Slip boundaries in nanopores

The flow of liquid water confined within slit pores formed from amorphous surfaces of carbon and polydimethylsiloxane (PDMS) has been investigated using molecular dynamics techniques. For PDMS (including plasma treated forms) the slip length is found to be very small, and there are essentially stick boundary conditions. The slip lengths for amorphous carbon surfaces are significant; however, they are much smaller than those measured experimentally for nanopipes. We show, for the first time, that the slip length can be predicted using the Sokhan-Quirke equation for amorphous surfaces using only equilibrium properties.