Preparation of Manganese Oxide–Polyethylene Oxide Hybrid Nanofibers Through In Situ Electrospinning Mohammad Madani, 1 Naser Sharifi-Sanjani, 1 Sepideh Khoee, 1 Ahmad Hasan-Kaviar, 1 Abbass Kazemi 2 1 School of Chemistry, University College of Science, University of Tehran, Tehran, Iran 2 Division of Polymer Science and Technology, Research Institute of Petroleum Industry, Tehran, Iran Received 30 May 2009; accepted 15 December 2009 DOI 10.1002/app.31990 Published online 2 March 2010 in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: Manganese oxide nanoparticles–polyethyl- ene oxide nanofibers as organic–inorganic hybrid were prepared via in situ electrospinning. Thus, electrospinning of polyethylene oxide solution with different manganese chloride concentration was carried out in gaseous ammo- nia atmosphere containing oxygen. The reaction of manganese chloride with ammonia produces manganese hydroxide, and then oxygen in the reaction media reacts with manganese hydroxide to yield manganese oxide. These two reactions occur during fiber formation. Trans- mission electron microscopy and scanning electron micros- copy showed that manganese oxide (MnO 2 ) nanoparticles were formed on the produced nanofibers of 100–600 nm in diameter. The existence of the formed MnO 2 was also proved by X-ray diffraction analysis, and it showed that the k-MnO 2 nanoparticles were produced. Differential scanning calorimetry (DSC) analysis was used to deter- mine the melting point and to calculate the crystallinity of the produced hybrid nanofibers. The DSC and thermogra- vimetric analysis results of the obtained nanofibers were compared with those of the nanofibers produced in elec- trospinning of pure polyethylene oxide solution. V C 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 243–249, 2010 Key words: in situ electrospinning; polyethylene oxide; manganese oxides nanoparticles INTRODUCTION Manganese oxides have long been known as materi- als of technological importance for electrochemical applications, 1 electrode materials for electrochemical energy storage systems such as cathode materials in alkaline cells, 2 intercalation hosts for lithium bat- teries, 3,4 and electrode materials in supercapacitors, 1,5 because of their excellent electrochemical perform- ance, low cost, nonpoisonous nature, environmental friendliness, and convenient preparation. 6–8 Further- more, it can be used in the photovoltaic devices. 9,10 Polymer nanocomposites containing metal oxides have attracted a great deal of interest from research- ers because they frequently exhibit unexpected hybrid properties, synergically derived from both components. 11 Enhanced conductivity and special mechanical, electrochemical, optical, magnetic as well as thermal properties of these composites make them promising materials. In the past decade, electrospinning has attracted tremendous interests in the research community simply because it provides a facile and effective means in producing ultrafine fibers with diameters ranging from microns down to a few nanometers. Moreover, this procedure can produce functional nanofibers having optical, electrical, or catalytic properties by incorporating inorganic nanoparticles into the nanofibers. Most of the reported manufac- turing methods of polymer–inorganic composite nanofibers are based on electrospinning of polymer solution blended with inorganic nanoparticles. 12,13 Another way of preparing polymeric–inorganic com- posite nanofibers is based on electrospinning of a polymer precursor having metal ions and subse- quently post-treating of the produced nanofibers. 14 The aim of this work is to manufacture organic– inorganic nanofiber hybrids based on a new method through in situ electrospinning and is also to show the possibility of these two reactions occurring on the traveling polymer jet in electrospinning with an active atmosphere. Thus, we are reporting in situ synthesis of manganese oxide nanoparticles on poly- ethylene oxide (PEO) nanofibers through electrospin- ning. Extensive characterization of nanofibers was carried out using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetery (DSC), and thermogravimetric analysis (TGA) tech- niques, and the results were compared with those of the nanofibers produced in electrospinning of pure PEO solution. Correspondence to: M. Madani (mmadani@khayam.ut.ac. ir). Journal of Applied Polymer Science, Vol. 117, 243–249 (2010) V C 2010 Wiley Periodicals, Inc.