中文摘要：

为了研究等离子体射流在薄膜表面改性方面的应用,利用大气压氩等离子体射流对聚丙烯（polypropylene,简称PP）薄膜进行表面改性来增强其表面亲水性,通过测量电压电流波形、Lissajous图形和发射光谱等来诊断其放电特性,通过水接触角和表面能测量等手段来研究等离子体射流处理对PP薄膜表面特性的影响,为实际应用选择最优的处理条件提供参考。研究了改性距离、处理时间和功率密度等参数对改性效果的影响,考察了处理后的PP薄膜放置在空气中的老化效应,并对所得到的结果进行了分析。结果表明,氩等离子体射流产生的粒子主要有OH、N2、Ar和少量的O,其气体温度在317～362K范围内变化,是典型的低温等离子体。PP薄膜经大气压氩等离子体射流处理后,其表面水接触角下降,表面能上升,两者均在一定处理时间内达到饱和状态。处理后表面水接触角可下降到最小值55°,表面能可增加到最大值45.313mJ/m2。通过减小改性距离、增加功率密度可以缩短时间并提高改性效果,从而提高处理效率。改性后的PP薄膜存在老化效应,但即使放置10d后,其表面水接触角仍为70.5°,远低于处理前的值。

英文摘要：

In order to study the application of plasma jet in film surface modification, the surfaces of polypropylene （PP） films were modified using atmospheric pressure plasma jet in Ar to improve hydrophilicity. The discharge characteristics were studied by means of voltage and current waveforms measurement, Lissajous figures measurement, light-emission pictures taking, and optical emission spectra measurement, and the surface properties of the untreated and plasma jet treated samples were characterized by means of contact angle and surface energy measurement, providing reference for selecting optimum processing condition in practical application. The influences of discharge and treatment parameters, such as treatment distance, treatment time, and power density on PP surface modification, are studied, the aging effect of treated PP that was exposed to open air was also investigated, and the modification mechanism was discussed. Results show that the generated gas in Ar plasma jet is a typical non-thermal one, in which the main species are OH, Nz, Ar, and O, and gas temperature is the range of 317 K to 362 K. After atmospheric pressure plasma jet treatment, the water contact angle decreases and surface energy increases, and both of them reach saturated values at certain treatment time. The water contact angle can reach minimum value of 55° after treatment, and the surface energy can reach maximum value of 45. 313 mJ/m2. The treatment time can be shortened by decreasing treatment distance and increasing power density, then the treatment efficiency can be improved. Aging effect occurs on the plasma treated PP surface, but the value of water contact angle is still 70. 5° even after 10 days storage in ambient air, much lower than that of the untreated one.