掺杂改性纤维素复合气凝胶的制备及吸附性能

Preparation and Adsorption Properties of Modified Regenerated Cellulose Composite Aerogels

为提高纤维素材料在废水处理中的吸附性能,利用蒙脱土(MMT)和壳聚糖(CS)对再生纤维素(RC)掺杂改性,制备了多元复合气凝胶。对气凝胶结构进行了表征,评价了气凝胶对重金属离子的吸附性能。结果表明:CS的加入增强了与纤维素分子的作用力,能构建具有均匀微孔结构的复合气凝胶,提高了气凝胶的机械性能及其孔隙率,降低了密度。相对于纯RC气凝胶,复合气凝胶对重金属离子的吸附性能明显提升,其中RC-MMT-CS复合气凝胶对Pb^(2+)、Cd^(2+)、Co^(2+)和Cu^(2+)的最大吸附量分别达到220.9、153.1、134.5、65.5mg/g,是RC-MMT复合气凝胶的1.4、1.5、1.6、2.1倍,RC气凝胶的12.3、10.0、10.6、6.7倍。同时,RC-MMT-CS复合气凝胶具有良好的再生利用性能,5次循环后对4种重金属离子的吸附能力仍均能保持在75%以上。

In order to enhance the adsorptive property of cellulosic material in wastewater treatment,a regenerated cellulose(RC)based composite aerogel was prepared by doping montmorillonite(MMT)and chitosan(CS).The structure of the prepared aerogels was characterized.The adsorption performance of the aerogels for heavy metal ions was evaluated.The results show that the addition of CS enhances the interaction force with cellulose macromolecules,facilitates the construction of composite aerogels with uniform microporous structure,enhances the mechanical properties,improves the porosity,and reduces the density of the composite aerogels.Compared with pure RC aerogel,the adsorption performance of composite aerogels for heavy metal ions is significantly improved.In particular,the RCMMT-CS composite aerogel has a maximum adsorption capacity of 220.9,153.1,134.5 and 65.5 mg/g for Pb^(2+),Cd^(2+),CO^(2+)and Cu^(2+),respectively,which is 1.4,1.5,1.6 and 2.1 times of RC-MMT composite aerogel,and 12.3,10.0,10.6 and 6.7 times of RC aerogel.Meanwhile,RC-MMT-CS composite aerogel also has good recycling performance.After 5 cycles,the adsorption capacity for the four heavy metal ions can be still maintained.at more than 75%.