Abstract: Plasma was generated by high voltage direct current, and four working gases were Ar, Ar/O₂, Ar/O₂/N₂ and He/O₂. The treatment time of each gas group was 1, 2, 4, 6, 8, 10 min, respectively. There were 9 samples in each group. Contact angle measurement instrument was employed to detect the contact angle before and after treatment; plasma components were analyzed by the optical emission spectroscopy (OES); elemental composition and chemical bond changes were measured by X-ray photoelectron spectroscopy analysis (XPS). After four plasma treatments, the surface wettability of the heat curing acrylic resin was significantly improved. After 1 min treatment, the water contact angle was significantly reduced (p<0.001), and presented clear slowdown trend over time. There existed plenty of ?OH in the plasma components according to the OES result. XPS analysis result indicated reduction of C and O proportion, and a new hydrophilic group C?OH was generated. After plasma treatments, the new hydrophilic group C?OH was formed on the surface of the heat curing acrylic resin, and this is a reasonable explanation of why the surface wettability was significantly improved after plasma treatment. It is suggested that non-thermal atmospheric pressure plasma may possess a good perspective in clinical use of denture base resin.

Key words: non-thermal atmospheric pressure plasma, heat curing acrylic resin, contact angle, wettability, X-ray photoelectron spectroscopy analysis (XPS), optical emission spectroscopy (OES)

摘要： 使用直流电激发4种工作气体(Ar, Ar/O₂, Ar/O₂/N₂和He/O₂)来产生等离子体, 分别处理热凝树脂样本1, 2, 4, 6, 8, 10分钟, 每组9个样本。使用接触角测量仪测量处理前后各样本的接触角; 利用发射光谱(OES)对等离子体的活性成分进行分析; 采用X射线光电子能谱(XPS)分析其表面的元素价键改变。经过Ar, Ar/O₂, Ar/O₂/N₂和He/O₂等离子体处理后, 热凝树脂表面的润湿性均显著增加, 处理 1 分钟时, 样本表面的接触角与原始值相比, 显著减小(p<0.001), 随着时间的延长, 减小趋势变缓。OES结果显示等离子体的活性成分中包含有大量的?OH; XPS分析表明: 经过等离子体处理后, 热凝树脂表面的C元素与O元素的比例减小, 有新的亲水性基团C?OH产生。大气压低温等离子体处理热凝树脂表面后, 产生新的亲水性基团C?OH, 从而增加表面亲水性。研究结果提示低温等离子体可能为临床上处理义齿基托树脂提供新方法。

关键词: 低温等离子体, 热凝丙烯酸树脂, 接触角, 润湿性, X射线光电子能谱, 发射光谱