Single Wall Carbon Nanotube Amplification: En Route to a Type-Specific Growth Mechanism

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• 作者：Richard E. Smalley ; Yubao Li ; Valerie C. Moore ; B. Katherine Price ; Ramon Colorado ; Jr. ; Howard K. Schmidt ; Robert H. Hauge ; Andrew R. Barron ; James M. Tour
• 刊名：Journal of the American Chemical Society
• 出版年：2006
• 出版时间：December 13, 2006
• 年：2006
• 卷：128
• 期：49
• 页码：15824 - 15829
• 全文大小：635K
• 年卷期：v.128,no.49(December 13, 2006)
• ISSN：1520-5126

文摘

With the desire to mass produce any specific n,m type of single wall carbon nanotube (SWNT)from a small sample of the same material, we disclose here the preliminary work directed toward that goal.The ultimate protocol would involve taking a single n,m-type nanotube sample, cutting the nanotubes inthat sample into many short nanotubes, using each of those short nanotubes as a template for growingmuch longer nanotubes of the same type, and then repeating the process. The result would be anamplification of the original tube type: a parent SWNT serving as the prolific progenitor of future identicalSWNT types. As a proof-of-concept, we use here a short SWNT seed as a template for vapor liquid solid(VLS) amplification growth of an individual long SWNT. The original short SWNT seed was a polymer-wrapped SWNT, end-carboxylated, and further tethered with Fe salts at its ends. The Fe salts were to actas the growth catalysts upon subsequent reductive activation. Deposition of the short SWNT-Fe tippedspecies upon an oxide surface was followed by heating in air to consume the polymer wrappers, thenreducing the Fe salts to Fe(0) under a H₂-rich atmosphere. During this heating, the Fe(0) can etch backinto the short SWNT so that the short SWNT acts as a template for new growth to a long SWNT thatoccurs upon introduction of C₂H₄ as a carbon source. Analysis indicated that the templated VLS-grownlong SWNT had the same diameter and surface orientation as the original short SWNT seed, althoughamplifying the original n,m type remains to be proven. This study could pave the way for an amplifiedgrowth process of SWNTs en route to any n,m tube type synthesis from a starting sample of pure nanotubes.