Preparation Of Functional Magnetic Nano-particles And Their Adsorption Capability

Magnetic nano-particles are a kind of novel functional materials, which exhibit extensive application prospect, such as bio-separation, targeted drug delivery, immunoassay and biological sensors and so on. magnetic properties of nano magnetic material is different from conventional magnetic materials, for its small particle size, large surface area and excellent magnetic properties, so it is favored by many researchers. However compared to other nano-materials, they are easier to aggregate with each other or oxidized, thus the modified magnetic nanoparticles are as the starting point of the magnetic nano-materials. Modification means changing the physical and chemistry properties of nano-particles by physical or chemical methods, including the surface chemistry properties, wettability, chemical adsorption and reaction characteristics. According to the surface properties of nano-particles, people usually adopt the method of coating organic or inorganic materials to improve the oxidation resistance, bio-compatibility and stability. The main content of this paper such as following:1.3-aminopropyltriethoxysilane functionalized nanoscale zero-valent iron for the removal of dyes from aqueous solution to adsorb dyes (acid brilliant scarlet GR and reactive brilliant red K-2BP) from aqueous solution. APS-NZVI has shown good adsorption performance at different concentrations of dyes. Under the adsorption conditions of pH 4.5, initial concentration was 100 mg/L, and time is 12h, the adsorption capacity of APS-NZVI for 121.06mg/g and 191.5mg/g, respectively. The results revealed that the adsorption behavior of the dyes on the nano-particles fitted well with the Langmuir model and the sorption kinetics fits well the pseudo-second-order rate equation model.2. In our work, we successfully prepared TETA-coated Fe3O4(?)SiO2 microspheres by using environmentally friendly KH-560 silane coupling agent as the connecting agents between Fe3O4(?) SiO2 spheres and TETA. The advantage of the material are as follows (1) the magnetic core can provide a convenient platform for the facile separation; (2) the silica shell can efficiently prevent the aggregation and chemical decomposition of Fe3O4 in harsh environment; (3) The KH-560 and TETA are without additional toxicity for the further application. (4) This material with excellent solubility are easily scattered, which makes adsorption process easier. (5) This material can be recycled. In this study, silica was selected to encapsulate the obtained magnetite microspheres, because the silica coating could not only effectively screen the magnetic dipolar attraction between magnetite microspheres, which favors the dispersion of magnetite microspheres in liquid media and protects them from leaching in an acidic environment, but also provides them with a silica-like surface, which allows further modification with various groups that are useful for practical applications.