Magnetic chitosan micron spheres: Synthesis and adsorption property for Cu2+
MS@SiO 2 @CS magnetic micron spheres were fabricated by successively coating the ball-milled coal fly ash magneticsphere (MS) particles with SiO 2 and chitosan (CS) through a sol-gel and an inverse microemulsion method, respectively. The structures and properties were carefully characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The results showed that the MS particles were coated layer by layer of SiO 2 and CS, respectively, and relative evenly distributed in the CS substrate. Since MSs are magnetic, the MS@SiO 2 @CS samples also show relatively strong magnetism with a specific saturation magnetization of 7.04 emu·g -1 . Adsorption experiments indicated that the magnetic composite micronspheres showed the good adsorption capability for Cu 2+ ions, and the adsorption capacity was up to 11.08 mg·g -1 . In addition, after Cu 2+ adsorption, the adsorbents could be separated effectively from water by magnetic separation. According to the adsorption kinetics simulation, the Cu 2+ adsorption of MS@SiO 2 @CS corresponds to pseudo second order kinetics, which implies a dominant chemical adsorption.