Structural, compositional, thermal resistant and hydro-oleophobic properties of fluorine based block-co-polymer films on quartz substrates by wet chemical process

Crack free and smooth surfaces of poly [4,5-difluoro 2,2-bis (trifluoromethyl)-(1,3 dioxole)-co-tetrafluoroethylene] (TFE-co-TFD) thin films have been deposited by wet chemical dip coating technique on polished quartz and glass slide substrates. The deposited films have been subjected to annealing at different temperatures ranging from 100 to 500 degrees C for 1 h in argon atmosphere. The elemental composition of the as-deposited (xerogel) thin film as well as film annealed at 400 degrees C was measured by X-ray photoelectron spectroscopy and observed that there was no change in the composition of the film. X-ray diffraction pattern revealed the amorphous behaviour of both as-deposited and film annealed at 400 degrees C. Surface morphology and elemental composition of the films have been examined by employing scanning electron microscopy attached with energy dispersive X-ray analyser, respectively. It was found that as the annealing temperature increased from 100 degrees to 400 degrees C, nano-hemisphere-like structures have been grown, which in turn has shown increase in the water contact angle from 122 degrees to 148 degrees and oil (peanut) contact angle from 85 degrees to 96 degrees. No change in the water contact angle (122) has been observed when the films deposited at room temperature were heated in air from 30 to 80 degrees C as well as exposed to steam for 8 days for 8 h/day indicating thermal stability of the film. (c) 2006 Elsevier Ltd. All rights reserved.