The basis of the hydrophobicity of lanthanide rare earth oxides (REOs) has been the subject of considerable debate. To explore this question, the wetting behaviors and surface compositions of hierarchically-structured Yb₂O₃ (one of the REOs) coatings and non-REO Al₂O₃ coatings deposited via solution precursor plasma spray process were investigated in this work. The Yb₂O₃ coatings were subjected to a number of post-deposition treatments including vacuum (1−15 Pa) treatment, Ar-plasma treatment, heat treatment (400 °C), long-time air exposure and ultra-high vacuum (1 × 10⁻⁷ Pa) treatment. Subsequent characterization showed that different post-deposition treatments resulted in different wetting behavior for the Yb₂O₃ coatings which correlated with the content of hydrocarbon on the surface. Yb₂O₃ coatings exhibited reversible transitions between superhydrophobicity after vacuum treatment and superhydrophilicity after Ar-plasma or heat treatment, linked to hydrocarbon adsorption onto and desorption from the surface. Yb₂O₃ coatings after long-time air exposure and ultra-high vacuum treatment both remained hydrophilic and showed a smaller hydrocarbon content than coatings after vacuum treatment. Al₂O₃ coatings with hierarchical surface structures similar to the Yb₂O₃ coatings showed an increase in WCA to only ∼17° after the same vacuum treatment, indicating the REO has a much higher affinity for hydrocarbon adsorption than Al₂O₃, and that the content of hydrocarbon adsorbed on the surface of the REO determined the wetting behavior.

镧系稀土氧化物（REOs）的疏水性基础已经引起了广泛的争论。为了探索这个问题，在这项工作中研究了通过溶液前驱体等离子喷涂工艺沉积的分层结构Yb ₂ O ₃（REO之一）涂层和非REO Al ₂ O ₃涂层的润湿行为和表面组成。对Yb ₂ O ₃涂层进行了许多后沉积处理，包括真空（1-15 Pa）处理，氩等离子体处理，热处理（400°C），长时间暴露于空气和超高真空（ 1×10 ^-7霸）治疗。随后的表征表明，不同的沉积后处理导致Yb ₂ O ₃涂层的润湿行为不同，这与表面碳氢化合物的含量有关。Yb ₂ O ₃涂层在真空处理后的超疏水性与Ar等离子或热处理后的超亲水性之间表现出可逆转变，这与烃在表面的吸附和解吸有关。长时间暴露于空气和超高真空处理后的Yb ₂ O ₃涂层均保持亲水性，并显示出比真空处理后的涂层更小的烃含量。铝₂ O ₃具有类似于Yb ₂ O ₃涂层的分层表面结构的涂层在相同的真空处理后显示WCA仅增加到约17°，这表明REO对烃类吸附的亲和力比Al ₂ O ₃高得多，并且含量吸附在REO表面的碳氢化合物确定了润湿行为。