Belyaeva Liubov A, Tang Chen, Juurlink Ludo, Schneider Grégory F
Faculty of Science, Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC Leiden, The Netherlands.
Langmuir. 2021 Apr 13;37(14):4049-4055. doi: 10.1021/acs.langmuir.0c02817. Epub 2021 Mar 2.
Interactions between water and graphene can be probed on a macroscopic level through wettability by measuring the water contact angle and on a microscopic level through water desorption kinetic studies using surface science methods. The contact angle studies of graphene pinpointed the critical role of sample preparation and measurement conditions in assessing the wettability of graphene. So far, studies of water desorption from graphene under the conditions of ultrahigh vacuum provided superior control over the environment but disregarded the importance of sample preparation. Here, we systematically examined the effect of the morphology of the growth substrate and of the transfer process on the macroscopic and microscopic wettability of graphene. Remarkably, the macroscopic wetting transparency of graphene does not always translate into microscopic wetting transparency, particularly in the case of an atomically defined Cu(111) substrate. Additionally, subtle differences in the type of substrates significantly alter the interactions between graphene and the first monolayer of adsorbed water but have a negligible effect on the apparent macroscopic wettability. This work looks into the correlations between the wetting properties of graphene, both on the macroscopic and microscopic scales, and highlights the importance of sample preparation in understanding the surface chemistry of graphene.
水与石墨烯之间的相互作用可以通过测量水接触角在宏观层面上通过润湿性进行探究，也可以在微观层面上通过使用表面科学方法进行水脱附动力学研究来探究。石墨烯的接触角研究指出了样品制备和测量条件在评估石墨烯润湿性方面的关键作用。到目前为止，在超高真空条件下对石墨烯水脱附的研究对环境提供了更好的控制，但忽略了样品制备的重要性。在这里，我们系统地研究了生长衬底的形态和转移过程对石墨烯宏观和微观润湿性的影响。值得注意的是，石墨烯的宏观润湿透明度并不总是转化为微观润湿透明度，特别是在原子级定义的Cu(111)衬底的情况下。此外，衬底类型的细微差异会显著改变石墨烯与吸附水的第一单层之间的相互作用，但对表观宏观润湿性的影响可以忽略不计。这项工作研究了石墨烯在宏观和微观尺度上的润湿性质之间的相关性，并强调了样品制备在理解石墨烯表面化学中的重要性。
