羧甲基化壳聚糖-Fe_3O_4纳米粒子的制备及对Zn^(2+)的吸附行为

Carboxymethyl Chitosan-Fe_3O_4 Nanoparticles: Preparation and Adsorption Behaviors towards Zn^(2+) Ions

以共沉淀法制备纳米Fe3O4通过在颗粒表面接枝羧甲基化壳聚糖(CMC),制备一种新型磁性纳米吸附剂,用透射电镜(TEM)、X射线衍射分析(XRD)等对其进行了表征,并考察了吸附剂对Zn2+的吸附性能．结果表明,制备的磁性纳米吸附剂平均粒径18 nm,粒子中CMC的含量约5％．该吸附剂对Zn2+吸附速率很快,在2 min内基本达到平衡,能有效去除Zn2+等温吸附数据符合Langmuir模型,饱和吸附容量为20.4 mg·g-1,吸附常数为0．0314 L·mg-1．热力学计算表明吸附为放热过程,焓变为-5．68 kJ·mol-1．

A novel magnetic nanoadsorbent was prepared by the covalent binding of carboxymethyl chitosan （CMC） onto the surface of Fe：3O4 magnetic nanoparticles, which was developed using a coprecipitation method. This nanoadsorbent was characterized by transmission electron microscopy （TEM） and X-ray diffraction patterns （XRD）, etc. Moreover, the adsorption performance of the nanoadsorbent towards Zn^2＋. ions was investigated. The results showed that the mean diameter of the magnetic nanoadsorbent was 18 nm and the amount of CMC was about 5%. The nanoadsorbent showed high efficiency for the removal of Zn^2＋ ions. The adsorption rate was so rapid that the equilibrium was achieved within 2 min. The isotherm adsorption data obeyed the Langmuir model, with a maximum adsorption capacity of 20.4, mg ·g- 1 and an adsorption equilibrium constant of 0.0314, L ·mg^-1. The thermodynamic calculation indicated that the adsorption process was exothermic and the enthalpy change was -5.68 kJ· mol^-1.