尿素水热法制备PET@LDH纳米纤维膜及其除铬性能研究

Preparation and Cr(Ⅵ)-removal performance of PET@LDH composite nanofibrous membrane by urea-hydrothermal method

通过静电纺丝法制备聚酯(PET)纳米纤维膜,并运用尿素水热法在其表面原位生长水滑石(LDH)微晶层,得到PET@LDH纳米纤维膜。采用扫描电子显微镜、红外光谱仪、X-射线衍射仪和能谱仪等对PET@LDH纳米纤维膜进行表征。结果表明:水热反应8h,水滑石晶片良好生长在PET纳米纤维表面,成功制备出PET@LDH纳米纤维膜。运用电感耦合等离子体测试技术对PET@LDH纳米纤维膜的除铬效果进行了探究,结果表明:当Mg/Al摩尔比为2∶1,Cr(Ⅵ)溶液的pH=2~3时,此纳米纤维膜吸附10d时达到吸附平衡,对Cr(Ⅵ)的平衡吸附量为14mg/g,并且符合准二级动力学吸附方程。因此,PET@LDH纳米纤维膜是一种有效的去除水中Cr(Ⅵ)的吸附剂,对当前水环境的改善提供了一个可行的方法。

PET@LDH nanofiber membrane was prepared by electrospinning combined urea-hydrothermal method and its chromium removal performance was studied.By using scanning electron microscopy（SEM）,infrared spectroscopy（FT-IR）,X-ray diffraction（XRD）and spectroscopy（EDX）the fiber membrane was characterized.Scanning electron microscopy（SEM）,fourier transform infrared spectroscopy（FT-IR）,energy dispersive detector（EDX）and X-ray diffraction（XRD）were characterized to confirm the formation of LDH on the PET nanofibers.The result of SEM revealed that the membrane had a better morphology.FT-IR,EDX and XRD proved that surface of nanofiber was LDH.Cr-removal experiment showed that the prepared membrane exhibited outstanding Cr-removal performance,the best Mg/Al molar ratio was2,the optimal pH of Cr-removal was 2~3,the minimum time of absorption was 10 days.Moreover,the adsorption experiment also showed that the adsorption process belonged to Langmuir adsorption model and the kinetics of adsorption followed the pseudo-second-order model.Therefore,the work not only provided a highly efficient adsorbent to remove hexavalent chromium from waste water,but also offered a simple and efficient new method for environmental restoration field.