Hybrid PANI/CNT Nanocomposites Prepared by an Inverse Emulsion Polymerization Technique

摘要

Carbon nanotubes (CNT) have drawn much attention in recent years. CNT have remarkable properties i.e. mechanical properties, electrical and thermal conductivity, thus offering opportunities for development of new nanocomposites. An homogeneous dispersion of nanoparticles in polymers using conventional processing techniques is difficult to produce since nanoparticles tend to agglomerate, thus efficient methods for agglomerate breakdown have been sought in recent years. The combination of CNT with intrinsically conductive polymers may lead to new and improved properties of the resulting materials. This work describes an in-situ inverse emulsion polymerization method of aniline in the presence of multi-walled carbon nanotubes (MWNT) in organic solvents using ultrasonication. PANI dispersion, as a reference, and the PANI/MWNT dispersions were stable for long periods of time without visible precipitation. High-resolution scanning electron microscopy (HRSEM) has shown that MWNT are coated with PANI, leading to a remarkably improved dispersability of the nanotubes, thus PANI coating reduces the tendency of MWNT to re-agglomerate. The neat MWNT have a diameter of ~10nm, while the core-shell MWNT/PANI nanofibers exhibit a diameter of ~40nm. The dispersions obtained may have important potential applications in the fields of sensors, acoustic actuators, semi-conductors, solar cells and more. CNT containing materials suitable for the manufacture of thin, transparent, electrically conductive films have poor mechanical properties and are expensive. Our work on hybrid conducting nanocomposites has led to a remarkable combination of high conductivity and transparency along with low haze and good mechanical properties, aiming at competing with the existing ceramic materials, such as Indium Tin Oxide, (ITO).