MD simulations were conducted to study the traction-separation behaviors for wet adhesion between graphene and a-SiO_2. Three stages of the traction-separation relations are identified and they are analyzed by simple continuum models. The work of separation (per unit area) is found to be close to the theoretical value (60.0 mJ/m~2) dictated by the interaction potential between graphene and water. The maximum traction is found to be set by the critical stress for cavitation at the water/graphene interface (around 90 MPa in the present study). With morphological evolution of water from cavitation to capillary bridging, the range of interaction extends to about 3 nm before complete separation of graphene. Compared to van der Waals interactions for dry adhesion between graphene and a-SiO2, the work of separation for wet adhesion is considerably smaller, the maximum traction is lower, but the range of interaction is longer. It is noted that the properties of wet adhesion depend sensitively on the graphene-water interactions, which may vary considerably between hydro-phobic and hydrophilic interactions.
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