215 results about "FORMALDEHYDE SOLUTION" patented technology

The invention provides a preparation method of high-viscosity water-soluble melamine formaldehyde resin, which comprises the following steps: adding a first part of formaldehyde solution and water into a reaction kettle, fully and uniformly stirring, adjusting the pH value of the system in the reaction kettle, and controlling the reaction temperature in the reaction kettle at 25-30 DEG C; adding polyvinyl alcohol into the reaction kettle, raising the temperature in the reaction kettle to 48-52 DEG C, and keeping the temperature for 10-30 minutes; slowly raising the temperature in the reaction kettle to 90 DEG C, adding melamine and an environment-friendly accelerant into the reaction kettle, stirring and preserving heat for 8-12 minutes, and adding a melamine prepolymer modifier into the reaction kettle; adding a first part of formaldehyde solution into the reaction kettle, controlling the reaction temperature in the reaction kettle to be 92-95 DEG C, adding a second part of formaldehyde solution into the reaction kettle after reacting for 10 minutes, continuously stirring, and controlling the reaction temperature in the reaction kettle to be quickly reduced to 58-62 DEG C; and adding urea into the reaction kettle, naturally cooling to room temperature, and discharging glue. The melamino-formaldehyde resin prepared by the invention has the advantages of high viscosity, good water solubility, low free formaldehyde and longer storage life.

The utility model discloses a stirring and mixing device for formaldehyde production, and relates to the technical field of stirring equipment, the stirring and mixing device for formaldehyde production comprises a tank body, a rotating shaft is rotatably arranged in the tank body, the outer side of the rotating shaft is fixedly connected with a spiral blade, and the spiral blade is fixedly connected with the tank body. A second rotating cylinder matched with the spiral blade is arranged on the outer side of the spiral blade, a fixing disc is fixedly connected to the bottom end of the rotating shaft, a first rotating cylinder is fixedly connected to the top of the fixing disc, a plurality of openings are formed in the bottom of the first rotating cylinder, and drainage plates are fixedly connected to one sides of the openings. According to the stirring and mixing device for formaldehyde production, a solution at the bottom of the tank body is conveyed to the position above the solution under the action of the spiral blades, so that the formaldehyde solution and a polymerization inhibitor are mixed more rapidly and uniformly, the mixing efficiency is improved, the polymerization inhibitor is rapidly dispersed after flowing into the formaldehyde solution through a flow guide ring and a flow guide groove, and the situation that the concentration of the local polymerization inhibitor of the formaldehyde solution is too high is prevented; the uniformity and the stability of the solution are influenced.

The invention provides a polyglutamic acid granular fertilizer and a preparation method thereof, and the preparation method comprises the following steps: S1, dissolving lignin in an alkaline solution, and heating until the lignin is dissolved; adding epsilon-polylysine fermentation liquor, mixing, heating, adding a formaldehyde solution, and carrying out grafting reaction to obtain epsilon-polylysine grafted lignin; s2, mixing the epsilon-polylysine grafted lignin solution and the gamma-polyglutamic acid solution, adding N-hydroxysuccinimide, standing at a low temperature, adding 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride, and mixing; carrying out gradient temperature reaction to obtain lignin grafted epsilon-polylysine / gamma-polyglutamic acid hydrogel; and S3, homogenizing the lignin-grafted epsilon-polylysine / gamma-polyglutamic acid hydrogel, carrying out normal-temperature high-pressure airflow crushing, and spraying the crushed hydrogel to the surfaces of particles obtained by granulating a basic material through high-pressure electrostatic spraying, so as to obtain the polyglutamic acid granular fertilizer. The obtained polyglutamic acid granular fertilizer has relatively strong water-retaining and slow-release (releasing water, urea and the like) effects.

