中文摘要：

用空气中射流低温等离子体对聚甲基丙烯酸甲酯（PMMA）薄膜进行表面改性,比较了改性前后PMMA表面水接触角和表面能的变化。研究了等离子体改性时间及改性距离对改性效果的影响,测量了改性后PMMA在空气中放置时的老化效应,并对改性机理进行了分析。结果表明,PMMA薄膜经射流低温等离子体改性后,水接触角下降,表面能上升,两者均在一定改性时间时达到饱和状态。当改性时间固定时,减小改性距离,可以得到更好的改性效果。改性后的材料存在老化效应,放置9天后,老化效应趋于稳定,但其表面水接触角仍远低于改性前的值。

英文摘要：

The surfaces of polymethylmetacrylate（PMMA） films were modified by cold plasma jets in air,and the change in surface contact angle and surface energy of the PMMA before and after the modification were compared.The effects of modification time and modification distance on the hydrophilicity of PMMA surface were studied,and the aging effect of treated materials that are exposed in open air was measured,with the modification mechanism being discussed.Results show that the contact angle decreases and the surface energy increases with the increase of modification time,and both of them reach saturation values as the modification time increases to a certain value.It is found that a better modifying effect can be achieved by reducing modification distance when the modification time is kept to be constant.Aging effect occurs on the PMMA surface after modification,but the value of water contact angle is still much lower than that of untreated one even after 9 days storage in ambient air.