To reduce the oxygen transmission rate through a polyethylene terephthalate (PET) bottle (an organic plastic)
diamond-like carbon (DLC) coatings on the inner surface of the PET bottle were deposited by radio frequency plasmaenhanced chemical vapour deposition (RF-PECVD) technology with C2H2 as the source of carbon and Ar as the diluted gas. As the barrier layer to humidity and gas permeation, this paper analyses the DLC film structure, composition,
morphology and barrier properties by Fourier transform infrared, atomic force microscopy, scanning electron microscopy
and oxygen transmission rate in detail. From the spectrum, it is found that the DLC film mainly consists of sp3 bonds. The barrier property of the films is significantly relevant to the sp3 bond concentration in the coating, the film thickness and morphology. Additionally, it is found that DLC film deposited in an inductively coupled plasma enhanced capacitively coupled plasma source shows a compact, homogeneous and crack-free surface, which is beneficial for a good
gas barrier property in PET bottles.