Modification of 1H,1H,2H,2H-Perfluorooctyltrichlorosilane Self-Assembled Monolayers by Atomic Hydrogen
Modification of 1H,1H,2H,2H-Perfluorooctyltrichlorosilane Self-Assembled Monolayers by Atomic Hydrogen
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原子氢对1H,1H,2H,2H-全氟辛基三氯硅烷自组装单层膜的改性
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Fairbrother
中科院分区：
文献类型：
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作者：
J. Gorham;A. Stover;D. Fairbrother
用X射线光电子能谱和接触角测量相结合的方法研究了氢原子对Si((CF3)(CF2)5(CH2)2−Si)上形成的半氟自组装膜的化学组成和界面性质的影响。XPS结果表明，AH与SAM以动力学控制的方式发生反应，其中速率控制步骤涉及从C-−-H键中抽出H原子，形成束缚在Si衬底上的碳心自由基。这些以碳为中心的自由基随后与AH反应，导致含有吸附链的氟碳(CF3(CF2)5)部分的物种解吸。这一机制解释了许多实验观察结果，包括薄膜中CF3和CF2基团的比例在AH曝光过程中保持不变，以及氟的损失遵循一级动力学，其速率常数与AH通量成正比。测定了CF3+CF2g的损失速率常数。
The effect of atomic hydrogen (AH) on the chemical composition and interfacial properties of a semifluorinated self-assembled monolayer (SAM) formed on Si ((CF3)(CF2)5(CH2)2−Si) has been studied by using a combination of X-ray photoelectron spectroscopy (XPS) and contact angle measurements. XPS results indicate that AH reacts with the SAM in a kinetically controlled process where the rate-determining step involves H atom abstraction from C−H bonds to form carbon-centered radicals tethered to the Si substrate. Subsequent reactions of these carbon-centered radicals with AH lead to desorption of species that contain the fluorocarbon (CF3(CF2)5) portion of the adsorbate chain. This proposed mechanism accounts for a number of experimental observations, including the fact that the ratio of CF3 to CF2 groups within the film remains constant during AH exposure and that the loss of fluorine exhibits first-order kinetics with a rate constant proportional to the AH flux. The rate constant for the loss of CF3 + CF2 g...