氨基功能化纤维素的制备及其吸附性能研究

Preparation of amino functionalized cellulose adsorbent materials and their adsorption properties

采用氢氧化钠/尿素水溶液体系,以α-纤维素(CELL)为原料,分别以多乙烯多胺(CAS)、超支化聚乙烯亚胺(HPEI)为改性试剂,戊二醛为交联剂,制备了氨基化改性纤维素CAS-CELL和HPEI-CELL,并对产品进行了IR、UV、SEM、XPS结构表征,结果表明,CAS和HPEI成功接枝到纤维素上。吸附实验结果表明:随着CAS和HPEI用量的增加,氨基功能化纤维素吸附效果增强,HPEI-CELL03对甲基橙(MO)溶液的饱和吸附量为95.07 mg/g;氨基化改性纤维素同时具有pH敏感性,当pH=3时,氨基功能化纤维素对甲基橙溶液吸附效果最好。HPEI-CELL对甲基橙的吸附过程符合准二级动力学模型,说明以化学吸附为主;与Freundlich模型相比,Langmuir模型能更好地描述氨基功能化纤维素的吸附过程。

Amino-modified cellulose-based adsorbent materials CAS-CELL and HPEI-CELL were prepared by using sodium hydroxide/urea aqueous solution system,α-cellulose(CELL)as raw material,polyethylene polyamine(CAS)and hyperbranched polyethyleneimine(HPEI)as modification reagents,glutaraldehyde as cross-linking agent,respectively.The products were characterized by IR,UV,SEM and XPS.The results showed that CAS and HPEI were successfully grafted to cellulose.Adsorption results showed that with the increase of CAS and HPEI dosage,the adsorption property of amino-functionalized cellulose was enhanced.The adsorption capacity of HPEI-CELL03 on methyl orange solution was 95.07 mg/g.The amino-modified cellulose adsorbent materials also had pH sensitivity.When pH=3,the amino-functionalized cellulose adsorbent materials had the best adsorption amount on methyl orange solution.The adsorption process of methyl orange by HPEI-CELL03 conforms to the pseudo-second-order kinetic model,indicating that chemical adsorption is the main process.Compared with Freundlich model,Langmuir model can better describe the adsorption process of amino-functionalized cellulose adsorbent materials.