Preparation And Adsorption Properties Of Functionalized Magnetic Microspheres

Fe₃O₄ magnetic nanoparticles has high coercivity,superparamagnetic, strong wide-band absorption and low Curietemperature as its performance, so that it has a wide range of applications in the field of physics, chemistry, such as magnetic refrigerant material applications, application of stealth wave absorbing materials and application in magnetic record materials. Thus preparation and research of functionalized nano magnetic is one of the focus of the world.Chitosan molecular chain containing a large number of active groups- NH₂?-OH, very good adsorption of metal ions and humic acids and so on, realize the removal of soluble pollutants in the water, often used as water treatment agent of raw materials, However, it is difficult to separate the water from the water after the adsorption of chitosan, so it is restricted in the application. This paper using chitosan and Fe₃O₄ as a raw material for preparation of chitosan magnetic microspheres with magnetic separation method using simple can the advantages of the adsorbed dyes and metal ions of chitosan magnetic microspheres and matrix separation.?1? The magnetic beads with particle size of about 500 nm were successfully prepared.The method: respectively with oleic acid, citric acid, silicate tetra ethyl orthosilicate?TEOS?surface modified Fe₃O₄, the Fe₃O₄ surface with a large number of active groups, after the TEOS modified Fe₃O₄ and 4-chlorophenyl isocyanate modified chitosan are connected by hexamethylene diisocyanate?HDI? of chitosan magnetic microspheres:Fe₃O₄@SiO₂- chitosan magnetic microspheres, and the infrared spectrometer, scanning electron microscope?SEM?and transmission electron microscope, the income of various magnetic microspheres were characterized.?2? Study on chitosan modified agent of Rhodamine B, methylene blue, copper ions,nickel ion and cadmium ion adsorption characteristics. The effects of the different factors such as adsorption time, pH value, ion initial concentration and adsorbent dosage. The effects of the adsorption kinetics and thermodynamics, the study found that chitosan magnetic spherules of Rhodamine B, methylene blue, copper ions, nickel ion and cadmium ion maximum adsorption capacity?mg/g? were: rhodamine B 1.497, methylene blue 7.008, Cu²⁺101.1, Ni²⁺ 7.314, Cr3+ 288.6.?3? cellulose and chitosan have similar structure, successful preparation of functionalized magnetic cellulose microspheres and of copper ion by adsorption experiments were conducted to study and discuss the adsorption kinetics model. The research results show that: resulting magnetic microspheres average particle size about 520 nm, dispersed well, Cu2 + adsorption equilibrium was reached within 30 minutes, in adsorbent dosage of 0.1g, concentration of Cu²⁺is 0.02mol/L. When pH = 5, adsorption amount can reach 55.46mg/g, adsorption isotherm data conforms to the Langmuir model, also with the Freundlich model.