The invention discloses an akabane virus inactivated vaccine preparation method, which comprises: carrying out Vero cell passage in a cell bottle, taking well growing cells until the cells grow to 80-90%, adding into a DMEM culture medium containing 10% of fetal calf serum, taking out the cells growing to 80-90% and having a good state, adding akabane virus CH-JL-01-2022 according to a volume ratio of 0.1%, and carrying out culture at a temperature of 80-90 DEG C so as to obtain the akabane virus inactivated vaccine. Culturing for 2-3 days in an incubator with the temperature of 37 DEG C and 5% CO2; the method comprises the following steps: preparing 0.25 M BEI, 0.1 M BPL and a 40% formaldehyde solution as inactivators, setting five concentration gradients according to the volume ratios of 0.01%, 0.05%, 0.1% and 0.5%, and collecting after 6 hours, 12 hours, 24 hours, 36 hours and 48 hours after adding; the screening of the akabane virus inactivation conditions according to the types, concentrations and inactivation time of inactivators finds that 0.5% formaldehyde shows a complete inactivation effect after inactivation for 36 hours. The inactivated virus liquid is mixed with MONTANIDETM ISA 201, an ImjectI aluminum adjuvant and a manganese adjuvant according to the volume ratio of 1: 1, and then immunization is carried out, and the protection effect of the ImjectI aluminum adjuvant is found to be optimal.

The invention provides a microcapsule type self-early-warning and self-repairing epoxy coating as well as a preparation method and application thereof, and belongs to the technical field of anticorrosive coatings. The method comprises the following steps: mixing urea, resorcinol, ammonium chloride and a polyethylene grafted maleic anhydride aqueous solution, and adjusting the pH value of the mixed solution to obtain a water phase; mixing the PU prepolymer, DCF, TO and ethyl phenylacetate to obtain an oil phase; the water phase and the oil phase are mixed, a formaldehyde solution is added into the mixed solution for a reaction, and microcapsules are obtained; and adding the microcapsule into the epoxy coating to obtain the microcapsule type self-early-warning and self-repairing epoxy coating. According to the microcapsule, PU / UF serves as a shell of DCF and TO, DCF serves as an early warning agent, and TO serves as a repairing agent; the DT coated PU / UF microcapsule has good dispersibility in the coating, when the coating is damaged, the microcapsule is broken to release DCF and TO, the self-early warning and self-repairing performance of the coating is achieved, and metal corrosion is delayed.

The invention belongs to the technical field of drug synthesis, and relates to a dotenorad synthesis method, which comprises: weighing 100 g of a compound 1 as a raw material, and carrying out a substitution reaction with dimethyl sulfate to obtain a compound 2; taking the compound 2 as a raw material, and carrying out esterification reaction with methanol under an acidic condition; taking the compound 3 as a raw material, and obtaining a compound 4 after chlorination; hydrolyzing the compound 4 serving as a raw material to obtain a compound A; reacting the compound 5 serving as a raw material with a formaldehyde aqueous solution to obtain a compound 6; taking the compound 6 as a raw material, and performing thioether oxidation to obtain a compound B; taking a compound A as a raw material, and carrying out amide condensation reaction with a compound B to obtain a compound C; and 6, demethylating the compound C serving as a raw material under the action of lithium chloride to obtain a compound D, namely the final product dotenorad. According to the synthesis method of dotenorad, oxidation after condensation is not needed, generation of by-products is avoided, raw materials are low in cost and easy to obtain, and the synthesis method is suitable for industrial production.

The invention relates to a water-soluble ultraviolet absorbent 4-disubstituted aminobenzyl subunit camphorsulfonic acid and a synthesis method and application thereof, and the synthesis method comprises the following steps: in a toluene-methanol mixed solvent, carrying out heating reflux reaction on camphorsulfonic acid and 2 equivalent weight of sodium methoxide, and after enolation conversion is completed, carrying out reduced pressure distillation to obtain the 4-disubstituted aminobenzyl subunit camphorsulfonic acid. Slowly dropwise adding a corresponding 4-disubstituted aminobenzaldehyde solution with the molar weight equal to that of camphorsulfonic acid, continuously heating and stirring to react for 6-12 hours, adding water to terminate the reaction, acidifying the reaction solution by using hydrochloric acid or sulfonic acid type cation exchange resin, separating to remove methylbenzene, adjusting the pH value of a water phase to about 6.5, performing rotary evaporation dehydration under reduced pressure, and extracting a crude product by using a conventional method; a target product can be obtained through column chromatography purification, and the target product not only has water solubility, but also has the characteristic of absorbing UVA and UVB ultraviolet light at the same time; the composition can be applied to sun-screening agent products, cosmetics or home care products, and also can be applied to various industrial products such as paint, varnish, plastics, textiles and rubber to improve the light resistance of the industrial products.

