acetate and silicon dioxide are added into a mixed solution of water and ethanol and uniformly mixed, and a mixed reaction solution is obtained; adding a sodium hydroxide aqueous solution into the mixed reaction solution, carrying out a first reaction, and standing to obtain a suspension; and adding an L-ascorbic acid aqueous solution into the suspension, carrying out a second reaction, carrying out solid-liquid separation, and calcining the solid part in an air atmosphere to obtain the product. The prepared zinc oxide modified silicon dioxide nano material can be used as a catalyst to be applied to alcoholysis recovery of waste polyester, the product yield reaches up to 92% or above, the product selectivity is high, metal residues are avoided, the catalyst is easy to recover and can be recycled, and the application prospect is wide.

The invention discloses a copper oxide / cuprous oxide heterogeneous nano-material with chiral morphology and a preparation method thereof, and the method comprises the following steps: 1, mixing a copper salt aqueous solution and a surfactant aqueous solution to obtain a mixed solution A, taking a chiral ligand aqueous solution to add into the mixed solution A under a stirring state, and stirring at room temperature to obtain a copper oxide / cuprous oxide heterogeneous nano-material; a copper ion reaction precursor solution is obtained; and 2, adding a sodium hydroxide aqueous solution into the copper ion reaction precursor solution, stirring at room temperature to obtain a mixed solution B, transferring the mixed solution B into a hydrothermal reaction kettle, putting the hydrothermal reaction kettle into a drying oven, reacting at 120-160 DEG C for 2-6 hours, after the reaction is finished, centrifugally separating out a precipitate, and sequentially washing and drying in vacuum to obtain the copper ion catalyst. The copper oxide / cuprous oxide heterogeneous nano material with chiral morphology is obtained. The preparation method is simple, low in cost and easy to implement, and the obtained chiral copper oxide / cuprous oxide heterogeneous nano material has good structural stability and crystallinity.

The invention discloses a dextran microsphere preparation method, which comprises: S1, preparing a sodium hydroxide aqueous solution containing a cross-linking agent I and dextran to obtain a water phase; s2, preparing an oil phase containing a surfactant; s3, under the stirring condition, dropwise adding the water phase into the oil phase at a constant speed, and fully emulsifying and cross-linking the mixture by using homogeneous emulsification equipment to form a W / O solution; s4, adding a cross-linking agent II into the W / O solution, and fully cross-linking to obtain a cured product; and S5, washing and drying the cured product to obtain the product. The cross-linking agent is added by adopting a two-step method, the cross-linking agent is firstly added into the water phase, then the water phase and the oil phase are mixed, and then the cross-linking agent is added, so that the prepared glucan microspheres are good in morphology, relatively low in dry sphere water absorption (relatively high in solid content) and slow in in-vitro degradation. And the prepared microspheres are round and full in appearance, controllable in particle size and slow in in-vitro degradation, and have good biological safety, stability and clinical application prospects.

The invention belongs to the technical field of high polymer materials, and particularly discloses closed-loop recyclable high-thermal-conductivity liquid crystal epoxy resin and a preparation method thereof. Comprising the following steps: mixing 4, 4-dihydroxybiphenyl, a binary carboxyl compound and a catalyst, and reacting to obtain the carboxyl-terminated biphenyl polyester. And cross-linking the carboxyl-terminated biphenyl polyester and bisphenol A epoxy resin to obtain the high-thermal-conductivity liquid crystal epoxy resin capable of being recycled in a closed-loop manner. The high-thermal-conductivity liquid crystal epoxy resin capable of being subjected to closed-loop recovery can be subjected to closed-loop recovery and rapid degradation in a sodium hydroxide aqueous solution at normal temperature. The obtained closed-loop recyclable high-thermal-conductivity liquid crystal epoxy resin has excellent mechanical properties, thermal conductivity, self-repairing performance and recycling performance, is simple in preparation process, and is expected to be applied to the fields of microelectronic devices, electrical insulation equipment and the like.

