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Global alignment of solution-based single-wall carbon nanotube films via machine-vision controlled filtration



Jeffrey A. Fagan, Angela R. Hight Walker, Adam J. Biacchi, Joshua S. Walker, William D. Rice, Thomas Searles, Valerie A. Kuehl


Over the past decade, substantial progress has been made in the chemical processing (chiral enrichment, length sorting, handedness selectivity, and filling substance) of single- wall carbon nanotubes (SWCNTs). Recently, it was shown that large, horizontally-aligned films could be created out of post-processed SWCNT solutions. Here, we improve upon this filtration technique through the use of machine-vision-based automation and parallelization. Feedback control enables filtration to occur with a constant ow rate that not only improves the nematic ordering of the SWCNT films, but also gives us the ability to align a wide range of SWCNT types and nanoporous membranes using the same filtration parameters. Using polarized optical spectroscopic techniques, we show that meniscus combing produces a two- dimensional radial SWCNT alignment on one side of the film. After we flatten the meniscus through silanation, spatially-resolved nematicity maps on both sides of the SWCNT film show global alignment across the entire structure. From experiments changing ionic strength and membrane tribocharging, we propose that the SWCNT alignment mechanism stems from an interplay of intertube interactions and ordered membrane charging. This work opens up the possibility of creating globally aligned SWCNT film structures for a new-generation of nanotube electronics and optical control.
Nano Letters


single-wall carbon nanotube, SWCNT, alignment, filtration


Fagan, J. , Hight, A. , Biacchi, A. , Walker, J. , Rice, W. , Searles, T. and Kuehl, V. (2019), Global alignment of solution-based single-wall carbon nanotube films via machine-vision controlled filtration, Nano Letters, [online], (Accessed April 17, 2024)
Created September 11, 2019, Updated February 24, 2020