The present invention relates to a preparation method of beta-methylenepyridine-2-ethanol. The preparation method of beta-methylenepyridine-2-ethanol uses 2-picoline as a first raw material, formaldehyde solution or paraformaldehyde as a second raw material, and urotropine as a catalyst, and reacts according to the following steps: (1) the first raw material, the second raw material, the catalyst and water are mixed and placed in an autoclave, the temperature is raised to 140-160° C., and after reacting for 18-20 hours, a solution containing beta-methylenepyridine-2-ethanol is obtained; (2) the solution containing beta-methylenepyridine-2-ethanol is distilled to obtain a product. The present application uses urotropine as a catalyst, utilizes its unique spatial structure and charge distribution, improves the selectivity of the reaction, and the reaction process is solvent-friendly, the steps are simple, and beta-methylenepyridine-2-ethanol can be obtained by a one-pot method, which is suitable for industrialization.

The invention relates to the technical field of preparation of phase change materials, and discloses a preparation method of a high-stability double-framework composite phase change material. The preparation method comprises the following steps: firstly, dissolving resorcinol in deionized water, adding hexadecyl trimethyl ammonium bromide, stirring and dissolving, then adding a formaldehyde solution, fully mixing, and reacting in a drying oven to prepare phenolic resin; then, carrying out high-temperature carbonization on phenolic resin in a tubular furnace to obtain phenolic resin carbide with a porous structure; then, enabling the carbonized phenolic resin to adsorb phase-change materials such as paraffin in a molten state through a vacuum impregnation method, and after adsorption is completed, crushing the carbonized phenolic resin into fine powder; and finally, mixing the powder with high-molecular polymers such as epoxy resin, and performing curing reaction to form a double-framework composite structure. According to the invention, a double-support system is constructed through the synergistic effect of a phenolic resin carbide skeleton and a high-molecular polymer skeleton, so that the thermal stability and the shape retention capability of the phase-change material are remarkably improved, and the problems that a traditional phase-change material is easy to leak and poor in cycle performance are effectively solved. The obtained composite phase change material has important application value in the heat energy storage fields of building energy saving, waste heat recovery and the like.

The invention belongs to the technical field of synthesis of extraction agents, and particularly relates to a preparation method and application of amido diphosphinic acid. The preparation method comprises the following steps: (1) mixing a solvent, primary amine, cyclohexylphosphinic acid and inorganic acid, and heating until the solution is clear and transparent; (2) adding a formaldehyde solution or paraformaldehyde into the clear and transparent solution for reaction; and (3) removing a water phase from the mixture obtained after the reaction in the step (2) is finished, dissolving jelly obtained after the water phase is removed by using dichloromethane, and carrying out washing, rotary evaporation and drying to obtain the amido diphosphinic acid.

The invention discloses a lignin-based composite condensation water pipeline corrosion inhibition agent as well as a preparation method and application thereof. The lignin-based composite condensation water pipeline corrosion inhibition agent is prepared from the following raw materials: alkali lignin, a formaldehyde solution, an amine monomer, sodium molybdate and ethanolamine ascorbic acid. The preparation method comprises the following steps: dissolving alkali lignin in a solvent, adding a formaldehyde solution, sufficiently and uniformly mixing, slowly dropwise adding an amine monomer, carrying out Mannich reaction on the alkali lignin and the amine monomer at a certain temperature to obtain aminated lignin, and then cooling; after cooling is completed, sodium molybdate, ethanolamine and ascorbic acid are added into a system, continuous stirring is conducted, an obtained reaction solution is dried, and the lignin-based composite condensation water pipeline corrosion inhibition agent is prepared. The lignin-based composite corrosion inhibition agent for the condensed water pipeline is applied to be added into the condensed water pipeline to regulate and control the quality of condensed water, and a passive film is generated on the inner wall of the condensed water pipeline, so that the corrosion prevention of the condensed water pipeline is realized.

The invention belongs to the field of polymer adhesive materials, and particularly relates to a naringenin modified lignin phenolic resin adhesive and a preparation method thereof. The naringenin modified lignin phenolic resin adhesive is prepared from the following raw materials in parts by mass: 60 to 70 parts of formaldehyde solution, 65 to 85 parts of phenol, 6 to 14 parts of naringenin, 10 to 20 parts of lignin, 12 to 18 parts of alkali metal hydroxide and 25 to 30 parts of water. The mass concentration of the formaldehyde solution is 35%-40%. The phenolic resin adhesive is prepared by taking the biological phenol naringenin and the lignin as raw materials to replace part of phenol, so that the aim of environmental protection is fulfilled by replacing non-renewable resources with renewable resources, the bonding strength and the thermal performance of phenolic resin are improved, and the application field of the biological phenolic resin adhesive is widened.