The invention belongs to the technical field of adhesives, and relates to a production process of ENF-grade moisture-proof urea-formaldehyde resin, which comprises the following steps: adding 100 parts of formaldehyde into a reaction kettle, and adjusting the pH value of the reaction solution to 5.0-9.0 by using a sodium hydroxide aqueous solution; adding 40-65 parts of melamine M1, raising the temperature to 80-95 DEG C, and carrying out constant-temperature reaction for 40-60 minutes; adding 30-40 parts of urea U1, and carrying out heat preservation reaction for 10-20 minutes; adding 15-20 parts of melamine M2 and 20-25 parts of urea U2, reacting at the temperature of 90-95 DEG C to the end point, and adjusting the pH value to 9.5-10.0; and cooling to 40 DEG C, and discharging glue for later use. The ENF-grade moisture-proof urea-formaldehyde resin prepared according to the process is applied to preparation of ENF-grade moisture-proof fiberboards or shaving boards. According to the ENF-grade moisture-proof urea-formaldehyde resin production process disclosed by the invention, by adjusting process parameters, the prepared urea-formaldehyde resin is low in formaldehyde emission and excellent in performance, the ENF-grade moisture-proof urea-formaldehyde resin is applied to production of ENF-grade moisture-proof plates, the physical and chemical properties of the plates meet the national standard, and the requirements of consumers for moisture prevention and ultralow formaldehyde of the plates are met.

The invention provides a fibrous degradable flexible pressure sensor with ultralow detection limit and a preparation method and application thereof.The preparation method comprises the steps that lignin powder is dispersed in a sodium hydroxide aqueous solution, ultrasonically crushed and stirred to be uniform, then polyethylene oxide powder is uniformly dissolved in the solution in four times, stirring is conducted till the solution is uniform, and the pressure sensor is obtained; putting the solution into a vacuum cavity, and removing bubbles at room temperature to obtain an electrostatic spinning precursor solution; then preparing a lignin fiber thin film by adopting an electrostatic spinning process, and then drying the thin film; and finally, cutting the obtained lignin fiber film into a square film, placing an interdigital electrode mask on the square film, spraying a metal silver nanowire electrode by using a silver nanowire solution, and then embedding the fiber film in a polyimide film to prepare the flexible pressure sensor. According to the invention, the integrated design of the capacitive pressure sensor is realized, the cost is low, the process is simple, and the pressure sensor has excellent flexibility and sensitivity.

The invention discloses a laser-induced lignin-derived porous carbon wave-absorbing material and a preparation method thereof, and belongs to the field of material preparation and microwave absorbing materials. The method comprises the following steps: dissolving lignin in a sodium hydroxide aqueous solution, and uniformly mixing with a polyethylene oxide aqueous solution to obtain a lignin ethylene oxide solution; the method comprises the following steps: preparing a lignin membrane by using a lignin ethylene oxide solution, performing laser irradiation, washing, performing suction filtration, and performing vacuum drying to obtain the laser-induced lignin-derived porous carbon wave-absorbing material. The lignin-derived porous carbon material prepared by taking industrial waste lignin as a raw material has the performance characteristics of being harmonious, low in density, high in reflection loss and wide in wave band absorption. The preparation method is green, environment-friendly, simple to operate and low in cost, and the waste lignin in the papermaking industry is successfully converted into a high-value adjustable functional material. The method meets actual application requirements and has huge application potential in the technical field of microwave absorbing materials.

