6results about How to "Complete crystal form" patented technology

The invention belongs to the technical field of dibromohydantoin production, and particularly provides a dibromohydantoin synthesis method which comprises the following steps: S1, preparing a raw material aqueous solution, namely respectively mixing dimethyl hydantoin, sodium bromide and liquid caustic soda NaOH with deionized water to form a dimethyl hydantoin aqueous solution, a sodium bromide aqueous solution and a liquid caustic soda NaOH aqueous solution; s2, premixing the raw material aqueous solution, namely mixing the aqueous solution of dimethyl hydantoin, sodium bromide and caustic soda liquid NaOH prepared in S1 to obtain a premix; s3, electrochemical in-situ bromination reaction: introducing the premix into a micro-channel reactor provided with an electrolysis electrode, and applying current to the premix to obtain a dibromohydantoin initial solution; and S4, crystallizing, separating and drying the product, carrying out cooling crystallization through a three-stage stepped cooling method to obtain a dibromohydantoin crystal, carrying out centrifugal separation to obtain a dibromohydantoin wet product, and then drying to obtain a dibromohydantoin finished product. The method can improve the generation stability and the product quality of the dibromohydantoin.

The application discloses a method for preparing arsenic-cadmium alloy by using arsenic-cadmium acid waste liquid, and belongs to the technical field of wastewater treatment. The application realizes the selective precipitation of arsenic and cadmium in the form of Cd5H2(AsO4)4.4H2O with high purity and complete crystal form by precisely controlling the molar ratio of cadmium to arsenic in the waste liquid to be 1.2-1.6 and adjusting the pH of the precipitation to be 4-6, thereby realizing the deep removal of the two toxic elements of arsenic and cadmium, and the removal rate of arsenic can reach more than 96.70%, and the process flow is greatly reduced. The Cd5H2(AsO4)4.4H2O-based precipitation slag is converted into high-purity arsenic-cadmium alloy by carbon thermal reduction, the amount of slag is greatly compressed, and the storage and landfill of waste materials are significantly reduced. The alloy can be further used to prepare downstream products such as semiconductor materials as a high-value-added product, realizes the high-value conversion from harmful waste to high-end raw materials, and has remarkable green disposal and resource utilization benefits.

This invention discloses a continuous crystallization method for fluorine-containing complex salts, belonging to the field of chemical crystallization technology. It solves the problems of low efficiency in manual cleaning, interference between stirring and wall scraping, and low automation in existing technologies. The method includes: initiating a crystallization stirring process to stir the fluorine-containing complex salt solution in the crystallization tank while keeping the scraper assembly stationary; real-time monitoring of the duration of crystallization stirring and the solution temperature; when the duration reaches t and the solution temperature reaches T, the crystallization process is determined to be complete, and the process automatically switches to the wall scraping process: driving the scraper assembly to rotate and scrape off the crystal scale layer against the inner wall of the tank, while simultaneously discharging the crystal product; after the wall scraping process is completed, the scraping is automatically stopped, and the next batch of fluorine-containing complex salt solution is automatically injected, repeating steps S1 to S3. This invention simplifies the equipment structure, avoids interference of the scraper with crystal growth, improves cleaning efficiency, product yield and quality, and has a high degree of automation.

The invention discloses a composite modified resin anticorrosive coating and a preparation method thereof, and belongs to the technical field of coatings. The method comprises the following steps: by taking water-borne epoxy resin as a film forming substrate, firstly preparing graphene oxide, carrying out amination on 2, 5-diaminobenzene sulfonic acid to introduce amino and sulfonic acid groups which are covalently bonded, and then carrying out defect engineering reduction through hydrazine hydrate to obtain defect engineering amino modified graphene oxide with high-density reaction sites; lamellar double hydroxides grow on the surface in situ, molybdate radicals are intercalated to construct a core-shell structure filler, and finally the filler is dispersed in a waterborne epoxy / aliphatic polyamide curing system to prepare the composite anticorrosive coating. According to the invention, the adhesive force and impact resistance of the coating and a metal matrix are remarkably improved, the water absorption rate is reduced, the shielding and slow-release corrosion inhibition capabilities on a corrosive medium are enhanced, and the long-term corrosion resistance superior to that of a conventional waterborne epoxy anticorrosive coating is shown in neutral salt mist and low-frequency impedance tests.

The invention relates to the technical field of nano materials and biochemistry, in particular to a Fe3O4 (at) SiO2 (at) ZIF-8 composite compound for enzyme immobilization and fluorescence dual-mode detection based on a spatial isolation structure and a preparation method of the Fe3O4 (at) SiO2 (at) ZIF-8 composite compound. The composite compound has a multi-layer structure which sequentially comprises a Fe3O4 core, a SiO2 isolation layer, a ZIF-8 shell layer and an outer layer carbon quantum dot from inside to outside, enzyme molecules are loaded in pore channels of the ZIF-8 shell layer, and Fe3O4 is magnetic nanoparticles; the SiO2 is a continuous compact silicon dioxide layer coated on the surface of the Fe3O4; the ZIF-8 is a metal organic framework material formed by in-situ growth on the surface of SiO2; the carbon quantum dots are fixed on the outer surface of the ZIF-8 / SiO2 through chemical bonding; the enzyme is loaded in the ZIF-8 in a pore diffusion manner and is fixed by light cross-linking.

The application relates to the technical field of gas adsorption materials, in particular to a high-hydrophobic MOF material for air purification of an intelligent automobile cabin and a preparation method and application thereof. The MOF material is prepared from 2,3,5,6-tetrafluoro-p-xylylene dimethyl ester as raw material through low-temperature nitration, sodium hydrosulfide nucleophilic substitution and in-situ protection treatment of acetic anhydride, and has 2,3,5,6-tetrafluoro-4-mercapto methyl benzoate with super-hydrophobic fluorine groups and high-activity mercapto groups; a solvent hot method modulated by hydrochloric acid is adopted to realize in-situ coordination crystallization of zirconium metal clusters and hybrid ligands, to complete the deprotection and activation of mercapto groups, and to prepare the MOF material with a stable zirconium cluster framework, a hydrophobic pore environment and specific adsorption sites. The MOF material of the application constructs a hydrophobic barrier through tetrafluoro groups to inhibit competitive adsorption of water molecules, utilizes mercapto groups to provide polar interaction and coordination sites to enhance the selective capture capacity of isopropyl alcohol, and significantly improves the adsorption efficiency and stability of the material in a humid environment.