Imbibition dynamics and steady flows in graphene nanochannels with sparse geometric and chemical defects

Geometric and chemical defects are frequently found or created on smooth graphene for applications of nanofluidics. In this work, imbibition dynamics steady flows water in nanochannels with sparse explored by molecular dynamics. The contact angle is raised slightly geometric (hole protrusion) but lowered significantly (hydroxyl epoxide groups). flows, the mean velocity slip length always reduced effect more significant than that defects. Moreover, it interesting to find profile plug-like becomes parabolic defects, regardless length. Sparse nanoslits also affect remarkably, which generally follows Washburn's equation For surface friction (slip length) dominates over driving force associated wettability (contact angle). Nonetheless, protrusion stick-slip behavior caused line pinning thermal fluctuations can be observed. Our new novel findings indicate defect nature crucial nanoscale processes, conventional hydrodynamic theory fails depict.