(421b) Assembly and Characterization of Length-Sorted, Aligned Boron Nitride/Carbon Nanotube Thin Films Via Slow Dead-End Filtration

Globally aligned single-wall carbon nanotubes (SWCNTs) are a promising, scalable platform for studying fundamental physical phenomena and an important vehicle for optoelectronic device applications. Recent work by Rust et al. [1] has identified nanotube length as an important mediating factor in the degree and scale of SWCNT alignment via dead-end vacuum filtration.

Building on this work and that of Walker et al. [2,3], we explore the co-assembly of length-sorted SWCNTs and boron nitride nanotubes (BNNTs) atop polycarbonate track-etched membranes. BNNTs have recently gained interest as a chirality-agnostic, wide-bandgap material for encapsulation, insulation, thermal/mechanical robustness, and visible-light transparency, while also having a similar high aspect ratio morphology, making them an exceptional and alignable host matrix for individualized CNT species. To prepare such hybrid assemblies, a polymer-assisted, depletion-based method was used to length-sort different diameter SWCNT (alkane filled electric-arc, CoMoCAT, metallic-sorted Tuball), and BNNT nanotube populations. Thereafter, we investigated the impacts of tube lengths, relative BN/C fraction, mass loading, and presence of a global director force on the multi-scale assembly behavior. A combination of birefringence microscopy and polarized Raman spectroscopy probed and identified trends in global and local nematic ordering under these conditions.

[1] Rust, C., Shapturenka, P., et al. (2022) Small, 2206774.

[2] Walker, J. S., Fagan, J. A., et al. (2019) Nano Letters, 19(10), 7256–7264.

[3] Walker, J. S., et al. (2022). Small, 18, 2105619.