A study on defect controlled morphology of Organic/Inorganic composite nanofibers with different heat flow rates

One dimensional nanofibers of organic and inorganic materials have been used in filters, optoelectronic devices, sensors etc. It is difficult to obtain ultra fine fibers of inorganic materials having lengths in the order of millimeter as they tend to break during formation due to thermal and other mechanical stresses. In this study, we have investigated the mechanism to prevent the defect formation and the breaking ZnO nanofibers by using optimized heat flow rates. ZnO nanofibers were obtained by heat treating the PVA composites fibers formed by electrospinning. The morphology and structural characteristic of prepared samples were investigated by Scanning electron microscopy and X-ray diffraction. It was found that the morphology of the composite and annealed nanofibers could be influenced by the concentration of the polymer content and heat flow rate during thermal treatment respectively. A lower concentration favors the formation of defects along the fiber and the number of defects reduces when the concentration is increased. The reasons for the formation of defects and their reduction, and the observed structural changes of ZnO nanofibers during heat treatment are also discussed. (C) 2010 Elsevier B.V. All rights reserved.