Superhydrophobicity on transparent fluorinated ethylene propylene films with nano-protrusion morphology by Ar + O{sub 2} plasma etching: Study of the degradation in hydrophobicity after exposure to the environment

Journal Article · Mon Oct 28 00:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4826897· OSTI ID:22217881

Gupta, Nitant; Kavya, M. V.; Singh, Yogesh R. G.; Jyothi, J.; Barshilia, Harish C. ^[1]

---

1. Nanomaterials Research Laboratory, Surface Engineering Division, CSIR-National Aerospace Laboratories, Post Bag No. 1779, Bangalore 560 017 (India)

Fluorinated ethylene propylene (FEP) films were made superhydrophobic by Ar + O{sub 2} plasma etching process. Field emission scanning electron microscopy and atomic force microscopy studies of the plasma-treated FEP samples detected the presence of uniformly distributed nano-protrusions exhibiting a low surface roughness necessary for maintaining the transparency of the samples. In fact, optical transmittance measurements showed an improvement in the transparency of FEP samples after plasma treatment. The X-ray photoelectron spectroscopic analysis showed the presence of –CF{sub x}–O–CF{sub x}– (x = 1, 2, or 3) linkages in both untreated and plasma-treated samples which explains the hydrophilic nature (contact angle below 90{sup ∘}) of the untreated sample. Fourier transform infrared spectroscopy showed no changes in the bulk properties of the plasma-treated samples. Moreover, exposure to the environment caused the surfaces to lose their superhydrophobic property in an indefinite amount of time. This has been further studied through a water immersion experiment and explained through the wetting state transition from Cassie state to Wenzel state.

• OSTI ID: 22217881
• Journal Information: Journal of Applied Physics, Vol. 114, Issue 16; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ATOMIC FORCE MICROSCOPY
ETCHING
ETHYLENE
FILMS
FOURIER TRANSFORM SPECTROMETERS
FOURIER TRANSFORMATION
INFRARED SPECTRA
MORPHOLOGY
NANOSTRUCTURES
OPACITY
PLASMA
PROPYLENE
ROUGHNESS
SCANNING ELECTRON MICROSCOPY
SPUTTERING
SURFACES
ULTRAVIOLET SPECTRA
X RADIATION
X-RAY PHOTOELECTRON SPECTROSCOPY