Free radical scavengers may be useful as stabilizers for aqueous formaldehyde solutions. For example, an aqueous formaldehyde solution may include 40 wt % or greater of water, 30 wt % or greater of formaldehyde, and 250 ppm or less of a free radical scavenger, each concentration based on a total weight of the aqueous formaldehyde solution.

The invention belongs to the technical field of magnesium ion batteries, and particularly relates to an in-situ synthesized aqueous magnesium ion battery organic composite negative electrode material, a preparation method and a negative electrode. The negative electrode material provided by the invention is a negative electrode material PDBM (at) KB obtained by introducing a formaldehyde solution into a suspension liquid of 2, 5-dihydroxy-1, 4-benzoquinone and conductive carbon which are uniformly mixed, carrying out quinone-aldehyde condensation polymerization under the catalysis of glacial acetic acid and carrying out in-situ synthesis; meanwhile, the distribution of KB in the negative electrode material PDBM (at) KB is further improved through the technological means of ultrasonic dispersion, vacuum infiltration and the like, a rapid ion transmission channel is constructed, the utilization rate of PDBM active substances is remarkably increased, and the aqueous magnesium ion battery with the PDBM / KB as the negative electrode shows high capacity, long circulation, high rate performance and high power performance; therefore, the technical problem that an existing magnesium ion battery electrode material is low in performance is solved.

The application discloses a carbon carrier material for relieving sodium dendrite growth, rich in micropores and closed pore structure, and a preparation method and application thereof, and belongs to the technical field of low-dimensional material energy storage devices. The preparation method comprises the following steps: SO1, cross-linking reaction of a phenol source, a cross-linking catalyst and a formaldehyde solution; SO2, obtaining an impurity-containing sample through a high-temperature carbonization reaction; and SO3, adding the impurity-containing sample into a solvent for soaking, suction filtration, washing and drying to obtain the carbon carrier material. The carbon carrier material prepared by the application is uniformly distributed, the selection and pore size of the pores are adjustable, can effectively provide rich sodium-philic sites for inducing uniform deposition of sodium, and can inhibit the dendrite growth of a sodium metal battery in a cycle process; the pores serve as three-dimensional Na + Transmission channels are beneficial to forming a good ion migration path, reducing the current density of a local material, reducing the possibility of forming dendrites, and improving the safety and service life of the energy storage device.

The application discloses a method for recycling waste lithium ion battery positive electrode material into nanoflower functional material, and relates to the technical field of battery recycling, which comprises the following steps: discharging and disassembling a recycled waste lithium cobalt oxide lithium battery to obtain a positive electrode sheet; performing heat treatment on the cleaned and dried positive electrode sheet to separate an aluminum foil and a positive electrode material; performing hydrothermal reaction on the obtained positive electrode material and formaldehyde solution; drying the obtained filter residue to obtain a transition metal oxide nanoflower functional material product rich in oxygen vacancies and active groups; and further performing precipitation, filtration and drying on the mother liquor to obtain lithium carbonate powder. The method has the advantages that the recycled positive electrode material and formaldehyde solution are subjected to hydrothermal reaction, the preparation of nanoflower functional material is realized, lithium carbonate is selectively recycled, and formaldehyde is efficiently degraded.

The invention discloses a photocatalyst for hydrogen production by reforming a formaldehyde solution and a preparation method of the photocatalyst, and belongs to the crossing field of catalyst preparation and a hydrogen energy technology. The photocatalyst is a bimetallic structure material with different Mn and Ni molar ratios, and the molecular formula of the photocatalyst is MnxNiy / C3N4. The preparation method comprises the following steps: adding manganese acetate and nickel chloride in different proportions to adjust the feeding ratio of Mn to Ni in the catalyst, uniformly dispersing the mixture in deionized water containing C3N4, dropwise adding a sodium borohydride solution, continuously stirring to obtain a precursor, and calcining in a hydrogen atmosphere to obtain the catalyst. The photocatalyst can synchronously realize formaldehyde degradation and stable hydrogen production, and the hydrogen production rate can reach 134.53 mmol.h <-1 >. G <-1 >. The photocatalyst shows excellent photocatalytic formaldehyde reforming hydrogen production performance under the mild reaction condition without a sacrificial agent, the problem that a traditional catalyst depends on the sacrificial agent can be solved, and the dual benefits of pollutant degradation and clean energy preparation can be achieved through efficient conversion of formaldehyde.

