Electrospinning of Polymer Nanofibers for Continuous CNT Production

The Army desires carbon nanotube (CNT) based fibers with exceptional strength and stiffness to provide high performance composite materials. Physical Sciences Inc. (PSI) has demonstrated a method to fabricate continuous CNT from electrospun polymer nanofibers. Because these CNT are continuous, their mechanical strength is limited primarily to their defect population. During a Phase I program PSI will demonstrate electrospining derived MWNT with tensile strength exceeding 37 GPa and modulus of 375 GPa at a 10 cm gauge length. We will provide low defect CNT production through the use of a dumbbell polymer with the molecular structure required to electrospin CNT precursor nanofibers. During a potential Phase II program we will reduce the precursor nanofiber diameter to provide continuous SWNT. A system will be fabricated to produce these continuous CNT tows based upon a successful DARPA program to manufacture carbon microfibers using electrospinning. We will work with Prof. Yury Gogotsi, Director of the Drexel Nanotechnology Institute, to improve our understanding of the nanofiber derived CNT growth mechanism. We will work to minimize defect population through tuning of the precursor polymer and the conversion conditions. Lockheed Martin has agreed to provide applications development on the proposed program.