(Georgia Institute of Technology, 2012-05)
Hildreth, Owen; Cola, Baratunde A.; Graham, Samuel; Wong, C. P.
Conformally coating vertically aligned carbon nanotubes (v-CNT) with metals or oxides can be difficult because standard line-of-sight deposition methods, such as dc sputter coating and electron-beam evaporation, are hindered by the low mean-free-path with
(Georgia Institute of Technology, 2012)
Salazar, Pablo F.; Kumar, Satish; Cola, Baratunde A.
We explore the prospects of using doped carbon nanotube (CNT) electrodes to increase the output power of thermo-electrochemical cells (TECs). CNT buckypaper electrodes doped with nitrogen and boron were characterized using cyclic voltammetry, impedance spectroscopy, and TEC test with potassium ferri/ferrocyanide electrolyte. Both doping states increased the electrochemically active surface area of CNT electrodes. Electrostatic interactions with potassium ions altered the charge transfer kinetics for doped CNT electrodes; yet, the symmetry of the charge transfer remained approximately equal to that of pristine CNTs. In TEC test, accumulation of potassium ions at doped CNT electrodes was found to reduce short-circuit current.
(Georgia Institute of Technology, 2010-10)
Wang, X. J.; Wang, L. P.; Adewuyi, O. S.; Cola, Baratunde A.; Zhang, Zhuomin
Specular black materials have important applications, such as in absolute cryogenic radiometers, space-borne spectroradiometers, and some energy conversion devices. While vertically aligned carbon nanotubes (VACNT) can have close-to-unity absorptance, so far the reported reflection has been essentially diffuse. This letter describes a highly specular black absorber made of VACNT. Both the bidirectional reflectance distribution function and specular reflectance were measured at the wavelength λ = 635 nm using a laser scatterometer. The ordinary and extraordinary optical constants were obtained by fitting the specular reflectance, calculated from modified reflectance formulae for light incident from air to a uniaxial medium, considering surface roughness. Furthermore, the absorptance at λ = 635 nm was shown to be 0.994±0.002, based on the measured directional-hemispherical reflectance.