The invention provides a synthesis method of [1, 3, 5]-triazinane-1, 3, 5-trimethyl triacetate, which comprises the following steps: reacting glycine methyl ester hydrochloride with alkali in a solvent, and separating the generated product to obtain glycine methyl ester and salt; the preparation method comprises the following steps: carrying out efficient cyclization on glycine methyl ester and a formaldehyde solution under the catalysis of a catalyst to generate [1, 3, 5]-triazinane-1, 3, 5-trimethyl triacetate; and gradient separation of the solvent, the by-product and the product is realized through a gradient separation process, so that the high-content trimethyl [1, 3, 5]-triazinane-1, 3, 5-triacetate is obtained.

The application belongs to the technical field of diamine and polyamine of diphenylmethane series, and particularly relates to a preparation method of diamine and polyamine (DAM) of diphenylmethane series, that is, before a condensation reaction, a mixing characteristic parameter 1.0<=M<=1.5 of a pre-reaction liquid for the condensation reaction is controlled; the pre-reaction liquid is a mixed liquid formed after a mixture of a formaldehyde solution and aniline hydrochloride or a mixture of the formaldehyde solution and aniline hydrochloride / condensation reaction liquid is pre-mixed. In the method, the mixing characteristic parameter M is controlled in a suitable range, so that the content of N-methyl impurities and the content of macromolecular polymers in the DAM product can be maximally reduced, and the running stability of a production device and the quality of downstream products can be improved.

The application provides a preparation method of a composite aerogel material for VOCs adsorption, wherein 3-aminopropyl triethoxysilane is added into a nanocellulose aqueous solution, and a nanocellulose suspension N-CNF modified by amino is obtained through reaction; the N-CNF suspension is refrigerated overnight, and then dried in a drying box to obtain N-CNF aerogel; the N-CNF aerogel is reacted with a terephthaldehyde solution at 150 DEG C to obtain modified N-CNF aerogel; tetrakis(4-aminophenyl)methane, the terephthaldehyde solution and the N-CNF aerogel are put into a hydrothermal reaction kettle to react, washed with dioxane and ethanol, and dried under vacuum to obtain COF-300@N-CNF composite aerogel. The production cost of the application is low, the preparation process is simple, the adsorption amount of the composite COF-300 material for VOCs gas can be improved, and the VOCs gas treatment capacity can be enhanced.

The invention discloses a preparation method of anti-cracking impregnated bond paper and application of the anti-cracking impregnated bond paper in a core-board. The preparation method comprises the following steps: adding water and a formaldehyde solution into a reaction kettle, adding melamine while stirring, adjusting the pH value to an alkaline range, heating for polycondensation to reach the standard, cooling, and adding a water-soluble mixture to obtain anti-cracking impregnated bond; and after the pre-impregnated gummed paper is impregnated with the anti-cracking impregnating adhesive twice and is subjected to segmented drying, the surface layer is coated with a glue solution containing a curing agent and a release agent in a rolling manner, and the anti-cracking impregnated paper is obtained after drying. Aiming at the problems that the impregnated decorative paper for artificial board decoration is easy to break, the storage life of the impregnating adhesive is short, the veneer artificial board is easy to crack and the like, the toughening type melamine formaldehyde resin is prepared by adopting a compounding technology and is applied to melamine paper and the veneer artificial board, and the method is simple and easy to implement.

The application provides a method for preparing FFPE quality control products by using cell lines, a reference product and a kit, and belongs to the fields of medicine, clinical laboratory science and biotechnology, and comprises the following steps: culturing cell lines by using microcarriers; mixing different cell lines based on requirements; centrifuging the mixed cell microcarrier suspension in a sealed malt pipe at one end; removing supernatant after the treatment; packaging the two ends of the malt pipe by using a semi-permeable membrane; removing the semi-permeable membrane after fixing, dehydrating and transparentizing the malt pipe by using a formaldehyde solution; separating the cell microcarriers after the wax immersion treatment from the malt pipe; and embedding the cell microcarriers into a paraffin block by using wax. The quality control product can be used in subsequent quality control processes, the mutation frequency of the quality control product can be kept in good uniformity, and batch production and large-scale production of the quality control product can be realized.

