Effect of water deposition on the surface dynamics of mesopores in MCM-41

Abstract

The surface acoustic waves in empty cylindrical pores in the amorphous silica MCM-41 as well as in the same pores partially filled with water are studied with the use of a continuum model. The model is shown to be adequate to predict dispersion relations, cut-off wave vectors and the Airy phases for the secular surface waves of the lowest azimuthal indices n. Quantitative predictions are presented both in the liquid and in the polycrystalline solid phase of water. Two sagittal surface waves exist when water is in the liquid phase. The phase transition to the solid phase (ice) results in the disappearance of the high-frequency mode. All the effects occur in the Terahertz frequency region.

Keywords:

• true surface waves
• dispersion relations
• mesopores
• silica
• polycrystalline ice

PACS:

• 64.70.ph
• 43.20.Bi
• 46.40.Cd
• 68.60.Bs

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the KrakowskieKonsorcjum ‘Materia-Energia-Przyszłość’ im. Mariana Smoluchowskiego [grant KNOW 2012-2017, KKS123/8-09985].