Electron microscopy approach to the wetting dynamics of single organosilanized mesopores
C. Rodriguez,
V. Torres-Costa,
A.M. Bittner,
S. Morin,
M. Cascajo Castresana,
S. Chiriaev,
E. Modin,
A. Chuvilin,
M. Manso Silván
Affiliations
C. Rodriguez
Departamento de Física Aplicada, Centro de Microanálisis de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain; Mecwins, Roda de Poniente 15, Tres Cantos, Madrid 28760, Spain
V. Torres-Costa
Departamento de Física Aplicada, Centro de Microanálisis de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
A.M. Bittner
CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain; Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
S. Morin
CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain; Department of Chemistry, York University, 4700 Keele Street, Toronto M3J 1P3, Canada
Mads Clausen Institute, University of Southern Denmark, 6400 Sønderborg, Denmark
E. Modin
CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
A. Chuvilin
CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain; Ikerbasque, Basque Foundation for Science, 48013 Bilbao, Spain
M. Manso Silván
Departamento de Física Aplicada, Centro de Microanálisis de Materiales and Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain; Corresponding author
Summary: Columnar mesoporous silicon (PSi) with hydrophobic vs. hydrophilic chemistries was chosen as a model for the local (pore-by-pore) study of water-pore interactions. Tomographic reconstructions provided a 3D view of the ramified pore structure. An in situ study of PSi wetting was conducted for categorized pore diameters by environmental scanning TEM. An appropriate setting of the contrast allows for the normalization of the gray scale in the images as a function of relative humidity (RH). This allows constructing an isotherm for each single pore and a subsequent averaging provides an isotherm for each pore size range. The isotherms systematically point to an initial adsorption through the formation of water adlayers, followed by a capillary filling process at higher RH. The local isotherms correlate with (global) gravimetric determination of wetting. Our results point at the validation of a technique for the study of aging and stability of single-pore nanoscale devices.
