This Small Business Innovation Research Phase II project is to extend the Phase I results to optimize a unique temperature gradient vacuum sublimation process which will significantly reduce the cost of fullerene purification. Phase I demonstrated that high purity C60 (99.8%) can be produced by the solvent-free process. The Phase II program will optimize the purification process by investigating a large number of processing variables such as fullerene mean-free path, unconverted re-distributed fullerenes, temperature distribution, geometric dimension, etc. Two different temperature gradient vacuum sublimation systems, i.e., direct sublimation and sublimation through a porous bed, will be designed and utilized in the investigations. It is anticipated that the Phase II program will successfully develop a solvent-free purification process to produce pure C60 at 2 to 10 % of the current cost. Fullerenes are materials that have been demonstrated to have near-term applications in superconductors, nonlinear optics, polymers, gas storage for fuel and batteries, diamond nucleation and synthesis, low porosity pure carbon composites and fibers, and three-dimensional organic synthesis.
