Nano-Roughened Teflon-Like Film Coated Polyethylene Terephthalate Substrate with Trifluoromethane Plasma Enhanced Hydrophobicity and Transparency

Nano-roughened Teflon-like films with manipulated topography and chemical bonds are demonstrated to concurrently enhance hydrophobicity and transparency. By fluorocarbon plasma deposition with tunable F/C precursor ratio on polyethylene terephthalate substrate, the nano-roughened Teflon-like film prepared with an F/C precursor ratio of 3 reveals a repellent water-contact angle with long-term bonding stability due to its extremely low surface energy density of 28 mN/m caused by enhancing the highly cross-linking -CF(2) functional groups. Increasing the F/C precursor ratio up to 4 oppositely reduces the F/C composition ratio and down-shifts the XPS binding energy peak of the C-F bond in -CF(x) groups with increasing bond length, which inevitably shrinks the water contact angle after thermal stability test for 24 h. Enlarging the reaction time with trifluoromethane plasma enriches the fluorine atom content to improve the cross-linking capability of -CF(x) and -C-CF(x) bonds, simultaneously promoting the high hydrophobicity and transparent surface with water contact angle up to 133 degrees and minimum absorption coefficient of 5623 cm(-1) at 450 nm, respectively. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3596712] All rights reserved.