射频等离子体改性PTFE表面液滴撞击接触起电对润湿性的影响  

Effect of Contact Electrification During Water Droplet Impact on the Wettability of PTFE Surfaces Modified by Radio Frequency Plasma

作　　者：李昱鹏[1] 孟祥任 刘玉霞 霍磊 雷明凯[1] STARINSKIY Sergey V TEREKHOV Vladimir LI Yupeng;MENG Xiangren;LIU Yuxia;HUO Lei;LEI Mingkai;STARINSKIY Sergey V;TEREKHOV Vladimir(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;Kutateladze Institute of Thermophysics,Siberian Branch of Russian Academy of Sciences,Novosibirsk 630090,Russia)

机构地区：[1]大连理工大学材料科学与工程学院,大连116024 [2]俄罗斯科学院西伯利亚分院热物理研究所,俄罗斯新西伯利亚630090

出　　处：《中国表面工程》2023年第6期145-154,共10页China Surface Engineering

基　　金：国家自然科学基金(51975086,52111530043,U21B2078);中央高校基本科研业务费(DUT22LAB107)资助项目。

摘　　要：液滴撞击固体表面是自然界的常见现象,研究超疏水表面的液滴撞击对其润湿性的影响,对于超疏水性材料的潜在应用具有重要的科学意义。采用3、10、20 min氧等离子体处理(OPT)和1 min八氟环丁烷等离子体聚合沉积(PPD)的等离子体方法改性聚四氟乙烯(PTFE)表面,获得具有不同尺寸和间距的微/纳米锥的超疏水PTFE表面,研究射频等离子体改性PTFE表面的液滴静态接触角、滚动角及液滴撞击动力学行为,分析在不同个数液滴撞击后PTFE表面的润湿性和液滴撞击行为变化,确定PTFE表面液滴撞击起电效应的影响机制。结果表明:通过1~9个液滴撞击后,PTFE表面的静态接触角随撞击液滴数量增加而减小,导致静态接触角低于150°;液滴滚动角随撞击液滴数量增加而增大,造成液滴滚动角高于10°。撞击液滴的接触时间随撞击液滴数量增加而增大,回弹系数随撞击液滴数量增加而减小。随撞击液滴数量增加,回弹液滴的正电荷和PTFE表面的负电压增大,PTFE表面的负电荷对液滴产生强吸引作用,导致低粘附超疏水性被破坏。3 min OPT和1 min PPD改性PTFE表面的纳米锥间距小,密度大,表面负电荷量增加明显,造成PTFE表面的疏水性降低的程度最显著。研究结果可为改善超疏水稳定性的表面织构设计提供理论依据。A water droplet impacting a solid surface is a natural universal phenomenon.The impact behavior of water droplets and their effect on the superhydrophobicity of anti-wetting surfaces are important for the practical application of anti-wetting materials.In this study,radio frequency plasma modification methods including oxygen plasma treatment(OPT) and octafluorocyclobutane(C_4F_8)plasma polymerization deposition(PPD) are used to fabricate superhydrophobic surfaces on polytetrafluoroethylene(PTFE)substrates.Micro/nanocone arrays with different heights and spacing distances and fluorocarbon films with a low surface energy are fabricated on superhydrophobic PTFE surfaces by OPT for 3,10,and 20 min,and PPD for 1 min.The height and distance of the cone structure on the PTFE surfaces increase as the OPT duration increases.The transition from a nanocone to a microcone array is achieved on the PTFE surfaces when the OPT duration is increases to 10 min.Complete droplet rebound behavior is achieved on superhydrophobic PTFE surfaces with a micro/nanocone array.The water contact angle increases,and the rolling angle decreases on the superhydrophobic PTFE surfaces as the OPT duration increases.Superhydrophobic surfaces with microcones having a wide spacing distance and low array density preserve a low adhesive force on water droplets under static conditions.The contact time increases and the restitution coefficient decreases when the water droplet impactes the superhydrophobic surfaces with an increased OPT duration.Superhydrophobic PTFE surfaces with nanocones having a low spacing distance and high array density exhibit a low adhesive force to the water droplet during droplet impact.Changes in the wettability and impacting behaviors of the water droplets are investigated after water droplet impact by changing the number of impacting droplets.The contact electrification on the PTFE surfaces with micro/nanocone arrays at different heights and spacing distances is analyzed by measuring the accumulated potentials of the PTFE sur

关 键 词：超疏水性表面 液滴撞击 接触起电 聚四氟乙烯(PTFE) 接触角 

分 类 号：TG156[金属学及工艺—热处理] TB114[金属学及工艺—金属学]