Self-Assembled Conductive Network of Carbon Nanotubes in Polyaniline Forming Potential Nanocomposites Sanju Gupta 1 , V. Kandagor 2 , R. Hauge 3 , Y. Ding 4 , and R. J. Patel 5 1 Electrical and Computer Engineering, University of Missouri-Columbia, 6th St. 303 EBW, Columbia, MO, 65211-2300 2 Physics, Missouri State University, 901 S. National Ave., Springfield, MO, 65897 3 Chemistry, Rice University, Houston, TX, 77251 4 Crosslink Inc., St. Louis, MO, 63122 5 Physics and Materials Science, Missouri State University, 901 S. National Ave., Springfield, MO, 65897 ABSTRACT Carbon nanotubes (CNTs) are of great interest because of several unsurpassable physical (mechanical, electrical, thermal, and chemical) properties. Especially their large elastic modulus and breaking strength make them highly attractive for their use as reinforced agents in forming a new class of multifunctional advanced materials - nanocomposites, in addition to high conductivity (either in semiconducting or metallic regimes) achieved through lower percolation thresholds for several electronic applications. Among the known conducting polymers, polyaniline (PANI) has a high potential due to its ease of synthesis, excellent environmental, and thermal stability and reversible control of its electrical/electronic properties. In this work, PANI- single-/multiwalled NTs composites films containing different nanotube content of both kinds were synthesized by spin-cast preceded by ultrasonic mixing of the constituents. They were characterized using complementary techniques including scanning electron microscopy, X-ray diffraction, infrared and Raman spectroscopy, and conductivity revealing their microscopic structure and physical properties thus helping in establishing process-structure-property correlations. The present work will discuss some of these findings in terms of (a) self-alignment of nanotubes in conducting polymer (b) their optical and electrical properties, and (c) their design with a view to electronic and sensor applications, all ascribed due to long range π-π interaction between the constituents. I. INTRODUCTION Carbon is a unique element that serves as a fertile playground for a variety of nanoscale structures with varying structure and morphology [1]. The discovery of carbon nanotubes (CNs) has generated a great and sustained interest in carbon-based materials and nanotechnologies. Multiwall nanotubes and fullerenes [2] also exist. CNs has been shown to possess exceptional electrical, mechanical and thermal properties, which are attractive for diverse potential applications ranging from nanoelectronics to biomedical devices [3]. It is known that one- dimensional quantum nano-wires play a significant role as interconnecting and active components in optoelectronic nano-devices and their orientation has an important impact on the performance of these devices. However, using CNs in practical applications has been largely limited by their poor processability, since they are practically insoluble and infusible [4, 5]. CNs can be divided into two main categories: single-walled carbon nanotubes (SWs) and multi-walled carbon nanotubes (MWs). Mater. Res. Soc. Symp. Proc. Vol. 963 © 2007 Materials Research Society 0963-Q20-01