Abstract: The present disclosure provides systems and methods for producing a volume of substantially all armchair nanotubes of a preselected chirality for fabricating yarn consisting of substantially all metallic conducting armchair tubes. The systems and methods can be used for the synthesis of (10,10), (11,11), and (12,12) metallic armchair carbon nanotubes and potentially other chiralities. The elements of the present disclosure include: (i) a carbon source that provides substantial numbers of ethylene and acetylene radicals in combination with a high population of ethylene groups and a small amount of methane, (ii) a hydrogen to carbon ratio sufficient to “passivate” all other chiral growth sites to a higher degree than armchair growth sites, and (iii) a CVD process that can be tuned to create a well-controlled population of catalyst with tight diameter distribution with sparse modal distribution that falls within a range of the desired single wall diameters.

Abstract: The present disclosure provides systems and methods for producing a volume of substantially all armchair nanotubes of a preselected chirality for fabricating yarn consisting of substantially all metallic conducting armchair tubes. The systems and methods can be used for the synthesis of (10,10), (11,11), and (12,12) metallic armchair carbon nanotubes and potentially other chiralities. The elements of the present disclosure include: (i) a carbon source that provides substantial numbers of ethylene and acetylene radicals in combination with a high population of ethylene groups and a small amount of methane, (ii) a hydrogen to carbon ratio sufficient to “passivate” all other chiral growth sites to a higher degree than armchair growth sites, and (iii) a CVD process that can be tuned to create a well-controlled population of catalyst with tight diameter distribution with sparse modal distribution that falls within a range of the desired single wall diameters.