The invention belongs to the technical field of sodium hypochlorite production, and particularly relates to a method for producing sodium hypochlorite. A method for producing sodium hypochlorite comprises the following steps: adding a compound additive into a sodium hydroxide aqueous solution, and uniformly stirring to obtain a compound alkali-containing raw material solution; respectively introducing the composite alkali-containing raw material solution and chlorine into the micro-channel reactor through a metering pump, and controlling reaction conditions to generate a reaction solution containing sodium hypochlorite; introducing the reaction liquid into a ceramic membrane separation device, separating and removing unreacted solid impurities and by-product salts, and collecting permeate; unreacted sodium hydroxide is recycled and reused; and detecting the permeate liquid to be qualified to obtain a sodium hypochlorite finished product. According to the invention, four key links of compound additive addition, microchannel reaction, ceramic membrane separation and resin recovery are organically linked to form a systematic solution. Aiming at the core pain points of insufficient reaction, more byproducts, raw material waste, equipment corrosion and the like in the traditional process, the product purity is improved through the synergistic effect of all links.

The invention discloses a method for processing and preparing a hole transport layer of an organic solar cell, and relates to the technical field of solar cells, and the method comprises the following steps: S1, preparing a nickel oxide hole transport layer film, and cleaning the nickel oxide film with deionized water; s2, preparing a to-be-adjusted liquid, and measuring the initial pH value of the to-be-adjusted liquid; s3, calculating the volume of the required sodium hydroxide aqueous solution, and adding a proper amount of the sodium hydroxide aqueous solution into the to-be-adjusted liquid in the step S2 to adjust the pH value of the solution to a proper range; s4, uniformly spreading the solution in the step S3 on the surface of the cleaned nickel oxide hole transport layer thin film, and soaking for 1-15 minutes to ensure sufficient reaction; s5, the nickel oxide hole transport layer thin film is washed with deionized water, redundant sodium hydroxide aqueous solution is removed, then the washed thin film is dried, and aftertreatment is completed; according to the invention, the problem of disordered arrangement of the ionic liquid at the interface is solved, and the performance and stability of the perovskite device are improved.

The invention discloses a method for preparing brominated polystyrene, and belongs to the technical field of brominated polystyrene preparation. The method comprises: preparing a main chain bromination inhibitor, preparing a catalyst, and reacting; in the reaction, polystyrene and ethylene dichloride are mixed, stirred at 35-40°C for 30-40min under the protection of nitrogen, then cooled to 0-2°C, the main chain bromination inhibitor and the catalyst are added, stirred for 20-30min, and a dichloroethane solution of N-bromosuccinimide is added dropwise, and after the addition is completed, the mixture is stirred at room temperature for 1.5h, the reaction is terminated, and the mixture is washed with a sodium hydroxide aqueous solution, washed with water, and then filtered, and the filtrate is evaporated and crystallized, filtered, and vacuum dried to obtain brominated polystyrene; the brominated polystyrene prepared by the invention has good color performance and thermal stability, high bromine content, narrow molecular weight distribution, good reaction controllability, and short reaction time.

The present disclosure provides a preparation method of a porous hydrogel adsorbent based on Radix astragali residues, including the following steps: subjecting residues of Chinese herbal medicine Radix astragali as a precursor to bleaching with NaClO2, alkaline washing with KOH, and high power ultrasonic treatment, thereby obtaining a precursor solution of uniformly dispersed cellulose nanofibers (CNFs); adding the precursor solution of CNFs to a mixed solution of N,N′-methylene bisacrylamide (MBA), acrylic acid (AA) and ammonium persulfate (APS), shaking evenly, and initiating a polymerization reaction at a predetermined temperature to form a monolithic gel; and cleaning the monolithic gel, putting the cleaned monolithic gel into a dimethyl sulfoxide (DMSO) solution containing epichlorohydrin to allow reaction, and transferring the product of the reaction to an aqueous sodium hydroxide solution containing triethylene tetramine to allow reaction, thereby finally obtaining an amino-functionalized porous hydrogel adsorbent.

