鞣酸模板交联壳聚糖/凹凸棒粘土复合树脂的吸附性能

Adsorption Properties of Crosslinked Chitosan/Attapulgite Composite Resin with Tannic Acid as Template Molecule

以鞣酸(TA)为模板,采用乳化交联法制备了壳聚糖/凹凸棒粘土复合树脂(TA-CAR)。利用红外光谱(FT-IR)和扫描电镜(SEM)对树脂的结构和形态进行表征。结果表明,与非模板树脂相比,TA-CAR对TA的吸附量从185 mg/g提高到232 mg/g,且具有一定的吸附选择性,树脂的吸附等温线和动力学可以用Langmuir方程和伪二级动力学模型很好地拟合,TA-CAR较高的吸附能力归因于树脂中特异吸附位点的识别作用和表面吸附的协同作用。树脂的再生性能研究表明,凹土的加入不但提高了复合树脂的吸附量,而且显著改善了树脂的耐酸能力,可实现树脂的再生利用。

The crosslinked chitosan/attapulgite composite resin（TA-CAR） was prepared by emulsion cross-linking with tannic acid（TA） as template molecule.The structure and the morphology of the resin were characterized by FT-IR and SEM,respectively.Compared with non-template resin（185 mg/g）,TA-CAR shows higher adsorption selectivity and higher adsorption capacity（232 mg/g） for TA at the same adsorption conditions.The study of adsorption kinetics and isotherms shows that the sorption processes are better fitted by the pseudo-second-order equation and the Langmuir equation,respectively.The higher adsorption capacity of TA-CAR maybe attribute to the synergistic effect of special recognition site and surface adsorption on the resin.Furthermore,the desorption study implies that the introduction of attapulgite not only improves the absorbability,but also enhances the acid resistance of the resin,which ensures the recyclable of the composite resin.