基于交流电源和纳秒脉冲电源激励等离子体射流的憎水性陶瓷表面改性研究

Enhancement of Ceramic Hydrophobicity With Plasma Jet Excited by AC and Nanosecond Pulse Power Supply

为优化陶瓷表面憎水改性效果,并探索等离子体改性机制,分别采用交流和纳秒脉冲电源激励Ar/PDMS等离子体射流对陶瓷表面进行憎水改性,通过扫描电子显微镜、原子力显微镜和X射线光电子能对处理后的陶瓷表面物理形貌和化学成分进行测量分析,比较两种电源激励下的改性效果,通过改变PDMS浓度,对改性效果进行优化,并结合放电特性和表面特性分析探讨改性机制。结果表明,在PDMS浓度为2.25%时,纳秒脉冲激励射流改性陶瓷可达到水接触角152°的超憎水效果,而交流电源激励下仅能达到92°。交流电源条件下,处理后的陶瓷表面形成以(—Si(CH_(3))_(2)O—)_(n)有机成分为主的微米级簇状凸起和纳米级苔藓状小颗粒产物;而纳秒条件下,陶瓷表面形成以O—Si—O无机成分为主的微纳米薄膜。相较于交流电源,纳秒脉冲电源激励射流具有更高的电子温度,相同条件下PDMS分子碎片化程度更深,能够在陶瓷表面沉积形成超憎水薄膜。

In order to optimize the hydrophobic modification effect of ceramic surface and explore the plasma modification mechanism,Ar/PDMS plasma jet excited by AC power and nanosecond pulse power was applied to perform hydrophobic modification on the ceramic surface.The physical morphology and chemical composition of ceramic surface were further analyzed by SEM,AFM and XPS to compare the modification effects under the two power sources.In addition,through optimizing the modification effect by changing the concentration of PDMS,the modification mechanism was discussed combined with the analysis of discharge characteristics and surface characteristics.The results show that when the concentration of PDMS is 2.25%,the surface of ceramics modified with plasma jet excited by nanosecond pulse power can achieve a super-hydrophobicity where water contact angle(WCA)reaches 152°;by contrast,the WCA only reaches 92°under AC power.After treatment by AC power,the ceramic surface forms micron-scale cluster-like protrusions and nano-scale moss-like small particles mainly composed of(-Si(CH_(3))_(2)O-)_(n) organic components;while after treatment by nanosecond pulse power,the ceramic surface forms micro-nano thin film mainly composed of O—Si—O inorganic structure,leading to the super-hydrophobicity.Compared with the AC power,the nanosecond pulsed power excitation jet has a higher electron temperature,and the degree of fragmentation of PDMS molecules is deeper under the same conditions,resulting in the formation of dense films on ceramic surface.