发射光谱解析常压均匀放电等离子体处理服用丙纶表面的反应机理研究

Taken He and N2 as the main discharge gases, the emission spectra before, in and after processing PP fiber's surface treated using atmospheric pressure Homogeneous Dielectric Barrier Discharge Plasma (AHDBDP) are analyzed comparatively. Combing the physical and chemical variation of PP fiber's surface obtained utilizing these test methods, ATR-FTIR, XPS and SEM etc., the reaction process and mechanism during the process of treating the PP fiber's surface by the active particles in AHDBDP plasma are studied. Based on this, using the gas-phase dynamics and surface dynamics, considering the diffusing of neutral particles and the movement of the high energy electrons and ions in the electric field, the mathematical model of the various reaction processes between the active particles and the PP fiber's surface is built. The competition mechanism of them and loss probability of active particles are analyzed. The simulation results calculated using the presented theory are compared with the above experiment results. The reaction mechanism of AHDBDP treatment on the PP fiber's surface is revealed. Based on the above content, the PP fiber's surface is treated using atmospheric pressure gas-liquid two-phase homogeneous plasma (AGLHP), in this process, the liquid is vaporized by the ultrasonic vibration so as to increase the types and concentrations of active particles in plasma. The discharge characteristics of AGLHP and the factors influencing the plasma treatment efficiency are researched. The emission spectrums before, in and after processing PP fiber's surface treated using AGLHP are measured. And these results are compared with the gas phase plasma treatment process. This has further understand for the reaction mechanism of plasma treatment on the fiber's surface. The advantages and disadvantages of the gas-liquid two-phase plasma are presented. This reseach can provide a theoretical guidance for the promotion of the plasma surface treatment technology in the industry.

本项目以He和N2为放电气体，对比分析常压均匀介质阻挡放电等离子体对丙纶纤维表面处理前、中与后的发射光谱，结合ATR-FTIR、XPS、SEM等得到的纤维表面物理化学变化，研究等离子体中活性粒子与纤维表面的反应过程和作用机理。基于气相动力学和表面动力学，考虑中性粒子的扩散、高能电子和离子在电场中的运动，对活性粒子与纤维表面的各种反应过程进行建模，分析他们的竞争机制及活性粒子的损失机率，结合实验结果，揭示AHDBDP处理丙纶纤维表面的反应机理。使用常压气液两相均匀等离子体处理丙纶纤维表面，并用超声振动将液体溶质汽化，增加等离子体中活性粒子的种类和浓度；分析该等离子体的放电特性及影响等离子体处理效果的因素，测量对纤维表面处理前、中与后的发射光谱，与气相等离子体处理相比较，进一步了解等离子体对纤维表面处理的反应机理，发现气液两相等离子体处理的优势和不足，为等离子体表面处理技术的推广提供理论指导。

大气压介质阻挡放电等离子体对聚合物的表面改性有着其独特的优势，但是由于等离子体空间内的活性粒子与聚合物表面的作用过程包括物理化学过程而非常复杂，目前仍不是完全清楚。本项目主要对大气压气液两相介质阻挡放电等离子体的放电特性及与聚合物表面相互作用机理进行研究。结果表明：放电间隙和放电频率均相同时，对于开始放电电压和稳定放电电压（放电刚铺满整个电极时的电压）来说，大气压单一空气介质阻挡放电的放电电压最高，而空气+去离子水的气液两相介质阻挡放电的次之，空气+丙酮+去离子水的气液两相介质阻挡放电电压最低。其次，大气压空气+去离子水和空气＋氧气＋去离子水气液两相介质阻挡放电等离子体对聚四氟乙烯薄膜的表面处理效果比单一空气和空气＋氧气等离子体对其的处理效果要好，通过扫描电镜、XPS和ART-FTIR分析可知，大气压空气＋去离子水和空气＋氧气+去离子水等离子体对聚四氟乙烯进行表面处理后，表面O和N的含量比大气压单一空气和空气+氧气的分别高0.4%/0.4%和0.55%/0.65%，说明聚四氟乙烯薄膜经大气压空气＋去离子水和空气＋氧气+去离子水等离子体处理后表面接入更多的含氧含氮官能团，从而导致其对聚四氟乙烯薄膜表面的处理效果更好。此外，随着等离子体处理时间的加长，处理效果达到饱和，XPS结果显示，此时聚四氟乙烯表面的O的含量降低而N含量增加，这说明聚四氟乙烯表面改性效果的提高主要是由于表面氧化引起的。再者，大气压氮气介质阻挡放电等离子体对聚丙烯织物的改性效果比大气压氮气+二氧化碳等离子体的改性效果要好，通过发射光谱分析发现，亚稳态氮分子在改善聚丙烯织物的亲水性上起着关键的作用。氮气、氧气、二氧化碳被加入大气压氦气多电流峰放电中后，放电逐渐从辉光放电过度到丝状放电，主要是因为放电空间内的亚稳态氦原子逐渐减少的缘故。为了更好的研究大气压气液两相等离子体的放电特性及其应用，课题组开发了第一代和第二代大气压气液两相等离子体产生装置，并分别申请了发明专利和实用新型专利，均被授权。