Abstract
Deformation of superhydrophobic cylindrical mesopores is studied during a cycle of forced water filling and spontaneous drying by in situ small-angle neutron scattering. A high-pressure setup is put forward to characterize the deformation of ordered mesoporous silanized silica up to 80 MPa. Strain isotherms of individual pores are deduced from the shift of the Bragg spectrum associated with the deformation of the hexagonal pore lattice. Due to their superhydrophobic nature, pore walls are not covered with a prewetting film. This peculiarity gives the ability to use a simple mechanical model to describe both filled and empty pore states without the pitfall of disjoining pressure effects. By fitting our experimental data with this model, we measure both the Young's modulus and the Poisson ratio of the nanometric silica wall. The measurement of this latter parameter constitutes a specificity offered by superhydrophobic nanopores with respect to hydrophilic ones.
Originalsprache | Englisch |
---|---|
Seiten (von - bis) | 211-220 |
Seitenumfang | 10 |
Fachzeitschrift | Langmuir |
Jahrgang | 38.2022 |
Ausgabenummer | 1 |
DOIs | |
Publikationsstatus | Veröffentlicht - 11 Jan. 2022 |
Bibliographische Notiz
Funding Information:The authors thank the Institut Laue-Langevin (Grenoble, France) for the allocation of neutron beam time. This work was supported by the French Research Agency (ANR LyStEn 15-CE06-0006). We thank Claude Payre for high-pressure equipment and the design of the high-pressure cell as well as Olivier Aguettaz for the technical support during the experiment. We thank Christophe Martin and Charles Josserond for the access to traction machine at the SIMAP/GPM2 laboratory needed for intrusiometry experiments, Jérôme Giraud for the design of the intrusiometry cell, Stéphane Coindeau for X-ray characterization and Vincent Martin for nitrogen adsorption and TGA analysis. Finally, we thank Benoit Coasne for fruitful discussion concerning the silica structure of MCM-41 matrixes.
Publisher Copyright:
© 2021 American Chemical Society.