Synopsis:
Carbon nanotubes are famous for their strength, light weight, flexibility, and conductivity (both electronic and thermal). Fabricated films, arrays, and composite coatings of carbon nanotubes, also known as buckypapers, are at the forefront of realized industrial applications, such as lightweight armor and field emission video displays. We have developed a facile way to produce wholly size scalable, flexible, resilient buckypapers via electrophoretic deposition for use in these and other applications for which such carbonaceous materials are desirable.
Major Achievement:
Carbon nanotube heterostructures as architectures for energy storage devices.
Publicity:
This research was featured in The London Centre for Nanotechnology and SPIE Newsroom.
Detailed Discussion:
Freestanding films of carbon nanotubes (CNTs) with paper-like morphology (Synopsis Figure), also known as buckypapers (BPs), have been demonstrated for applications such as catalysis, filtration, and energy storage. Buckypapers can be fabricated using single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs). The properties of buckypapers—electrical conductivity, tensile strength, and specific surface area, to name a few—depend on the composition of the CNTs, e.g., length of SWCNTs vs. MWCNTs, their alignment in the BPs, and whether any polymer binders are included. We discovered that BPs can be fabricated via EPD. The large electric fields associated with EPD drive the nanomaterials very close together. Along with the large aspect ratio of the nanotubes, this gives rise to large steric and van der Waals interactions between the constituents. To explore the increased particle-particle interactions in EPD-fabricated buckypapers, we probed the mechanical properties of the films. Figure Detailed Discussion shows representative force-strain and stress-strain plots for sample buckypapers, as measured by SEM. The data suggested that we formed brittle films that do not exhibit typical plastic deformation characteristics, which is somewhat atypical of carbon nanotube mats.
Reference Articles:
a. J.L Rigueur, S.A Hasan, S.V Mahajan, and J.H. Dickerson, Buckypaper fabrication via liberation of electrophoretically deposited carbon nanotubes, Carbon 48, 4090-4099, 2010.
b. S.A. Hasan, S.V. Mahajan, D. W. Kavich, and J. H. Dickerson, Electrophoretic Deposition of CdSe Nanocrystal Films Onto Dielectric Polymer Thin Films, Thin Solid Films, 517, 2665-2669, 2009.
c. James H. Dickerson, Sameer V. Mahajan, Saad A. Hasan, Johann Cho, Milo S. Shaffer, and Aldo R. Boccaccini, Electric field assisted fabrication of carbon nanotube-nanocrystal composite structures, SPIE Newsroom, DOI: 10.1117/2.1200902.1492, 2009.
d. S. V. Mahajan, S.A. Hasan, J Cho, M. S. P. Shaffer, A. R Boccaccini, and J. H. Dickerson, Carbon nanotube–nanocrystal heterostructures fabricated by electrophoretic deposition, Nanotechnology 19, 195301, 2008.
e. S.V. Mahajan, J Cho, M.S.P. Shaffer, A. R Boccaccini, and J. H. Dickerson, Electrophoretic deposition and characterization of Eu2O3 nanocrystal—Carbon nanotube Heterostructures, Journal of the European Ceramics Society 30, 1145, 2010.