Carbon Nanotube Synthesis with Microwave Plasma Chemical Vapor Deposition

Carbon nanotubes consist of tiny cylinders of graphite and have superior stiffness, strength, toughness, thermal conductivity, and unique electrical properties. They have many potential applications in nanotechnology. We have synthesized long and highly-aligned carbon nanotubes with a microwave plasma chemical vapor deposition method. The nanotubes are characterized with Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The target applications are in field emission display, electronic devices, and polymer reinforcement.

Conversion of Biomass into Fuel and Chemicals

The ultimate depletion of gaseous and liquid fuels, largely derived from petroleum, provides a strong incentive for the development of alternative energy and chemical feedstocks. Biomass is a potential renewable source for both energy and chemical feedstocks. Catalytic processes to convert intermediate chemicals of primary biomass conversion to useful chemicals such as 1,3-propanediol, ethylene glycol, and propylene glycol are being explored.

Electromagnetic Processing of Polymers and Composites

Electromagnetic processing offers several potential improvements to conventional processing of polymers and composites. These potential advantages include a) fast processing, b) ability to process high temperature thermoplastics, c) controlled heating of the matrix, interface and fiber, d) enhancement of bonding between the fibers and matrix. In electromagnetic processing, energy is coupled directly to molecular dipoles, and to conducting species. This increased control results in a more uniform temperature within the matrix and a reduction in properties degradation relative to conventional processing. One emphasis is on processing of composites, both thermoplastic and thermosetting matrices, to produce superior properties and/or to shorten the processing time. Another emphasis is on developing a model for an adaptable microwave applicator, and designing and evaluating control strategies with non-invasive monitoring methods.

Reviewed Journal Publications

Zong, L.; Kempel, L.C.; Hawley, M.C. "Dielectric studies of three epoxy resin systems during microwave cure," Polymer 46, 2638-2645, (2005).

Sun, R.; Kempel, L.C.; Zong, L.; Zhou, S.; Hawley, M.C. "Electromagnetic Modeling of an Adaptable Multimode Microwave Applicator for Polymer Processing," Applied Computational Electromagnetic Society (ACES) Journal, 20(1), 43-49, (2005).

Zong, L.; Sun, R.; Kempel, L.C., Hawley, M.C. "Dielectric relaxation of curing DGEBA/mPDA system at 2.45 GHz". Submitted to Composite Structures.

Zong, L.; Zhou, S.; Sun, R.; Sgriccia, N.; Kempel, L.C.; Hawley, M.C. "Dielectric Properties of an Epoxy-Amine System at a High Microwave Frequency," Polymer Engineering and Science, (2005).

Zong, L.; Zhou, S.; Sun, R.; Kempel, L.C.; Hawley, M.C. "Dielectric Analysis of a Crosslinking Epoxy Resin at a High Microwave Frequency," Journal of Polymer Science Part B: Polymer Physics 42(15), 2871-2877, (2004).

Zhou, S.; Hawley, M.C. "A study of Microwave Reaction Rate Enhancement Effect in Adhesive Bonding of Polymers and Composites", Composite Structures 61, 303-309, (2003).

Wang, K.; Hawley, M.C.; Furney, T.D. "A Selectivity Study Of 2,4-Pentanediol Hydrogenolysis Combining Experiments And Computer Simulation", Chem. Eng. Sci. 58(18), 4271 - 4285, (2003).

Wang, K.; Hawley, M.C.; DeAthos, S.J. "Conversion of Glycerol to 1,3-Propanediol via Selective Dehydroxylation", Ind. Eng. Chem. Res. 42(13), 2913-2924, (2003).

Zong, L.; Zhou, S.; Sgriccia, N.; Hawley, M.C.; Kempel, L.C. "A Review of Microwave-Assisted Polymer Chemistry (MAPC)", The Journal of Microwave Power and Electromagnetic Energy. 38 (1), 49 - 74, (2003).

