Preparation And Properties Study Of Highly Oriented ZnO Nanorods Loaded Electrospun Fibers

Due to the excellent optical,electrical,mechanical and chemical properties,the nanometer zinc oxide-loaded organic nanofiber composites have shown great potential in optoelectronic devices,sensors,photocatalysts etc.This thesis introduces the preparation method and application of inorganic ZnO nanocomposites.Based on the previous researches,we propose an efficient method for the preparation of aligned organic nanofiber composited with highly oriented ZnO nanorods.Firstly,we prepared the PVDF/Zn（CH₃COO）₂ nanofiber by electrospinning.Then the resulting nanofiber subjected to heat treatment with low temperature to obtain ZnO nanocrystalline loaded organic fibers.Subsequently,the effects of polymer concentration,zinc acetate content and heat treatment temperature on the morphology and mechanical property of electrospun nanofiber membrane were investigated.The results show that the morphology and mechanical propertie of obtained fiber are better when the concentration of the spinning solution is 10%and the mass ratio of PVDF to zinc acetate is 10:3.From the results,we concluded that the growth of ZnO nanocrystals with low crystallinity through heat treatment over 140℃due to the hydrolysis or decompose of zinc acetate.The breaking strength increased significantly and the elongation at break decreased of the fiber membrane after the heat treatment tempreture higher than 140℃.Secondly,Hierarchical composites,which were composed of radially oriented ZnO nanorods growing on the surface of nanofibers,were obtained subsequently via a facile hydrothermal growth process.The experimental results show that the vertically growth of ZnO nanorods on the fiber orientation is the highest when the growth of the concentration is 0.1 M;ZnCl₂ and HMTA molar ratio is 1:1 and the ammonia volume is 5 ml.The smallest diameter of the ZnO nanorods is 159 nm when the hydrothermal temperature is100℃.In addition,the aligned PVDF/Fe₂O₃/ZnO nanofibers with highly oriented ZnO nanorods were prepared by the combination of magnetic-field-assisted electrospinning and hydrothermal method.The results show that when the magnetic distance,the receiving distance and the spinning voltage are 4 cm,12 cm and 15 kv respectively,the fiber as-spun with the best orientation and the highest breaking strength and the elongation at break.Finally,this thesis also studies the photocatalytic degradation ability of ZnO nanocomposites of rhodamine B.The catalytic degradation efficiency of aligned organic nanofiber composites with highly oriented ZnO nanorods is the highest,followed by ZnO nanorods grown on disordered fibers,and the degradation efficiency of ZnO nanocrystalline loaded nanocomposites is the lowest.