脉冲微波表面波PECVD在有机PET表面沉积DLC薄膜的阻隔性研究

Barrier Properties of PET Coated by DLC Film through Microwave Surface Wave Plasma Enhanced Chemical Vapor Deposition

目的探讨使用脉冲微波表面波等离子体辅助化学气相沉积技术在聚对苯二甲酸乙二醇酯(PET)材料表面沉积类金刚石薄膜作为阻隔层的可行性。方法以C2H2为单体,氩(Ar)为放电气体,采用脉冲微波表面波等离子体化学气相沉积(PECVD)技术在有机PET材料表面沉积类金刚石(Diamond-like Carbon,DLC)薄膜。研究工艺参数,如脉冲微波放电功率、工作气压、单体与工作气体的体积比等,对DLC薄膜沉积速率和阻隔性能的影响。通过傅里叶变换红外光谱(FT-IR)、原子力显微镜(AFM)、氧气和水蒸气透过率测试仪等对薄膜结构与性能进行表征。结果DLC薄膜的结构和成分随着等离子体放电工艺参数的变化而改变,造成其阻隔性能也随之发生变化。PET表面沉积纳米级DLC薄膜后,氧气透过率和水蒸气透过率可以分别降至0.58 mL/(m^2·d)和2.5 g/(m^2·d)。结论DLC薄膜对氧气和水蒸气都表现出良好的阻隔性,可以应用于食品、药品的阻隔包装。

The research aims to study the feasibility of forming diamond-like carbon(DLC)films deposited on the PET surface through microwave surface-wave PECVD technique with barrier layer.With C2H2 as monomer and Ar as discharge gas,the DLC film was deposited on the organic PET material surface through microwave surface-wave PECVD technique.The influences of process parameters such as microwave discharge power,working pressure and monomer to working gas ratio on the deposition rate and barrier performance of DLC film were studied.The chemical structures and properties of DLC films were characterized by Fourier transform infrared spectroscopy(FTIR),atom force microscope(AFM)and some conventional surface probes.The structure and composition of DLC films varied with different process parameters of plasma discharge.The OTR and WVTR of the coated PET film can be reduced to 0.58 mL/(m^2·d)and 2.5 g/(m^2·d),respectively.DLC film has good barrier property to both oxygen and steam oxygen and can be used in high barrier packaging of food and drug.