Rosso Michel, Arafat Ahmed, Schroën Karin, Giesbers Marcel, Roper Christopher S, Maboudian Roya, Zuilhof Han
Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, Wageningen, The Netherlands.
Langmuir. 2008 Apr 15;24(8):4007-12. doi: 10.1021/la704002y. Epub 2008 Mar 7.
This work presents the first alkyl monolayers covalently bound on HF-treated silicon carbide surfaces (SiC) through thermal reaction with 1-alkenes. Treatment of SiC with diluted aqueous HF solutions removes the native oxide layer (SiO2) and provides a reactive hydroxyl-covered surface. Very hydrophobic methyl-terminated surfaces (water contact angle theta = 107 degrees ) are obtained on flat SiC, whereas attachment of omega-functionalized 1-alkenes also yields well-defined functionalized surfaces. Infrared reflection absorption spectroscopy, ellipsometry, and X-ray photoelectron spectroscopy measurements are used to characterize the monolayers and show their covalent attachment. The resulting surfaces are shown to be extremely stable under harsh acidic conditions (e.g., no change in theta after 4 h in 2 M HCl at 90 degrees C), while their stability in alkaline conditions (pH = 11, 60 degrees C) also supersedes that of analogous monolayers such as those on Au, Si, and SiO2. These results are very promising for applications involving functionalized silicon carbide.
这项工作展示了通过与1-烯烃的热反应首次在氢氟酸处理过的碳化硅表面（SiC）上共价结合的烷基单分子层。用稀释的氢氟酸水溶液处理SiC可去除天然氧化层（SiO2）并提供一个被反应性羟基覆盖的表面。在平坦的SiC上可获得非常疏水的甲基封端表面（水接触角θ = 107度），而ω-官能化的1-烯烃的附着也能产生明确的官能化表面。红外反射吸收光谱、椭偏仪和X射线光电子能谱测量被用于表征单分子层并显示它们的共价附着。结果表明，所得表面在苛刻的酸性条件下极其稳定（例如，在90℃的2 M HCl中4小时后θ无变化），而它们在碱性条件（pH = 11，60℃）下的稳定性也超过了类似的单分子层，如在金、硅和二氧化硅上的单分子层。这些结果对于涉及官能化碳化硅的应用非常有前景。
