Isolation of Pristine Electronics Grade Semiconducting Carbon Nanotubes by Switching the Rigidity of the Wrapping Polymer Backbone on Demand

YONGHO JOO; GERALD J. BRADY; MATTHEW J. SHEA; MARÍA BELÉN OVIEDO; CATHERINE KANIMOZHI; SAMANTHA K. SCHMITT; BRYAN M. WONG; MICHAEL S. ARNOLD; PADMA GOPALAN

ACS NANO

AMER CHEMICAL SOC

Lugar: Washington; Año: 2015 vol. 9 p. 10203 - 10203

1936-0851

onjugated polymers are among the most selective carbon nanotube sorting agents discovered and enable the isolation of ultrahigh purity semiconducting singled-walled carbon nanotubes (s-SWCNTs) from heterogeneous mixtures that contain problematic metallic nanotubes. The strong selectivity though highly desirable for sorting, also leads to irreversible adsorption of the polymer on the s-SWCNTs, limiting their electronic and optoelectronic properties. We demonstrate how changes in polymer backbone rigidity can trigger its release from the nanotube surface. To do so, we choose a model polymer, namely poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(6,60-(2,20-bipyridine))] (PFO-BPy), which provides ultrahigh selectivity for s-SWCNTs, which are useful specifically for FETs, and has the chemical functionality (BPy) to alter the rigidity using mild chemistry. Upon addition of Re(CO)5Cl to the solution of PFO-BPy wrapped s-SWCNTs, selective chelation with the BPy unit in the copolymer leads to th