Pressure-induced structural modifications of imogolite nanotubes and of their methylated analogues

• Published in: Applied clay science Vol. 254; p. 107372
• Main Authors: Rouzière, Stéphan, Balédent, Victor, Bodin, Jennifer, Elkaim, Erik, Paineau, Erwan, Launois, Pascale
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2024; Elsevier
• Subjects: Condensed Matter; Imogolite; Materials Science; Nanotubes; Physics; Pressure; Structure; X-ray scattering; Young's modulus; Imogolite; Young's modulus; X-ray scattering; Structure; Pressure; Nanotubes
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2024.107372

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. [Display omitted] •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.