3 results about "Fe3o4 magnetic nanoparticles" patented technology

This invention relates to a self-triggered demulsification Pickering emulsion cascade catalytic system, its preparation method, and its application. The preparation method includes: preparing Fe3O4 magnetic nanoparticles by co-precipitation; coating their surface with a SiO2 shell using a modified Stöber method to obtain Fe3O4@SiO2 core-shell nanoparticles; simultaneously grafting a triamine silane coupling agent and octyltrimethoxysilane onto the Fe3O4@SiO2 surface using a one-pot method to obtain magnetic amphiphilic nanoparticles; dividing the magnetic amphiphilic nanoparticles into two batches, and immobilizing glucose oxidase and Candida antarcticis lipase B respectively via EDC / NHS-mediated amide coupling reaction to obtain nanoparticle catalysts; using the nanoparticle catalysts as solid emulsifiers in Pickering emulsions to construct an oil-water two-phase cascade catalytic system, realizing a cascade catalytic reaction of glucose oxidation – peracidification – olefin epoxidation; utilizing the accumulation of gluconic acid during the reaction to lower the pH, triggering emulsion demulsification, achieving product separation and magnetic recovery of the nanoparticle catalysts.

The application discloses a kind of magnetic nanocomposite and its application in dye wastewater treatment, belong to water treatment functional material technical field.The magnetic nanocomposite with Fe3O4 Magnetic Nanoparticle as core, successively coats silica layer, graphene nanosheet layer and chitosan crosslinking layer, through the synergistic effect of chitosan liquid ultrasonic modification and graphene nanosheet surface modification, realize efficient adsorption and magnetic separation recovery to dye molecule.The preparation process of the application is mild controllable, environment-friendly, cost moderate, has wide application prospect in printing and dyeing wastewater advanced treatment, industrial dye pollution control field, graphene nanosheet greatly promotes specific surface area and adsorption site, chitosan provides a large number of amino / hydroxyl active groups, three synergies realize high adsorption capacity.Graphene nanosheet is reduced by liquid phase ultrasonic stripping, avoids stacking;Chitosan is modified by ultrasonic and TiO2 is scattered, combination is more firm, material structure is stable, not easy to lose, acid and alkali resistant.

This invention belongs to the field of environmental functional materials and wastewater treatment technology, and discloses an aminopolycarboxylic acid modified chitosan-sodium alginate composite magnetic gel sphere, its preparation method, and its application. Method: Chitosan, an aminopolycarboxylic acid compound, and water are mixed and stirred until homogeneous. The pH is adjusted to 5-6 with alkali to obtain a mixed solution. This solution is then mixed, stirred, and reacted with an aqueous solution of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide under ice-water bath conditions to obtain aminopolycarboxylic acid modified chitosan. This chitosan is then mixed with Fe3O4 magnetic nanoparticles and an aqueous solution of sodium alginate to obtain a suspension. This suspension is then added dropwise to a mixture of calcium chloride and polyacrylic acid to carry out a cross-linking and solidification reaction. After washing with water and magnetic separation, aminopolycarboxylic acid modified chitosan-sodium alginate composite magnetic gel spheres are obtained. The gel spheres of this invention not only have a large adsorption capacity and good selectivity, but also have a stable mechanical structure, are easy to separate and recover, and have good reusability.