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采用静电纺丝法制备聚丙烯腈(PAN)纳米纤维膜,再以盐酸羟胺为改性剂对PAN纳米纤维膜进行偕胺肟化处理成功制备出偕胺肟化纳米纤维膜(AOPAN).通过扫描电子显微镜(SEM)、红外光谱(FTIR)、水接触角等对其物理化学性质进行表征并研究其吸附重金属Cr(Ⅵ)的能力.结果表明,PAN纳米纤维在水浴温度60℃,水热时间3.5 h条件下进行改性后,纤维直径明显变粗,并且有一定程度的弯曲.由红外光谱(FTIR)分析发现改性后的PAN纳米纤维膜在3500~3300 cm~(-1)范围内出现了2个双峰,并且接触角由114.5°变为29.8°,说明成功地将PAN纳米纤维改性为含有—NH_2基团的AOPAN纳米纤维.该AOPAN纳米纤维膜对铬的吸附实验表明,在p H=2时,吸附约5 h后达到最佳除铬效果,吸附量可达102.5 mg/g,并且满足准一级动力学方程,符合Langmuir吸附模型.主要是由于制备的AOPAN含有—NH_2基团,在酸性条件下被质子化为—NH_3~+,更易与HCr O_4~-结合.而且这种膜材料在使用后便于取出,经稀Na OH溶液洗涤后,能够重复使用,循环4次后仍能保持50%以上的去除率,在处理重金属离子方面具有非常大的潜力.
Polyamido-nitrile (PAN) nanofibrous membranes were prepared by electrospinning method, and amidoximation of nanofibrous membranes (AOPAN) was successfully prepared by amidoximation of PAN nanofibers with hydroxylamine hydrochloride as modifier. The physicochemical properties of Cr (Ⅵ) were studied by SEM, FTIR and water contact angle. The results showed that the PAN nanofibers could be adsorbed on Cr (Ⅵ) Time was 3.5 h, the diameter of the fiber became thicker and a certain degree of bending was observed.FTIR analysis showed that the modified PAN nanofibrous film has a diameter in the range of 3500 ~ 3300 cm ~ (-1) There were two bimodal peaks and the contact angle changed from 114.5 ° to 29.8 °, which indicated that the PAN nanofibers were successfully modified into AOPAN nanofibers containing -NH_2 groups.The adsorption experiment of chromium on AOPAN nanofibers showed that , And reached the best chromium removal efficiency at p H = 2 for about 5 h, with an adsorption capacity of 102.5 mg / g, which satisfied the quasi-first order kinetic equation and fitted the Langmuir adsorption model. The main reason was that the prepared AOPAN contained -NH 2 groups, which are protonated to -NH 3 ~ + under acidic conditions, And easy to combine with HCr O_4 ~ - and this membrane material is easy to remove after use, diluted with NaOH solution, it can be reused, and can still maintain more than 50% removal rate after 4 times of recycling, in the treatment of heavy metal ions Has great potential.