交流和纳秒脉冲Ar/H2O介质阻挡放电聚丙烯材料表面亲水改性对比研究

为了提高等离子体对聚合物材料表面处理的应用效果，优化亲水处理的条件，研究了交流和纳秒脉冲氩气介质阻挡放电（DBD）中添加适量H₂O，对聚丙烯（PP）亲水改性的处理效果。利用电学和光学诊断方法，系统地对比了交流DBD和纳秒脉冲DBD的放电特性，结果表明，纳秒电源驱动DBD具有更高的放电瞬时功率，更好的放电均匀性和更高的能量效率。通过测量不同水蒸气含量下DBD的OH发射光谱强度，确定了PP材料亲水性处理中H₂O添加的最优含量。利用交流和纳秒脉冲电源驱动DBD分别对PP材料进行亲水改性的处理，测量了不同条件下改性处理后的表面水接触角，并利用原子力显微镜（AFM）和傅里叶红外光谱（FTIR）分别对处理前后PP材料的表面物理形貌和表面化学成分进行分析。结果发现，经DBD处理后PP材料的水接触角明显降低，表面粗糙度明显增大，表面的亲水性含氧基团，羟基（?OH）和羰基（C=O）的数量大幅增加。相比交流电源，纳秒脉冲DBD处理的改性效果更好，其处理后的材料表面水接触角，比交流DBD处理的低5°左右，表面粗糙度也有所提升。而水蒸气的加入可使PP材料的表面水接触角进一步减小4°左右，表面粗糙度明显提升。研究结果为优化DBD聚合物材料表面改性实验条件及处理的效果提供了重要的参考依据。

Comparison study of PP hydrophilic surface modification by Ar/H2O dielectric barrier discharge excited by AC and nanosecond pulse voltage

To improve the effect of plasma on the surface modification of polymer materials and optimize the hydrophilic treatment conditions, the hydrophilic modification of polypropylene (PP) by AC and nanosecond pulse argon dielectric barrier discharge (DBD) was studied. The discharge characteristics of AC DBD and nanosecond pulse DBD were systematically compared by using electrical and optical diagnostic.The results show that the DBD excited by nanosecond power supply has higher instantaneous discharge power, better discharge uniformity and higher energy efficiency. The optimal content of H₂O in hydrophilic treatment of PP was determined by measuring the intensity of OH. The hydrophilic modification of PP was carried out by using DBD driven by AC and nanosecond pulse power supply, respectively. The water contact angle of PP was measured under different conditions. The surface physical morphology and chemical composition of PP were analyzed by atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR).The result shows that, after DBD treatment, the water contact angle of PP surface was obviously reduced, the surface roughness increased significantly, and the number of hydrophilic oxygen-containing groups, hydroxyl (?OH) and carbonyl groups (C=O), increased significantly. Compared with the AC power supply treatment, the modification effect of nanosecond pulse DBD treatment is obviously better, by which the water contact angle of the treated material surface is about 5° lower and the surface roughness is larger. In addition, the water contact angle of PP was further reduced about 4° and the surface roughness was significantly improved with the addition of water vapor. The results have significant value for optimizing the experimental conditions and treatment effect of surface modification of DBD polymer materials.