Gorham Justin, Torres Jessica, Wolfe Glenn, d'Agostino Alfred, Fairbrother D Howard
Department of Chemistry, Johns Hopkins University, 3400 North Charles Street, Baltimore, MA 21218, USA.
J Phys Chem B. 2005 Nov 3;109(43):20379-86. doi: 10.1021/jp0521196.
The surface reactions of atomic and molecular oxygen with carbon phosphide films have been studied using X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Carbon phosphide films were produced by ion implantation of trimethylphosphine into polyethylene. Atmospheric oxidation of carbon phosphide films was dominated by phosphorus oxidation and generated a carbon-containing phosphate surface film. This oxidized surface layer acted as an effective diffusion barrier, limiting the depth of phosphorus oxidation within the carbon phosphide film to < 3 nm. The effect of atomic oxygen (AO) exposure on this oxidized carbon phosphide layer was subsequently probed in situ using XPS. Initially AO exposure resulted in a loss of carbon atoms from the surface, but increased the surface concentration of phosphorus atoms as well as the degree of phosphorus oxidation. For more prolonged AO exposures, a highly oxidized phosphate surface layer formed that appeared to be inert toward further AO-mediated erosion. By utilizing phosphorus-containing hydrocarbon thin films, the phosphorus oxides produced during exposure to AO were found to desorb at temperatures >500 K under vacuum conditions. Results from this study suggest that carbon phosphide films can be used as AO-resistant surface coatings on polymers.
利用X射线光电子能谱（XPS）和原子力显微镜（AFM）研究了原子氧和分子氧与磷化碳薄膜的表面反应。通过将三甲基膦离子注入聚乙烯中来制备磷化碳薄膜。磷化碳薄膜的大气氧化以磷氧化为主，并生成了含碳磷酸盐表面膜。这种氧化表面层起到了有效的扩散屏障作用，将磷化碳薄膜内磷氧化的深度限制在<3 nm。随后使用XPS原位探测了原子氧（AO）暴露对这种氧化磷化碳层的影响。最初，AO暴露导致表面碳原子损失，但增加了磷原子的表面浓度以及磷的氧化程度。对于更长时间的AO暴露，形成了高度氧化的磷酸盐表面层，该表面层似乎对进一步的AO介导侵蚀呈惰性。通过使用含磷碳氢化合物薄膜，发现在真空条件下，暴露于AO期间产生的磷氧化物在温度>500 K时会解吸。该研究结果表明，磷化碳薄膜可用作聚合物上的抗AO表面涂层。
