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

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(CH₃)₂O—)_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.