Vibration-induced deagglomeration and shear-induced alignment of carbon nanotubes in air

Morteza Miansarigavzan, Aisha Qi, Leslie Yu-Ming Yeo, James Robert Friend

Research output: Contribution to journalArticleResearchpeer-review

26 Citations (Scopus)

Abstract

Carbon nanotubes (CNTs) are widely known to agglomerate into diffi cult to
separate, 10–100 μm bundles, even after suspension in solution. Here, a dry
and rapid (≈10 s) method to deagglomerate bulk, unbound multi-walled CNT
bundles due to surface acoustic waves (SAW) in a piezoelectric substrate is
reported for the fi rst time. The process fi rst forms 1-μm CNT bundles from
extremely large (≈10 Mm/s 2 ) mechanical accelerations due to the SAW;
these bundles are consequently susceptible to SAW-induced evanescent,
quasistatic electric fi elds that couple into the bundles and form a mat of long
(1–10 μm) individual CNTs on the substrate surface. These CNTs may then
be aligned along the direction of shear provided by sliding a glass cover slip
10 mm across the CNT mat. This alignment is notably independent of the
SAW propagation direction. Further, the intrinsic structure of the nanotubes
is unaffected as verifi ed using Raman spectroscopy. Uniquely simple, the
approach avoids the many shortcomings of other CNT deagglomeration
techniques—particularly surface modifi cation and suspension in solution—to
rapidly separate and align large numbers of CNTs, thereby overcoming a key
limitation in their use for a diverse range of applications.
Original languageEnglish
Pages (from-to)1014 - 1023
Number of pages10
JournalAdvanced Functional Materials
Volume25
Issue number7
DOIs
Publication statusPublished - 2015

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