强激光与粒子束, 2020, 32 (7): 075001, 网络出版: 2020-07-10
氮离子注入对聚四氟乙烯表面电荷积聚和消散特性的影响
Influence of nitrogen ion implantation on surface charge accumulation and dissipation of polytetrafluoroethylene
聚四氟乙烯 氮离子注入 表面电荷 积聚消散 表面电阻率 表面陷阱特性 PTFE nitrogen ion implantation surface charge accumulation and dissipation surface resistivity surface trap characteristics
摘要
为了抑制聚四氟乙烯材料表面电荷积聚,采用射频产生氮等离子体对其表面进行等离子体浸没离子注入以改善其表面性能。对注入前后的聚四氟乙烯材料样品进行了X射线光电子能谱分析(XPS)、傅里叶红外光谱测试(FTIR)、水接触角测量、表面电阻率测量以及表面电位衰减测量,并基于等温表面电位衰减理论对其表面陷阱能级和密度分布进行了计算,以分析聚四氟乙烯样品经离子注入处理后其表面成分和物理性能的变化,并研究了这些变化对聚四氟乙烯样品表面电荷积聚和消散特性的影响。结果表明:氮离子注入后,聚四氟乙烯材料表面化学成分的主要变化是自身分子结构的破坏和转化,部分CF2结构转变为CF和CF3结构,导致样品表面陷阱能级变浅;水接触角升至140°左右,比未处理样品上升了约27°,表面电阻率降至3×1015 Ω,比未处理样品下降了两个数量级;表面电晕放电1 min后,经氮离子注入处理的聚四氟乙烯材料表面积聚电荷量减少,消散速度加快,这是因为表面陷阱能级变浅有利于表面电荷脱陷,同时表面电阻率降低也促进了表面电荷沿面传导的消散过程,聚四氟乙烯样品表面陷阱能级分布曲线也证实了这一论点。
Abstract
To suppress the accumulation of charge on the surface of polytetrafluoroethylene (PTFE) material, radio frequency nitrogen plasma was generated to perform plasma immersion ion implantation (PIII) on the PTFE surface to improve its surface properties. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), water contact angle measurement, surface resistivity measurement and surface potential attenuation measurement were performed on the samples of PTFE material before and after injection to analyze the changes in surface composition and physical properties of PTFE samples after ion implantation treatment. Based on the theory of isothermal surface potential attenuation, the energy levels and density distributions of the surface traps were calculated. The results show that after nitrogen ion implantation, the main change in the chemical composition of the surface of the PTFE material is the destruction and conversion of its own molecular structure, and part of the CF2 structure is transformed into the CF and CF3 structures, resulting in shallower trap levels on the sample surface. The results also show that the water contact angle rose to about 140°, which is about 27° higher than that of the unprocessed sample. The surface resistivity drops to 3×1015 Ω, which is two orders of magnitude lower than that of the unprocessed samples. After 1 min of corona discharge on the surface, the amount of accumulated charge on the surface of the PTFE material processed with nitrogen ion implantation decreased, and the rate of dissipation increased. This is because the lower surface trap level is conducive to surface charge trapping, and the reduction in surface resistivity also promotes the dissipation process of surface charge along the surface. The curve of trap level distribution on the surface of PTFE sample also confirmed this.
刘畅, 宋法伦, 朱明冬, 李春霞, 张北镇, 李飞, 王淦平, 龚海涛, 甘延青, 金晓. 氮离子注入对聚四氟乙烯表面电荷积聚和消散特性的影响[J]. 强激光与粒子束, 2020, 32(7): 075001. Chang Liu, Falun Song, Mingdong Zhu, Chunxia Li, Beizhen Zhang, Fei Li, Ganping Wang, Haitao Gong, Yanqing Gan, Xiao Jin. Influence of nitrogen ion implantation on surface charge accumulation and dissipation of polytetrafluoroethylene[J]. High Power Laser and Particle Beams, 2020, 32(7): 075001.