【摘要】 为了提升羧甲基纤维素钠(CMC)阳离子交换膜(CEMs)的污染物迁移性能,以纤维素纳米晶须(CNCs)和纤维素纳米纤维(CNFs)为掺杂材料,通过流延法制备复合阳离子交换膜.表征了复合膜的形貌、溶胀度、亲水性、J-V曲线,并以氨氮为目标污染物,测试了纯CMC及复合膜在电渗析过程中的氨氮迁移性能.结果表明,CMC-CNCs和CMC-CNFs复合膜较纯CMC膜表面光滑,亲水性提升,膜阻抗及工作电压均减少,在酸性溶液中能保持较好的结构稳定性.同时,以m(CMC)∶m(CNCs)=1.0∶2.0及m(CMC)∶m(CNFs)=1.5∶1.5为例,适量掺杂CNCs和CNFs均可以降低复合膜在工作过程中的槽电压,提升电流密度,3 h内对氨氮的迁移能力分别从86.6%提升到93.2%及94.5%.更多还原

【Abstract】 To enhance the contaminant migration performance of sodium carboxymethyl cellulose(CMC)cation exchange membranes(CEMs),composite CEMs were prepared by flow-casting method using cellulose nanocrystalline whisker(CNCs)and cellulose nanofibers(CNFs)as dopant materials.The morphology, swelling degree, hydrophilicity, and J-V curve of membranes were conducted.The migration performance of pure CMCs and composite membranes during electrodialysis was tested with ammonia nitrogen as the target pollutant.The results showed that the CMC-CNCs and CMC-CNFs composite membranes had smoother surface, improved hydrophilicity, reduced membrane impedance and operating voltage, and maintained better structural stability in acidic solutions than the pure CMC membranes.Meanwhile, taking m(CMC)∶m(CNCs)=1.0∶2.0 and m(CMC)∶m(CNFs)=1.5∶1.5,as examples, moderate doping of CNCs and CNFs in CMC can reduce the tank voltage of the composite membrane during operation, while the current density in the composite membrane system increases,and the migration ability of ammonia nitrogen increases from 86.6% to 93.2% and 94.5% within 3 hours.更多还原