CA@CS-MMT复合纳米纤维的制备及其对Cr(Ⅲ)的吸附

Fabrication of cellulose acetate@chitosan-montmorillonite composite nanofibers and its adsorption of Cr(Ⅲ) from wastewater

摘要:

采用静电纺丝结合溶液插层法制备了醋酸纤维素@壳聚糖改性蒙脱土生物复合纳米纤维（CA@CS-MMT），并研究其对模拟废水中Cr(Ⅲ)的吸附性能。首先采用CS插层改性MMT制得CS-MMT复合材料，改性后的CS-MMT的层间距由1.2450 nm增加至2.2198 nm。然后采用溶液共混静电纺丝法制备不同CS-MMT质量比的CA@CS-MMT复合纳米纤维，采用SEM、FTIR、XRD及TGA等研究了复合纳米纤维的结构与性能，结果表明随着CS-MMT含量的增加，纳米纤维平均直径下降，当CS-MMT含量为2 wt%时，其片层结构与CA组装后在纤维内部形成连续结构，复合纳米纤维热稳定性提高，润湿性有所改善。复合纳米纤维对水中Cr(Ⅲ)的具有良好的吸附性能，25℃下pH为5.5?0.1时其饱和吸附量为144.93 mg/g，吸附过程符合Langmiur等温吸附和伪二级动力学，脱附3次后吸附量仍可达95.0 mg/g。

Abstract:

Cellulose acetate@chitosan modified montmorillonite composite nanofibers were fabricated by electrospinning and solution intercalation (CA@CS-MMT). And the adsorption properties of CA@CS-MMT nanofibers for Cr (Ⅲ) in wastewater were studied. Firstly, the CS-MMT composite was prepared by intercalation modification of MMT with CS, and the interlayer spacing of modified CS-MMT was significantly increased from 1.2450 nm to 2.2198 nm. Then CA@CS-MMT composite nanofibers were prepared by solution blending electrospinning. The structure and properties of the composite nanofibers were studied by SEM, FTIR, XRD and TGA etc. The results showed that the average diameter of nanofibers decreased with the increase of CS-MMT content. And the thermal stability and wettability of nanofibers were improved. When the content of CS-MMT is 2 wt%, the lamellar structure of CS-MMT is assembled with CA to form a continuous structure in the nanofiber. The adsorption capacity of the composite nanofibers was 144.93 mg/g when pH was 5.5 ? 0.1 at 25 ℃. The adsorption process was in accordance with Langmuir isothermal adsorption and pseudo second order kinetics. The adsorption capacity was still 95.0 mg/g after three times of desorption.