Preparation method of magnetic cadmium ion surface imprinted polymer

Abstract

The invention relates to a preparation method of a magnetic cadmium ion surface imprinted polymer, which comprises the following steps: synthesizing magnetic Fe3O4@SiO2 microspheres through a coprecipitation method and a sol-gel method, and treating with acid to increase the surface hydroxyl content; introducing polymerizable double bonds onto the surfaces of the Fe3O4@SiO2 microspheres through a two-step method, namely grafting amino groups onto the surfaces of the microspheres by using aminosilane coupling agent, and generating the double bonds through reaction between acid anhydride and the amino groups; and finally, performing polymerization reaction by taking the Fe3O4@SiO2 microspheres as carriers, taking Cd(II) as a template, taking ethylene glycol dimethacrylate as crosslinking agent and taking methacrylic acid and salicylaldoxime as monomers, and washing off the template Cd(II) after the reaction, thus obtaining a polymer layer with a large number of Cd(II) imprinted holes distributed on the surfaces of the Fe3O4@SiO2 microspheres. The magnetic cadmium ion surface imprinted polymer provided by the invention can be used for separation and removal of cadmium ions.

Description

technical field [0001] The invention relates to a preparation method of a magnetic cadmium ion surface imprinted polymer, in particular to a magnetic cadmium ion surface imprinted polymer with a core-shell structure. Background technique [0002] Cadmium is mainly used in the manufacture of alloys, atomic reactor (neutron absorption) control rods, electroplating, and rechargeable batteries. Cadmium compounds have been widely used in the manufacture of (yellow) pigments, plastic stabilizers, (TV image tube) phosphors, and insecticides. Agents, fungicides, paints, etc. With the continuous development of modern industry, a large amount of cadmium-containing wastewater is discharged into rivers, causing cadmium pollution. When the environment is polluted by cadmium, cadmium can be enriched in organisms and enter the human body through the food chain to cause chronic poisoning. After cadmium is absorbed by the human body, it forms cadmium-sulfur protein in the body, which selec...

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Problems solved by technology

[0004] The above methods usually have the following problems: (1) Generally, the magnetic imprints synthesized are based on Fe 3 o 4 As the core, a layer of SiO is coated on the outside 2 , and then using SiO 2 The hydroxyl groups on the surface are directly grafted with functional monomers, or undergo silanization and related subsequent reactions to synthesize imprinted materials

But SiO 2 The hydroxyl content on the surface is limited, which will affect the grafting rate of functional monomers or the effect of silane coupling agent surface modification

(2) Grafting polymerizable double bonds on the outer layer of the carrier, mostly using γ-(methacryloyloxy)propyltrimethoxysilane to introduce double bonds (Zhang Shuanhong, Sun Changmei, Qu Rongjun. Surface molecules (ions) Advances in the preparation and performance of imprinted silica gel / polymer. Polymer Bulletin, 2010(4):17-29.), but it is thermally unstable, under conventional silanization conditions (110°C toluene as solvent for reflux ) will undergo thermal polymerization, but if the temperature is lowered, the efficiency of the introduction of double bonds will be reduced

However, the rigidity of methacrylic acid is not good, and the rigidity of the synthesized imprinted holes is small, which affects the reuse performance

(4) In the reported literature and patents, the adsorbent is often used alone for the adsorption of trace or trace ions, which limits the scope of use of the adsorbent

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