Solvation Enhances the Distinction between Carboxylated Armchair and Zigzag Single-Wall Carbon Nanotubes (SWNT-COOH)
| Autor: | Felipe S. S. Schneider, Tapas Kar, Steve Scheiner, Renato L. T. Parreira, Ajit K. Roy, Upendra Adhikari, Pedro A. S. Bergamo, Giovanni F. Caramori |
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| Přispěvatelé: | American Chemical Society |
| Rok vydání: | 2017 |
| Předmět: |
carbon nanotubes stability
02 engineering and technology Carbon nanotube 010402 general chemistry 01 natural sciences law.invention law Computational chemistry Group (periodic table) Physical Sciences and Mathematics polarity Physical and Theoretical Chemistry Basis set Chemistry Solvation Charge density 021001 nanoscience & nanotechnology 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Crystallography solvents General Energy Zigzag functionalization Surface modification Density functional theory 0210 nano-technology |
| Zdroj: | Chemistry and Biochemistry Faculty Publications |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.6b10676 |
| Popis: | The effect of various solvents on the structures and properties of carboxylated SWNTs has been explored using the Same Level Different Basis Set approach (SLDB), where B3LYP functional of density functional theory (DFT) was applied. Armchair (4,4) and zigzag (8,0) and (9,0) tubes were considered as the test bed. In order to simulate varying concentration of –COOH groups, one to five acids groups were placed at one end of these tubes. These samples were placed in different solvents (namely, CS2, THF and water) with varying polarity and results were compared with gas-phase properties. Similar to the gas-phase, zigzag tubes also exhibit both regular (r-COOH, v(C=O) above 1700 cm-1) and low-frequency (lf-COOH, v(C=O) below 1700 cm-1) acid groups. Characteristics of r-COOH group are not affected much in solvents, but lf-COOH of the zigzag tube is the one that makes these tubes distinguishable from its armchair cousin. Stability and charge distribution of SWNT-COOH strongly depend on the number of acid groups in different solvents which may help controlling further functionalization. Vibrational analyses reveal certain features in the 1400-1600 cm-1 range that are characteristic of lf-COOH in different solvents, which may help in the assignment of experimental spectra of oxidized SWNT in solvents. |
| Databáze: | OpenAIRE |
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