Octafluorocyclobutane and acrylic acid (C₄F₈-co-AA) are plasma copolymerized onto low-density polyethylene (LDPE) and glass slides under various pulsation periods of radio frequency pulsed plasma. The surface wettability of plasma polymer coating is traditionally considered as a substrate-independent property. The combined effect of ultrathin C₄F₈-co-AA coatings and LDPE substrate on surface wettability is presented. The high concentration of the carboxylic acid functional groups gives rise to hydrophilicity via lowering duty cycle, and substrate impact gives rise to hydrophobicity for ultrathin coatings. The X-ray photoelectron spectroscopy and coating thickness measurements confirmed that the sudden increase in water contact angle for the lower duty cycle is influenced by the hydrophobic substrate for ultrathin polymer coatings. It is highlighted that the precise control over the surface wettability is attained by tuning the plasma parameters. The substrate-dependent wettability for flat substrate persisted for longer than 8 weeks, which demonstrates wetting stability for ultrathin coatings.

中文翻译：

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脉冲等离子体聚合法制备八氟环丁烷与丙烯酸共聚物LDPE基体的可调节表面化学性质和润湿性

在射频脉冲等离子体的各种脉冲周期下，将八氟环丁烷和丙烯酸（C ₄ F ₈ -co-AA）等离子体共聚到低密度聚乙烯（LDPE）和载玻片上。传统上将等离子聚合物涂层的表面润湿性视为与基材无关的特性。超薄C ₄ F ₈的综合作用介绍了-co-AA涂料和LDPE基材的表面润湿性。高浓度的羧酸官能团可通过降低占空比来提高亲水性，而底材的冲击则可为超薄涂料带来疏水性。X射线光电子能谱法和涂层厚度测量结果证实，在较低占空比下，水接触角的突然增加受到超薄聚合物涂层疏水性基材的影响。要强调的是，通过调节等离子体参数可以实现对表面润湿性的精确控制。平坦基材的基材依赖性润湿性持续超过8周，这证明了超薄涂料的润湿稳定性。