This Small Business Innovation Research (SBIR) Phase II project will develop and characterize a novel class of polymer matrix composite materials using a continuous NanoFiber Fused-Microfiber (Nf2-M) reinforcement technology. This patented approach, carbon nanofibers are grown in a continuous manner directly from the surface of continuous filaments (introduced in tow form) in a continuous, easily scaled process. Unlike traditional approaches which involve difficult mixing operations to introduce carbon nanofibers into the matrix resin at very low loading levels and with questionable dispersion, this approach produces continuous three-dimensional reinforcement networks which are easily incorporated into composites using standard fabrication techniques, including filament winding and prepreg wet lay-up processes. No additional or modified composite fabrication steps are needed. This technology has enormous potential for a multitude of commercial applications.
The broader/commercial impact of this project are threefold: 1) providing a foundation for a new technology in materials science research; 2) utilizing the fundamental findings to develop and engineer enabling materials to meet growing needs in industry for current and future applications; and 3) providing a low cost, commercially available, high performance carbon fiber reinforcement technology that has the potential to change the face of the composite materials industry. Global market forecast for reinforcing carbon fibers is ~$12.2 billion annually by 2011, and the approach of this project can take advantage of the multitude of existing markets, such as sporting goods, electronics, consumer products, commercial aerospace and automotive industries.
" focused on the growth of carbon nanotubes (CNTs) from the surface of continuous carbon fibers in a P2SI-patent-pending continuous process. The resultant product is a three-dimensional hybrid reinforcement, and is referred to as Nanofiber-fused Microfiber (Nf2-M). By utilizing this hybrid reinforcement for the fabrication of composite laminates, increases in composite properties including electrical conductivity, thermal conductivity, and interlaminar shear strength were expected. The research carried out under this Phase II program consisted of carbon fiber surface modifications, the investigation of alternative catalyst systems for CNT growth, the optimization of Nf2-M growth parameters, and the development of an Nf2-M composite property database. Additional research actions performed under this program included process scale-up from a batch reaction process to a continuous reaction process, and the optimization of composite processing parameters for Nf2-M materials. The results of the program include the successful production of Nf2-M materials in a continuous manufacturing process, demonstrated increases in composite interlaminar shear strength of 35-40%, demonstrated increases in transverse thermal conductivity of 500%, and demonstrated increases in composite electrical conductivity in the fiber direction and perpendicular to the fiber direction of 97% and 2500%, respectively. Additionally, a second U.S. patent was issued by P2SI in this area of research. It was also discovered during the course of this program that this technology is applicable to parent fiber substrates other than carbon including glass and alumina fibers. Utilizing the Nf2-M technology to grow CNTs from the surfaces of each of these substrates produces unique material properties that can be engineered to satisfy the requirements of a multitude of composites applications, and is expected to play a role in the future development and maturity of the hybrid composite materials market.
