Authors: Raad A. Alawajji, Ganesh K. Kannarpady, Alexandru S. Biris
Publication: Applied Surface Science, Volume 444, 30 June 2018, Pages 208-215. https://doi.org/10.1016/j.apsusc.2018.02.206
Abstract:
Polytetrafluoroethylene (PTFE) thin films were successfully deposited on glass substrates using pulsed laser deposition, with deposition times ranging from 30 to 120 minutes (min). The surface roughness of the films increased as deposition time increased, with micro/nanoscale roughness developing when deposition time increased over 60 min. This roughness made the surface superhydrophobic, having a contact angle of about 151.6°±1. UV–vis spectroscopic analysis of the PTFE films revealed that they were highly transparent, up to ∼90% in visible and near-infrared ranges. Furthermore, when the deposition time was increased—which increased the films’ thickness—the films were able to absorb 80–90% of ultraviolet light in the wavelength range <300 nm. The researchers used an x-ray photoelectron spectrometer to find the chemical and elemental composition of the films’ surfaces. Atomic force microscopy was used to determine the effect of surface roughness on the films’ hydrophobicity. The fabricated superhydrophobic films have many potential practical uses, from self-cleaning materials to solar cell panel coatings. Additionally, the low dielectric properties of PTFE make the films’ ideal for communication antenna coatings and similar applications.