聚甲基丙烯酸修饰壳聚糖微球的制备及其对Zn^(2+)和Cu^(2+)的吸附

Preparation of Chitosan Microspheres Grafted by Poly(Methacrylic Acid) and Its Adsorption Behavior of Zn^(2+) and Cu^(2+)

以过硫酸钾为引发剂,通过热引发聚合合成了聚甲基丙烯酸修饰壳聚糖微球(PMAA-GLA-CTS).用红外光谱和X射线光电子能谱表征了产物的结构,并考察了它对水溶液中Zn2+和Cu2+的吸附行为.结果表明,其吸附等温线符合Langmuir方程;pH 4.0时,对Zn2+和Cu2+的最大吸附容量分别为99.1,67.8 mg/g.用二级吸附动力学模拟反应过程有很好的线性相关性,据此确定该吸附过程为化学吸附.以0.2 mol/L的HCl为解吸剂,Zn2+和Cu2+的二次再生率分别为98.0%和96.0%.

The thermal initiation graft copolymerization of methacrylic acid onto chitosan was carried out in aqueous medium by using potassium persulfate as initiator.The structure of the mocrospheres was characterized by FT-IR and XPS,and the adsorption behavior of the modified microspheres for Zn2＋ and Cu2＋ was investigated.The equilibrium process conforms to the Langmuir isotherm.The maximum adsorption capacities for Zn2＋ and Cu2＋ are 99.1 mg/g and 67.8 mg/g at pH 4.0,respectively.The kinetic simulation shows good correlation coeffcients for pseudo-second-order kinetic model,confirming that the soption rate is controlled by chemical adsorption.The regeneration of the adsorbent can be carried out by treating the loaded microspheres with 0.2 mol/L HCl.The regeneration rate for Zn2＋ and Cu2＋ can be achieved to 98.0% and 96.0%,respectively.