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Outer Tubes (outer + tubes)
Selected AbstractsRobust, Conducting, and Transparent Polymer Composites Using Surface-Modified and Individualized Double-Walled Carbon Nanotubes,ADVANCED MATERIALS, Issue 23 2008Yong Chae Jung Double-walled carbon nanotubes (DWNTs), consisting of two concentric coaxial tubes, are proposed as the preferable reinforcing filler in polymers. Chemical moieties, which are selectively introduced on the outer tubes, impart the ability to individualize and provide effective anchoring sites for strong bonding with polymers, while the optical properties of the inner tubes of the DWNTs remain unchanged. [source] Raman scattering from double-walled carbon nanotubesJOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2008H. Kuzmany Abstract Raman scattering from double-walled carbon nanotubes is reported with particular emphasis on the response from the radial breathing mode (RBM) of the inner-shell tubes. The unexpected large number of very narrow lines observed is explained by the growth of one and the same inner tube type in different outer tubes in a highly shielded environment. The response of the RBM and of the G-line is used to analyze the transition from peapods to double-walled carbon nanotubes. During the transformation process the Raman response disappears for a short time, indicating the existence of some Raman dark matter. By preparing the starting peapods from heterofullerenes such as (C59N)2 or 13C-substituted fullerenes, hetero-nanotubes can be grown where nitrogen or the 13C atoms are incorporated into the inner tube wall. Copyright © 2007 John Wiley & Sons, Ltd. [source] High pressure Raman study of the second-order vibrational modes of single- and double-walled carbon nanotubesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11 2007K. Papagelis Abstract The pressure response of the second-order Raman G, band of bundled double- (DWCNTs) and single-wall carbon nanotubes (SWCNTs) has been investigated by means of Raman spectroscopy using the 632.8 nm excitation. The different pressure responses of the G, peak in SWCNTs and its corresponding components associated with the inner and the outer tubes in DWCNTs can be attributed to the different diameters of the resonantly probed tubes and the strength of the inner-outer tube interaction. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] High pressure studies of the radial breathing modes in double-wall carbon nanotubesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 1 2007J. Arvanitidis Abstract This work focuses on the high pressure Raman study of the radial breathing modes (RBMs) of bundled double-wall carbon nanotubes (DWCNTs) using different excitation energies. The detailed examination of the Raman peaks attributed to the RBMs of the inner and outer tubes comprising the DWCNTs as a function of pressure provides a wealth of information concerning the pressure response of individual nanotubes as well as the inner-outer tube (intratube) interactions. The outer tube acts as a protection shield for the inner tube whereas the latter increase the structural stability of the externals upon pressure application. More importantly, the pressure response of the inner tubes, expressed by the normalized pressure slopes ,i = (1/,i) (,,i /,P) vs. frequency of their RBMs, shows a remarkable grouping in quasi-linear distributions wherein ,i increases with ,. This behavior is explained by assuming that the pressure response of an internal tube is crucially dependent on the intratube spacing and thus the structural characteristics of the encapsulating tube. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] The Intermediate Frequency Modes of Single- and Double-Walled Carbon Nanotubes: A Raman Spectroscopic and In Situ Raman Spectroelectrochemical StudyCHEMISTRY - A EUROPEAN JOURNAL, Issue 16 2006Martin Kalbac Dr. Abstract The intermediate frequency modes (IFM) of single-walled carbon nanotubes (SWCNTs) and double-walled carbon nanotubes (DWCNTs) were analyzed by Raman spectroscopy and in situ Raman spectroelectrochemistry. The inner and outer tubes of DWCNTs manifested themselves as distinct bands in the IFM region. This confirmed the diameter dependence of IFM frequencies. Furthermore, the analysis of inner tubes of DWCNTs allowed a more-precise assignment of the bands in the IFM region to features intrinsic for carbon nanotubes. Although the inner tubes in DWCNTs are assumed to be structurally perfect, the role of defects on IFM was discussed. The dependence of IFM on electrochemical charging was also studied. In situ spectroelectrochemical data provide a means to distinguish the bands of the outer and inner tubes. [source] | ||||||||||