纤维素/二氧化钛复合纳米纤维膜的制备及对Cu^(2+)吸附性能

Preparation of Cellulose/Titanium Dioxide Composite Nanofiber Membrane and Its Cu^(2+) Adsorption Performance

采用静电纺丝技术与水解后处理的方法相结合,制备了纤维素/TiO_2复合纳米纤维膜。通过扫描电镜、红外光谱、X射线衍射、接触角及力学性能测试对复合纳米纤维膜进行了表征。结果表明,复合纳米纤维膜表面光滑,纤维呈三维杂乱排列;加入TiO_2后,纳米纤维的平均直径略有下降,纤维素的结晶度减小,断裂强度降低;但亲水性大幅提升。Cu^(2+)吸附试验结果表明,溶液pH、Cu^(2+)初始浓度和吸附时间是影响吸附效果的重要因素,Cu^(2+)的最大平衡吸附量可达66.54mg/g。Cu^(2+)在纤维素/TiO_2复合纳米纤维膜上的等温吸附规律可以用Langmuir和Freundlich吸附等温模型进行描述,从相关系数来看,纤维素/TiO_2复合纳米纤维对Cu^(2+)的吸附行为用Freundlich模型描述更为合理。

The cellulose/TiO2 composite nanofiber membrane was prepared by combining electrospinning technique and hydrolysis reaction method. The characteristics of the cellulose/TiO2 composite nanofiber membrane were investigated by SEM,FT-IR,XRD,water contact angle and tensile test. It is found that the composite nanofiber has a smooth surface and random orientation. After adding TiO2,the crystallinity of the cellulose decreases and the breaking strength decreases,but the hydrophilicity becomes much better. The Cu2＋adsorption test results show that the pH value,Cu2＋initial concentration and adsorption time are the important factors affecting the adsorption performance. The maximum equilibrium adsorption capacity of Cu2＋could reach 66. 54 mg/g. The Cu2＋isothermal adsorption by the cellulose/TiO2 composite nanofiber membrane can be described by the Langmuir and Freundlich adsorption isothermal models. From the view of correlation coefficient,the adsorption behavior of the cellulose/TiO2 composite nanofibers for Cu2＋is more suitably described by the Freundlich model.