Conference Proceedings

Sgriccia, N.; Zong, L.; Zhou, S.; Hawley, M.C.; Zuo, S.; Asmussen, J. "Synthesis of aligned carbon nanotubes by microwave plasma chemical vapor deposition," Poster presentation at Applied Diamond Conference/Nanocarbon (2005), Argonne National Laboratory: IL, 15-19, (2005).

Zong, L.; Sun, R.; Sgriccia, N.; Kempel, L.C.; Hawley, M.C. "Dielectric Properties of Two Curing Epoxy/Amine Systems at 2.45 GHZ," Proceedings of the ICCM-15 (Fifteenth International Conference on Composite Materials): Durban, South Africa, (2005).

Sun, R.; Zong, L.; Kempel, L. C.; Hawley, M.C.; and Benard, A. "Coupled Electromagnetic Thermal and Kinetic Modeling for Microwave Processing of Polymers with Temperature-Dependent Permittivity using 3D FEM," Proceedings of the 39th International Microwave Power Symposium: Seattle, WA, (2005).

Zhou, S.; Wood, A.; Boyapati, K.; Hawley, M.C.; Lee, A.; Kempel, L. C. "Epoxy/Organoclay Nanocomposites Synthesized with Thermal and Microwave Methods," Proceedings of the annual Global Environmental Conference (GPEC 2004) of Society of Plastics Engineers, Detroit, Michigan, February 18-19 (2004).

Sun, R.; Kempel, L.C.; Zhou, S.; Zong, L.; Hawley, M.C. "Electromagnetic Modeling of an Adaptable Multimode Microwave Applicator for Polymer Processing," Proceedings of the 20th Annual Review of progress in Applied Computational Electromagnetics (ACES), Syracuse, NY, April (2004).

Zhou, S.; Zou, S.; Grummon, D.; Liang, X.; Asmussen, J.; Hawley, M.C.; Zhang, Y. "Synthesis of Long and Well-aligned Carbon Nanotubes", Society For the Advancement of Material and Process Engineering 2004 (49thISSE), Long Beach, CA, May 18-20, (2004).

Sun, R.; Kempel, L.; Zhou, S.; Hawley, M. "Modeling of a Novel Multimode Cylindrical Cavity for Microwave Processing of Polymers and Composite Material," URSI/USNC Meeting, Boulder, CO, January (2004).

Sun, R.; Zong, L.; Zhou, S.; Sgriccia, N.; Kempel, L.; Benard, A.; Hawley, M. "Modeling Thermoset Curing in a Microwave Cavity," URSI/USNC Meeting, Boulder, CO, January (2004).

Hawley, M.C.; Kempel, L.C.; Benard, A., "Simulations and Novel Methods for Microwave Processing of Polymers and Composite Materials", 2004 NSF Design, Service and Manufacturing Grantees and Research Conference, Dallas, TX, January(2004).

Hawley, M.C. "Overview of Emerging Multifunctional Polymer Composite Materials and Processes," Defense Manufacturing Summit, Santa Ana Pueblo, NM, February (2004).

Sun, R.; Zhou, S.; Zong, L.; Mandal, D.; Kempel, L.C.; Hawley, M.C.; Benard, A. "Coupled Electromagnetic Thermal and Kinetic Modeling for Microwave Processing of Polymers," the Fourth World Congress on Microwave and Radio Frequency Applications, Austin, TX (2nd Place in Academic Poster Competition) November (2004).

Zhou, S.; Hawley, M.C. "Review of polymers and composites joining with microwave energy", The 14th International Conference on Composite Materials (ICCM-14), July 14-18, 2003, San Diego, California, (2003).

Zhou, S.; Hawley, M. "Effect of Carbon Fillers on the Dielectric Properties and Microwave Cure Kinetics of Epoxy", The Fourth Canadian International Composites Conference, August 19-22, 2003, Ottawa Congress Centre, Ottawa, Canada, (2003).