Synthetic Metals 172 (2013) 49–53 Contents lists available at SciVerse ScienceDirect Synthetic Metals journal h om epage: www.elsevier.com/locate/synmet Synthesis of MnO 2 -polyaniline nanofiber composites to produce high conductive polymer Sepideh Amjad Iranagh a,∗ , Ladan Eskandarian b , Rahim Mohammadi c a Department of Chemistry, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran b Department of Textile Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran c Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran a r t i c l e i n f o Article history: Received 17 November 2012 Received in revised form 2 April 2013 Accepted 4 April 2013 Keywords: Polyaniline nanofiber MnO2 nanofibers Seeding polymerization Supercapacitor a b s t r a c t Present article is an attempt to develop a method to increase the conductivity of polyaniline (PANi) nanofibers. Nanofibers of MnO 2 that have been prepared by a chemical precipitation method were used as the seeds to facilitate the polymerization of aniline and thereby manufacturing of metal-PANi nanofibers. High conductivity and good electrochemical capacitor property was observed for these metal-PANi nanofiber composites against PANi nanofibers. SEM, FT-IR and UV–vis were utilized for characteriza- tion of the manufactured composites. The I–V characteristics of samples investigated by two-probe and their resistance were compared. The viability of the composites to be used as an electrode material for supercapacitor application was tested by electrochemical methods. © 2013 Elsevier B.V. All rights reserved. 1. Introduction Over the last three decades, researchers gave much consid- eration to the intrinsic conductive polymers (ICPs) due to their excellent chemical, electrical and optical properties [1–4]. Polyani- line (PANi) is one of the most important conductive polymers, and because of its high electrical conductivity, it has received extensive attention in recent two decades [5,6]. For synthesis of nanostructured PANi, several approaches including template and nontemplate processes have been developed [1,2]. Among them, the ‘nanofiber seeding’ polymerization, is recognized as a new typical template process and has been utilized for the synthe- sis of PANi nanofibers by using a small amount of nanofibers, heedless of their chemical nature; as a result of this process a precipitate with bulk fibrillar morphology has been obtained by seeding the reaction to obtain PANi nanofiber [5,6]. PANi has the added advantages of easy and economical preparation, unique redox properties, good environmental stability and large variety of applications such as, microelectronics devices [7], capacitors [8–11], transistors [12–15], corrosion protections, chemical sen- sors [16,4,17,18], flexible organic devices [19], dye-sensitized solar cells (DSSCs) [20,21], organic light-emitting diodes (OLEDs) [22–24] and PANi hydrogels which showed a new record conductivity also possesses good processability to be used for bioelectronics ∗ Corresponding author at: Department of Chemistry, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran. Tel.: +98 2164543174. E-mail address: amjad i s@aut.ac.ir (S. Amjad I). and energy storage electrodes [25] electronic property and supe- rior electrode performance. Because of its outstanding structural flexibility combined with novel chemical and physical proper- ties, manganese dioxides and their derivative compounds have attracted special attention and are used in various application such as molecular sieves, catalysts, and Li/MnO 2 batteries [26], alkaline Zn/MnO 2 cells [27], sensors [28] and electrochemical supercapaci- tors [29–34]. Crystalline structure along with, particle size, shape and surface area influence the MnO 2 properties. Many applications of MnO 2 are based on the use of nanostructured films, which have been produced by electrochemical deposition, sol–gel and other meth- ods [35]. There are important interests in development of chemical methods for synthesis MnO 2 nanoparticles to be used in fabrication of films and composites [36,37]. Synthesis of MnO 2 nanofibers and nanowires is included in many studies, such as solid state synthesis [38], sol–gel template synthesis [39], electrospinning [40], poly- mer precursor [41], hydrothermal [42] and other chemical methods which are related to the synthesis of such materials [43,44]. MnO 2 nanofibers and nanowires have the specific characteristics of large surface-area-to-volume ratio [40] and this advantage make the MnO 2 nanowires useful for fabrication of electrochemical devices [40–42]. The use of nanofibers and nanowires enhances the per- formance of batteries and electrochemical supercapacitors; their nanofibrous structures and high surface area make them suitable for fabrication of high performance electrodes [45,46]. In this work, a simple approach to synthesize PANi nanofibers by utilizing MnO 2 nanofibers as ‘seeds’ was developed to pro- duce nanofibers with uniform and consistent morphology and with 0379-6779/$ – see front matter © 2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.synthmet.2013.04.002