Synthesis and Characterization of Magnetic Fe<sub>3</sub>O<sub>4</sub>/PAAm/LMSH Nanocomposite Hydrogel

Abstract

Based on the preparation of polyacrylamide/clays lithium magnesium silicate hydrate (PAAm/LMSH, abbreviated as AP) nanocomposite hydrogel by in-situ free radical polymerization, Fe3O4 nanoparticles were introduced by chemical co-precipitation method, to form magnetic Fe3O4/PAAm/LMSH (abbreviated as MAP) nanocomposite hydrogel. With ESEM, XRD, and TGA technologies, the structures of MAP nanocomposite hydrogel and Fe3O4 nanoparticles formed. Magnetic characteristic of MAP nanocomposite hydrogel was characterized by VSM. The tensile test with Universal Testing Machine was employed for mechanical properties. Furthermore, taking cationic dye Crystal Violet (CV) and anionic dye Methyl Orange (MO) for example, the adsorption properties of MAP nanocomposite hydrogel were analyzed with UV-visible spectrophotometer method. The results show that MAP nanocomposite hydrogel had strong superparamagnetic properties. The introduced Fe3O4 magnetic particles illustrated spinel structure, and nanoparticle size of 8.52 nm. The swelling rate of MAP sample was up to 30.542, showing excellent swelling ability. Compared with AP nanocomposite hydrogel, MAP nanocomposite hydrogel had stronger mechanical strength with the tensile stress of 0.39MPa. Adsorption experiments indicated that MAP nanocomposite hydrogel had favorable adsorption properties on CV with removal rate of 97.6%, 1.27 times that of AP nanocomposite hydrogel. The conclusions confirm the application prospect of MAP nanocomposite hydrogel as dye adsorbent in textile printing and dyeing wastewater treatment.