SBIR Phase I: Multimodal Acoustic Mixing of Carbon Nanotube Composites

This Small Business Innovative Research Phase I project will demonstrate the feasibility of using multiple acoustic frequencies as a multimodal approach to mixing small diameter carbon nanotubes into a polymer matrix to create a high-performance nanocomposite material. Multiple acoustic frequencies are employed to effect distributive and dispersive mixing. Conventional, industrial polymer mixers, such as kneaders and twin screws, do not show sufficient nanotube dispersion to realize the full potential of the nanotube reinforcements. A unique Resonant Acoustic Mixing (RAM) technology has been shown to be very effective for mixing high viscosity materials such as polymers. This research will utilize a multimodal acoustic RAM technology, for its distributive and dispersive mixing mechanisms, to produce nanocomposite polymers. The project will gather data on the interaction of acoustic energy with the heterogeneous medium comprised of carbon nanotubes and an epoxy polymer. The data will be used to design mixing vessels and guide experiments. The experiments will quantify the mixer performance for comparison against existing "silent" mixing methods by evaluating the mixedness of the nanocomposite and the mechanical properties of test specimens. The results of the Phase I will establish the proposed mixing approach as a viable mixing alternative for the polymer industry. Commercially, although laboratory researchers commonly disperse carbon nanotubes into solvents and polymers, only modest systematic work has been conducted to make the hardware more effective or efficient, and the transfer of these bench-scale practices to industrial processes for the manufacture of nanotube products has received even less attention. By working toward a scalable mixing process, the research, development and manufacture of high-performance nanocomposite materials can be advanced. Polymer material manufacturers in the U.S. benefit from the proposed technology in that higher performance products may be produced with limited capital by incorporating nanotube additives. Replacing conventional plastics with nanoreinforced plastics offers the potential to substantially reduce weight without sacrificing properties. A clear example would be improved fuel economy in cars and planes. The initial commercial targets of the nanocomposite mixer are manufacturing processes for highvalue, structural composites as can be found in sporting goods.