Enhanced ordering in length-polydisperse carbon nanotube solutions at high concentrations as revealed by small angle X-ray scattering
| Autor: | Fred C. MacKintosh, Yeshayahu Talmon, Paul van der Schoot, Yachin Cohen, Lucy Liberman, Matteo Pasquali, Evan G. Biggers, Vida Jamali, Francesca Mirri, Robert A. Pinnick |
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| Přispěvatelé: | Soft Matter and Biological Physics, ICMS Core |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Materials science
FOS: Physical sciences 02 engineering and technology Carbon nanotube Condensed Matter - Soft Condensed Matter 010402 general chemistry 01 natural sciences law.invention Condensed Matter::Materials Science law Phase (matter) Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Texture (crystalline) Condensed Matter - Materials Science Cloud point Polarized light microscopy Condensed Matter - Mesoscale and Nanoscale Physics Small-angle X-ray scattering Scattering Materials Science (cond-mat.mtrl-sci) General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Condensed Matter::Soft Condensed Matter Chemical physics Soft Condensed Matter (cond-mat.soft) sense organs 0210 nano-technology Order of magnitude |
| Zdroj: | Soft Matter, 17(20), 5122-5130. Royal Society of Chemistry |
| ISSN: | 1744-6848 1744-683X |
| Popis: | Carbon nanotubes (CNTs) are stiff, all-carbon macromolecules with diameters as small as one nanometer and few microns long. Solutions of CNTs in chlorosulfonic acid (CSA) follow the phase behavior of rigid rod polymers interacting via a repulsive potential and display a liquid crystalline phase at sufficiently high concentration. Here, we show that small-angle X-ray scattering and polarized light microscopy data can be combined to characterize quantitatively the morphology of liquid crystalline phases formed in CNT solutions at concentrations from 3 to 6.5 % by volume. We find that upon increasing their concentration, CNTs self-assemble into a liquid crystalline phase with a pleated texture and with a large inter-particle spacing that could be indicative of a transition to higher-order liquid crystalline phases. We explain how thermal undulations of CNTs can enhance their electrostatic repulsion and increase their effective diameter by an order of magnitude. By calculating the critical concentration, where the mean amplitude of undulation of an unconstrained rod becomes comparable to the rod spacing, we find that thermal undulations start to affect steric forces at concentrations as low as the isotropic cloud point in CNT solutions. |
| Databáze: | OpenAIRE |
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