Experimental data and modeling of wettability on graphene-coated copper

Abstract

Changes in the graphene wettability over time limit the use of high-sensitivity sensors of new generation. In addition, for technical applications, it is also important to reduce the defectiveness of the graphene layer. As a result of adsorption of hydrocarbons from the air, the hydrophilicity of graphene decreases significantly with time. Experimental data and modeling, using molecular dynamics methods, serve to evaluate the influence of key factors on the wettability of graphene. The experimental data correspond to the calculated estimates. It is shown that the low wettability of a graphene coating on a copper substrate is associated with partial delamination, uneven synthesis of graphene, as well as with the adsorption of hydrocarbons. In the absence of these factors, the contact angle on the graphene coating (graphene-copper) would correspond to 25-30°, rather than to 80-90°, as follows from numerous experimental data.