羧甲基纤维素/Fe_3O_4复合纳米磁性材料的制备、表征及吸附性能的研究

Preparation,Characterization and Adsorbability of Magnetic Carboxymethyl Cellulose/Fe_3O_4 Nano-Composite Particles

采用改进的氧化沉淀法在羧甲基纤维素(CMC)体系中制备了以磁性纳米Fe3O4为核心,外层包覆羧甲基纤维素的复合磁性纳米材料.用透射电镜、X射线衍射、红外光谱、Zeta电位和震动样品磁强计对复合纳米Fe3O4进行了表面形貌、结构和磁学的表征.在此基础上研究了复合纳米Fe3O4对Cu2+的吸附性能,探讨了溶液pH、反应时间和Cu2+的初始浓度对其吸附性能的影响.实验结果表明,复合Fe3O4粒子为反尖晶石型,平均粒径在40nm左右,羧甲基纤维素在Fe3O4粒子表面是化学吸附,复合Fe3O4粒子的饱和磁化强度为36.74emu/g,在中性溶液中Cu2+的吸附量最高,吸附平衡时间为1.5h,二级动力学模型能够很好地拟合吸附动力学数据,吸附等温数据符合Langmuir模型.复合纳米Fe3O4对Cu2+的吸附机理主要为表面配位反应。

CMC-Fe3O4 nano-composite particles were prepared in the carboxymethyl cellulose（CMC） solution by a modified oxidation deposition method,and characterized by TEM,XRD,IR,ZP（zeta potential） and VSM（vibrating sample magnetometer）.The adsorption of Cu^2＋ on CMC-Fe3O4 was further researched.Different pH,reaction time and Cu^2＋ initial concentration affecting adsorption of CMC-Fe3O4 was studied.The results show that CMC-Fe3O4 is inverse spinel structure;the particle size is 40 nm on an average and dispersed homogeneously in water.Carboxymethyl cellulose molecules are chemically adsorbed on the surface of Fe3O4 nano-particles.Its saturation magnetization is 36.74 emu/g.The maximum adsorption for Cu^2＋ occurred at pH=7 in water.The adsorption equilibrium time was reached in 1.5 h.The adsorption kinetics and isotherm data were well described by pseudo-second-order equation and Langmuir isotherm models,respectively.The adsorption mechanism of Cu^2＋ was main complexation reaction.