Noncovalent Functionalization of Single-Walled Carbon Nanotubes with a Photocleavable Polythiophene Derivative.

Jyorthana Rajappa Muralidhar,Yoshihiro Ito,Masuki Kawamoto,Takuji Hirose,Koichi Kodama

doi:10.3390/nano12010052

Jyorthana Rajappa Muralidhar, Yoshihiro Ito + Show 3 more

Open Access

https://doi.org/10.3390/nano12010052

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Abstract

Single-walled carbon nanotubes (SWCNTs) have received extensive research attention owing to their extraordinary optical, electrical, and mechanical properties, which make them particularly attractive for application in optoelectronic devices. However, SWCNTs are insoluble in almost all solvents. Therefore, developing methods to solubilize SWCNTs is crucial for their use in solution-based processes. In this study, we developed a photocleavable polythiophene-derivative polymer dispersant for SWCNTs. The noncovalent surface functionalization of SWCNTs with a polymer allows their dispersal in tetrahydrofuran. The resultant solution-processed polymer/SWCNT composite film undergoes a hydrophobic-to-hydrophilic change in surface properties upon light irradiation (313 nm) because hydrophilic carboxyl groups are formed upon photocleavage of the hydrophobic solubilizing units in the polymer. Furthermore, the photocleaved composite film displays a 38-fold increase in electrical conductivity. This is due to the removal of the solubilizing unit, which is electrically insulating.

Highlights

Single-walled carbon nanotubes (SWCNTs) show unique electrical and optical properties [1]
The use of SWCNTs has led to important advances in the development of next-generation solar cells [2,3], field-effect transistors [4,5], and thermoelectric devices [6,7]
We have successfully developed a photocleavable polymer dispersant PC56 T44 for SWCNTs

Summary

Introduction

Single-walled carbon nanotubes (SWCNTs) show unique electrical and optical properties [1]. The use of SWCNTs has led to important advances in the development of next-generation solar cells [2,3], field-effect transistors [4,5], and thermoelectric devices [6,7]. SWCNTs show high mechanical durability owing to their extended π-conjugated lattices of sp2 -bonded carbon atoms, yielding high-performance nanotube fibers [8]. While there are a variety of applications for SWCNTs, they present certain drawbacks. SWCNT surfaces are hydrophobic, leading to unfavorable aggregation. SWCNTs are poorly dispersible and quickly precipitate in most organic solvents. The development of new SWCNT-dispersion strategies is required for their use in solution-based processes and applications

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