The invention discloses a pretreatment process and application of a TAC film, the pretreatment process of the TAC film comprises the step of carrying out alkali washing on the TAC film by using alkali liquor, the alkali liquor uses a sodium hydroxide aqueous solution with the mass fraction of 9%-11%, the temperature of the alkali liquor is 45-55 DEG C, and the alkali washing time is 5-8 s.According to the pretreatment process of the TAC film, the defects in the prior art are overcome, and the TAC film can be recycled. By adjusting the concentration and the temperature of the sodium hydroxide aqueous solution used in the alkali washing process, on the premise of ensuring that a coating on the surface of the TAC film is not damaged, separation of crystals on the film surface in the alkali washing process of the TAC film is effectively avoided, the problems of aggregation and accumulation of the crystals separated out in the alkali washing process on a clamping roller are solved, and the service life of the TAC film is prolonged. The number of membrane surface defects after alkali washing and water washing of the TAC membrane is greatly reduced, and continuous and stable operation of a TAC membrane alkali washing system is guaranteed.

The present invention belongs to the field of pharmaceutical synthesis technology, and in particular to a new crystal form of fosfomycin sodium and its preparation method and application. The X-ray powder diffraction pattern of the new crystal form of fosfomycin sodium has characteristic peaks at the following 2θ angle positions: 6.59 ± 0.2°, 6.90 ± 0.2°, 15.88 ± 0.2°, 18.43 ± 0.2°, 18.72 ± 0.2°, 20.94 ± 0.2° and 30.65 ± 0.2°. Its preparation method includes: fosfomycin left phosphorus right amine salt is dissolved in sodium hydroxide aqueous solution, liquid separation, water layer is added to alcohol solvent and stirred for crystallization, filter cake is washed after filtration, filter cake is passed through saturated water nitrogen and purged to the filter cake surface to appear molten state, vacuum drying, obtains fosfomycin sodium new crystal form. Fosfomycin sodium provided by the present invention is a hemihydrate crystal form, and its hygroscopicity is low, which is more conducive to subpackaging and mixing in production.

The invention discloses a preparation method of an arfamarana key intermediate, which comprises the following steps: carrying out nucleophilic addition reaction on a compound I and 1-[3-chloro-5-(trifluoromethyl) phenyl]-2, 2, 2-trifluoroethanone under the action of an organic solvent A and alkali to obtain a compound II; dissolving the compound II in an organic solvent B, adding concentrated sulfuric acid, carrying out intramolecular dehydration and cyanogen hydrolysis, and after the reaction is finished, cooling to room temperature for crystal growing to obtain a compound III; dissolving the compound III in an organic solvent C, carrying out intramolecular cyclization and ester hydrolysis reaction on the compound III and hydroxylamine hydrochloride under the action of a certain amount of sodium hydroxide aqueous solution, and after the reaction is finished, collecting a water phase and adjusting the pH value of the water phase, so as to obtain the key intermediate of arfampanaga. The reaction in each step has a high conversion rate, the purity of the prepared arfamarin intermediate is high, and powerful support and guarantee are provided for preparation of high-purity arfamarin.

The invention discloses a method for purifying sodium citrate, which comprises the following steps: first, fermenting corn flour and Aspergillus niger to produce citric acid fermentation broth; then, separating citric acid from the fermentation broth by countercurrent extraction with a mixed extractant; then, reacting with a sodium hydroxide aqueous solution to generate sodium citrate, and obtaining a sodium citrate solution by oil-water separation, and then further improving the purity by using an adsorption material and anion exchange resin. Finally, a high-purity sodium citrate product is obtained by crystallization, centrifugation and drying steps. Compared with the prior art, the method has the advantages of improving the purity and yield of sodium citrate, while reducing production costs and environmental impacts.

