Pressure-induced structural modifications of imogolite nanotubes and of their methylated analogues
Structural modifications of single-walled aluminosilicate clay nanotubes have been studied under hydrostatic pressure by in situ synchrotron X-ray scattering. Imogolite nanotubes (INT) of nominal composition (OH)3Al2O3SiOH, and methyl-modified imogolite nanotubes (m-INT), (OH)3Al2O3SiCH3, have hydro...
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Published in | Applied clay science Vol. 254; p. 107372 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
15.06.2024
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Structural modifications of single-walled aluminosilicate clay nanotubes have been studied under hydrostatic pressure by in situ synchrotron X-ray scattering. Imogolite nanotubes (INT) of nominal composition (OH)3Al2O3SiOH, and methyl-modified imogolite nanotubes (m-INT), (OH)3Al2O3SiCH3, have hydrophilic and hydrophobic internal cavities, respectively. Nanotube chiralities also differ, with zigzag (INT) and armchair (m-INT) chirality. In this work, pressure-induced changes in nanotube morphology and atomic structure are studied as a function of chirality, affinity of the inner cavity, and the pressure-transmitting medium used. Radial deformation and collapse of nanotubes are evidenced below 3 GPa, followed by the formation of a lamellar phase at higher pressures. In the case of INT, the collapse pressure value depends on the pressure transmitting medium chosen. Axial compressibility is measured, and a pseudo Young's modulus Y is determined to be equal to ∼265 GPa for INT and below 80 GPa for m-INT, underpinning the role of nanotube chirality in mechanical properties.
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•Aluminosilicate imogolite nanotubes collapse radially at Pc≤3 GPa..•Strong structural modification occurs at high pressures which is reminiscent of a lamellar phase.•A pseudo Young's modulus is determined for imogolite nanotube and its methylated analogue.•Axial compressibility strongly depends on nanotube chirality. |
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ISSN: | 0169-1317 1872-9053 |
DOI: | 10.1016/j.clay.2024.107372 |