Sulphur Hexafluoride Plasma Treatment to Enhance the Hydrophobicity of CVD Carbon Coatings Produced on Cornstarch Plasticized Films

• Published in: Macromolecular symposia. 2006-12, Vol.245-246 (1), p.519-524
• Main Authors: Simão, Renata A., da Silva, Monica L.V.J., Martins, Moema, Thiré, Rossana M.S.M., Andrade, Cristina T.
• Format: Article
• Language: English
• Subjects: Atomic force microscopy; atomic force microscopy (AFM); biopolymers; Carbon; Chemical vapor deposition; Coatings; Hydrophobicity; Methane; plasma processing and deposition; Strategy; Sulfur hexafluoride; thermoplastic starch; wettability
• ISSN: 1022-1360; 1521-3900
• DOI: 10.1002/masy.200651374

In this work, a new coating strategy was successfully developed and promising results indicate a significant reduction of the water sensibility of cornstarch films coated by chemical vapour deposition (CVD). Amorphous carbon coatings (a‐C:H) produced from methane (CH4) were submitted to different sulphur hexafluoride plasma treatments. The best results were obtained for cornstarch films coated with a 50 nm‐thick CH4 plasma coating and treated with SF6 for 60 s. This surface modification led to a significant increase in the surface hydrophobicity, with measured contact angle of 85°. Atomic force microscopy (AFM) was used to evaluate local surface modifications upon the a‐C:H coating and after the SF6 plasma treatment. Results indicate that the cornstarch films were homogeneously coated using CH4. SF6 treatment led to a plasma etching of the surface, changing completely the observed morphology. Fluorine was incorporated to the surface.