Tielens Frederik, Humblot Vincent, Pradier Claire-Marie, Calatayud Monica, Illas Francesc
UPMC Univ Paris 06, Laboratoire de Réactivité de Surface, Tour 54-55, 2èmeétage - Casier 178, Paris, France.
Langmuir. 2009 Sep 1;25(17):9980-5. doi: 10.1021/la901127g.
A simple model is presented to describe the mixing process of acid- and alcohol-terminated thiol self-assembled monolayers (SAMs) on Au(111). It was found that the low-concentration acid-terminated SAMs are enriched in acid thiol compared with the original solution from which the SAM is made. Due to the relatively strong interaction between acid and alcohol head groups, homogeneously mixed SAMs showing alcohol/acid pairs are preferred when the acid-terminated thiol fraction in solution is below or equal to 50%. This particular behavior affecting the mixing process is explained using atomistic first-principle thermodynamics. The calculated phase diagram has been discussed and interpreted with the help of XPS.
提出了一个简单模型来描述金（111）表面上酸端基和醇端基硫醇自组装单分子层（SAMs）的混合过程。研究发现，与制备自组装单分子层的原始溶液相比，低浓度酸端基自组装单分子层中酸硫醇的含量更高。由于酸和醇头基之间的相互作用相对较强，当溶液中酸端基硫醇的比例低于或等于50%时，呈现醇/酸对的均匀混合自组装单分子层是更可取的。利用原子第一性原理热力学解释了这种影响混合过程的特殊行为。借助X射线光电子能谱（XPS）对计算得到的相图进行了讨论和解释。
