pH值响应的壳聚糖纳米微球的合成及吸附镍离子研究

Synthesis of pH-Responsive Chitosan Nanospheres and Adsorption of Nickel(II)from Aqueous Solution

本工作于水中简单地合成了生物相容且可生物降解的壳聚糖/聚丙烯酸纳米微球,产物具有优异的水稳定性和单分散性。通过傅里叶变换红外光谱、动态光散射、透射电子显微镜、扫描电子显微镜和zeta电位对所得纳米微球的理化性质进行表征,结果显示壳聚糖纳米微球的表面结构和zeta电位对pH值改变具有响应性。携带丰富官能团的产物微球为装填其它活性材料提供了功能位点,因此,可将该纳米微球用作水中去除镍离子的吸附剂。本文从吸附时间、pH值、温度及起始离子浓度等方面研究了纳米微球的吸附行为,发现壳聚糖微球对镍离子的吸附量可以高达44.41mg/g。此外,吸附等温线遵循Freundlich等式,而其动力学符合拟二级模型。

In this work,biocompatible and biodegradable chitosan nanospheres were successfully prepared by a simple method in water.The nanospheres were well monodispersed and stable in aqueous solution.The physicochemical properties of nanospheres were investigated by using Fourier transform infrared spectroscopy,dynamic light scattering,transmission electron microscope,scanning electron microscopy and zeta potential.It was found that the surface structure and zeta potential of nanospheres can be manipulated by changing pH.The obtained chitosan nanospheres provide the functional sites with abundant functional groups for embedding of other active materials.Thus,the chitosan nanospheres were employed as absorbents for removal of nickel(II)ions from aqueous solutions.The adsorption behaviors of nanospheres were investigated including the effects of adsorption time,pH value,temperature and initial concentration by the batch method.The adsorption capacity of the chitosan nanospheres for nickel(II)ions was observed to be as high as 44.41mg/g.Moreover,the adsorption isotherms obeyed the Freundlich equation,and kinetics followed a pseudo-second order model.