静电纺丝技术制备一维氧化物纳米材料/Fabrication of one-dimensional metal oxide nanomaterials by el

2019-03-16 11:19:24

直径 纤维 fibers PVA oxide



本文通过溶胶-凝胶过程,采用静电纺丝技术技术,以聚乙烯醇(PVA Mn=80000)和各种无机盐为前驱物,制备了ZnO、CeO2、α-Fe2O3等单组分纳米纤维和NiO/ZnO和Cr2O3/Al2O3等复合组分纳米纤维,为一维无机纳米材料的制备提供了一条崭新的途径。

系统研究了材料制备的各种过程因素对纤维形貌、尺寸、均匀度等特性的影响,发现PVA浓度、乙醇的加入、无机盐的含量以及接收距离、电压和热处理的升温速率是影响纤维特性的主要因素。PVA的最佳浓度约为5-6%,浓度过小,纤维呈念珠状,浓度过大,纤维直径分布不均,成丝速率低;乙醇的加入降低了溶液的表面张力(有利于在液滴表面形成喷射流),同时使纤维直径变大;无机盐含量增大引起了直径的显著增大,并最终使纤维出现了类似“吸潮”的现象;接收距离及电压的增加都会使纤维直径减小,但电压过大会使直径分布不均;热处理过程中升温过快会使纤维断裂,不利于纤维形貌的保持,升温速率应控制在50C/h以下。

采用扫描电镜、红外光谱、拉曼光谱、X射线粉末衍射、差热-热重等分析手段对样品进行了表征。结果表明,经过对各种有机-无机杂化纤维进行热处理,得到了纯净的ZnO、CeO2、α-Fe2O3等单组份纳米纤维和NiO/ZnO和Cr2O3/Al2O3复合组分纳米纤维,这些纤维形貌为规则的一维结构,直径为50-150nm,直径分布均匀。



Zinc oxide, cerium oxide, alpha-iron oxide, zinc oxide/nickel oxide and chromium oxide/alumina nanofibers were fabricated by sol-gel process and electrospinning technique, using polyvinyl alcohol (PVA Mn=80000) and various of inorganic salts as precursor. This method offered a brand-new way for fabricating one-dimensional inorganic nanomaterial.

The morphology of fibers were discussed by adjusting conditions such as the concentration of PVA, the volume of ethanol added to the sol, the mass of metal salts added to the sol, the capillary screen distance, the voltage, the velocity of calcination. As a result, with increasing the concentration of PVA, the diameter of electrospun fibers increased and the morphology changed from beads to regular and then unregular. Increasing the concentration of ethanol decreased the surface tension and increased the viscosity of solution. Increasing the concentration of inorgnic salts made the diameter of fibers increased and lead to the deliquescence of fibers. Both increasing the distance of collection and increasing the electrospinning voltage decreased the diameter of the fibers. The fibers ruptured when the temperature rose quickly, then the velocity should be controled below 50C/h.

The procucts were characterized by scanning electron microscope(SEM), infrared spectra(IR), raman shift(Raman), X-ray diffraction(XRD), thermogravimetric analysis(TGA). All the results show that five kinds of favorite nanofibers with smooth surface, homogeneous diameters of 50-150nm and uniform morphology were obtained.