脒基硫脲接枝聚乙烯醇/细菌纤维素吸附剂的制备及其对Cu(Ⅱ)的选择性吸附

Preparation of amidyl thiourea grafted polyvinyl alcohol/bacterial cellulose adsorbent and its selective adsorption of Cu(Ⅱ)

本研究将脒基硫脲(GLA)接枝到交联聚乙烯醇(SPVA)/细菌纤维素(BC)制备了一种新吸附剂(GLA-SPVA/BC),并研究其对铜离子的选择性吸附.FT-IR中C=N和—(C=S)—N特征吸收峰的出现以及mapping图像中N和S元素的均匀分布表明脒基硫脲成功接枝在SPVA/BC表面;TG-DSC的结果表明吸附剂GLA-SPVA/BC在吸附过程中具有很好的热稳定性.该吸附剂GLA-SPVA/BC对Cu(Ⅱ)离子的吸附符合Langmuir等温线模型,30℃时最大吸附容量为91.86 mg·g^(−1);Elovich动力学模型拟合显示在吸附剂表面发生了化学吸附作用;XPS谱图中N、S特征峰值的变化进一步证实是主要通过配位作用完成吸附.GLA-SPVA/BC吸附剂在铜锌铅镍4元离子体系中,对Cu(Ⅱ)表现出高的选择性.

In this study,we studied that the amidyl thiourea(GLA)was grafted to the matrix of cross-linked polyvinyl alcohol(SPVA)and bacterial cellulose(BC)to prepare a new adsorbent(GLA-SPVA/BC),selectively adsorbing copper ions.The C=N and—(C=S)—N characteristic absorption peaks in FT-IR spectrum of GLA-SPVA/BC and the uniform distribution of N and S elements in the element mapping image confirmed that GLA was successfully grafted onto the surface of SPVA/BC.The results of TG-DSC showed that GLA-SPVA/BC had good thermal stability during the adsorption process.The adsorption of Cu(Ⅱ)ions by the adsorbent GLASPVA/BC complies with the Langmuir isothermal model,and there is a maximum adsorption capacity of(91.86 mg·g^(−1))at 30℃.The fitting dynamical model verified a chemo-adsorption on the surface of the GLA-SPVA/BC.The adsorption by coordination way was confirmed by the change of N1s and S1s characteristic peak in the XPS spectrum.GLA-SPVA/BC shown high selectivity to Cu(Ⅱ)in Cu-Zn-Pb-Ni 4 ion system.