Photo-initiated chemical vapor deposition of thin films using syngas for the functionalization of surfaces at room temperature and near-atmospheric pressure

• Published in: Surface & coatings technology Vol. 244; pp. 98 - 108
• Main Authors: Dorval Dion, C.A., Raphael, W., Tong, E., Tavares, J.R.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.04.2014; Elsevier
• Subjects: Chemical vapor deposition; Contact; Contact angle; Cross-disciplinary physics: materials science; rheology; Deposition; Energy consumption; Exact sciences and technology; Materials science; Mathematical models; Methods of deposition of films and coatings; film growth and epitaxy; Photopolymerization; Physics; PICVD; Polymerization; Precursors; Surface functionalization; Surface treatments; Syngas; Thin film; Thin films; Surface functionalization; PICVD; UV; Photopolymerization; Syngas; Thin film; Atmospheric pressure; Surface temperature; Surface treatments; Thin films; CVD; Vapor deposition; Ambient temperature; Chemical deposition
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2014.01.043

Hydrophilic and hydrophobic thin films have been deposited onto flat metallic substrates through photo-initiated chemical vapor deposition (PICVD), using syngas as a precursor, and affordable UVC germicidal lamps as a source of light. This study is the first experimental investigation of what has been previously concluded to be the potential solution to the current widespread nanoparticle functionalization problem. This study addresses the current limiting factor, namely the cost issue, by using simple gas precursors, using an affordable initiation source and operating under normal conditions. This approach differs from the current approaches which use expensive solvents as precursors, energy consuming-sources of initiation (e.g. high temperature, plasma and VUV) and operate under high vacuum and/or high temperatures. While the current paradigm is to target the peak absorption of a molecule, the present study indicates that long chain polymerized products can be formed from off-peak wavelengths. It has been found that photo-initiated deposition occurs and that a wide range of water contact angles, from 5° to 118°, can be obtained by manipulating the experimental conditions. A multilinear empirical model has been derived, and it predicts fairly well the contact angles obtained as a function of the different experimental parameters. •New method for versatile and scalable surface functionalization using PICVD with syngas•Exploration of the role of pressure and reactant ratio on resulting properties through multivariate analysis•Characterization of the surface properties attainable through this photoinitiated approach•Comparison of results attainable both with and without the use of an initiator compound