Fe_3O_4/壳聚糖复合纳米粒子吸附剂的制备及其对Pb^(2+)吸附性能

Preparation and its adsorption performance for Pb(Ⅱ)of adsorbent of Fe_3O_4/chitosan nanoparticles composite

用乙二醇为溶剂,三氯化铁和尿素为起始反应试剂,柠檬酸为粒子表面修饰剂,通过一步溶剂热法制备Fe3 O4纳米粒子,然后以一定浓度配比的Na2 SO4与NaOH混合液为沉淀剂,通过沉淀聚合法制备Fe3 O4/壳聚糖复合纳米粒子吸附剂。利用X射线衍射仪(XRD)、红外光谱(IR)、透射电子显微镜(TEM)和物理特性测试仪(PPMS)表征样品的结构、形貌和磁性能,并使用原子吸收分光光度计(AAS)评价吸附剂对Pb2+的吸附去除性能。结果表明,Fe3O4/壳聚糖复合纳米粒子吸附剂是由磁性Fe3O4纳米球形粒子和鱼卵状壳聚糖纳米粒子聚集体复合而成,该吸附剂对Pb2+有很好的吸附去除性能,它对Pb2+的等温吸附线符合Langmuir模型,在温度298k和pH值5时,吸附剂对Pb2+的饱和吸附量为105.5mg/g。

Fe3 O4nanoparticles were successfully synthesized firstly by a simple and one-step solvothermal route ,using ethylene glycol （EG）as reaction solvent, FeCI3 · 6H2O and urea as the starting materials, citric acid as particle surface modifier. Then an adsorbent of Fe3O4/chitosan nanoparticles composite was prepared by precipitation polymerization,using sodium sulphate and sodium hydroxide as the mixed precipitator. Phase structure, morphology and magnetic properties of its corresponding products were characterized by X-ray diffraction（XRD） ,Fourier transform infrared spectroscopy（FT-IR） ,high-resolution transmission electron microscopy （TEM）, and physical property measurement system （PPMS） , moreover, the adsorption property of the adsorbent for Pb（ Ⅱ ）ions was investigated by atomic absorption spectrometry （AAS）. The results show that the adsorbent of Fe3 O4/chitosan nanoparticles composite was composed of spherical Fe304 nanoparticles and fish egg-like aggregate of chitosan nanoparticles,which possessed a high adsorption performance for Pb（ Ⅱ ） ions. The adsorption data obeyed the Langmuir equation. Its maximum adsorption capacity for Pb （ Ⅱ ）inns at pH=5 and 298k are 105.5mg/g.