DBD plasma assisted atomic layer deposition alumina barrier layer on self-degradation polylactic acid film surface

In this work, the plastic of polylatic acid (PLA) film is coated by alumina (Al₂O₃) through dielectric barrier discharge plasma assisted atomic layer deposition (DBD PA-ALD) for the proposal of the barrier property enhancement. The influence of ALD Al₂O₃ thickness on properties of barrier, mechanical, optical and degradation is investigated in detail. It is obtained that the growth rate of Al₂O₃ in DBD PA-ALD is as quick as 0.12 nm/cycle. After coated ～40 nm Al₂O₃, the water vapor transmission rate of PLA is reduced by two orders of magnitude. Additionally, it is noticed that the tension strength of the coated film is improved slightly, whereas the light transmission rate is decreased with the increase of Al₂O₃ thickness. The degradation test shows that Al₂O₃ coating almost does not affect the self-degradation rate of PLA film