Assembly of organic monolayers on polydicyclopentadiene.
Assembly of organic monolayers on polydicyclopentadiene.
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DOI：
10.1021/la8015782
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发表时间：
2008-08
期刊：
影响因子：
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通讯作者：
Mathew Perring;N. Bowden
中科院分区：
文献类型：
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作者：
Mathew Perring;N. Bowden
报道了第一个在聚双环戊二烯上组装的明确的有机单层。商业级二环戊二烯与Grubbs的第二代催化剂在通风柜中以非常低的单体与催化剂负载（20,000比1）在环境条件下进行聚合。这种简单的方法产生的聚合物是坚硬的固体，看起来有点黄。通过x射线光电子能谱（XPS）和衰减全反射-红外（ATR-IR）光谱显示，将这种聚合物短暂地暴露在br2上几秒钟，表面上大约有一半的烯烃溴化。ATR-IR光谱是将聚合物与Harrick的GATR附件中的Ge半球接触进行的。将溴化多双环戊二烯与4-（三氟甲基）苄胺一起浸入DMF中组装成单层。胺取代了表面上的Br，形成了一层暴露在表面上的cf3基团。采用Tougaard描述的方法对表面进行了广泛的XPS研究，以确定F在面层内的分布。峰面积Ap与背景高度B的比值为109.8 eV，比峰值低30 eV。这个值清楚地表明F只存在于表面，而不存在于聚合物内部。估计每纳米表面覆盖1.37个胺(2)，并表明单层的密度是由硫醇在金上组装的类似单层的28%。最后，描述了一种使用软光刻技术对这些单层进行图案制作的简单方法。这项工作至关重要，因为它报道了一种相对较新的新兴聚合物上的第一个单分子层，这种聚合物具有许多理想的物理特性，如高硬度、化学稳定性和易于形成不同形状。
The first well-defined organic monolayers assembled on polydicyclopentadiene is reported. Commercial grade dicyclopentadiene was polymerized with the Grubbs' second-generation catalyst in a fume hood under ambient conditions at very low monomer to catalyst loadings of 20 000 to 1. This simple method resulted in a polymer that was a hard solid and appeared slightly yellow. Brief exposures of a few seconds of this polymer to Br 2 lead to a surface with approximately half of the olefins brominated as shown by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection-infrared (ATR-IR) spectroscopy. The ATR-IR spectroscopy was carried out with the polymer in contact with a Ge hemisphere housed in a GATR accessory from Harrick. This brominated polydicyclopentadiene was immersed in DMF with 4-(trifluoromethyl)benzylamine to assemble a monolayer. The amines displaced Br on the surface to form a monolayer that exposed a CF 3 group on the surface. The surface was extensively studied by XPS using the method described by Tougaard to find the distribution of F within the surface layer. The ratio for the peak area, Ap, to the background height, B, measured 30 eV below the peak maximum was 109.8 eV. This value clearly indicated that F was found only at the surface and was not found within the polymer. A surface coverage of 1.37 amines per nm (2) was estimated and indicated that the monolayer was 28% as dense as a similar monolayer assembled from thiols on gold. Finally, a simple method to pattern these monolayers using soft lithography is described. This work is critically important because it reports the first monolayers on a relatively new and emerging polymer that has many desirable physical characteristics such as high hardness, chemical stability, and ease of forming different shapes.