Hidden by graphene: effective screening of interface van der Waals interactions via monolayer coating

Recent atomic force microscopy experiments [ACS Nano 2014, 8, 12410–12417] conducted on graphene (G)-coated SiO₂ demonstrated that monolayer G can effectively screen dispersion van der Waals (vdW) interactions deriving from the underlying substrate. This G vdW opacity has far reaching implications, encompassing stabilization of multilayer heterostructures, micromechanical phenomena and heterogeneous catalysis. By quantum many-body analysis and ab-initio Density Functional Theory, here we provide theoretical rationalization of the observed G vdW screening on weakly interacting substrates: despite single atom thickness, the strong non-locality of G density response ensures large compensation between standard attractive vdW terms and many-body repulsive contributions, enabling effective vdW opacity over a broad range of distances. By virtue of combined theoretical/experimental validation, G hence emerges as a promising ultrathin shield for modulation and switching of vdW interactions and electrostatic fields at interfaces and complex nanoscale devices.