  The motion of three-phase contact lines is one of the most relevant research
topics of micro- and nano-fluidics. According to many hydrodynamic and
molecular models, the dynamics of contact lines is assumed overdamped and
dominated by localised liquid-solid friction, entailing the existence of a
mobility relation between contact line speed and microscopic contact angle. We
present and discuss a set of non-equilibrium atomistic Molecular Dynamics
simulations of water nanodroplets spreading on or confined between silica-like
walls, showing the existence of the aforementioned relation and its invariance
under wetting modes (`spontaneous' or `forced'). Upon changing the wettability
of the walls, it has been noticed that more hydrophilic substrates are easier
to wet rather than de-wet; we show how this asymmetry can be automatically
captured by a contact line friction model that accounts for the molecular
transport between liquid layers. A simple examination of the order and
orientation of near-contact-line water molecules corroborates the physical
foundation of the model. Lastly, we propose an approach to discriminate between
contact line friction models which overcomes the limitations of experimental
resolution. This work constitutes a stepping stone towards demystifying wetting
dynamics on high-friction hydrophilic substrates and underlines the relevance
of contact line friction in modelling the motion of three-phase contact lines.
