Electrospinning of alumina nanofibers using different precursors

Excerpt

Electrospinning technique is becoming increasingly popular for the preparation of nanofibers [1‐5]. The process involves the application of a strong electrostatic field to a capillary connected with a reservoir containing a polymer solution or melt. Under the influence of the electrostatic field, a pendant droplet of the polymer solution at the capillary tip is deformed into a conical shape (Taylor cone). If the voltage surpasses a threshold value, electrostatic forces overcome the surface tension, and a fine charged jet is ejected. The jet moves towards a ground plate, which acts as a counter electrode. The solvent begins to evaporate immediately after the jet is formed. The result is the deposition of nanofibers on a substrate located above the counter electrode. Initially, this technique was used for the preparation of polymer nanofibers [6‐9]. In recent years; this technique has been used for the preparation of metal oxide/ceramic nanofibers such as silica, zirconia, titania, nickel oxide, barium titanate, lead zirconate titanate and other oxide materials [10‐30]. The nanofibers formed could be aligned (parallel and cross patterns) when an insulated cylinder attached to the axel of a DC motor is used as the substrate [31]. Xia et al. [32] prepared polymeric and ceramic nanofibers as axially aligned arrays by the use of a collector consisting of two pieces of electrically conductive substrate separated by a gap. Katta et al. used copper wires spaced evenly in the form of a circular drum as a collector of the electro spun nanofibers [33]. …