  The maximum speed at which a liquid can wet a solid is limited by the need to
displace gas lubrication films in front of the moving contact line. The
characteristic height of these films is often comparable to the mean free path
in the gas so that hydrodynamic models do not adequately describe the flow
physics. This Letter develops a model which incorporates kinetic effects in the
gas, via the Boltzmann equation, and can predict experimentally-observed
increases in the maximum speed of wetting when (a) the liquid's viscosity is
varied, (b) the ambient gas pressure is reduced or (c) the meniscus is
confined.
