The meniscus on a fibre

We describe the capillary rise along a vertical thin fibre. We first recall what the final height of the meniscus is, and give some predictions about the dynamics of the rise. Then we present an experiment, in a situation of complete wetting: a fibre is brought into contact with a reservoir of silicone oil, and the dynamic contact angle is measured, from 90° (just at the contact) to 0° (the equilibrium position). Most of the rising time is spent in a long regime of relaxation towards equilibrium, where θ(t) varies as 1/√t. A characteristic time τ is also measured, and studied as a function of the liquid viscosity.