United States Patent | 5,304,366 |
Lorents, et. al. | Apr. 19, 1994 |
Inventors: | Lorents; Donald C. (Palo Alto, CA); Malhotra; Ripudaman (San Carlos, CA). |
Assignee: | SRI International (Menlo Park, CA). |
Appl. No.: | 814,721 |
Filed: | Dec. 24, 1991 |
Intl. Cl.: | C01B 31/02; C09C 1/44; |
U.S. Cl.: | 423/445.B; 422/152.; |
Field of Search: | 445;445 B;460;449;449.1;449.2 |
4,542,007 | Sept., 1985 | Murray | 423/450 |
PCT/US91/05983 | Mar., 1992 | WOX | |
PCT/US92/04350 | Nov., 1992 | WOX |
Haufler et al., "Carbon Arc Generation of C(60) ", Mat. Res., Soc., Symp. Proc. vol 206, pp. 627-637, Nov. 29, 1990.
Johnson et al., "C(60) Has Icosahedral Symmetry", J. Am. Chem. Soc, vol. 112, pp. 8983-8984, Nov. 21, 1990.
Stoddart et al., "The Third Allotropic Form of Carbon" Agnew. Chem. Int. Ed. Eng, vol. 30, 1991, pp. 70-71.
Perry, Chemical Engineers Handbook, 3rd ed., pp. 660-665 (1950).
Ajie, Henry, et al., "Characterization of the Soluble All-Carbon Molecules C(60) and C(70) ", Journal of Physical Chemistry, vol. 94, No. 24, 60, pp. 8630-8633, Dec. 1990.
Bae, Y. K. et al., "Production, Characterization, and Deposition of Carbon Clusters", Document prepared for Symposium on Clusters and Cluster Assembled Materials Special Session on Buckminsterfullerene, Boston, Mass., Nov. 29, 1990, pp. 1-9.
Hare, J. P. et al., "Preparation and UV/Visible Spectra of fullerenes C(60) and C(70) ", Chemical Physics Letters, vol. 177, No. 4.5, Mar. 1, 1991, pp. 394-398.
Haufler, R. E., et al., "Efficient Production of C(60) (Buckminsterfulleren), C(60) H(36), and the Solvated Buckide Ion", Journal of Physical Chemistry, vol. 94, No. 24., 1990, pp. 8634-8636.
Koch, A. S., et al., "Preparation of Fullerenes with a Simple Benchtop Reactor", Journal of Organic Chemistry, vol. 56, No. 14, 1991, pp. 4543-4545.
Kratschmer, W. et al., "Solid C(60) : A New Form of Carbon", Nature, vol. 347, Sep. 27, 1990, pp. 354-357.
A process and apparatus is described for the production of purified fullerenes using a non-reactive gas to collect and transport impure fullerenes from an evaporation zone to a heated filter zone in which solid impurities may be filtered out of the mixture. If one or more condensed fullerenes are present in the gas stream entering the filter zone, such condensed fullerenes may be vaporized in the filter zone and carried to a condensation zone in which one or more vaporized fullerenes may be recovered. When more than one vaporized fullerene is present in the gas entering either the filter zone or the condensation zone, a temperature gradient may be used to permit separation and recovery of purified portions of different fullerenes.