Metallic versus Semiconducting SWCNT Chemiresistors: A Case for Separated SWCNTs Wrapped by a Metallosupramolecular Polymer
| Autor: | Tomonobu Nakayama, Takashi Nakanishi, Timothy M. Swager, Shinsuke Ishihara, Takeshi Tanaka, Yoshitaka Shingaya, Curtis J. O’Kelly, Takeo Ohsawa, Hiromichi Kataura, Jan Labuta |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
02 engineering and technology Carbon nanotube Conductivity 010402 general chemistry 01 natural sciences law.invention Metal chemistry.chemical_compound law General Materials Science Composite material chemistry.chemical_classification business.industry Polymer 021001 nanoscience & nanotechnology 0104 chemical sciences Supramolecular polymers Diethyl chlorophosphate Semiconductor chemistry visual_art visual_art.visual_art_medium 0210 nano-technology Selectivity business |
| Zdroj: | ACS applied materialsinterfaces. 9(43) |
| ISSN: | 1944-8252 |
| Popis: | As-synthesized single-walled carbon nanotubes (SWCNTs) are a mixture of metallic and semiconducting tubes, and separation is essential to improve the performances of SWCNT-based electric devices. Our chemical sensor monitors the conductivity of an SWCNT network, wherein each tube is wrapped by an insulating metallosupramolecular polymer (MSP). Vapors of strong electrophiles such as diethyl chlorophosphate (DECP), a nerve agent simulant, can trigger the disassembly of MSPs, resulting in conductive SWCNT pathways. Herein, we report that separated SWCNTs have a large impact on the sensitivity and selectivity of chemical sensors. Semiconducting SWCNT (S-SWCNT) sensors are the most sensitive to DECP (up to 10000% increase in conductivity). By contrast, the responses of metallic SWCNT (M-SWCNT) sensors were smaller but less susceptible to interfering signals. For saturated water vapor, increasing and decreasing conductivities were observed for S- and M-SWCNT sensors, respectively. Mixtures of M- and S-SWCNTs revealed reduced responses to saturated water vapor as a result of canceling effects. Our results reveal that S- and M-SWCNTs compensate sensitivity and selectivity, and the combined use of separated SWCNTs, either in arrays or in single sensors, offers advantages in sensing systems. |
| Databáze: | OpenAIRE |
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