arrow
Return

Superhydrophobic Breakdown of Nanostructured Surfaces Characterized in Situ Using ATR-FTIR

delete2017-04-10
delete24
delete
OA
AI
N
Nandi Vrancken *
S
Stefanie Sergeant
G
Guy Vereecke
G
Geert Doumen
F
Frank Holsteyns
H
Herman Terryn
S
Stefan De Gendt
X
XiuMei Xu *
DOI:10.1021/acs.langmuir.6b04471delete
deleteOriginal
deleteShare
deleteSave
View PDF
Abstract

Abstract

En 中文
In situ characterization of the underwater stability of superhydrophobic micro-. and nanostructured surfaces is important for the development of self-cleaning and antifouling materials. In this work, we demonstrate a novel attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy-based method for large-area wetting characterization of silicon nanopillars. When air is present in between the structures, as is characteristic of the Cassie Baxter state, the relative intensities of the water bands in the absorption spectrum change because of the wavelength dependent attenuation of the evanescent wave. This phenomenon enables unambiguous identification of the wetting state and assessment of liquid impalement. Using mixtures of isopropanol and water with different concentrations, the breakdown of superhydrophobic states and the wetting hysteresis effects are systematically studied on uniform arrays of silicon nanopillars. A transition from the Cassie Baxter to Wenzel state is observed when the isopropanol concentration exceeds 2.8 mol %, corresponding to a critical surface tension of 39 mN/m. Spontaneous dewetting does not occur upon decreasing the isopropanol concentration, and pure water can be obtained = in a stable Wenzel state on the originally superhydrophobic substrates. The developed ATR FTIR method can be promising for real-time monitoring of the wetting kinetics on nanostructured surfaces.
Keywords:
ROUGH SURFACES
WETTING TRANSITION
CASSIE-BAXTER
IMPALEMENT TRANSITIONS
WATER DROPLETS
WENZEL STATE
THIN-FILMS
SILICON
INTERFACES
SPECTROSCOPY
AI Summary

AI Summary

Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.

Journal

Langmuir cover
Langmuir
IF:
3.9
Papers:
5.4W
Citations:
10.6W

Organization

I
interuniversity microelectronics centre
Scholars:
6.2K
Papers: 3.9K
Citations: 0
V
Vrije Universiteit Brussel
Scholars:
1.4W
Papers: 1.3W
Citations: 129