Ondarçuhu Thierry, Thomas Vincent, Nuñez Marc, Dujardin Erik, Rahman Atikur, Black Charles T, Checco Antonio
Nanosciences group, CEMES-CNRS, 29 rue Jeanne Marvig, Toulouse 31055, France.
Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA.
Sci Rep. 2016 Apr 13;6:24237. doi: 10.1038/srep24237.
The dependence of the wettability of graphene on the nature of the underlying substrate remains only partially understood. Here, we systematically investigate the role of liquid-substrate interactions on the wettability of graphene by varying the area fraction of suspended graphene from 0 to 95% by means of nanotextured substrates. We find that completely suspended graphene exhibits the highest water contact angle (85° ± 5°) compared to partially suspended or supported graphene, regardless of the hydrophobicity (hydrophilicity) of the substrate. Further, 80% of the long-range water-substrate interactions are screened by the graphene monolayer, the wettability of which is primarily determined by short-range graphene-liquid interactions. By its well-defined chemical and geometrical properties, supported graphene therefore provides a model system to elucidate the relative contribution of short and long range interactions to the macroscopic contact angle.
石墨烯的润湿性对底层衬底性质的依赖性仍只是部分为人所知。在此，我们通过纳米纹理化衬底将悬浮石墨烯的面积分数从0变化到95%，系统地研究了液-衬底相互作用对石墨烯润湿性的作用。我们发现，与部分悬浮或支撑的石墨烯相比，完全悬浮的石墨烯表现出最高的水接触角（85°±5°），而与衬底的疏水性（亲水性）无关。此外，80%的远程水-衬底相互作用被石墨烯单层屏蔽，其润湿性主要由短程石墨烯-液体相互作用决定。因此，通过其明确的化学和几何性质，支撑的石墨烯提供了一个模型系统，以阐明短程和长程相互作用对宏观接触角的相对贡献。
