Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10378398 | Journal of Colloid and Interface Science | 2005 | 6 Pages |
Abstract
Monodisperse chitosan-bound Fe3O4 nanoparticles were developed as a novel magnetic nano-adsorbent for the removal of heavy metal ions. Chitosan was first carboxymethylated and then covalently bound on the surface of Fe3O4 nanoparticles via carbodiimide activation. Transmission electron microscopy micrographs showed that the chitosan-bound Fe3O4 nanoparticles were monodisperse and had a mean diameter of 13.5 nm. X-ray diffraction patterns indicated that the magnetic nanoparticles were pure Fe3O4 with a spinel structure, and the binding of chitosan did not result in a phase change. The binding of chitosan was also demonstrated by the measurement of zeta potential, and the weight percentage of chitosan bound to Fe3O4 nanoparticles was estimated to be about 4.92 wt%. The chitosan-bound Fe3O4 nanoparticles were shown to be quite efficient for the removal of Cu(II) ions at pH>2. In particular, the adsorption rate was so fast that the equilibrium was achieved within 1 min due to the absence of internal diffusion resistance. The adsorption data obeyed the Langmuir equation with a maximum adsorption capacity of 21.5 mgâgâ1 and a Langmuir adsorption equilibrium constant of 0.0165 Lâmgâ1. The pH and temperature effects revealed that the adsorption capacity increased significantly with increasing pH at pH 2-5, and the adsorption process was exothermic in nature with an enthalpy change of â6.14Â kJâmolâ1 at 300-330 K.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Colloid and Surface Chemistry
Authors
Yang-Chuang Chang, Dong-Hwang Chen,