The application discloses a preparation method and application of a bimodal linear polyethylene chromium carbene catalyst, and belongs to the technical field of chemical synthesis. The preparation method comprises the following steps: 1-nitro-2-aromatic sulfide benzene is prepared by taking 1-fluoro-2-nitrobenzene, aromatic mercaptan and potassium tert-butanolate as raw materials; 1-amino-2-aromatic sulfide benzene is prepared by taking 1-nitro-2-aromatic sulfide benzene and hydrazine hydrate as raw materials; 8-hydroxyimidazol[1,5-alpha] quinolinium salt is prepared by taking 1-amino-2-aromatic sulfide benzene, 8-hydroxyquinoline-2-methyl formaldehyde, formaldehyde solution and hydrogen chloride-1,4-dioxane solution as raw materials; and finally, the reaction is carried out by taking 8-hydroxyimidazol[1,5-alpha] quinolinium salt, silver trifluoromethanesulfonate, sodium bis(trimethylsilyl) amide and chromium trichloride as raw materials to obtain the bimodal linear polyethylene chromium carbene catalyst. According to the preparation method, the catalyst is effectively prevented from being poisoned, the catalytic activity of the catalyst is improved, and the catalyst has good thermal stability.

The utility model provides a formaldehyde concentration system which is provided with a formaldehyde concentration flow path and a cleaning flow path, the formaldehyde concentration system comprises a formaldehyde concentration assembly arranged on the formaldehyde concentration flow path, and the formaldehyde concentration assembly is used for concentrating a formaldehyde solution flowing from the inlet side of the formaldehyde concentration flow path to the outlet side of the formaldehyde concentration flow path. The formaldehyde concentration flow path and the formaldehyde concentration assembly are filled with cleaning liquid through the cleaning flow path so as to clean paraformaldehyde in the formaldehyde concentration flow path and the formaldehyde concentration assembly, the cleaning flow path comprises a liquid inlet flow path and a liquid discharge flow path, and the liquid inlet flow path is communicated with the inlet side of the formaldehyde concentration flow path in an on-off mode to form a first communication position; the liquid discharge flow path is communicated with the outlet side of the formaldehyde concentration flow path in an on-off manner to form a second communication position, and the formaldehyde concentration assembly is located between the first communication position and the second communication position. According to the technical scheme provided by the utility model, the cleaning effect on paraformaldehyde in the formaldehyde concentration flow path can be improved while the formaldehyde concentration effect is ensured.

The application belongs to the technical field of electronic materials, and particularly relates to a high-conductivity silver / graphene composite solute and a preparation method thereof. The method comprises the following steps: acidizing graphene to obtain an acidized graphene dispersion liquid; mixing the acidized graphene dispersion liquid with a formaldehyde solution to perform an aldehyde reaction, and obtaining an aldehyde graphene dispersion liquid; mixing the aldehyde graphene dispersion liquid with a silver-ammonia solution to perform a silver mirror reaction, and obtaining a silver / graphene composite solute. The graphene is subjected to acidization and aldehyde treatment, and then is subjected to a silver mirror reaction with a silver-ammonia solution to form a silver / graphene composite solute. A small amount of the prepared silver / graphene composite solute is added to commercial silver paste, which not only optimizes the conductive path of the silver paste, but also effectively reduces the porosity problem in the sintering process, thereby significantly enhancing the electron transmission performance, greatly improving the conductivity of the silver paste, and finally promoting the solar cell to achieve higher photoelectric conversion efficiency.