The utility model relates to the technical field of waste oil regeneration, and discloses a waste white oil alkali washing device which comprises a tank body, a heating assembly is installed on the periphery of the tank body, a sleeve, a servo motor and a feeding pipe are sequentially and fixedly connected to the top of the tank body from left to right, and a liquid discharging pipe is fixedly connected to the bottom of the tank body. A stirring assembly is installed in the tank body, a top ring is slidably connected to the middle of a sleeve, a filtering barrel is fixedly connected to the bottom of the top ring, a connecting pipe is fixedly connected to the top of the top ring, an elastic assembly is installed in the middle of the top ring, a clamping block is slidably connected to the middle of the top ring, and a clamping groove is formed in the middle of the sleeve; and the middle part of the sleeve is slidably connected with a push rod. According to the utility model, firstly, waste white oil is input through the connecting pipe, and larger impurities can be filtered under the action of the filtering barrel at the bottom of the connecting pipe, so that the mixing efficiency of the waste white oil and a sodium hydroxide aqueous solution is ensured, and the impurities are prevented from blocking the pipeline.

The invention relates to chemical technology for producing high-purity magnesium oxide used in the pharmaceutical, cosmetic, and food industries, in the production of ceramics, glasses, optical materials, electronic materials, catalysts, polymer materials, transformer steel.High-purity magnesium oxide having a specific surface area, determined by the BET method, in the range from 5 to 70 m2 / g, an average particle size (d50), determined by laser diffraction, of not more than 5 μm, characterized in that it has a mass fraction of impurity elements of each of Pb, Cd, As, Hg of not more than 0.1 ppm, a mass fraction of impurity elements of each of Ba, Zn, Ti, Mn, Co, Mo, V, Sb, Sr of not more than 1 ppm, a mass fraction of impurity elements of each of Al, F of not more than 5 ppm, a mass fraction of impurity elements of each of P, Cr, Ni, K, Li of not more than 10 ppm, a mass fraction of Fe of not more than 50 ppm, a mass fraction of Si of not more than 0.01%, a mass fraction of impurity elements of each of Ca, B of not more than 0.02%, a mass fraction of sulphates SO42−k of not more than 0.02%, a mass fraction of Na impurity of not more than 0.05%, a mass fraction of chloride impurity of not more than 0.05% and includes primary particles and agglomerates consisting of primary particles.High-purity magnesium oxide is obtained by calcination of magnesium hydroxide obtained by reacting a purified concentrated aqueous solution of magnesium chloride with an aqueous solution of sodium hydroxide in a continuous manner at a temperature of 40-90° C., stirring at a speed of 20-300 rpm at a molar ratio of OH−:Mg++ ions within the range (1.9÷2.1):1 with the continuous supply of a suspension of magnesium hydroxide seed crystals into the reaction mass in an amount of 5-200% of the total mass of the supplied initial reagents, and the magnesium hydroxide seed crystals are pre-treated with a concentrated aqueous solution of magnesium chloride, after interaction of the reagents, a suspension of magnesium hydroxide is sent for aging at a temperature of 40-90° C., then hydrothermal crystallization of magnesium hydroxide particles is carried out in the presence of dihydric alcohol: ethylene glycol or propylene glycol, at a temperature in the range from 120 to 220° C., pressure in the range from 0.1 to 2.3 MPa, and a duration ranging from 1 to 10 hours, the resulting suspension of magnesium hydroxide is filtered, washed, and calcination of magnesium hydroxide is carried out at a temperature of 700-1100° C.The obtained high-purity magnesium oxide has high chemical purity, adjustable specific surface area, pore volume and pore size distribution, particle size distribution and activity.

The invention provides polyimide and a preparation method thereof. The preparation method comprises the following steps: adding a sodium hydroxide aqueous solution into a monomer solution containing a dianhydride monomer and an aprotic solvent, mixing, adding diisocyanate, carrying out a polymerization reaction to obtain a reaction product system, and precipitating from the reaction product system to obtain polyimide, wherein the feeding time of the diisocyanate is 4 to 5 hours; in the monomer solution, the molar concentration of the dianhydride monomer is 0.5-0.6 mol / L; the obtained polyimide has the advantages of high specific concentration viscosity, high molecular weight and excellent high temperature resistance.