纤维素纳米纤维膜的改性及其染料吸附性能

Modification of Cellulose Nanofiber Membrane and Its Adsorption Properties for Dyes

摘要:

采用静电纺丝技术制备醋酸纤维素纳米纤维膜，用氢氧化锂水解后得到纤维素纳米纤维膜。通过3-氯-2-羟丙基三甲基氯化铵（CHPTAC）和一氯乙酸共同改性，制备了双性纤维素纳米纤维膜。利用紫外分光光度计测试双性纤维素纳米纤维膜对茜素绿（AG25）和亚甲基蓝（MB）的吸附性能，并考察了pH、温度、染料初始浓度对吸附量的影响。结果表明，双性纤维素纳米纤维膜对AG25和MB染料的最大吸附量分别达到 240 mg/g和 128 mg/g，并且对两种染料在第4个循环时仍保持84%的吸附效率。同时，发现pH是影响双性纤维素纳米纤维膜的染料吸附性能的关键因素，在吸附没有饱和之前，染料吸附量随着染料浓度的增加而增加，而吸附效果对温度没有依赖性。

Abstract:

Cellulose acetate nanofiber membrane was fabricated by electrospinning technology, which was hydrolyzed to synthesize cellulose nanofiber membrane by lithium hydroxide. The as-obtained cellulose nanofiber membrane was modified to prepare the amphoteric cellulose nanofiber membrane by 3-chloro-2-hydroxypropyl trimethylammonium chloride and monochloroacetic acid. The UV spectrophotometer was utilized to evaluate the adsorption properties of alizarin green (AG25) and methylene blue (MB) on amphoteric cellulose nanofiber membrane and the effect of pH value, temperature and initial concentration of dye on adsorption was studied. The results presented that after modification, the adsorption properties of the amphoteric cellulose nanofiber membrane to AG25 and MB dyes were greatly improved. Especially, the maximum adsorption capacity reached 240 mg/g and 128 mg/g, respectively, and adsorption efficiency still maintain 84 % for the two dyes in the fourth cycle. Meanwhile, it was found that the pH value was the most critical factor affecting the dye adsorption property of the amphoteric cellulose nanofiber membrane. Before adsorption unsaturation of the amphoteric cellulose nanofiber membrane, the dye adsorption amount increased with the increased of the dye concentration and the adsorption effect had no dependence on temperature.