Highly Oriented Carbon Ribbons for Advanced Multifunctional Material Engineering

Abstract

Two classes of carbon fibers—one based on MP (Mesophase Pitch) precursors and another on PAN (Polyacrylonitrile) precursors—are well known. Thermomechanical properties depend strongly on the initial precursor, particularly PAN tacticity. Regular, highly oriented carbon fibers require a syndiotactic PAN that is virtually impossible to reach. To improve the attributes of these materials, a new technique was developed, consisting of the deposition of thin films in a high centrifugal field with simultaneous thermal treatment. This technique makes it possible to obtain carbon ribbons made up of well‐aligned micro‐ and nanocarbon fibers. Our first investigations, which were conducted with regular precursors for PAN‐fiber, using deposition in a centrifugal‐thermal field, showed good potential for carbon coating at different stages of carbonization. The centrifugal field and thermal treatment simultaneously applied induced transformations in preferential directions. PAN‐carbon ribbon (PAN‐CR) deposited onto A1‐foil at different stages of carbonization is characterized. The dependence of initial precursor and ribbon properties on molecular orientation (monitored by FT‐IR, XRD, Raman) is presented.