The utility model relates to the technical field of formaldehyde production, in particular to a mixing and stirring device for formaldehyde production, which comprises a stirring tank, the left side of the upper surface of the stirring tank is communicated with a feeding hopper, and a mixing mechanism for mixing water and a formaldehyde solution is mounted in the stirring tank. When the device works, a formaldehyde solution and purified water are poured into the stirring tank along the feeding hopper, the motor drives the connecting shaft, the driving bevel gear, the driven bevel gear, the stirring shaft and the stirring rod to rotate to mix and stir the solution, and one end of the piston rod of the electric cylinder extends to drive the suction hood to move to the position over the feeding hopper. Formaldehyde gas volatilized in the mixing and stirring process flows upwards along a feeding hopper, suction force is generated through work of an exhaust fan, the formaldehyde gas is sucked into a purification box along a suction hood and a telescopic hose, formaldehyde molecules are effectively adsorbed by an activated carbon plate, and the situation that the body health of workers is affected by the volatilized formaldehyde is avoided; the safety of formaldehyde production work is improved.

The invention relates to a heavy metal flocculant as well as a preparation method and application thereof, and the preparation method comprises the following steps: (1) dissolving a polyamine substance in alkali liquor, dropwise adding carbon disulfide, continuously reacting for 1-2 hours after dropwise adding, and crystallizing to obtain an addition product containing a dithiocarboxylic acid group; (2) preparing an aluminum hydroxide gel solution, adding acrylamide and an initiator, and carrying out polymerization reaction in an inert atmosphere to obtain a polymerization product; adding a formaldehyde solution into the product, and continuously reacting to the end to obtain a formaldehyde grafted polymerization product; and (3) adding an addition product into the formaldehyde-grafted polymerization product, adjusting the pH value to alkalescence, and keeping heating until the reaction is completed to obtain the heavy metal flocculant. The heavy metal flocculant provided by the invention can synchronously remove heavy metals and suspended solids in wastewater, and does not need to add excessive precipitants; and the synthesized flocculant does not contain a large amount of alkali and does not cause obvious change of the pH value of a water body.

The invention provides a method for synchronously preparing adsorption materials with different functions by modifying waste straws, and belongs to the technical field of material science. The method comprises the following steps: mixing straw, an alkali solution 1 and a formaldehyde solution to obtain a first mixture, and then heating to carry out a reaction 1; after the reaction 1 is finished, adding a sodium sulfite solution into the reaction system to obtain a second mixture, and then heating to carry out a reaction 2; after the reaction 2 is finished, carrying out solid-liquid separation to respectively obtain a first solid and a first liquid; mixing the first solid with an alkali solution 2 to obtain a third mixture, and then heating for reaction 3; after the reaction 3 is finished, adding a first reaction solution into the reaction system, and heating for reaction 4 to obtain resin; and adding a second reaction solution into the first liquid, and heating for reaction 5 to obtain the hydrosol. According to the method, the waste liquid is subjected to solution polymerization by utilizing the solvent characteristic of straw pretreatment, so that all-component utilization of the straw and modification of the waste liquid are realized.

This application provides a continuous titration method for the sulfuric acid and ammonium nitrate content of silicon etching solution. The continuous titration method includes the following steps: weigh m grams of silicon etching solution sample into a sample bottle, add phenolphthalein indicator, titrate with a first sodium hydroxide standard solution of concentration C1 until a pink color is achieved, and record the volume consumed V1. Calculate the sulfuric acid content. Add neutral formaldehyde solution to the same solution and let it stand for a first preset time to generate a free acid solution. Continue titrating the free acid solution with a second sodium hydroxide standard solution of concentration C2 until the solution turns pink. Gently heat the solution to a preset temperature and maintain this temperature for a second preset time. If the pink color persists, the titration endpoint is determined, and the volume consumed V2 is recorded. Calculate the ammonium nitrate content. This method achieves continuous titration of two components with a single sample, eliminates mutual interference between components, optimizes the endpoint determination method, and thus achieves a simple operation, high accuracy, low sample consumption, and high detection efficiency.

The invention relates to the technical field of water hardness detection, in particular to a water hardness detection reagent as well as a preparation method and application thereof. Comprising the following raw materials in parts by weight: 0.8-1.5 parts of ethanolamine, 5-7 parts of diethanolamine, 35-40 parts of triethanolamine, 52-57 parts of an ammonia-ammonium chloride buffer solution, 1.5-2 parts of a chrome black T indicator, 1-1.5 parts of ethylene diamine tetraacetic acid disodium magnesium salt, 0.1-0.3 part of sodium chloride and 0.1-0.3 part of a formaldehyde aqueous solution. The prepared water hardness detection reagent has the characteristics of good stability and high sensitivity.