Fluid viscosity in nanochannels

The viscosity of fluids in a nanochannel between flat plates has been investigated by molecular dynamics method. The effective viscosity coefficient was determined using the previously derived from the nonequilibrium statistical theory fluctuation-dissipation theorem. It has been found that the fluid viscosity in a nanochannel depends strongly on the interaction potential between the fluid and channel walls molecules. Increasing the depth of the potential well of this interaction leads to an increase in the effective viscosity coefficient. At the same time, if the depth of the potential well is small, the fluid viscosity in a nanochannel may be lower than its viscosity in a bulk system. Thus, the fluid viscosity in a nanochannel and hence the channel flow resistance can be varied by changing the material of the nanochannel walls.