PMID- 28770923
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20180719
LR  - 20180719
IS  - 2040-3372 (Electronic)
IS  - 2040-3364 (Linking)
VI  - 9
IP  - 32
DP  - 2017 Aug 17
TI  - Exploring the upper limit of single-walled carbon nanotube purity by 
      multiple-cycle aqueous two-phase separation.
PG  - 11640-11646
LID - 10.1039/c7nr03302h [doi]
AB  - Ultrahigh purity semiconducting single-walled carbon nanotubes (S-SWCNTs) are 
      required for high-performance transistors. Aqueous two-phase (ATP) separation is 
      an attractive method to obtain such SWCNTs due to its simplicity and scalability. 
      This work targeted two questions; namely what is the upper limit of S-SWCNT 
      purity that can be achieved by multiple cycles of ATP separation from the most 
      commonly used polyethylene glycol and dextran system and how accurately can 
      commonly used methods characterize the improvement in purity? SWCNT purity in 
      nanotube dispersions obtained by multi-cycle ATP separation (2, 4, 6 and 8 
      cycles) was evaluated by three methods, including UV-vis-NIR absorption 
      spectroscopy analysis, performance of thin-film field effect transistors (FETs) 
      prepared by drop casting and short-channel FET devices prepared by 
      dielectrophoresis deposition. Absorption spectroscopic analysis and the 
      performance of the thin-film FET devices can hardly differentiate metallic SWCNT 
      residues in the dispersions obtained after 4 cycles with the purity above 99.5%, 
      and the short channel FET devices prepared by dielectrophoresis deposition are 
      more sensitive towards tiny metallic SWCNT residues. A new method was also 
      demonstrated to visualize the minor metallic content in the nanotube suspension 
      using voltage contrast imaging in a scanning electron microscope, which enables 
      rapid screening of many devices and the accurate obtainment of metallic content 
      without performing a large number of individual transconductance measurements.
FAU - Wei, Li
AU  - Wei L
AD  - The University of Sydney, School of Chemical and Biomolecular Engineering, NSW 
      2006, Australia. yuan.chen@sydney.edu.au.
FAU - Flavel, Benjamin S
AU  - Flavel BS
FAU - Li, Wenshan
AU  - Li W
FAU - Krupke, Ralph
AU  - Krupke R
FAU - Chen, Yuan
AU  - Chen Y
LA  - eng
PT  - Journal Article
PL  - England
TA  - Nanoscale
JT  - Nanoscale
JID - 101525249
EDAT- 2017/08/05 06:00
MHDA- 2017/08/05 06:01
CRDT- 2017/08/04 06:00
PHST- 2017/08/05 06:00 [pubmed]
PHST- 2017/08/05 06:01 [medline]
PHST- 2017/08/04 06:00 [entrez]
AID - 10.1039/c7nr03302h [doi]
PST - ppublish
SO  - Nanoscale. 2017 Aug 17;9(32):11640-11646. doi: 10.1039/c7nr03302h.