AVS 60th International Symposium and Exhibition
    Advanced Surface Engineering Thursday Sessions
       Session SE-ThP

Paper SE-ThP1
Gas Barrier Properties of Hydrogenated Amorphous Carbon Films Synthesized by Atmospheric Pressure Plasma on Nitrogen-Plasma-Treated Polyethylene Terephthalate Substrates

Thursday, October 31, 2013, 6:00 pm, Room Hall B

Session: Poster Session
Presenter: Y. Futagami, Keio University, Japan
Authors: Y. Futagami, Keio University, Japan
T. Hirako, Keio University, Japan
M. Noborisaka, Keio University, Japan
A. Shirakura, Keio University, Japan
T. Suzuki, Keio University, Japan
Correspondent: Click to Email
Gas barrier properties of hydrogenated amorphous carbon (a-C:H) films synthesized at atmospheric pressure have been investigated for applications to packaging materials. In this study, a-C:H films were synthesized on N2-plasma-treated polyethylene terephthalate (PET) substrates by atmospheric pressure plasma enhanced chemical vapor deposition method. PET substrates were treated with various plasma treatment time at atmospheric pressure prior to synthesis of 500-nm-thick a-C:H films. The effects of N2 plasma treatment on the properties of PET surface and a-C:H/PET were investigated in terms of chemical binding structure, surface free energy, roughness, adhesion and oxygen transmission rate (OTR). Formation of new C-N bonds were observed on the PET surfaces by N2 plasma treatment from X-ray photoelectron spectroscopy analysis, and the adhesion strength between a-C:H films and PET substrates was improved in tape tests. As the plasma treatment time increased from 0 to 5 s, OTR of the a-C:H films on N2-plasma-treated PET substrates decreased from 5.6 to 3.1 cc/(m2∙24h∙atm), which is five times less OTR than those of uncoated PET substrates. However by increasing the plasma treatment time from 5 to 40 s, the surface roughness of PET substrate and OTR of a-C:H/PET were increased to 10.5 nm and 4.2 cc/(m2∙24h∙atm). This result indicates that the proper time of N2 plasma treatment on PET substrates is effective for improving adhesion and gas barrier properties of a-C:H films.