|AVS 55th International Symposium & Exhibition|
|Nanomanufacturing Focus Topic||Thursday Sessions|
|Session:||Nanomanufacturing II: Nanostructures|
|Presenter:||L. Lozzi, CNISM and University of L'Aquila, Italy|
|Authors:||M. Rinaldi, University of L'Aquila, Italy
F. Ruggieri, University of L'Aquila, Italy
L. Lozzi, CNISM and University of L'Aquila, Italy
S. Santucci, CNR-INFM and University of L'Aquila, Italy
|Correspondent:||Click to Email|
The growth of metal oxide nanowire is an important challenge for the realization of nanostructured devices, as for example highly sensitive gas sensors.1 A very easy method to deposit metal oxides is the electrospinning.2 This simple and low cost technique allows the growth of very thin nanofibers, whose diameter can be varied from 50 nm to about 1 μm. It is based on the effect of an electric field on a charged liquid (polymer or solution) ejected from a nozzle. The charged jet is accelerated by the electric field, dries and is deposited onto a grounded substrate, forming nanofibers. Generally the nozzle-substrate distance is about 10-15 cm and the applied voltage is about 10-15 kV. Unfortunately this method does not allow easily the growth of well ordered nanofibers. In the present study TiO2 nanofibers were electrospun with a novel approach of electrospinning called NFES (Near-Field Electrospinning), in which the tip-substrate distance is strongly reduced to few millimetres, decreasing also the applied bias voltage to few hundreds of volts.3 Significant advancement in collecting aligned electrospun nanofibers has been made with this improved technique that complements conventional electrospinning by providing the feasibility of controllable deposition for sub-100-nm nanofabrication. Well aligned TiO2 nanofibers were grown onto a silicon dioxide substrate. These nanofibers were up to several millimetres long with a diameter of about 200-400 nm. The scanning electron microscopy showed the presence of microcystallites, whose crystalline nature was confirmed by X-ray diffraction measurements after a thermal process, also used for removing the polymer. The chemical composition was investigated by X-ray photoemission spectroscopy showing that the nanofibers are composed by stoichiometric TiO2 crystallites.
1 S. Piperno, M. Passacantando, S. Santucci, L. Lozzi, S. La Rosa, J. Appl. Phys., vol. 101, (2007) 124504.
2 W.E. Teo and S. Ramakrishna, Nanotechnology, vol. 17, (2006) R89.
3 D. Sun, C. Chang, S. Li, and L. Lin, Nanoletters, vol 6, (2006), p. 839.